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Sample records for klab maailm nii

  1. The NII and the New World Trade Agreement.

    ERIC Educational Resources Information Center

    Smoot, Oliver

    1994-01-01

    Examines the relationship between the National Information Infrastructure (NII) and the new General Agreement on Tariffs and Trade. Topics discussed include the reduction or elimination of tariffs on NII products; protection of copyrighted works; unresolved trade issues, including the European telecommunications market; standards; and privacy and…

  2. Energy utilities in the Internet and NII: Users or providers?

    SciTech Connect

    Aiken, R.J.; Cavallini, J.S.; Scott, M.A.

    1995-04-01

    In its bid to respond to evolving business requirements, the energy utility industry is exploring new ways to provide cost effective quality energy to its constituency while concurrently reducing the need for additional generation plants, consumption of non-renewable fuel resources, and generation of emissions. Their options cover a full spectrum that includes the utilities providing the ``last mile`` access to its customers for both generic internet access required for empowering the users as well as supporting the necessary utility applications. In one scenario the Energy utilities provide high speed NII access to both residences and industry over utility owned infrastructure in order to obtain the level off reliability they need as well as providing the infrastructure necessary to support real time energy supply and consumption management. In a second scenario, the energy utilities make use of a combination of their own infrastructure and that of existing service providers, such as cable and telecommunications companies to satisfy the same set of requirements. Either scenario can greatly increase the number of active nodes on the National Information Infrastructure (NII) and the Global Information Infrastructure (GII); and therefore have a large impact on the network. This paper will outline the major areas and issues with respect to (1) the energy utilities use and possible provision of network services, (2) the current major business and regulatory issues, (3) the technical challenges facing an utility company wishing to use the Internet, NII, and GII to support both its internal and customer based communications needs; and (4) explore what models and technologies are required by both the utilities and their customers (e.g. premises LAN, the gateway to the premises, and the utility infrastructure) to support both energy demand management and possibly generic Internet/NII/GII access to the end user.

  3. VizieR Online Data Catalog: NiI transition probability measurements (Wood+, 2014)

    NASA Astrophysics Data System (ADS)

    Wood, M. P.; Lawler, J. E.; Sneden, C.; Cowan, J. J.

    2014-04-01

    As in much of our previous branching fraction work, this NiI branching fraction study makes use of archived FTS data from both the 1.0m Fourier Transform Spectrometer (FTS) previously at the National Solar Observatory (NSO) on Kitt Peak and the Chelsea Instruments FT500 UV FTS at Lund University in Sweden. Table 1 lists the 37 FTS spectra used in our NiI branching fraction study. All NSO spectra, raw interferograms, and header files are available in the NSO electronic archives. The 80 CCD frames of spectra from commercial Ni HCD lamps of the echelle spectrograph are listed in Table 2. (6 data files).

  4. Catching a Ride on the NII: The Federal Policy Vehicles Paving the Information Highway.

    ERIC Educational Resources Information Center

    Fletcher, Patricia D.; Westerback, Lisa K.

    1999-01-01

    Discusses implications to the management of the U.S. federal government information resources from recent legislation. Examines relevant policy instruments in light of the federal government's high-level commitment to the development of a National Information Infrastructure (NII) which promotes accessible and high-quality services to its citizens.…

  5. The fallacy of using NII in analyzing aircraft operations. [Noise Impact Index

    NASA Technical Reports Server (NTRS)

    Melton, R. G.; Jacobson, I. D.

    1984-01-01

    Three measures of noise annoyance (Noise Impact Index, Level-Weighted Population, and Annoyed Population Number) are compared, regarding their utility in assessing noise reduction schemes for aircraft operations. While NII is intended to measure the average annoyance per person in a community, it is found that the method of averaging can lead to erroneous conclusions, particularly if the population does not have uniform spatial distribution. Level-Weighted Population and Annoyed Population Number are shown to be better indicators of noise annoyance when rating different strategies for noise reduction in a given community.

  6. Policy Initiatives and Strategies for Enhancing the Role of Public Libraries in the National Information Infrastructure (NII): Final Report.

    ERIC Educational Resources Information Center

    McClure, Charles R.; And Others

    The purpose of this research was to explore the possible roles and responsibilities that public libraries might assume in the National Information Infrastructure (NII). Data was collected from September 1994 through June 1995, relying on the following data collection techniques: focus groups, personal interviews, survey data analysis, case…

  7. The utility`s role in the future of PC services and the NII. Final report

    SciTech Connect

    1998-01-01

    The paper is a report by C3 Communications (formerly CSW Communications) summarizing the experience and lessons learned during an 18 month Department of Energy Grant to evaluate how electric utilities can further the growth of the NII by developing a hybrid Internet-energy management service. In addition, the project was also expanded to include evaluation of residential gateway issues, in particular the energy management aspects of this developing area. The report is broken up into three sections, the first section focuses on the issues surrounding the start-up of a traditional ISP and provides a road map for utilities interested in this area. The second section provides an overview of the Internet energy management projects which were undertaken and the key lessons learned from each. Lastly, the third section outlines the gateway progress made during the grant and provides some of the recommendations which the work produced.

  8. Studies on structural and physical characteristics of a novel exopolysaccharide from Pseudozyma sp. NII 08165.

    PubMed

    Sajna, Kuttuvan Valappil; Sukumaran, Rajeev K; Gottumukkala, Lalitha Devi; Jayamurthy, Himani; Dhar, Kiran S; Pandey, Ashok

    2013-08-01

    The aim of this work was to study the production of exopolysaccharide (EPS) from a novel ustilaginomycetes yeast strain Pseudozyma sp. NII 08165. The culture produced 3.5g/l EPS on fourth day of fermentation in a glucose-based medium. The structural characterization revealed that the EPS was a polymer of glucose, galactose and mannose in the ratio of 2.4:5.0:2.6 with a molecular weight of 1.7MDa. The pseudoplastic behaviour of aqueous EPS with a thermal stability up to 220°C indicated its potential utility as a thickening or gelling agent in food industry. SEM studies of the EPS showed that it had compact film-like structure, which could make it a useful in preparing plasticized films. The AFM studies showed that EPS had spike-shaped microstructure. Physical properties of the exopolysaccharide determined further indicated its possible potential in different industrial applications.

  9. ISM band to U-NII band frequency transverter and method of frequency transversion

    DOEpatents

    Stepp, Jeffrey David; Hensley, Dale

    2006-04-04

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz-6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  10. ISM band to U-NII band frequency transverter and method of frequency transversion

    DOEpatents

    Stepp, Jeffrey David; Hensley, Dale

    2006-09-12

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz 6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  11. Isolation and characterization of novel plant growth promoting Micrococcus sp NII-0909 and its interaction with cowpea.

    PubMed

    Dastager, Syed G; Deepa, C K; Pandey, Ashok

    2010-12-01

    A phosphate-solubilizing bacterial strain NII-0909 isolated from the Western ghat forest soil in India was identified as Micrococcus sp on the basis of phenotypic characteristics, carbon source utilization pattern, fatty acid methyl esters analysis, and 16S rRNA gene sequence. The strain exhibited the plant growth-promoting attributes of phosphate solubilization, auxin production, 1-aminocyclopropane-1-carboxylate deaminase activity, and siderophore production. It was able to solubilize (122.4μg of Ca(3)PO(4) ml(-1)), and produce IAA (109μgml(-1)) at 30°C. P-solubilizing activity of the strain NII-0909 was associated with the release of organic acids and a drop in the pH of the NBRIP medium. HPLC analysis detected two organic acids in the course of P-solubilization. A significant increase in the growth of cow pea was recorded for inoculations under controlled conditions. Scanning electron microscopic study revealed the root colonization of strain on cow pea seedlings. These results demonstrate that isolates NII-0909 has the promising PGPR attributes to be develop as a biofertilizer to enhance soil fertility and promote the plant growth. PMID:20951599

  12. Spermine stimulation of a nuclear NII kinase from pea plumules and its role in the phosphorylation of a nuclear polypeptide

    NASA Technical Reports Server (NTRS)

    Datta, N.; Schell, M. B.; Roux, S. J.

    1987-01-01

    We have previously demonstrated that spermine stimulates the phosphorylation of a 47 kilodalton nuclear polypeptide from pea plumules (N Datta, LK Hardison, SJ Roux 1986 Plant Physiol 82: 681-684). In this paper we report that spermine stimulates the activity of a cyclic AMP independent casein kinase, partially purified from a chromatin fraction of pea plumule nuclei. This effect of spermine was substrate specific; i.e. with casein as substrate, spermine stimulated the kinase activity, and with phosvitin as substrate, spermine completely inhibited the activity. The stimulation by spermine of the casein kinase was, in part, due to the lowering of the Mg2+ requirement of the kinase. Heparin could partially inhibit this casein kinase activity and spermine completely overcame this inhibition. By further purification of the casein kinase extract on high performance liquid chromatography, we fractionated it into an NI and an NII kinase. Spermine stimulated the NII kinase by 5- to 6-fold but had no effect on the NI kinase. Using [gamma-32P]GTP, we have shown that spermine promotes the phosphorylation of the 47 kilodalton polypeptide(s) in isolated nuclei, at least in part by stimulating an NII kinase.

  13. Esterase Active in Polar Organic Solvents from the Yeast Pseudozyma sp. NII 08165.

    PubMed

    Alex, Deepthy; Shainu, Anju; Pandey, Ashok; Sukumaran, Rajeev K

    2014-01-01

    Esterases/lipases active in water miscible solvents are highly desired in biocatalysis where substrate solubility is limited and also when the solvent is desired as an acyl acceptor in transesterification reactions, as with the case of biodiesel production. We have isolated an esterase from the glycolipid producing yeast-Pseudozyma sp. NII 08165 which in its crude form was alkali active, thermo stable, halo tolerant and also capable of acting in presence of high methanol concentration. The crude enzyme which maintained 90% of its original activity after being treated at 70°C was purified and the properties were characterized. The partially purified esterase preparation had temperature and pH optima of 60°C and 8.0 respectively. The enzyme retained almost complete activity in presence of 25% methanol and 80% activity in the same strength of ethanol. Conditions of enzyme production were optimized, which lead to 9 fold increase in the esterase yield. One of the isoforms of the enzyme LIP1 was purified to homogeneity and characterized. Purified LIP1 had a K m and V max of 0.01 and 1.12, respectively. The purified esterase lost its thermo and halo tolerance but interestingly, retained 97% activity in methanol. PMID:24800063

  14. Estimation of small business activity by county for the National Infrastructure Information System (NIIS)

    SciTech Connect

    Bell, S.E.; Yoder, T.N.

    1992-09-01

    The Federal Emergency Management Agency (FEMA) has commissioned the design of an assessment system to perform rapid analysis of the economic impacts of various disasters. Oak Ridge National Laboratory (ORNL) developed the National Infrastructure Information System (NIIS) in response to this need. Its design includes several modules to support emergency assessment--the Facility Damage Assessment Module to provide rapid summaries of economic capacity at risk in a disaster area, the Regional Impacts Module (RIM) to estimate the change in a region`s production, consumption, and net exports as a result of capacity lost in the disaster area, the Inter-Regional Trade Flows Module to identify potential interruptions in commodity trade flows between regions, based on the results of the RIM analysis, and the National Economic Model to identify potential macroeconomic impacts of the disaster. In addition to the assessment system, FEMA needs a core data base that contains the comprehensive, county-level information required to conduct regional and national impact analyses. The effort is focused on a general overview of the seriousness of each disaster (e.g., how large is the relative impact) and not on detailed local effects. However, the core data file must be complete enough and accurate enough to support analysis of the relative costs of different disasters. Coverage must be comprehensive in order to address equity issues, as well as detailed in the specific industries that most affect the economy`s ability to respond to disaster.

  15. Estimation of small business activity by county for the National Infrastructure Information System (NIIS)

    SciTech Connect

    Bell, S.E. ); Yoder, T.N. )

    1992-09-01

    The Federal Emergency Management Agency (FEMA) has commissioned the design of an assessment system to perform rapid analysis of the economic impacts of various disasters. Oak Ridge National Laboratory (ORNL) developed the National Infrastructure Information System (NIIS) in response to this need. Its design includes several modules to support emergency assessment--the Facility Damage Assessment Module to provide rapid summaries of economic capacity at risk in a disaster area, the Regional Impacts Module (RIM) to estimate the change in a region's production, consumption, and net exports as a result of capacity lost in the disaster area, the Inter-Regional Trade Flows Module to identify potential interruptions in commodity trade flows between regions, based on the results of the RIM analysis, and the National Economic Model to identify potential macroeconomic impacts of the disaster. In addition to the assessment system, FEMA needs a core data base that contains the comprehensive, county-level information required to conduct regional and national impact analyses. The effort is focused on a general overview of the seriousness of each disaster (e.g., how large is the relative impact) and not on detailed local effects. However, the core data file must be complete enough and accurate enough to support analysis of the relative costs of different disasters. Coverage must be comprehensive in order to address equity issues, as well as detailed in the specific industries that most affect the economy's ability to respond to disaster.

  16. Esterase Active in Polar Organic Solvents from the Yeast Pseudozyma sp. NII 08165

    PubMed Central

    Shainu, Anju; Pandey, Ashok; Sukumaran, Rajeev K.

    2014-01-01

    Esterases/lipases active in water miscible solvents are highly desired in biocatalysis where substrate solubility is limited and also when the solvent is desired as an acyl acceptor in transesterification reactions, as with the case of biodiesel production. We have isolated an esterase from the glycolipid producing yeast-Pseudozyma sp. NII 08165 which in its crude form was alkali active, thermo stable, halo tolerant and also capable of acting in presence of high methanol concentration. The crude enzyme which maintained 90% of its original activity after being treated at 70°C was purified and the properties were characterized. The partially purified esterase preparation had temperature and pH optima of 60°C and 8.0 respectively. The enzyme retained almost complete activity in presence of 25% methanol and 80% activity in the same strength of ethanol. Conditions of enzyme production were optimized, which lead to 9 fold increase in the esterase yield. One of the isoforms of the enzyme LIP1 was purified to homogeneity and characterized. Purified LIP1 had a Km and Vmax of 0.01 and 1.12, respectively. The purified esterase lost its thermo and halo tolerance but interestingly, retained 97% activity in methanol. PMID:24800063

  17. The rotational spectrum of the NiI radical in the X 2Delta(5/2) and A 2Pi(3/2) states.

    PubMed

    Miyazawa, Toru; Okabayashi, Emi Y; Koto, Fumi; Tanimoto, Mitsutoshi; Okabayashi, Toshiaki

    2006-06-14

    The millimeter- and submillimeter-wave spectra of the NiI radical in the X (2)Delta(5/2) and A (2)Pi(3/2) states were observed by a source-modulated microwave spectrometer. The NiI radical was generated by a dc glow discharge in the mixture of CH(3)I vapor and Ar gas through the sputtering reaction with a Ni cathode. Observed transition frequencies for each electronic state were independently analyzed using a polynomial energy expression based on Hund's case (c) approximation. The deperturbed rotational constants were also estimated by the perturbation analysis including interaction terms between the ground state and the lowest excited state.

  18. The intergenic region between the divergently transcribed niiA and niaD genes of Aspergillus nidulans contains multiple NirA binding sites which act bidirectionally.

    PubMed Central

    Punt, P J; Strauss, J; Smit, R; Kinghorn, J R; van den Hondel, C A; Scazzocchio, C

    1995-01-01

    The niaD and niiA genes of Aspergillus nidulans, which code, respectively, for nitrate and nitrite reductases, are divergently transcribed, and their ATGs are separated by 1,200 bp. The genes are under the control of the positively acting NirA transcription factor, which mediates nitrate induction. The DNA binding domain of NirA was expressed as a fusion protein with the glutathione S-transferase of Schistosoma japonicum. Gel shift and footprint experiments have shown that in the intergenic region there are four binding sites for the NirA transcription factor. These sites can be represented by the nonpalindromic consensus 5'CTCCGHGG3'. Making use of a bidirectional expression vector, we have analyzed the role of each of the sites in niaD and niiA expression. The sites were numbered from the niiA side. It appeared that site 1 is necessary for the inducibility of niiA only, while sites 2, 3, and to a lesser extent 4 (which is nearer to and strongly affects niaD) act bidirectionally. The results also suggest that of the 10 binding sites for the AreA protein, which mediates nitrogen metabolite repression, those which are centrally located are physiologically important. The insertion of an unrelated upstream activating sequence into the intergenic region strongly affected the expression of both genes, irrespective of the orientation in which the element was inserted. PMID:7565720

  19. Replacement P212H altered the pH-temperature profile of phytase from Aspergillus niger NII 08121.

    PubMed

    Ushasree, Mrudula Vasudevan; Vidya, Jalaja; Pandey, Ashok

    2015-03-01

    Microbial phytase, a widely used animal feed enzyme, needs to be active and stable in the acidic milieu for better performance in the monogastric gut. Aspergillus niger phytases exhibit an activity dip in the pH range from 3.0 to 3.5. Replacement of amino acids, which changed the pKa of catalytic residues H82 and D362, resulted in alteration of the pH profile of a thermostable phytase from A. niger NII 08121. Substitution P212H in the protein loop at 14 Å distance to the active site amended the pH optimum from 2.5 to pH 3.2 nevertheless with a decrease in thermostability than the wild enzyme. This study described the utility of amino acid replacements based on pKa shifts of catalytic acid/base to modulate the pH profile of phytases. PMID:25595493

  20. The spatially resolved correlation between [NII] 205 μm line emission and the 24 μm continuum in nearby galaxies

    NASA Astrophysics Data System (ADS)

    Hughes, T. M.; Baes, M.; Schirm, M. R. P.; Parkin, T. J.; Wu, R.; De Looze, I.; Wilson, C. D.; Viaene, S.; Bendo, G. J.; Boselli, A.; Cormier, D.; Ibar, E.; Karczewski, O. Ł.; Lu, N.; Spinoglio, L.

    2016-03-01

    A correlation between the 24 μm continuum and the [Nii] 205 μm line emission may arise if both quantities trace the star formation activity on spatially-resolved scales within a galaxy, yet has so far only been observed in the nearby edge-on spiral galaxy NGC 891. We therefore assess whether the [Nii] 205-24 μm emission correlation has some physical origin or is merely an artefact of line-of-sight projection effects in an edge-on disc. We search for the presence of a correlation in Herschel and Spitzer observations of two nearby face-on galaxies, M 51 and M 83, and the interacting Antennae galaxies NGC 4038 and 4039. We show that not only is this empirical relationship also observed in face-on galaxies, but also that the correlation appears to be governed by the star formation rate (SFR). Both the nuclear starburst in M 83 and the merger-induced star formation in NGC 4038/9 exhibit less [Nii] emission per unit SFR surface density than the normal star-forming discs. These regions of intense star formation exhibit stronger ionization parameters, as traced by the 70/160 μm far-infrared (FIR) colour. These observations suggest the presence of higher ionization lines that may become more important for gas cooling, thereby reducing the observed [Nii] 205 μm line emission in regions with higher star formation rates. Finally, we present a general relation between the [Nii] 205 μm line flux density and SFR density for normal star-forming galaxies, yet note that future studies should extend this analysis by including observations with wider spatial coverage for a larger sample of galaxies.

  1. Comprehensive theoretical studies on the low-lying electronic states of NiF, NiCl, NiBr, and NiI.

    PubMed

    Zou, Wenli; Liu, Wenjian

    2006-04-21

    The low-lying electronic states of the nickel monohalides, i.e., NiF, NiCl, NiBr, and NiI, are investigated by using multireference second-order perturbation theory with relativistic effects taken into account. For the energetically lowest 11 lambda-S states and 26 omega states there into, the potential energy curves and corresponding spectroscopic constants (vertical and adiabatic excitation energies, equilibrium bond lengths, vibrational frequencies, and rotational constants) are reported. The calculated results are grossly in very good agreement with those solid experimental data. In particular, the ground state of NiI is shown to be different from those of NiF, NiCl, and NiBr, being in line with the recent experimental observation. Detailed analyses are provided on those states that either have not been assigned or have been incorrectly assigned by previous experiments.

  2. Emergency Preparedness technology support to the Health and Safety Executive (HSE), Nuclear Installations Inspectorate (NII) of the United Kingdom. Appendix A

    SciTech Connect

    O`Kula, K.R.

    1994-03-01

    The Nuclear Installations Inspectorate (NII) of the United Kingdom (UK) suggested the use of an accident progression logic model method developed by Westinghouse Savannah River Company (WSRC) and Science Applications International Corporation (SAIC) for K Reactor to predict the magnitude and timing of radioactivity releases (the source term) based on an advanced logic model methodology. Predicted releases are output from the personal computer-based model in a level-of-confidence format. Additional technical discussions eventually led to a request from the NII to develop a proposal for assembling a similar technology to predict source terms for the UK`s advanced gas-cooled reactor (AGR) type. To respond to this request, WSRC is submitting a proposal to provide contractual assistance as specified in the Scope of Work. The work will produce, document, and transfer technology associated with a Decision-Oriented Source Term Estimator for Emergency Preparedness (DOSE-EP) for the NII to apply to AGRs in the United Kingdom. This document, Appendix A is a part of this proposal.

  3. Predicting dissolved organic nitrogen export from a poorly drained loblolly pine plantation using the forestry version of DRAINMOD-NII

    NASA Astrophysics Data System (ADS)

    Tian, S.; Youssef, M. M.; Skaggs, R. W.; Chescheir, G. M.; Amatya, D. M.

    2010-12-01

    Dissolved organic nitrogen (DON) is one of the main nitrogen forms exported from terrestrial to aquatic ecosystems and it plays important ecological functions in receiving surface water bodies. The DRAINMOD-NII forestry model was developed to predict water, carbon and nitrogen dynamics in drained forest ecosystems. We present an extended version of the model to predict DON export from drained forested lands. A new module has been added to the model to describe key mechanisms and processes regulating DON losses from forested lands. DON production rates was linked to the surface letter and soil microbial compartments and root exudates. The Langmuir isotherm was used to quantify the assumed instantaneous equilibrium between DON in solid and aqueous phases. DON transport with groundwater flow is simulated using numerical solutions to the advection-dispersion-reaction equation. We calibrated and validated the modified model using 21 years of water flow and DON loading data measured at the outlets of three forested (loblolly pine plantations) watersheds located in eastern North Carolina, USA. Field-testing results indicated that the model is capable of reproducing DON export dynamics on both annual and monthly basis. Nash-Sutcliffe coefficients were above 0.70 for predicted annual DON losses and above 0.63 for monthly predictions. The good model performance is most likely attributed to accurate predictions of drainage rates and reasonable quantification of biotic and abiotic controls on DON dynamics. Although there are some uncertainties of assumptions and methods adapted by the model, the relatively accurate predictions of DON loads indicates a good performance of the model given the currently limited understanding of these inherent factors and mechanisms controlling DON dynamics.

  4. Model studies of methyl CoM reductase: methane formation via CH3-S bond cleavage of Ni(I) tetraazacyclic complexes having intramolecular methyl sulfide pendants.

    PubMed

    Nishigaki, Jun-ichi; Matsumoto, Tsuyoshi; Tatsumi, Kazuyuki

    2012-05-01

    The Ni(I) tetraazacycles [Ni(dmmtc)](+) and [Ni(mtc)](+), which have methylthioethyl pendants, were synthesized as models of the reduced state of the active site of methyl coenzyme M reductase (MCR), and their structures and redox properties were elucidated (dmmtc, 1,8-dimethyl-4,11-bis{(2-methylthio)ethyl}-1,4,8,11-tetraaza-1,4,8,11-cyclotetradecane; mtc, 1,8-{bis(2-methylthio)ethyl}-1,4,8,11-tetraaza-1,4,8,11-cyclotetradecane). The intramolecular CH(3)-S bond of the thioether pendant of [Ni(I)(dmmtc)](OTf) was cleaved in THF at 75 °C in the presence of the bulky thiol DmpSH, which acts as a proton source, and methane was formed in 31% yield and a Ni(II) thiolate complex was concomitantly obtained (Dmp = 2,6-dimesityphenyl). The CH(3)-S bond cleavage of [Ni(I)(mtc)](+) also proceeded similarly, but under milder conditions probably due to the lower potential of the [Ni(I)(mtc)](+) complex. These results indicate that the robust CH(3)-S bond can be homolytically cleaved by the Ni(I) center when they are properly arranged, which highlights the significance of the F430 Ni environment in the active site of the MCR protein. PMID:22439643

  5. A structurally rigid bis(amido) ligand framework in low-coordinate Ni(I), Ni(II), and Ni(III) analogues provides access to a Ni(III) methyl complex via oxidative addition.

    PubMed

    Lipschutz, Michael I; Yang, Xinzheng; Chatterjee, Ruchira; Tilley, T Don

    2013-10-16

    A structurally persistent bis-amido ligand framework capable of supporting nickel compounds in three different oxidation states has been identified. A highly unusual, isolable Ni(III) alkyl species has been prepared and characterized via a rare example of a two-electron oxidative addition of MeI to Ni(I).

  6. Study of the essentiality of the Aspergillus fumigatus triA gene, encoding RNA triphosphatase, using the heterokaryon rescue technique and the conditional gene expression driven by the alcA and niiA promoters.

    PubMed

    Monteiro, M Cândida; De Lucas, J Ramón

    2010-01-01

    The identification of essential genes represents a critical step in the discovery of novel therapeutic targets in Aspergillus fumigatus. Structural analyses of the Saccharomyces cerevisiae RNA triphosphatase pointed out this enzyme as an attractive therapeutic target for fungal infections. In addition, demonstration of the essentiality of the S. cerevisiae RNA triphosphatase encoding gene enhanced the value of this potential therapeutic target. Nevertheless, consideration of a fungal RNA triphosphatase as an ideal therapeutic target needs confirmation of the essentiality of the respective gene in a fungal pathogen. In this work, we analyzed the essentiality of the A. fumigatus triA gene, encoding RNA triphosphatase, by conditional gene expression and heterokaryon deletion. Using the conditional gene expression driven by the alcA promoter (alcA(P)), we found that TriA depletion causes morphological abnormalities that result in a very strong growth inhibition. Nevertheless, since a strict terminal phenotype was not observed, the essentiality of the triA gene could not be ensured. Accordingly, the essentiality of this gene was analyzed by the heterokaryon rescue technique. Results obtained unequivocally demonstrated the essentiality of the A. fumigatus triA gene, indicating the suitability of the RNA triphosphatase as an ideal therapeutic target to treat A. fumigatus infections. Besides, a second conditional gene expression system, based on the niiA promoter (niiA(P)), was utilized in this work. Although the niiA(P)-mediated repression of triA was less severe than that driven by the alcA(P), a strong growth inhibition was also found in niiA(P)-triA strains. Finally, E-tests performed to determine whether triA down-regulated cells became more sensitive to antifungals suggest a synergic effect between amphotericin B and another antifungal inhibiting the A. fumigatus RNA triphosphatase activity.

  7. Biomimetic mono- and dinuclear Ni(I) and Ni(II) complexes studied by X-ray absorption and emission spectroscopy and quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Schuth, N.; Gehring, H.; Horn, B.; Holze, P.; Kositzki, R.; Schrapers, P.; Limberg, C.; Haumann, M.

    2016-05-01

    Five biomimetic mono- or dinuclear nickel complexes featuring Ni(I) or Ni(II) sites were studied by X-ray absorption and emission spectroscopy and DFT calculations. Ni K-edge XANES spectra and Kβ main and satellite emission lines were collected on powder samples. The pre-edge absorption transitions (core-to-valence excitation) and Kβ2,5 emission transitions (valence-to-core decay) were calculated using DFT (TPSSh/TZVP) on crystal structures. This yielded theoretical ctv and vtc spectra in near-quantitative agreement with the experiment, showing the adequacy of the DFT approach for electronic structure description, emphasizing the sensitivity of the XAS/XES spectra for ligation/redox changes at nickel, and revealing the configuration of unoccupied and occupied valence levels, as well as the spin-coupling modes in the dinuclear complexes. XAS/XES-DFT is valuable for molecular and electronic structure analysis of synthetic complexes and of nickel centers in H2 or COx converting metalloenzymes.

  8. First Detections of the [NII] 122 Micrometer Line at High Redshift: Demonstrating the Utility of the Line for Studying Galaxies in the Early Universe

    NASA Technical Reports Server (NTRS)

    Ferkinhoff, Carl; Brisbin, Drew; Nikola, Thomas; Parshley, Stephen C.; Stacey, Gordon J.; Phillips, Thomas G.; Falgarone, Edith; Benford, Dominic J.; Staguhn, Johannes G.; Tucker, Carol E.

    2011-01-01

    We report the first detections of the [NIl] 122 {\\mu} m line from a high redshift galaxy. The line was strongly (> 6{\\sigma}) detected from SMMJ02399-0136, and HI413+ 117 (the Cloverleaf QSO) using the Redshift(z) and Early Universe Spectrometer (ZEUS) on the CSO. The lines from both sources are quite bright with line-to-FIR continuum luminosity ratios that are approx.7.0x10(exp -4) (Cloverleaf) and 2.1x10(exp -3) (SMMJ02399). With ratios 2-10 times larger than the average value for nearby galaxies, neither source exhibits the line-to-continuum deficits seen in nearby sources. The line strengths also indicate large ionized gas fractions, approx.8 to 17% of the molecular gas mass. The [OIII]/[NII] line ratio is very sensitive to the effective temperature of ionizing stars and the ionization parameter for emission arising in the narrow-line region (NLR) of an AGN. Using our previous detection of the [01II] 88 {\\mu}m line, the [OIII]/ [NIl] line ratio for SMMJ02399-0136 indicates the dominant source of the line emission is either stellar HII regions ionized by 09.5 stars, or the NLR of the AGN with ionization parameter 10g(U) = -3.3 to -4.0. A composite system, where 30 to 50% of the FIR lines arise in the NLR also matches the data. The Cloverleaf is best modeled by a superposition of approx.200 M82like starbursts accounting for all of the FIR emission and 43% of the [NIl] line. The remainder may come from the NLR. This work demonstrates the utility of the [NIl] and [OIII] lines in constraining properties of the ionized medium.

  9. NII Simulator 1.0

    2009-12-02

    The software listed here is a simulator for SAIC P7500 VACIS non intrusive inspection system. The simulator provides messages similar to those provided by this piece of equipment.To facilitate testing of the Second Line of Defense systems and similar software products from commercial software vendors, this software simulation application has been developed to simulate the P7500 that the Second Line of Defense communications software system must interface with. The primary use of this simulator ismore » for testing of both Sandia developed and DOE contractor developed software.« less

  10. X-ray Crystallographic, Multifrequency Electron Paramagnetic Resonance, and Density Functional Theory Characterization of the Ni(P(Cy)2N(tBu)2)2(n+) Hydrogen Oxidation Catalyst in the Ni(I) Oxidation State.

    PubMed

    Niklas, Jens; Westwood, Mark; Mardis, Kristy L; Brown, Tiara L; Pitts-McCoy, Anthony M; Hopkins, Michael D; Poluektov, Oleg G

    2015-07-01

    The Ni(I) hydrogen oxidation catalyst [Ni(P(Cy)2N(tBu)2)2](+) (1(+); P(Cy)2N(tBu)2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane) has been studied using a combination of electron paramagnetic resonance (EPR) techniques (X-, Q-, and D-band, electron-nuclear double resonance, hyperfine sublevel correlation spectroscopy), X-ray crystallography, and density functional theory (DFT) calculations. Crystallographic and DFT studies indicate that the molecular structure of 1(+) is highly symmetrical. EPR spectroscopy has allowed determination of the electronic g tensor and the spin density distribution on the ligands, and revealed that the Ni(I) center does not interact strongly with the potentially coordinating solvents acetonitrile and butyronitrile. The EPR spectra and magnetic parameters of 1(+) are found to be distinctly different from those for the related compound [Ni(P(Ph)2N(Ph)2)2](+) (4(+)). One significant contributor to these differences is that the molecular structure of 4(+) is unsymmetrical, unlike that of 1(+). DFT calculations on derivatives in which the R and R' groups are systematically varied have allowed elucidation of structure/substituent relationships and their corresponding influence on the magnetic resonance parameters.

  11. X-Ray Crystallographic, Multifrequency EPR, and DFT Characterization of the Ni(PCy2NtBu2)2n+ Hydrogen Oxidation Catalyst in the Ni(I) Oxidation State

    PubMed Central

    Niklas, Jens; Westwood, Mark; Mardis, Kristy L.; Brown, Tiara L.; Pitts-McCoy, Anthony M.; Hopkins, Michael D.; Poluektov, Oleg G.

    2016-01-01

    The Ni(I) hydrogen oxidation catalyst [Ni(PCy2NtBu2)2]+ (1+; PCy2NtBu2= 1,5bis(tert-butyl)-3,7-dicyclo-hexyl-1,5-diaza-3,7-diphosphacychlooctane) has been studied using a combination of EPR techniques (X-, Q-, and D-band; electron-nuclear double resonance, hyperfine sublevel correlation spectroscopy), X-ray crystallography, and density functional theory (DFT) calculations. Crystallographic and DFT studies indicate that the molecular structure of 1+ is highly symmetrical. EPR spectroscopy has allowed determination of the electronic g-tensor and the spin density distribution on the ligands, and revealed that the Ni(I) center does not interact strongly with the potentially coordinating solvents acetonitrile and butyronitrile. The EPR spectra and magnetic parameters of 1+ are found to be distinctly different from those for the related compound [Ni(PPh2NPh2)2]+ (4+). One significant contributor to these differences is that the molecular structure of 4+ is unsymmetrical, unlike that of 1+. DFT calculations on derivatives in which the R and R′ groups are systematically varied have allowed elucidation of structure/substituent relationships and their corresponding influence on the magnetic resonance parameters. PMID:26098955

  12. Useful Method for the Preparation of Low-Coordinate Nickel(I) Complexes via Transformations of the Ni(I) Bis(amido) Complex K{Ni[N(SiMe3)(2,6- (i) Pr2-C6H3)]2}

    PubMed

    Lipschutz, Michael I; Tilley, T Don

    2014-10-13

    A convenient method of preparing two- and three-coordinate Ni(I) complexes of the form L-Ni(I)-X (L = P (t) Bu3, P (i) Pr3, DPPE, NHC; X = -N(SiMe3)(2,6- (i) Pr-C6H3), -O(2,6- (t) Bu2-4-Me-C6H2)) is reported. Protonation of the easily prepared anionic Ni(I) bis(amido) complex K{Ni[N(SiMe3)(2,6- (i) Pr-C6H3)]2} in the presence of an appropriate L-type ligand results in loss of HN(SiMe3)(2,6- (i) Pr-C6H3) and trapping of the resulting neutral Ni(I)-amido fragment to yield neutral, paramagnetic, two- and three-coordinate Ni(I) complexes. Protonation of these neutral amido complexes by the bulky phenol HO(2,6- (t) Bu2-4-Me-C6H2) results in loss of the second amido moiety and trapping by the resulting phenoxide to yield Ni(I)-O(2,6- (t) Bu2-4-Me-C6H2) complexes. The hapticity of the phenoxide ligand is influenced by the π-accepting ability of the L-type ligand. Where L = P (t) Bu3, a poor π-acceptor, the phenoxide acts as a π-acceptor and adopts a η(5)-bonding mode through dearomatization of the phenyl ring. When L = NHC, a competent π-acceptor, the phenoxide acts as a π-donor, adopting a η(1)-bonding mode through the O atom. The modular nature of this synthetic strategy allows variation of both the L- and X-type ligands of the complex in a stepwise fashion and should be extendable to a wide variety of ligand types for new Ni(I) complexes.

  13. Carbon-carbon cross-coupling reactions catalyzed by a two-coordinate nickel(II)-bis(amido) complex via observable Ni(I) , Ni(II) , and Ni(III) intermediates.

    PubMed

    Lipschutz, Michael I; Tilley, T Don

    2014-07-01

    Recently, the development of more sustainable catalytic systems based on abundant first-row metals, especially nickel, for cross-coupling reactions has attracted significant interest. One of the key intermediates invoked in these reactions is a Ni(III) -alkyl species, but no such species that is part of a competent catalytic cycle has yet been isolated. Herein, we report a carbon-carbon cross-coupling system based on a two-coordinate Ni(II) -bis(amido) complex in which a Ni(III) -alkyl species can be isolated and fully characterized. This study details compelling experimental evidence of the role played by this Ni(III) -alkyl species as well as those of other key Ni(I) and Ni(II) intermediates. The catalytic cycle described herein is also one of the first examples of a two-coordinate complex that competently catalyzes an organic transformation, potentially leading to a new class of catalysts based on the unique ability of first-row transition metals to accommodate two-coordinate complexes.

  14. Field-Induced Slow Magnetic Relaxation in the Ni(I) Complexes [NiCl(PPh3)2]·C4H8O and [Ni(N(SiMe3)2)(PPh3)2].

    PubMed

    Lin, Weiquan; Bodenstein, Tilmann; Mereacre, Valeriu; Fink, Karin; Eichhöfer, Andreas

    2016-03-01

    Direct current (dc) and alternating current (ac) magnetic measurements have been performed on the three Ni(I) complexes: [NiCl(PPh3)3], [NiCl(PPh3)2]·C4H8O, and [Ni(N(SiMe3)2)(PPh3)2]. Fits of the dc magnetic data suggest an almost similar behavior of the three compounds, which display only moderate deviations from the spin-only values. The ac magnetic investigations reveal that the two complexes with trigonal planar coordination--[NiCl(PPh3)2]·C4H8O and [Ni(N(SiMe3)2)(PPh3)2]--display slow magnetic relaxation at low temperatures under applied dc fields, whereas tetrahedral [NiCl(PPh3)3] does not. Ground and excited states as well as magnetic data were calculated by ab initio wave function based multi-configurational methods, including dynamic correlation as well as spin-orbit coupling. The two trigonal planar complexes comprise well-isolated S = (1)/2 ground states, whereas two S = (1)/2 states with a splitting of less than 100 cm(-1) were found in the tetrahedral compound.

  15. Useful Method for the Preparation of Low-Coordinate Nickel(I) Complexes via Transformations of the Ni(I) Bis(amido) Complex K{Ni[N(SiMe3)(2,6-iPr2-C6H3)]2}

    PubMed Central

    2015-01-01

    A convenient method of preparing two- and three-coordinate Ni(I) complexes of the form L–NiI–X (L = PtBu3, PiPr3, DPPE, NHC; X = −N(SiMe3)(2,6-iPr-C6H3), −O(2,6-tBu2-4-Me-C6H2)) is reported. Protonation of the easily prepared anionic Ni(I) bis(amido) complex K{Ni[N(SiMe3)(2,6-iPr-C6H3)]2} in the presence of an appropriate L-type ligand results in loss of HN(SiMe3)(2,6-iPr-C6H3) and trapping of the resulting neutral Ni(I)-amido fragment to yield neutral, paramagnetic, two- and three-coordinate Ni(I) complexes. Protonation of these neutral amido complexes by the bulky phenol HO(2,6-tBu2-4-Me-C6H2) results in loss of the second amido moiety and trapping by the resulting phenoxide to yield Ni(I)-O(2,6-tBu2-4-Me-C6H2) complexes. The hapticity of the phenoxide ligand is influenced by the π-accepting ability of the L-type ligand. Where L = PtBu3, a poor π-acceptor, the phenoxide acts as a π-acceptor and adopts a η5-bonding mode through dearomatization of the phenyl ring. When L = NHC, a competent π-acceptor, the phenoxide acts as a π-donor, adopting a η1-bonding mode through the O atom. The modular nature of this synthetic strategy allows variation of both the L- and X-type ligands of the complex in a stepwise fashion and should be extendable to a wide variety of ligand types for new Ni(I) complexes. PMID:25328273

  16. A Practical and Cost Effective Demonstration of Efficient Energy Usage and Quality Management Using the NII

    SciTech Connect

    1999-05-01

    In order to be competitive in the changing electric power industry, and to promote energy efficiency and conservation, electric power providers need to have access to information on the power system to a level of detail that has not been available in the past. This level of detail extends beyond the usual voltage, current, power, and energy quantities obtained from traditional utility SCADA systems.

  17. XAS studies of Ni(I), Ni(II), and Ni(III) complexes

    SciTech Connect

    Furenlid, L.R.; Renner, M.W.; Fujita, E.

    1995-01-01

    XAS techniques for studying structural and electronic changes taking place during oxidation and reduction reactions of nickel complexes are described and applied to selected models for Factor 430, a nickel containing cofactor catalyzing an important step in the conversion of carbon dioxide to methane by methanogenic bacteria.

  18. 78 FR 37499 - Unlicensed National Information Infrastructure (U-NII) Devices in the 5 GHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-21

    ..., 2013, and released June 17, 2013. The full text of this document is available for inspection and... reply comment deadline to facilitate the development of a full and complete record. DATES: Reply...., Washington, DC 20554. The complete text of this document also may be purchased from the Commission's...

  19. 78 FR 21320 - Unlicensed National Information Infrastructure (U-NII) Devices in the 5 GHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ...). See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR 24121 (1998). Electronic Filers... $100 billion through avoidance of unnecessary costs. 11. In addition, Congress has enacted legislation...; (c) the device does not include configuration controls to change the frequency of operation to...

  20. Physical Properties of the Magellanic Bridge Tidal Remnant through Mapped Hα, [SII], and [NII] Emission

    NASA Astrophysics Data System (ADS)

    Barger, Kathleen; Haffner, L. Matthew

    2016-01-01

    We present the first kinematically resolved [S II] λ6716 and [N II] λ6583 emission maps of the entire Magellanic Bridge that were observed with the Wisconsin Hα Mapper Telescope. Combining these maps with the complementary Hα maps of Barger et al. (2013), we explore the temperature, sulfur and nitrogen ionization state, and sources of the ionization of the warm-ionized gas in the Magellanic Bridge, the SMC-Tail, and the LMC-Bridge interface region. Within the Magellanic Bridge, we find that the low velocity (+100 to +200 km s-1 ) and the high velocity (+200 to +300 km s-1 ) gas have different properties, suggesting that it is composed of at least two separate and coherent filaments. Within the high-velocity filament, a high-velocity ridge of gas—with different properties from the high-velocity structure—extends along the high-latitude edge of the Hα SMC-Tail to low latitude edge LMC-Bridge interface. This ridge coincides with a strip of early-type stars, suggesting that these stars are influencing this gas. We further find that the properties of both the SMC-Tail and LMC-Bridge interface regions have similar properties and therefore are likely affected by similar ionization sources.

  1. The Russian Scientific Research Institue Of Parachute Design And Production (NII Parachutostroyeniya, NIIPC)- History, Research And Collaboration In Space Projects

    NASA Astrophysics Data System (ADS)

    Lyalin, V.; Ladygin, V.; Komarov, V.; Kuleshov, V.; Wong, H.; Offerman, J.; Thirkettle, A.

    2011-05-01

    NIIPC was established in 1946 for the development of paradrop equipment and is one of a few companies in the world to perform the full cycle of parachute development, including scientific research, design, manufacturing, test and modification. NIIPC produced the parachute systems for Yuri Gagarin and all of the Russian manned space missions, Vistok, Voshod and Soyuz. It produced the parachutes for unmanned missions, Almaz, Bion, Cosmos as well as the reentry modules for Mars, Venus and from the Moon. NIIPC has its own school for training of scientific personnel and large scientific and technical archive. The existing knowledge and computer codes are used for the development of prospective parachute systems. Research includes all aspects such as payload- parachute dynamics, inflation, clusters, gliding parachutes, and aeroballistic heating and strength of supersonic parachutes. International collaboration included the Ariane 5 booster parachutes with Dutch Space and development of the current supersonic parachute system for EXPERT. An Ariane 5 booster weighs 41 tonnes dry and involves a 3-stage parachute system. The EXPERT parachute deploys a drogue supersonic parachute at Mach 1.7, before extracting a main cross-shaped parachute. The test campaign for EXPERT started in 2010 and will be completed by summer 2011.

  2. Education and Cultural Heritage: Solid Partners for the NII. Current and Emerging Projects and Approaches. Project Descriptions.

    ERIC Educational Resources Information Center

    Getty Art History Information Program, Santa Monica, CA.

    This booklet, distributed at a meeting, contains project descriptions from each participating organization and fact sheets on the Getty Art History Information Program's (AHIP's) initiatives. Held in conjunction with a national conference on transforming education with the arts, the discussion was conducted by representatives of many projects and…

  3. VizieR Online Data Catalog: [NII]205um emission in local luminous IR galaxies (Zhao+, 2016)

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Lu, N.; Xu, C. K.; Gao, Y.; Lord, S. D.; Charmandaris, V.; Diaz-Santos, T.; Evans, A.; Howell, J.; Petric, A. O.; van der Werf, P. P.; Sanders, D. B.

    2016-05-01

    The primary sample studied in this paper is from the Herschel open time project Herschel Spectroscopic Survey of Warm Molecular Gas in Local Luminous Infrared Galaxies (OT1nlu1; PI: N. Lu). The observations were conducted with the Herschel SPIRE/FTS in its point source spectroscopy mode and high spectral resolution configuration, yielding a spectral resolution of 0.04/cm (or 1.2GHz) over the spectral coverage of 194-672um. (1 data file).

  4. Building the National Information Infrastructure in K-12 Education: A Comprehensive Survey of Attitudes towards Linking Both Sides of the Desk. A Report of the Global Telecommunications Infrastructure Research Project. Research Report Series.

    ERIC Educational Resources Information Center

    Pereira, Francis; And Others

    This survey was designed to elicit the perceptions of the members of the educational community on four issues concerning the NII (National Information Infrastructure), and to test whether these visions of the NII were shared by educators. The issues were: (1) the benefits of the NII to the education sector and specifically whether the NII will be…

  5. Infrared and EPR spectroscopic characterization of a Ni(I) species formed by photolysis of a catalytically competent Ni(I)-CO intermediate in the acetyl-CoA synthase reaction.

    PubMed

    Bender, Güneş; Stich, Troy A; Yan, Lifen; Britt, R David; Cramer, Stephen P; Ragsdale, Stephen W

    2010-09-01

    Acetyl-CoA synthase (ACS) catalyzes the synthesis of acetyl-CoA from CO, coenzyme A (CoA), and a methyl group from the CH(3)-Co(3+) site in the corrinoid iron-sulfur protein (CFeSP). These are the key steps in the Wood-Ljungdahl pathway of anaerobic CO and CO(2) fixation. The active site of ACS is the A-cluster, which is an unusual nickel-iron-sulfur cluster. There is significant evidence for the catalytic intermediacy of a CO-bound paramagnetic Ni species, with an electronic configuration of [Fe(4)S(4)](2+)-(Ni(p)(+)-CO)-(Ni(d)(2+)), where Ni(p) and Ni(d) represent the Ni centers in the A-cluster that are proximal and distal to the [Fe(4)S(4)](2+) cluster, respectively. This well-characterized Ni(p)(+)-CO intermediate is often called the NiFeC species. Photolysis of the Ni(p)(+)-CO state generates a novel Ni(p)(+) species (A(red)*) with a rhombic electron paramagnetic resonance spectrum (g values of 2.56, 2.10, and 2.01) and an extremely low (1 kJ/mol) barrier for recombination with CO. We suggest that the photolytically generated A(red)* species is (or is similar to) the Ni(p)(+) species that binds CO (to form the Ni(p)(+)-CO species) and the methyl group (to form Ni(p)-CH(3)) in the ACS catalytic mechanism. The results provide support for a binding site (an "alcove") for CO near Ni(p), indicated by X-ray crystallographic studies of the Xe-incubated enzyme. We propose that, during catalysis, a resting Ni(p)(2+) state predominates over the active Ni(p)(+) species (A(red)*) that is trapped by the coupling of a one-electron transfer step to the binding of CO, which pulls the equilibrium toward Ni(p)(+)-CO formation.

  6. EEE Links, Volume 9, No. 1, January 2003 Focus on Plastic Parts

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The January 2003 issue of Electronic, Electromechanical, Electric (EEE) Links is presented. The Programmable Logic Application Notes column has been reinstated in this newsletter. Written by Rich Katz of NASA's Office of Logic Design (OLD), the application notes offer technical tips intended to prevent flight design errors and enhance research, development, and use of programmable logic and elements for space flight applications. An archive of these notes columns from previous issues of EEE Links is available at http://www.klabs.org/richcontent/eeelink s/EEE Links.htm.

  7. 32 CFR 310.9 - Privacy boards and office, composition and responsibilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Defense for Networks and Information Integration (ASD) (NII)/Chief Information Officer (CIO); the Director... designated by the Secretaries of the Military Departments; the DUSD(PI); the (ASD) (NII)/CIO; the GC,...

  8. 32 CFR 310.9 - Privacy boards and office, composition and responsibilities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Defense for Networks and Information Integration (ASD) (NII)/Chief Information Officer (CIO); the Director... designated by the Secretaries of the Military Departments; the DUSD(PI); the (ASD) (NII)/CIO; the GC,...

  9. 32 CFR 310.9 - Privacy boards and office, composition and responsibilities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Defense for Networks and Information Integration (ASD) (NII)/Chief Information Officer (CIO); the Director... designated by the Secretaries of the Military Departments; the DUSD(PI); the (ASD) (NII)/CIO; the GC,...

  10. 32 CFR 310.9 - Privacy boards and office, composition and responsibilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Defense for Networks and Information Integration (ASD) (NII)/Chief Information Officer (CIO); the Director... designated by the Secretaries of the Military Departments; the DUSD(PI); the (ASD) (NII)/CIO; the GC,...

  11. Technology Deployment and Interoperability in the National Information Infrastructure. Hearing before the Subcommittee on Technology, Environment and Aviation of the Committee on Science, Space, and Technology. House of Representatives, One Hundred Third Congress, Second Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Science, Space and Technology.

    This document presents the proceedings of a Congressional hearing on private sector initiatives to develop the National Information Infrastructure (NII) with a focus on understanding the nature of industry investment in the NII and how those investments will contribute to the Administration's goals for NII. Statements are provided by the following…

  12. Putting the Information Infrastructure to Work. Report of the Information Infrastructure Task Force Committee on Applications and Technology. NIST Special Publication 857.

    ERIC Educational Resources Information Center

    National Inst. of Standards and Technology, Gaithersburg, MD.

    An interconnection of computer networks, telecommunications services, and applications, the National Information Infrastructure (NII) can open up new vistas and profoundly change much of American life. This report explores some of the opportunities and obstacles to the use of the NII by people and organizations. The goal is to express how…

  13. The Uses of the National Information Infrastructure in Providing Services to Small Industry, State and Local Governments, and Education in Rural Areas. Hearing before the Subcommittee on Science, Technology, and Space of the Committee on Commerce, Science, and Transportation. United States Senate, One Hundred Fourth Congress, First Session (Billings, Montana).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Commerce, Science, and Transportation.

    The Senate Subcommittee on Science, Technology, and Space held a hearing in Billings, Montana, on rural America's access to the National Information Infrastructure (NII) and uses of NII in the provision of rural education and services. An Assistant Secretary of Commerce discussed the development of the Internet, problems in rural access to the…

  14. A systems configuration toolkit for modular integration of mechatronic resources

    SciTech Connect

    Oppel, F.J. III; Palmquist, R.

    1995-07-01

    The use of the NII (National Information Infrastructure) is growing rapidly in the number of users and in the areas in which it is being applied. Sandia is using, the NII to leverage the use of geographically distributed mechatronic (electromechanical) assets. This paper discusses the availability of networks, new challenges for robotics technology, and how the use of networks is helping to meet these challenges. A brief overview of the NII is provided, followed by a listing of ``needs`` within the intelligent systems community. An approach is then given for meeting, these needs and, finally, implementation, examples, and future research directions are discussed.

  15. Búsqueda de regiones de baja excitación en nebulosas planetarias

    NASA Astrophysics Data System (ADS)

    Vena Valdarenas, R. R.; Schmidt, E. O.; Volpe, M. G.; Weidmann, W.; Mudrik, A.

    2015-08-01

    We present early results from observations with narrow band filter ([NII], 6584 ) for a sample of austral planetary nebulae. The observations are being made from Bosque Alegre Astrophysical Station. The observation inherent aspects will be treated in detail.

  16. EFFECT OF ORGANOPHOSPHORUS FLAME RETARDANTS ON NEURONAL DEVELOPMENT IN VITRO

    EPA Science Inventory

    The increased use of organophosphorus compounds as alternatives to brominated flame retardants (BFRs) has led to widespread human exposure, There is, however, limited information on their potential health effects. This study compared the effects of nii ne organophosphorus flame...

  17. 3D Reconstruction of the Vortex in a Human Right Ventricle Model using High Speed PIV

    NASA Astrophysics Data System (ADS)

    Kheradvar, Arash; Falahatpisheh, Ahmad

    2011-11-01

    This work aims to characterize the formation process and translation of the vortex, which forms along with the trans-tricuspid jet in a realistic model of a human right ventricle (RV). A clear model of the RV made of silicone rubber was carefully casted in real size from echocardiographic data of an adult human heart. The RV model was used in our heart pulsed-flow simulator at KLAB at UCI to perform experiments. Bioprosthetic heart valves in appropriate sizes were used at tricuspid and pulmonary positions. Multi-planar high-speed PIV was performed to capture and reconstruct the 3D flow field with a 1-millisecond time gap between each two velocity frames. λ2 iso-surfaces were used to illustrate the evolution of vortex cores. The highly asymmetric shape of the RV chamber results in a complex 3D trans-tricuspid vortex that forms and translates toward right ventricular outflow tract, and finally departs RV from pulmonary valve. Through this study, -for the first time- the formation, evolution and pathway of the RV vortex have been characterized in vitro.

  18. Sequence homology requirements for transcriptional silencing of 35S transgenes and post-transcriptional silencing of nitrite reductase (trans)genes by the tobacco 271 locus.

    PubMed

    Thierry, D; Vaucheret, H

    1996-12-01

    The transgene locus of the tobacco plant 271 (271 locus) is located on a telomere and consists of multiple copies of a plasmid carrying an NptII marker gene driven by the cauliflower mosaic virus (CaMV) 19S promoter and the leaf-specific nitrite reductase Nii1 cDNA cloned in the antisense orientation under the control of the CaMV 35S promoter. Previous analysis of gene expression in leaves has shown that this locus triggers both post-transcriptional silencing of the host leaf-specific Nii genes and transcriptional silencing of transgenes driven by the 19S or 35S promoter irrespective of their coding sequence and of their location in the genome. In this paper we show that silencing of transgenes carrying Nii1 sequences occurs irrespective of the promoter driving their expression and of their location within the genome. This phenomenon occurs in roots as well as in leaves although root Nii genes share only 84% identity with leaf-specific Nii1 sequences carried by the 271 locus. Conversely, transgenes carrying the bean Nii gene (which shares 76% identity with the tobacco Nii1 gene) escape silencing by the 271 locus. We also show that transgenes driven by the figwort mosaic virus 34S promoter (which shares 63% identity with the 35S promoter) also escape silencing by the 271 locus. Taken together, these results indicate that a high degree of sequence similarity is required between the sequences of the silencing locus and of the target (trans)genes for both transcriptional and post-transcriptional silencing.

  19. Large scale excitation of the ISM in NGC 1068

    NASA Technical Reports Server (NTRS)

    Sokolowski, J.; Bland, Jonathan; Cecil, G. N.; Tully, R. B.

    1990-01-01

    Researchers have shown that photoionization by the continuum of the hidden Seyfert I nucleus in NGC 1068 can have a significant effect on the ionization state and energetics of this disk's Interstellar Medium (ISM). Photoionization models with appropriate power law spectra can produce (NII) lambda lambda 6538, 6584/H alpha line ratios of 1.25 for ionization parameters Q approx. 10 (exp -12). However the data indicate large regions where the (NII)/H alpha ratio is 1 to 3. Since the abundances are known to be solar, there must be additional heating sources. Hardening of the incident radiation field by intervening absorption should be able to raise T sub e, thereby raising the (NII)/H alpha ratio. Heating with moderate efficiency by the intense starburst ring should also be a significant factor in raising the temperature of the ISM. The photoionization models with additional heating predict enhanced emission from other forbidden lines including (OII) lambda 3727 and (SII) lambda 6731.

  20. EUV studies of N2 and O2 produced by low energy electron impact

    NASA Technical Reports Server (NTRS)

    Morgan, H. D.; Mentall, J. E.

    1983-01-01

    The emission spectra resulting from electron impact excitation on molecular nitrogen and oxygen in the 500-1200 A spectral region are investigated. Electron energies are from 0 to 300 eV. Numerous bands of N2 are found between 800 and 1000 A. Excitation functions are measured for the NII 916 A, the OI 879 A, and the OII 834 multiplets, and nitrogen band emission. Cross sections were measured at 200 eV for several of the band emissions plus the NI 1135 A, NI 1164 A, NI 1177 A, NII 776 A, NII 1084 A, OI 1152 A, OI 1041 A, OI 999 A, OI 989 A, OI 879 A, OII 834 A, OII 616 A, OII 555 A, OII 539 A, and OII 718 A multiplets.

  1. Communications satellites in the national and global health care information infrastructure: their role, impact, and issues

    NASA Technical Reports Server (NTRS)

    Zuzek, J. E.; Bhasin, K. B.

    1996-01-01

    Health care services delivered from a distance, known collectively as telemedicine, are being increasingly demonstrated on various transmission media. Telemedicine activities have included diagnosis by a doctor at a remote location, emergency and disaster medical assistance, medical education, and medical informatics. The ability of communications satellites to offer communication channels and bandwidth on demand, connectivity to mobile, remote and under served regions, and global access will afford them a critical role for telemedicine applications within the National and Global Information Infrastructure (NII/GII). The importance that communications satellites will have in telemedicine applications within the NII/GII the differences in requirements for NII vs. GII, the major issues such as interoperability, confidentiality, quality, availability, and costs, and preliminary conclusions for future usability based on the review of several recent trails at national and global levels are presented.

  2. Submillimeter and Far-Infrared Observations of the Carina Nebula

    NASA Astrophysics Data System (ADS)

    Oberst, Thomas E.; Parshley, S. C.; Nikola, T.; Stacey, G. J.; Loehr, A.; Lane, A. P.; Stark, A. A.; Kamenetzky, J.

    2011-05-01

    We present the results of a 250 arcmin2 mapping of the 205 μm [NII] fine-structure emission over the northern Carina Nebula, including the Car I and Car II HII regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) at South Pole. We supplement the 205 μm data with new reductions of far-IR fine-structure spectra from the Infrared Space Observatory (ISO) in 63 μm [OI], 122 μm [NII], 146 μm [OI], and 158 μm [CII]. Morphological comparisons are made with optical, radio continuum and CO maps. The 122 [NII] / 205 [NII] line ratio is used to probe the density of the low-ionization gas, and the 158 [C II] / 205 [NII] line ratio is used to probe the fraction of C+ arising from photodissociation regions (PDRs). From the [OI] and [CII] data, we construct a PDR model of Carina following Kaufman et al. (1999). When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than Galactic star-forming regions such as the Orion Bar, M17, or W49; this is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept away. These data constitute the first ever ground-based detection of the 205 μm [NII] line, and only the third detection overall since those of the COBE FIRAS and the KAO in the early 1990s.

  3. History of Early Research on MEMS in Russia (U.S.S.R.)

    NASA Astrophysics Data System (ADS)

    Vaganov, Vladimir

    An overview of early MEMS research and developments made in Russia (U.S.S.R.) from 1971 to 1985, which are not widely published and described in the western technical literature, is presented in this paper. Moscow Physics Engineering Institute was the first Russian organization, where MEMS research was initiated. The number of world pioneering developments was made there. Many other institutions in the former Soviet Union participated in early MEMS works. Among them were "Giredmet", "NiiTeplopribor", "Electronpribor", "Nii Physical Measurements", Bauman Technical University, Novisibirsk University, MIET, Kaunas Polytechnical Institute, Lvov Polytechnical Institute, Leningrad State University and other organizations.

  4. Children's Depression Screener (ChilD-S): Development and Validation of a Depression Screening Instrument for Children in Pediatric Care

    ERIC Educational Resources Information Center

    Fruhe, Barbara; Allgaier, Antje-Kathrin; Pietsch, Kathrin; Baethmann, Martina; Peters, Jochen; Kellnar, Stephan; Heep, Axel; Burdach, Stefan; von Schweinitz, Dietrich; Schulte-Korne, Gerd

    2012-01-01

    The aim of the present study was to develop and validate the Children's Depression Screener (ChilD-S) for use in pediatric care. In two pediatric samples, children aged 9-12 (NI = 200; NII = 246) completed an explorative item pool (subsample I) and a revised item pool (subsample II). Diagnostic accuracy of each of the 22 items from the revised…

  5. 47 CFR 15.407 - General technical requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... provide critical communications services should determine if there are any nearby Government radar systems... systems with an e.i.r.p. of less than 500 mW. (2) Radar Detection Function of Dynamic Frequency Selection (DFS). U-NII devices operating in the 5.25-5.35 GHz and 5.47-5.725 GHz bands shall employ a DFS...

  6. 47 CFR 15.407 - General technical requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... provide critical communications services should determine if there are any nearby Government radar systems... systems with an e.i.r.p. of less than 500 mW. (2) Radar Detection Function of Dynamic Frequency Selection (DFS). U-NII devices operating in the 5.25-5.35 GHz and 5.47-5.725 GHz bands shall employ a DFS...

  7. 77 FR 33753 - Privacy Act of 1974; Department of Homeland Security, U.S. Customs and Border Protection, DHS/CBP...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-07

    ... are incorporated from the following CBP and DHS systems: ATS (last SORN published at 72 FR 43650...)); Nonimmigrant Information System (NIIS) (last SORN published at 73 FR 77739 (December 19, 2008)); Seized Asset Case Tracking System (SEACATS) (last SORN published at 73 FR 77764 (December 19, 2008)); Department...

  8. Combined Spectroscopic and Electrochemical Detection of a NiI•••H–N Bonding Interaction with Relevance to Electrocatalytic H2 Production

    SciTech Connect

    Kochem, Amelie; O'Hagan, Molly J.; Wiedner, Eric S.; van Gastel, Maurice

    2015-07-13

    The [Ni(PR2NR’2)2]2+ family of complexes are exceptionally active catalysts for proton reduction to H2. In this manuscript, we explore the first protonation step of the proposed catalytic cycle by using a catalytically inactive NiI complex possessing a sterically demanding variation of the ligand. Due to the paramagnetic nature of the NiI oxidation state, the protonated NiI intermediate has been characterized through a combination of cyclic voltammetry, ENDOR, and HYSCORE spectroscopy. Both the electrochemical and spectroscopic studies indicate that the NiI complex is protonated at a pendant amine that is endo to Ni, which suggests the presence of an intramolecular NiI•••HN bonding interaction. Using density functional theory, the proton was found to hydrogen bond to three doubly-occupied, localized molecular orbitals: the 3dxz, 3dz2, and 3dyz orbitals of nickel. These studies provide the first direct experimental evidence for this critical catalytic intermediate, and implications for catalytic H2 production are discussed. Research was supported by the Max Planck Society (EPR, ENDOR, and HYSCORE spectroscopy, computational studies), and as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (electrochemistry, NMR spectroscopy). Pacific Northwest National Laboratory is operated by Battelle for DOE.

  9. Applications drivers for data parking on the Information Superhighway

    NASA Technical Reports Server (NTRS)

    Johnson, Clark E., Jr.; Foeller, Thomas

    1994-01-01

    As the cost of data storage continues to decline (currently about one-millionth of its cost four decades ago) entirely new applications areas become economically feasible. Many of these new areas involved the extraordinarily high data rates and universal connectivity soon to be provided by the National Information Infrastructure (NII). The commonly held belief is that the main driver for the NII will be entertainment applications. We believe that entertainment applications as currently touted (multi-media, 500 video channels, video-on-demand, etc.) will play an important but far from dominant role in the development of the NII and its data storage components. The most pervasively effective drivers will be medical applications such as telemedicine and remote diagnosis, education and environmental monitoring. These applications have a significant funding base and offer a clearly perceived opportunity to improve the nation's standard of living. The NII's wideband connectivity both nationwide and worldwide requires a broad spectrum of data storage devices with a wide-range of performance capabilities. These storage centers will be dispersed throughout the system. Magnetic recording devices will fill the majority of these new data storage requirements for at least the rest of this century. The storage needs of various application areas and their respective market sizes will be explored. The comparative performance of various magnetic technologies and competitive alternative storage systems will be discussed.

  10. 32 CFR 310.9 - Privacy boards and office, composition and responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Defense for Networks and Information Integration (ASD) (NII)/Chief Information Officer (CIO); the Director..., OMB Circular A-130, and DoD 5400.11-R, all computer matching programs involving personal records... computer matching agreements between the Department of Defense and the other Federal, State or...

  11. The Information Infrastructure: Reaching Society's Goals. A Report of the Information Infrastructure Task Force Committee on Applications and Technology.

    ERIC Educational Resources Information Center

    National Inst. of Standards and Technology, Gaithersburg, MD.

    Intended for public comment and discussion, this document is the second volume of papers in which the Information Infrastructure Task Force has attempted to articulate in clear terms, with sufficient detail, how improvements in the National Information Infrastructure (NII) can help meet other social goals. These are not plans to be enacted, but…

  12. 47 CFR 15.401 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Infrastructure Devices § 15.401 Scope. This subpart sets out the regulations for unlicensed National Information Infrastructure (U-NII) devices operating in the 5.15-5.35 GHz, 5.47-5.725 GHz and 5.725-5.825 GHz bands....

  13. 47 CFR 15.401 - Scope.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Infrastructure Devices § 15.401 Scope. This subpart sets out the regulations for unlicensed National Information Infrastructure (U-NII) devices operating in the 5.15-5.35 GHz, 5.47-5.725 GHz and 5.725-5.825 GHz bands....

  14. 47 CFR 15.401 - Scope.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Infrastructure Devices § 15.401 Scope. This subpart sets out the regulations for unlicensed National Information Infrastructure (U-NII) devices operating in the 5.15-5.35 GHz, 5.47-5.725 GHz and 5.725-5.825 GHz bands....

  15. 47 CFR 15.401 - Scope.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Infrastructure Devices § 15.401 Scope. This subpart sets out the regulations for unlicensed National Information Infrastructure (U-NII) devices operating in the 5.15-5.35 GHz, 5.47-5.725 GHz and 5.725-5.85 GHz bands....

  16. 47 CFR 15.401 - Scope.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Infrastructure Devices § 15.401 Scope. This subpart sets out the regulations for unlicensed National Information Infrastructure (U-NII) devices operating in the 5.15-5.35 GHz, 5.47-5.725 GHz and 5.725-5.825 GHz bands....

  17. Access to the Information Superhighway and Emerging Information Technologies by People with Disabilities.

    ERIC Educational Resources Information Center

    National Council on Disability, Washington, DC.

    This report discusses the growth of the National Information Infrastructure (NII), or the information superhighway, and its implications for people with disabilities. Advantages for people with disabilities include: increasing the ability of individuals with some types of disabilities to access and use information; decreasing personal isolation…

  18. Hα Star Formation Rates for z>1 Galaxy Clusters in the IRAC Shallow Cluster Survey Using WFC3 IR Grism Spectroscopy

    NASA Astrophysics Data System (ADS)

    Zeimann, Gregory; Stanford, A.; Brodwin, M.; Dey, A.; Stern, D.; Gonzalez, A.

    2011-05-01

    We present new HST WFC3 grism data for 17 z>1 galaxy clusters in the IRAC Shallow Cluster Survey (ISCS). Using the G141 grism (λ = 1.10 - 1.65 μm, 46.5 A/pixel), we identified ˜5-15 new cluster members in each cluster candidate with a visual inspection of emission line galaxies in the reduced 1-d and 2-d spectral extractions. Given the redshift range of the cluster candidates and the wavelength coverage of the G141 grism, the emission line most identified was the blended Hα+NII. Correlations found in the literature between the EW of Hα+NII and the line ratio of NII to Hα were used to deblend the two fluxes. Hα emission was used as an indicator of star formation. Our program is sensitive to an unobscured star formation rate of 4 M⊙ / Year for z=1.5 and a nominal 1:4 ratio of NII to Hα. Concurrent MIPS 24μm data allows for the comparison of different SFR tracers. Whenever possible, we also use the ratio of Hβ/Hα to estimate dust obscuration and correct the SFRs. This dataset allows the study of a wide-range of star formation rates in dense cluster cores during the peak epoch of galaxy formation.

  19. Improving Institutional Performance through IT-Enabled Innovation

    ERIC Educational Resources Information Center

    Graves, William H.

    2005-01-01

    In its report "Innovate America," the National Innovation Initiative (NII) calls for an "innovation infrastructure" as the foundation for the nation's future productivity and competitiveness. The report notes: "Innovation generates the productivity that economists estimate has accounted for half of U.S. GDP growth over the past 50 years... It's…

  20. Biodegradation of chlorpyrifos by bacterial consortium isolated from agriculture soil.

    PubMed

    Sasikala, Chitrambalam; Jiwal, Sonia; Rout, Pallabi; Ramya, Mohandass

    2012-03-01

    Organophosphorous pesticides are widely used in agriculture to control major insect pests. Chlorpyrifos is one of the major organophosphorous pesticides which is used to control insects including termites, beetles. The widespread use of these pesticides is hazardous to the environment and also toxic to mammals, thus it is essential to remove the same from the environment. From the chlorpyrifos contaminated soil nine morphologically different bacterial strains, one actinomycete and two fungal strains were isolated. Among those isolates four bacterial strains which were more efficient were developed as consortium. The four bacterial isolates namely Pseudomonas putida (NII 1117), Klebsiella sp., (NII 1118), Pseudomonas stutzeri (NII 1119), Pseudomonas aeruginosa (NII 1120) present in the consortia were identified on the basis of 16S rDNA analysis. The intracellular fractions of the consortium exhibited more organophosphorus hydrolase activity (0.171 ± 0.003 U/mL/min). The degradation studies were carried out at neutral pH and temperature 37°C with chlorpyrifos concentration 500 mg L(-1). LC-mass spectral analysis showed the presence of metabolites chlopyrifos-oxon and Diethylphosphorothioate. These results highlight an important potential use of this consortium for the cleanup of chlorpyrifos contaminated pesticide waste in the environment.

  1. 47 CFR 2.1091 - Radiofrequency radiation exposure evaluation: mobile devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... their effective radiated power (ERP) is 1.5 watts or more, or if they operate at frequencies above 1.5... millimeter wave devices and unlicensed NII devices authorized under §§ 15.253, 15.255, and 15.257, and... transmission of a signal. In general, maximum average power levels must be used to determine compliance. (3)...

  2. The High-Performance Computing and Communications program, the national information infrastructure and health care.

    PubMed

    Lindberg, D A; Humphreys, B L

    1995-01-01

    The High-Performance Computing and Communications (HPCC) program is a multiagency federal effort to advance the state of computing and communications and to provide the technologic platform on which the National Information Infrastructure (NII) can be built. The HPCC program supports the development of high-speed computers, high-speed telecommunications, related software and algorithms, education and training, and information infrastructure technology and applications. The vision of the NII is to extend access to high-performance computing and communications to virtually every U.S. citizen so that the technology can be used to improve the civil infrastructure, lifelong learning, energy management, health care, etc. Development of the NII will require resolution of complex economic and social issues, including information privacy. Health-related applications supported under the HPCC program and NII initiatives include connection of health care institutions to the Internet; enhanced access to gene sequence data; the "Visible Human" Project; and test-bed projects in telemedicine, electronic patient records, shared informatics tool development, and image systems.

  3. Towards Web/Java-based high performance distributed computing - an evolving virtual machine

    SciTech Connect

    Fox, G.; Furmanski, W.

    1996-12-31

    We discuss here the emergent Web based distributed environments for HPCC on the NII with the focus on Java as an enabling technology. We start with a review of the past, presence and the near term future of the {open_quotes}Java phenomenon{close_quotes}, exposed here in the background of some related previous approaches towards a distributed interpretative virtual machine architecture.

  4. The development of regulatory expectations for computer-based safety systems for the UK nuclear programme

    SciTech Connect

    Hughes, P. J.; Westwood, R.N; Mark, R. T.; Tapping, K.

    2006-07-01

    The Nuclear Installations Inspectorate (NII) of the UK's Health and Safety Executive (HSE) has completed a review of their Safety Assessment Principles (SAPs) for Nuclear Installations recently. During the period of the SAPs review in 2004-2005 the designers of future UK naval reactor plant were optioneering the control and protection systems that might be implemented. Because there was insufficient regulatory guidance available in the naval sector to support this activity the Defence Nuclear Safety Regulator (DNSR) invited the NII to collaborate with the production of a guidance document that provides clarity of regulatory expectations for the production of safety cases for computer based safety systems. A key part of producing regulatory expectations was identifying the relevant extant standards and sector guidance that reflect good practice. The three principal sources of such good practice were: IAEA Safety Guide NS-G-1.1 (Software for Computer Based Systems Important to Safety in Nuclear Power Plants), European Commission consensus document (Common Position of European Nuclear Regulators for the Licensing of Safety Critical Software for Nuclear Reactors) and IEC nuclear sector standards such as IEC60880. A common understanding has been achieved between the NII and DNSR and regulatory guidance developed which will be used by both NII and DNSR in the assessment of computer-based safety systems and in the further development of more detailed joint technical assessment guidance for both regulatory organisations. (authors)

  5. 20/20 Vision: The Development of a National Information Infrastructure.

    ERIC Educational Resources Information Center

    National Telecommunications and Information Administration (DOC), Washington, DC.

    After the publication of the Clinton Administration's "The National Information Infrastructure: Agenda for Action," a group of telecommunication specialists were asked to evaluate the proposals in order to broaden the policy discussion concerning the National Information Infrastructure (NII). This collection contains their visions of the nation's…

  6. Libraries and Their Role in the Information Infrastructure. Hearing on Examining the Role of Libraries in Developing America's New Information Infrastructure, before the Subcommittee on Education, Arts and Humanities of the Committee on Labor and Human Resources. United States Senate, One Hundred Third Congress, Second Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Labor and Human Resources.

    The purpose of this congressional hearing was to determine how libraries fit into the emerging national information infrastructure (NII). Testimony and prepared statements include those from Howard F. McGinn, Director, Emporia Public Library, Emporia, Kansas; James H. Billington, Librarian of Congress, Library of Congress, Washington D.C.,…

  7. College Psychotherapy at a Taiwanese Counseling Center

    ERIC Educational Resources Information Center

    Lin, Yii-nii

    2014-01-01

    This article introduces Yii-nii Lin, Professor in the Center for Teacher Education at the National Tsing Hua University in Taiwan, and prior director of the university's counseling center for a 3 year term. She has worked as a university counselling psychologist for more than 15 years when she participated in an online interview that…

  8. Using the National Information Infrastructure for social science, education, and informed decision making

    SciTech Connect

    Tonn, B.E.

    1994-01-07

    The United States has aggressively embarked on the challenging task of building a National Information Infrastructure (NII). This infrastructure will have many levels, extending from the building block capital stock that composes the telecommunications system to the multitude of higher tier applications hardware and software tied to this system. This ``White Paper`` presents a vision for a second and third tier national information infrastructure that focuses exclusively on the needs of social science, education, and decision making (NII-SSEDM). NII-SSEDM will provide the necessary data, information, and automated decision support and educational tools needed to help this nation solve its most pressing social problems. The proposed system has five components: `data collection systems; databases; statistical analysis and modeling tools; policy analysis and decision support tools; and materials and software specially designed for education. This paper contains: a vision statement for each component; comments on progress made on each component as of the early 1990s; and specific recommendations on how to achieve the goals described in the vision statements. The white paper also discusses how the NII-SSEDM could be used to address four major social concerns: ensuring economic prosperity; health care; reducing crime and violence; and K-12 education. Examples of near-term and mid-term goals (e.g., pre-and post Year 2000) are presented for consideration. Although the development of NII-SSEDM will require a concerted effort by government, the private sector, schools, and numerous other organizations, the success of NH-SSEDM is predicated upon the identification of an institutional ``champion`` to acquire and husband key resources and provide strong leadership and guidance.

  9. Excitation of emission lines by fluorescence and recombination in IC 418

    NASA Astrophysics Data System (ADS)

    Escalante, Vladimir; Morisset, Cristophe; Georgiev, Leonid

    2012-08-01

    We predict intensities of lines of CII, NI, NII, OI and OII and compare them with a deep spectroscopic survey of IC 418 to test the effect of excitation of nebular emission lines by continuum fluorescence of starlight. Our calculations use a nebular model and a synthetic spectrum of its central star to take into account excitation of the lines by continuum fluorescence and recombination. The NII spectrum is mostly produced by fluorescence due to the low excitation conditions of the nebula, but many CII and OII lines have more excitation by fluorescence than recombination. In the neutral envelope, the NI permitted lines are excited by fluorescence, and almost all the OI lines are excited by recombination. Electron excitation produces the forbidden optical lines of OI, but continuum fluorescence excites most of the NI forbidden line intensities. Lines excited by fluorescence of light below the Lyman limit thus suggest a new diagnostic to explore the photodissociation region of a nebula.

  10. Space-based Communications Infrastructure for Developing Countries

    NASA Technical Reports Server (NTRS)

    Barker, Keith; Barnes, Carl; Price, K. M.

    1995-01-01

    This study examines the potential use of satellites to augment the telecommunications infrastructure of developing countries with advanced satellites. The study investigated the potential market for using satellites in developing countries, the role of satellites in national information infractructures (NII), the technical feasibility of augmenting NIIs with satellites, and a nation's financial conditions necessary for procuring satellite systems. In addition, the study examined several technical areas including onboard processing, intersatellite links, frequency of operation, multibeam and active antennas, and advanced satellite technologies. The marketing portion of this study focused on three case studies: China, Brazil, and Mexico. These cases represent countries in various stages of telecommunication infrastructure development. The study concludes by defining the needs of developing countries for satellites, and recommends steps that both industry and NASA can take to improve the competitiveness of U.S. satellite manufacturing.

  11. Differences in Autism Spectrum Disorders Incidence by Sub-Populations in Israel 1992-2009: A Total Population Study

    PubMed Central

    Raz, Raanan; Weisskopf, Marc G; Davidovitch, Michael; Pinto, Ofir; Levine, Hagai

    2014-01-01

    We analyzed data from the Israeli National Insurance Institute (NII). Autism Spectrum Disorder (ASD) incidence was calculated for all children born in Israel 1992-2009, and by population groups. Overall, 9,109 ASD cases among 2,431,649 children were identified. ASD cumulative incidence by age 8 years increased 10-fold during 2000-2011, from 0.049% to 0.49%, while other child disabilities in NII increased only 1.65-fold. There was a consistent increase in ASD incidence with advancing birth cohorts born 1992-2004, stabilizing among those born 2005-2009. ASD rates among Israeli Arabs were substantially lower, and increased about 10 years later than the general population. The findings suggest a role for ASD awareness, accessing of the government benefit, or the way the concept of ASD is perceived. PMID:25287899

  12. Space-based communications infrastructure for developing countries

    NASA Astrophysics Data System (ADS)

    Barker, Keith; Barnes, Carl; Price, K. M.

    1995-08-01

    This study examines the potential use of satellites to augment the telecommunications infrastructure of developing countries with advanced satellites. The study investigated the potential market for using satellites in developing countries, the role of satellites in national information infrastructures (NII), the technical feasibility of augmenting NIIs with satellites, and a nation's financial conditions necessary for procuring satellite systems. In addition, the study examined several technical areas including onboard processing, intersatellite links, frequency of operation, multibeam and active antennas, and advanced satellite technologies. The marketing portion of this study focused on three case studies: China, Brazil, and Mexico. These cases represent countries in various stages of telecommunication infrastructure development. The study concludes by defining the needs of developing countries for satellites, and recommends steps that both industry and NASA can take to improve the competitiveness of U.S. satellite manufacturing.

  13. Kinematics of the symbiotic system R Aqr

    NASA Astrophysics Data System (ADS)

    Navarro, S.; Corral, L. J.; Steffen, W.

    2014-04-01

    We present the results of the kinematical analysis of the symbiotic system R Aqr. We obtained high dispersion spectra with the MES spectrograph at the 2.1 m telescope of San Pedro Mártir (MEZCAL). The used filter were Ha + [NII], (λc = 6575Å, Δλ = 90Å). We analyse the [NII] λλ6583 line. When the observations are compared with previous ones by Solf (1992) we detected an important change in the projected velocities of the observed knots, supporting the idea of a precessing jet. We are working also in a 3-D kinematic model for the object using the measured velocities and the state of the model is presented.

  14. Department of Defense counterdrug technology development of non-intrusive inspection systems

    NASA Astrophysics Data System (ADS)

    Pennella, John J.

    1997-02-01

    The Naval Surface Warfare Center Dahlgren Division serves as the executive agent for the DoD's Contraband Detection and Cargo Container Inspection Technology Development Program. The goal of the DoD non-intrusive inspection (NII) program is to develop prototype equipment that can be used to inspect containers and vehicles, quickly and in large numbers without unnecessary delays in the movement of legitimate cargo. This paper summaries the past accomplishments of the program, current status, and future plans.

  15. Evaluating and minimizing noise impact due to aircraft flyover

    NASA Technical Reports Server (NTRS)

    Jacobson, I. D.

    1980-01-01

    The results of a study on the evaluation and reduction of noise impact to a community due to aircraft landing and takeoff operations are presented. The case of multiple aircrafts flying on several trajectories, for either approach/landings or takeoffs was examined. An extremely realistic model of the flight path was developed. The annoyance criterion used was the noise impact index (NII). The algorithm was applied to Patrick Henry International Airport.

  16. The Federal Role in Bringing Education into the National Information Infrastructure

    NASA Technical Reports Server (NTRS)

    Cradler, John

    1995-01-01

    One of the most important issues facing Congress is to work with business, education, and the states to enable the nation's shools to better prepare students for a technological work force and to ensure that education has a place on the National Information Infrastructure (NII). This document provides background and important information for national leaders concerned about education, the information infrastructure, and related issues for the Federal government.

  17. Differences in Autism Spectrum Disorders Incidence by Sub-Populations in Israel 1992-2009: A Total Population Study

    ERIC Educational Resources Information Center

    Raz, Raanan; Weisskopf, Marc G.; Davidovitch, Michael; Pinto, Ofir; Levine, Hagai

    2015-01-01

    We analyzed data from the Israeli National Insurance Institute (NII). Autism Spectrum Disorder (ASD) incidence was calculated for all children born in Israel 1992-2009, and by population groups. Overall, 9,109 ASD cases among 2,431,649 children were identified. ASD cumulative incidence by age 8 years increased 10-fold during 2000-2011, from 0.49 %…

  18. Government Information Locator Service (GILS). Draft report to the Information Infrastructure Task Force

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a draft report on the Government Information Locator Service (GILS) to the National Information Infrastructure (NII) task force. GILS is designed to take advantage of internetworking technology known as client-server architecture which allows information to be distributed among multiple independent information servers. Two appendices are provided -- (1) A glossary of related terminology and (2) extracts from a draft GILS profile for the use of the American National Standard Information Retrieval Application Service Definition and Protocol Specification for Library Applications.

  19. VizieR Online Data Catalog: Nebular emission lines towards NGC3372 center (Damiani+, 2016)

    NASA Astrophysics Data System (ADS)

    Damiani, F.; Bonito, R.; Magrini, L.; Prisinzano, L.; Mapelli, M.; Micela, G.; Kalari, V.; Maiz Apellaniz, J.; Gilmore, G.; Randich, S.; Alfaro, E.; Flaccomio, E.; Koposov, S.; Klutsch, A.; Lanzafame, A. C.; Pancino, E.; Sacco, G. G.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Franciosini, E.; Hourihane, A.; Lardo, C.; Lewis, J.; Monaco, L.; Morbidelli, L.; Worley, C.; Zaggia, S.; Zwitter, T.; Dorda, R.

    2016-04-01

    Nebular emission lines of H-alpha, [NII] 6584Å, HeI 6678Å, [SII] 6717Å, [SII] 6731Å, towards the center of Carina nebula, are modeled with two gaussians each ('blue' and 'red' components). Best-fit parameters are given in the table. Line widths include the instrumental width of the Giraffe spectrograph (7km/s). Radial velocities are heliocentric. (1 data file).

  20. Remote use of distributed robotics resources to enhance technology development and insertion

    SciTech Connect

    Harrigan, R.W.; McDonald, M.J.; Davies, B.R.

    1994-04-01

    This paper describes Virtual Collaborative Environments (VCEs), an information architecture that enables remote sharing of mechatronic (intelligent electrochemical devices) resources. This architecture will leverage the proposed National Information Infrastructure (NII) or Information Highway to share valuable resources and reduce product-to-market cycles. Benefits of sharing mechatronic resources with VCEs are explored. An existing prototype VCE is described and experimental and illustrative results from using the prototype VCE system are discussed.

  1. Aspergillus nidulans galactofuranose biosynthesis affects antifungal drug sensitivity.

    PubMed

    Alam, Md Kausar; El-Ganiny, Amira M; Afroz, Sharmin; Sanders, David A R; Liu, Juxin; Kaminskyj, Susan G W

    2012-12-01

    The cell wall is essential for fungal survival in natural environments. Many fungal wall carbohydrates are absent from humans, so they are a promising source of antifungal drug targets. Galactofuranose (Galf) is a sugar that decorates certain carbohydrates and lipids. It comprises about 5% of the Aspergillus fumigatus cell wall, and may play a role in systemic aspergillosis. We are studying Aspergillus wall formation in the tractable model system, A. nidulans. Previously we showed single-gene deletions of three sequential A. nidulans Galf biosynthesis proteins each caused similar hyphal morphogenesis defects and 500-fold reduced colony growth and sporulation. Here, we generated ugeA, ugmA and ugtA strains controlled by the alcA(p) or niiA(p) regulatable promoters. For repression and expression, alcA(p)-regulated strains were grown on complete medium with glucose or threonine, whereas niiA(p)-regulated strains were grown on minimal medium with ammonium or nitrate. Expression was assessed by qPCR and colony phenotype. The alcA(p) and niiA(p) strains produced similar effects: colonies resembling wild type for gene expression, and resembling deletion strains for gene repression. Galf immunolocalization using the L10 monoclonal antibody showed that ugmA deletion and repression phenotypes correlated with loss of hyphal wall Galf. None of the gene manipulations affected itraconazole sensitivity, as expected. Deletion of any of ugmA, ugeA, ugtA, their repression by alcA(p) or niiA(p), OR, ugmA overexpression by alcA(p), increased sensitivity to Caspofungin. Strains with alcA(p)-mediated overexpression of ugeA and ugtA had lower caspofungin sensitivity. Galf appears to play an important role in A. nidulans growth and vigor.

  2. Probing the Ionized Medium in Early Universe with ZEUS(1 & 2)

    NASA Astrophysics Data System (ADS)

    Ferkinhoff, Carl; Brisbin, D.; Nikola, T.; Parshley, S.; Stacey, G.; Hailey-Dunsheath, S.; Phillips, T. G.; Falgarone, E.; Benford, D.; Staguhn, J.; Irwin, K.; Cho, S.; Niemack, M.

    2012-05-01

    Using the first generation Redshift(z) and Early Universe Spectrometer (ZEUS-1) on the Caltech Submillimeter Observatory we made the first detections of the [NII] 122 μm and [OIII] 88 μm lines from galaxies in the early Universe. We detect both lines from SMMJ02399-0136 at z 2.8, while from H1413+117 (the Cloverleaf QSO) at z 2.6 and APM08279+5255 at z 3.9 we detect only the [NII] and [OIII] lines respectively. All three sources are lensed, IR-luminous with intrinsic far-infrared (FIR) luminosities >1012 Lsun, and contain both an active galactic nucleus (AGN) and star-forming component. The lines detected from the sources are bright with line to FIR continuum luminosity ratios ranging between 5×10-4 and 2×10-3. The [NII] and [OIII] lines are excellent probes of the state of the ionized gas. The strengths of the lines provide a minimum ionized-gas mass, which for our sources is large, 8%-17% of the molecular gas mass. The ratio of the lines is very sensitive to the effective temperature of ionizing stars and the ionization parameter for emission arising in the narrow-line region (NLR) of an AGN. The [OIII]/[NII] line ratio for SMMJ02399 indicates that the dominant source of the line emission is either stellar H II regions ionized by O9.5 stars, or the NLR of the AGN with ionization parameter log(U) = -3.3 to -4.0. Both the Cloverleaf and APM08279 exhibit starbursts similar to that found in M82 and are respectively best modeled by a superposition of 200 and 270 M82 like starbursts. Follow-up observations with Herschel and ALMA, will constrain the fraction of line emission arising in the starburst and NLR. Using ZEUS-2 (Ferkinhoff et al. 2010) we will expand our sample of high-redshift galaxies with [NII] and [OIII] detections to fully understand the state and evolution of ionized medium in the early Universe.

  3. Submillimeter spectroscopy of the Carina Nebula: Observations, operations and upgrades of the South Pole Imaging Fabry-Perot Interferometer

    NASA Astrophysics Data System (ADS)

    Oberst, Thomas Edward

    2009-06-01

    We present the results of a ~ 250 arcmin 2 mapping of the 205 μm [NII] fine- structure line emission over the northern Carina Nebula, including the Car I and Car II HII regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Telescope and Remote Observatory (AST/RO) at South Pole. New upgrades and modifications to the SPIFI instrument are discussed, and full details of SPIFI-AST/RO integration and calibration are provided. At the time of these observations, SPIFI had a spectral resolving power of ~ 4250, a FWHM beam size of ~ 54'', and a noise equivalent power (NEP) referred to the front end of the receiver of ~ 2.5 × 10 -15 W Hz -1/2 (~ 1.4 times the background limit). These data constitute the first ground-based detection of the 205 μm [NII] line, and only the third detection overall since those of the Cosmic Background Explorer (COBE) Far Infrared Absolute Spectrophotometer (FIRAS) and the Kuiper Airborne Observatory (KAO) in the early 1990s. We supplement the 205 μm data with new reductions of far-infrared fine- structure spectra from the Infrared Space Observatory (ISO) in 63 μm [OI], 122 m [NII], 146 μm [OI], and 158 μm [CII]; the 146 μm [OI] data include 90 raster positions which have not been previously published. Morphological comparisons are made with optical, radio continuum and CO maps. The 122/205 [NII] line ratio is used to probe the density of the low-ionization gas, and the 158/205 [CII]/[NII] line ratio is used to probe the fraction of C + arising from photodissociation regions (PDRs). The [OI] and [CII] lines are used to construct a PDR model of Carina following Kaufman et al. (1999). When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than galactic star-forming regions such as Orion, M17, or W49. This is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept

  4. Abell 41: shaping of a planetary nebula by a binary central star

    NASA Astrophysics Data System (ADS)

    Jones, D.; Lloyd, M.; Santander-García, M.; López, J. A.; Meaburn, J.; Mitchell, D. L.; O'Brien, T. J.; Pollacco, D.; Rubio-Díez, M. M.; Vaytet, N. M. H.

    2010-11-01

    We present the first detailed spatiokinematical analysis and modelling of the planetary nebula Abell 41, which is known to contain the well-studied close-binary system MT Ser. This object represents an important test case in the study of the evolution of planetary nebulae with binary central stars as current evolutionary theories predict that the binary plane should be aligned perpendicular to the symmetry axis of the nebula. Deep narrow-band imaging in the light of [NII]6584Å, [OIII]5007 Å and [SII]6717+6731Å, obtained using ACAM on the William Herschel Telescope, has been used to investigate the ionization structure of Abell 41. Long-slit observations of the Hα and [NII]6584Å emission were obtained using the Manchester Echelle Spectrometer on the 2.1-m San Pedro Mártir Telescope. These spectra, combined with the narrow-band imagery, were used to develop a spatiokinematical model of [NII]6584Å emission from Abell 41. The best-fitting model reveals Abell 41 to have a waisted, bipolar structure with an expansion velocity of ~40 km s-1 at the waist. The symmetry axis of the model nebula is within 5° of perpendicular to the orbital plane of the central binary system. This provides strong evidence that the close-binary system, MT Ser, has directly affected the shaping of its nebula, Abell 41. Although the theoretical link between bipolar planetary nebulae and binary central stars is long established, this nebula is only the second to have this link, between nebular symmetry axis and binary plane, proved observationally. Based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. E-mail: david.jones-3@postgrad.manchester.ac.uk

  5. Searching for the Nearest Extragalactic Binary Black Hole: A Spectroscopic Study of NGC 4736

    NASA Astrophysics Data System (ADS)

    Gustafsson, Annika; Kwan, Teiler J.; Fisher, Robert Scott; Mason, Rachel

    2016-01-01

    In 1995 and 1996, Maoz et al. concluded that the nearby galaxy NGC 4736 (d=16 million light years) is in the late stages of a merger event. After further investigation, in 2005, Maoz et al. observed UV variability in the nuclear region of NGC 4736, revealing a second unknown source in the nucleus. Since late stage mergers are an ideal location to search for binary black holes (BBH), members of our team hypothesized that the second source could be a second black hole, making this a potential BBH system. This is important since observational evidence for their existence remains sparse, even though BBH are predicted by many theories and potentially play an important role in galaxy evolution. In January of 2008, NGC 4736 was observed with the GMOS-N instrument on Gemini North. Optical longslit spectra of the nuclear region were obtained with spatial resolution of 0.1454''/pixel and a spectral resolution of R~1700. At this resolution, the two nuclear sources are spatially resolved at a projected separation of 2.5''. As a result, we can classify the nature of the second source by looking at the optical line ratios following Ho et al. (1997). High signal-to-noise spectra of the unknown source displayed strong emission of [SII] and [NII], but an extremely weak [OIII] emission line. The unknown source has a calculated [NII]/[Hα] ratio of 1.37 and an upper limit of 0.6 for the [OIII]/[Hβ] ratio. Placing the unknown source on the BPT-NII diagram (Baldwin et al., 1981), we tentatively conclude that it is a low-luminosity second black hole potentially making NGC 4736 the nearest BBH system. The result will enable future high-spectral and spatial resolution observations of a low-luminosity system in extremely late stages of merging, which will be a significant step forward in validating models of galaxy mergers and AGN activity.

  6. The Impact of Diffuse Ionized Gas on Emission-line Ratios and Gas Metallicity Measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Yan, Renbin; MaNGA Team

    2016-01-01

    Diffuse Ionized Gas (DIG) is prevalent in star-forming galaxies. Using a sample of galaxies observed by MaNGA, we demonstrate how DIG in star-forming galaxies impact the measurements of emission line ratios, hence the gas-phase metallicity measurements and the interpretation of diagnostic diagrams. We demonstrate that emission line surface brightness (SB) is a reasonably good proxy to separate HII regions from regions dominated by diffuse ionized gas. For spatially-adjacent regions or regions at the same radius, many line ratios change systematically with emission line surface brightness, reflecting a gradual increase of dominance by DIG towards low SB. DIG could significantly bias the measurement of gas metallicity and metallicity gradient. Because DIG tend to have a higher temperature than HII regions, at fixed metallicity DIG displays lower [NII]/[OII] ratios. DIG also show lower [OIII]/[OII] ratios than HII regions, due to extended partially-ionized regions that enhance all low-ionization lines ([NII], [SII], [OII], [OI]). The contamination by DIG is responsible for a substantial portion of the scatter in metallicity measurements. At different surface brightness, line ratios and line ratio gradients can differ systematically. As DIG fraction could change with radius, it can affect the metallicity gradient measurements in systematic ways. The three commonly used strong-line metallicity indicators, R23, [NII]/[OII], O3N2, are all affected in different ways. To make robust metallicity gradient measurements, one has to properly isolate HII regions and correct for DIG contamination. In line ratio diagnostic diagrams, contamination by DIG moves HII regions towards composite or LINER-like regions.

  7. Mode of action uncovered for the specific reduction of methane emissions from ruminants by the small molecule 3-nitrooxypropanol.

    PubMed

    Duin, Evert C; Wagner, Tristan; Shima, Seigo; Prakash, Divya; Cronin, Bryan; Yáñez-Ruiz, David R; Duval, Stephane; Rümbeli, Robert; Stemmler, René T; Thauer, Rudolf Kurt; Kindermann, Maik

    2016-05-31

    Ruminants, such as cows, sheep, and goats, predominantly ferment in their rumen plant material to acetate, propionate, butyrate, CO2, and methane. Whereas the short fatty acids are absorbed and metabolized by the animals, the greenhouse gas methane escapes via eructation and breathing of the animals into the atmosphere. Along with the methane, up to 12% of the gross energy content of the feedstock is lost. Therefore, our recent report has raised interest in 3-nitrooxypropanol (3-NOP), which when added to the feed of ruminants in milligram amounts persistently reduces enteric methane emissions from livestock without apparent negative side effects [Hristov AN, et al. (2015) Proc Natl Acad Sci USA 112(34):10663-10668]. We now show with the aid of in silico, in vitro, and in vivo experiments that 3-NOP specifically targets methyl-coenzyme M reductase (MCR). The nickel enzyme, which is only active when its Ni ion is in the +1 oxidation state, catalyzes the methane-forming step in the rumen fermentation. Molecular docking suggested that 3-NOP preferably binds into the active site of MCR in a pose that places its reducible nitrate group in electron transfer distance to Ni(I). With purified MCR, we found that 3-NOP indeed inactivates MCR at micromolar concentrations by oxidation of its active site Ni(I). Concomitantly, the nitrate ester is reduced to nitrite, which also inactivates MCR at micromolar concentrations by oxidation of Ni(I). Using pure cultures, 3-NOP is demonstrated to inhibit growth of methanogenic archaea at concentrations that do not affect the growth of nonmethanogenic bacteria in the rumen. PMID:27140643

  8. Transfer and utilization of government technology assets to the private sector in the fields of health care and information technologies

    NASA Astrophysics Data System (ADS)

    Kun, Luis G.

    1995-10-01

    During the first Health Care Technology Policy conference last year, during health care reform, four major issues were brought up in regards to the efforts underway to develop a computer based patient record (CBPR), the National Information Infrastructure (NII) as part of the high performance computers and communications (HPCC), and the so-called 'patient card.' More specifically it was explained how a national information system will greatly affect the way health care delivery is provided to the United States public and reduce its costs. These four issues were: (1) Constructing a national information infrastructure (NII); (2) Building a computer based patient record system; (3) Bringing the collective resources of our national laboratories to bear in developing and implementing the NII and CBPR, as well as a security system with which to safeguard the privacy rights of patients and the physician-patient privilege; (4) Utilizing government (e.g., DOD, DOE) capabilities (technology and human resources) to maximize resource utilization, create new jobs, and accelerate technology transfer to address health care issues. This year a section of this conference entitled: 'Health Care Technology Assets of the Federal Government' addresses benefits of the technology transfer which should occur for maximizing already developed resources. This section entitled: 'Transfer and Utilization of Government Technology Assets to the Private Sector,' will look at both health care and non-health care related technologies since many areas such as information technologies (i.e. imaging, communications, archival/retrieval, systems integration, information display, multimedia, heterogeneous data bases, etc.) already exist and are part of our national labs and/or other federal agencies, i.e., ARPA. These technologies although they are not labeled under health care programs they could provide enormous value to address technical needs. An additional issue deals with both the technical

  9. Kinetic Analysis of Competitive Electrocatalytic Pathways: New Insights into Hydrogen Production with Nickel Electrocatalysts.

    PubMed

    Wiedner, Eric S; Brown, Houston J S; Helm, Monte L

    2016-01-20

    The hydrogen production electrocatalyst Ni(P(Ph)2N(Ph)2)2(2+) (1) is capable of traversing multiple electrocatalytic pathways. When using dimethylformamidium, DMF(H)(+), the mechanism of H2 formation by 1 changes from an ECEC to an EECC mechanism as the potential approaches the Ni(I/0) couple. Two electrochemical methods, current-potential analysis and foot-of-the-wave analysis (FOWA), were performed on 1 to measure detailed kinetics of the competing ECEC and EECC pathways. A sensitivity analysis was performed on the methods using digital simulations to understand their strengths and limitations. Chemical rate constants were significantly underestimated when not accounting for electron-transfer kinetics, even when electron transfer was fast enough to afford a reversible noncatalytic wave. The EECC pathway of 1 was faster than the ECEC pathway under all conditions studied. Buffered DMF:DMF(H)(+) mixtures afforded an increase in the catalytic rate constant (k(obs)) of the EECC pathway, but k(obs) for the ECEC pathway did not change when using buffered acid. Further kinetic analysis of the ECEC path revealed that base increases the rate of isomerization from exo-protonated Ni(0) isomers to the catalytically active endo-isomers, but decreases the rate of protonation of Ni(I). FOWA did not provide accurate rate constants, but FOWA was used to estimate the reduction potential of the previously undetected exo-protonated Ni(I) intermediate. Comparison of catalytic Tafel plots for 1 under different conditions reveals substantial inaccuracies in the turnover frequency at zero overpotential when the kinetic and thermodynamic effects of the conjugate base are not accounted for properly.

  10. Positioning the electric utility to build information infrastructure

    SciTech Connect

    Not Available

    1994-11-01

    In two particular respects (briefly investigated in this study from a lawyer`s perspective), electric utilities appear uniquely well-positioned to contribute to the National Information Infrastructure (NII). First of all, utilities have legal powers derived from their charters and operating authorities, confirmed in their rights-of-way, to carry out activities and functions necessary for delivering electric service. These activities and functions include building telecommunications facilities and undertaking information services that have become essential to managing electricity demand and supply. The economic value of the efficiencies made possible by telecommunications and information could be substantial. How great remains to be established, but by many estimates electric utility applications could fund a significant share of the capital costs of building the NII. Though utilities` legal powers to pursue such efficiencies through telecommunications and information appear beyond dispute, it is likely that the effort to do so will produce substantial excess capacity. Who will benefit from this excess capacity is a potentially contentious political question that demands early resolution. Will this windfall go to the utility, the customer, or no one (because of political paralysis), or will there be some equitable and practical split? A second aspect of inquiry here points to another contemporary issue of very great societal importance that could very well become the platform on which the first question can be resolved fortuitously-how to achieve universal telecommunications service. In the effort to fashion the NII that will now continue, ways and means to maximize the unique potential contribution of electric utilities to meeting important social and economic needs--in particular, universal service--merit priority attention.

  11. An ALMA view of the interstellar medium of the z = 4.77 lensed starburst SPT-S J213242-5802.9

    NASA Astrophysics Data System (ADS)

    Béthermin, M.; De Breuck, C.; Gullberg, B.; Aravena, M.; Bothwell, M. S.; Chapman, S. C.; Gonzalez, A. H.; Greve, T. R.; Litke, K.; Ma, J.; Malkan, M.; Marrone, D. P.; Murphy, E. J.; Spilker, J. S.; Stark, A. A.; Strandet, M.; Vieira, J. D.; Weiß, A.; Welikala, N.

    2016-02-01

    We present ALMA detections of the [NII] 205 μm and CO(12-11) emission lines, and the tentative detection of [CI] - for the strongly lensed (μ = 5.7 ± 0.5) dusty, star-forming galaxy SPT-S J213242-5802.9 (hereafter SPT2132-58) at z = 4.77. The [NII] and CO(12-11) lines are detected at 11.5 and 8.5σ levels, respectively, by our band 6 observations. The [CI] line is detected at 3.2σ after a reanalysis of existing band 3 data. The [CI] luminosity implies a gas mass of (3.8 ± 1.2) × 1010M⊙, and, consequently, a very short depletion timescale of 34 ± 13 Myr and a CO luminosity to gas mass conversion factor αCO of 1.0 ± 0.3 M⊙ (K km s-1 pc2)-1. SPT2132-58 is an extreme starburst with an intrinsic star formation rate of 1100 ± 200 M⊙/yr. We find a [CII]/[NII] ratio of 26 ± 6, which is the highest ratio reported at z > 4. This suggests that SPT2132-58 hosts an evolved interstellar medium (0.5 Z⊙< Z < 1.5 Z⊙), which may be dominated by photodissociation regions. The CO(2-1) and CO(5-4) transitions have lower CO to far-infrared ratios than local and high-redshift samples, while CO(12-11) is similar to these samples, suggesting the presence of an additional very excited component or an active galactic nucleus.

  12. An Examination of Strong-line Metallicity Diagnostics with Direct Gas-Phase Metallicities at Higher Redshifts

    NASA Astrophysics Data System (ADS)

    Ly, Chun; Rigby, Jane R.; Malkan, Matthew Arnold; Malhotra, Sangeeta

    2016-01-01

    The [OIII]λ4363 nebular emission line, which provides the most reliable determination of the gas metallicity by measuring the electron temperature of the gas, is intrinsically weak. As such, most metallicity studies at both low and high redshifts have utilized "strong-line" metallicity calibrations, such as [NII]λ6583/Hα or R23 = ([OII]+[OIII])/Hβ. However, there are growing concerns that these diagnostics may not be used for evolutionary studies due to differences in the physical conditions (e.g., density, ionization, abundance ratios) of the interstellar gas in galaxies. A clear demonstration for this concern is the offset on the Baldwin-Phillips-Terlevich diagnostic diagram ([OIII]λ5007/Hβ vs. [NII]λ6583/Hα) for high-z star-forming galaxies from local star-forming galaxies.To examine this issue, we investigate the accuracy that commonly-used strong-line diagnostics can explain the direct oxygen abundances. Here, we use a sample of ~100 low-mass galaxies at z=0.07 to 1.0 with detections of the [OIII]λ4363 emission line from Keck and MMT optical spectroscopy. These galaxies are pre-selected for their strong nebular emission lines from the Subaru Deep Field and the DEEP2 Survey. Utilizing the optical emission lines, we argue that "R23" is not a reliable diagnostic and that discrepancies from [OIII]λ4363-based metallicity cannot be explained simply by higher gas densities or higher ionization parameter. We do find that the [NII]-based metallicity diagnostics of Pettini & Pagel (2004) are in agreement with [OIII]λ4363-based metallicity at z~0.5. There is, however, a sub-population (25%) where [NII]-based estimates are overestimating the oxygen metallicities. We argue that enhanced nitrogen abundances, relative to oxygen, is responsible for this significant (~0.5 dex) offset in metallicity. We present preliminary results for a revised metallicity calibration that considers the N/O abundance ratio.

  13. Chemo-Kinematic Survey of z ~ 1 Star Forming Galaxies using Keck OSIRIS LGS-AO

    NASA Astrophysics Data System (ADS)

    Mieda, Etsuko; Wright, Shelley A.; Larkin, James E.; Armus, Lee; Juneau, Stephanie

    2015-02-01

    We present first results from the Intermediate Redshift OSIRIS Chemo-Kinematic Survey (IROCKS) of z ~ 1 star forming galaxies (Mieda et al. in prep). We have targeted Hα and [NII] emission lines in J-band and have spatially resolved the galaxies at sub-kilo parsec scale. We have combined our sample with deep HST continuum images, and are able to reveal the dynamics, morphologies, metallicity distribution, emission-line diagnostics, and star formation rates of galaxies spanning this crucial z ~ 1 epoch.

  14. Fibers and materials of medical application

    NASA Technical Reports Server (NTRS)

    Fridman, L. I.

    1993-01-01

    Efferent sorption methods of organism detoxication (by medical trend) are presented. Recently, specialists have shown their keen interest in the problem of treating exogenous and endogenous intoxications. This was stipulated by the growing production and accumulation of chemical products for industrial, agricultural, and domestic needs. To solve this problem the industrial production of carbon fibrous adsorbents was developed and implemented at NII Chimvolokno in St. Petersburg. A description of the carbon fibers is given. Also, application of modern composite materials for manufacturing compression-distraction apparatus used for setting fractured bones is described.

  15. Construction ahead: What regulators should ask about the information superhighway

    SciTech Connect

    Yaquinto, G.

    1994-06-15

    The emergence of competitive access providers, alternative local transport companies, and cable television companies may present a viable alternative to the traditional monopoly of telephone companies. The participation of electric utilities could expedite implementation of the National Information Infrastructure (NII), for they already have in place communication systems that rival and sometimes exceed systems operated by commercial communications providers. State and local regulations limit the ability of some utilities to provide telecommunications, but pending federal legislation may create regulatory parity among competing companies, primarily by applying common carrier obligations to virtually all telecommunications providers.

  16. Ternary semiconductors NiZrSn and CoZrBi with half-Heusler structure: A first-principles study

    NASA Astrophysics Data System (ADS)

    Fiedler, Gregor; Kratzer, Peter

    2016-08-01

    The ternary semiconductors NiZrSn and CoZrBi with C 1b crystal structure are introduced by calculating their basic structural, electronic, and phononic properties using density functional theory. Both the gradient-corrected PBE functional and the hybrid functional HSE06 are employed. While NiZrSn is found to be a small-band-gap semiconductor (Eg=0.46 eV in PBE and 0.60 eV in HSE06), CoZrBi has a band gap of 1.01 eV in PBE (1.34 eV in HSE06). Moreover, effective masses and deformation potentials are reported. In both materials A B C , the intrinsic point defects introduced by species A (Ni or Co) are calculated. The Co-induced defects in CoZrBi are found to have a higher formation energy compared to Ni-induced defects in NiZrSn. The interstitial Ni atom (Nii) as well as the VNiNii complex introduce defect states in the band gap, whereas the Ni vacancy (VNi) only reduces the size of the band gap. While Nii is electrically active and may act as a donor, the other two types of defects may compensate extrinsic doping. In CoZrBi, only the VCoCoi complex introduces a defect state in the band gap. Motivated by the reported use of NiZrSn for thermoelectric applications, the Seebeck coefficient of both materials, both in the p -type and the n -type regimes, is calculated. We find that CoZrBi displays a rather large thermopower of up to 500 μ V /K when p doped, whereas NiZrSn possesses its maximum thermopower in the n -type regime. The reported difficulties in achieving p -type doping in NiZrSn could be rationalized by the unintended formation of Nii2 + in conjunction with extrinsic acceptors, resulting in their compensation. Moreover, it is found that all types of defects considered, when present in concentrations as large as 3%, tend to reduce the thermopower compared to ideal bulk crystals at T =600 K. For NiZrSn, the calculated thermodynamic data suggest that additional Ni impurities could be removed by annealing, leading to precipitation of a metallic Ni2ZrSn phase.

  17. Esterases immobilized on aminosilane modified magnetic nanoparticles as a catalyst for biotransformation reactions.

    PubMed

    Alex, Deepthy; Mathew, Abraham; Sukumaran, Rajeev K

    2014-09-01

    Magnetite nanoparticles were prepared by reacting ferrous and ferric salts in presence of aqueous ammonia. The magnetic nanoparticles (MNPs) were amino functionalized by treating with 3-aminopropyl triethoxy silane (APTES) and was coupled with glutaraldehyde. A novel solvent tolerant esterase from Pseudozyma sp. NII 08165 was immobilized on the MNPs through covalent bonding to the glutaraldehyde. The magnetite nanoparticles had a size range of 10-100 nm, confirmed by DLS. Lipases immobilized on MNPs were evaluated for biotransformation reactions including synthesis of ethyl acetate and transesterification of vegetable oil for producing biodiesel. The MNP immobilized esterase had prolonged shelf life and there was no loss in enzyme activity. PMID:24968816

  18. Monitoring the Continuing Spectral Evolution of Nova Delphini 2013 (V339 Del) with Low Resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    Mooers, H. D.; Wiethoff, W. S.; Evich, A.

    2016-06-01

    The continuing spectral evolution of Nova Delphini 2013 is presented with low-resolution spectroscopy collected with a 100 line per millimeter diffraction grating. Spectra were collected on 3 July, 2014 and 14 September, 2015, +321 and +759 days after peak visible brightness on 16 August, 2013. Imaging system was mounted on an equatorially-mounted, 14-inch Schmidt-Cassegrain telescope. The continuum is no longer visible in the spectra, however, Oiii (5007 Å) and Ha (6563 Å) are prominent and Nii (5755), Hg (4340 Å) and Ciii/Niii (4640 Å) can still be discerned at +759 days.

  19. Z39.50 and GILS model. [Government Information Locator Service

    NASA Technical Reports Server (NTRS)

    Christian, Eliot

    1994-01-01

    The Government Information Locator System (GILS) is a component of the National Information Infrastructure (NII) which provides electronic access to sources of publicly accessible information maintained throughout the Federal Government. GILS is an internetworking information resource that identifies other information resources, describes the information available in the referenced resources, and provides assistance in how to obtain the information either directly or through intermediaries. The GILS core content which references each Federal information system holding publicly accessible data or information is described in terms of mandatory and optional core elements.

  20. Esterases immobilized on aminosilane modified magnetic nanoparticles as a catalyst for biotransformation reactions.

    PubMed

    Alex, Deepthy; Mathew, Abraham; Sukumaran, Rajeev K

    2014-09-01

    Magnetite nanoparticles were prepared by reacting ferrous and ferric salts in presence of aqueous ammonia. The magnetic nanoparticles (MNPs) were amino functionalized by treating with 3-aminopropyl triethoxy silane (APTES) and was coupled with glutaraldehyde. A novel solvent tolerant esterase from Pseudozyma sp. NII 08165 was immobilized on the MNPs through covalent bonding to the glutaraldehyde. The magnetite nanoparticles had a size range of 10-100 nm, confirmed by DLS. Lipases immobilized on MNPs were evaluated for biotransformation reactions including synthesis of ethyl acetate and transesterification of vegetable oil for producing biodiesel. The MNP immobilized esterase had prolonged shelf life and there was no loss in enzyme activity.

  1. A 'no-fault' cerebral palsy pension scheme would benefit all Australians.

    PubMed

    MacLennan, Alastair H

    2011-12-01

    The Australian Federal Productivity Commission is proposing two new schemes to better support those with major disability. The main National Disability Insurance Scheme (NDIS) will provide long-term care and support for the disabled. A smaller scheme, the National Injury Insurance Scheme (NIIS), will provide 'no-fault 'support for those following an accident or 'medical injury'. It is proposed that cerebral palsy (CP) is part of the NIIS. While this brings quicker and more equitable benefits to CP families, the scheme labels CP as a 'medical accident' and infers preventability. Obstetricians will fund much of the system. Despite being labelled a 'no-fault' system, maternity staff can still be litigated for extensive 'head of damages', eg loss of earning capacity. An additional option is for federal/state legislation to introduce a true 'no-fault' lifetime pension specifically for all children on CP registers. This pension would be graded by degree of disability and dependent on waiving civil litigation. Savings in medico-legal costs and potentially a 7% reduction in caesarean delivery would cover the estimated annual cost of $50 000 per annum indexed life pension for severe CP cases and the total annual cost of AUD $93 million for Australia. This pension and the NDIS would help cover the needs of children with CP without recourse to prolonged litigation and without detriment to the maternity services of Australia, caused by defensive obstetrics and maternity hospital closure because of CP litigation. PMID:22017320

  2. An analysis of emission lines in the spectrum of P Cygni.

    NASA Astrophysics Data System (ADS)

    Markova, N.; de Groot, M.

    1997-10-01

    Using the coude spectrograph of the NAO 2m telescope at the Rhodope Mountains, Bulgaria, 9 spectra in the blue and 8 spectra in the red photographic region of P Cygni were obtained during 1990. By averaging the spectra in each set a S/N-ratio of about 45 was achieved. Comparing the lists of identifications published by Beals (1950PDAO....9....1B), de Groot (1969BAN....20..225D), Ozemre (1978PIstO.101....1O), Stahl et al. (1993A&AS...99..167S), Markova (1994A&AS..108..561M) and Markova & Zamanov (1995A&AS..114..499M), we conclude that the emission spectrum of P Cygni in our days is probably much richer and intensive than 60 years ago. A number of line parameters of the pure emission lines are measured. An estimate of the electron density and temperature in the region of [NII]-lines formation is obtained. Different velocity laws yielding similar density structures are discussed aiming to account for the results obtained on the basis of the [NII] lines. Possible mechanisms for the formation of the permitted pure emission-line spectrum are proposed.

  3. VizieR Online Data Catalog: Spectral Atlas of P Cygni in range 4840-6760A (Markova+, 1995)

    NASA Astrophysics Data System (ADS)

    Markova, N.; Zamanov, R.

    1995-07-01

    Using the coude spectrograph of the NAO 2m RCC telescope at the Rhodope Mountains, Bulgaria, 11 spectra in the wavelength range from 4840 to 6760A of P Cygni were obtained during the years 1981, 1983 and 1985. By averaging these spectra we achieved a S/N-ratio of about 50. Here we present a spectral atlas with complete line identifications. Apart from the lines listed by de Groot (1969) many pure bright lines are identified. Most of them are lines of FeIII with high multiplet numbers and NII. Further emission lines are those of SiII multiplets 2, 4 and 5. A new feature is SII spectrum in absorption and emission. In addition to the forbidden lines discovered by Stahl et al. (1991, 1993) three new lines, [FeII19] λ5159, [FeII18] λ5273 and [FeII34] λ5477 are identified. The presence of some [TiII9] lines as well as the red lines of [NII1] is considered as quite probable. (1 data file).

  4. Fine structural analysis of the neuronal inclusions of frontotemporal lobar degeneration with TDP-43 proteinopathy.

    PubMed

    Thorpe, Julian R; Tang, Helen; Atherton, Joe; Cairns, Nigel J

    2008-12-01

    TAR DNA-binding protein of 43 kDa (TDP-43) is a major component of the pathological inclusions of frontotemporal lobar degeneration with TDP-43 proteinopathy, also called FTLD with ubiquitin-positive, tau-negative inclusions (FTLD-U), and motor neuron disease (MND). TDP-43 is predominantly expressed in the nucleus and regulates gene expression and splicing. In FTLD with TDP-43 proteinopathy, neuronal inclusions present variably as cytoplasmic inclusions (NCIs), dystrophic neurites (DNs), and intranuclear inclusions (NIIs), leading to a fourfold neuropathological classification correlating with genotype. There have been few fine structural studies of these inclusions. Thus, we undertook an immunoelectron microscopic study of FTLD with TDP-43 proteinopathy, including sporadic and familial cases with progranulin (GRN) mutation. TDP-43-immunoreactive inclusions comprised two components: granular and filamentous. Filament widths, expressed as mean (range) were: NCI, 9 nm (4-16 nm); DN, 10 nm (5-16 nm); NII, 18 nm (9-50 nm). Morphologically distinct inclusion components may reflect the process of TDP-43 aggregation and interaction with other proteins: determining these latter may contribute towards understanding the heterogeneous pathogenesis of FTLD with TDP-43 proteinopathy. PMID:18974920

  5. Security Assessment Simulation Toolkit (SAST) Final Report

    SciTech Connect

    Meitzler, Wayne D.; Ouderkirk, Steven J.; Hughes, Chad O.

    2009-11-15

    The Department of Defense Technical Support Working Group (DoD TSWG) investment in the Pacific Northwest National Laboratory (PNNL) Security Assessment Simulation Toolkit (SAST) research planted a technology seed that germinated into a suite of follow-on Research and Development (R&D) projects culminating in software that is used by multiple DoD organizations. The DoD TSWG technology transfer goal for SAST is already in progress. The Defense Information Systems Agency (DISA), the Defense-wide Information Assurance Program (DIAP), the Marine Corps, Office Of Naval Research (ONR) National Center For Advanced Secure Systems Research (NCASSR) and Office Of Secretary Of Defense International Exercise Program (OSD NII) are currently investing to take SAST to the next level. PNNL currently distributes the software to over 6 government organizations and 30 DoD users. For the past five DoD wide Bulwark Defender exercises, the adoption of this new technology created an expanding role for SAST. In 2009, SAST was also used in the OSD NII International Exercise and is currently scheduled for use in 2010.

  6. Interstellar Deuterium, Nitrogen and Oxygen Towards HZ43A: Results from the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission

    NASA Technical Reports Server (NTRS)

    Kruk, J. W.; Howk, J. C.; Andre, M.; Moos, H. W.; Oegerle, William R.; Oliveira, C.; Sembach, K. R.; Chayer, P.; Linsky, J. L.; Wood, B. E.

    2002-01-01

    We present an analysis of interstellar absorption along the line of sight to the nearby white dwarf star HZ43A. The distance to this star is 68+/-13 pc, and the line of sight extends toward the north Galactic pole. Column densities of O(I), N(I), and N(II) were derived from spectra obtained by the Far Ultraviolet Spectroscopic Explorer (FUSE), the column density of D(I) was derived from a combination of our FUSE spectra and an archival HST GARDENS spectrum, and the column density of H(I) was derived from a combination of the GARDENS spectrum and values derived from EUVE data obtained from the literature. We find the following abundance ratios (with 2 sigma uncertainties): D(I)/H(I)=(1.66+/-0.28)x10(exp -5), O(I)/H(I)=(3.63+/-0.84)x10(exp -4), and N(I)/H(I)=(3.80+/-0.74)x10(exp -5). The N(II) column density was slightly greater than that of N(I), indicating that ionization corrections are important when deriving nitrogen abundances. Other interstellar species detected along the line of sight were C(II), C(III), O(VI), Si(II), Ar(I), Mg(II) and Fe(II); an upper limit was determined for N(III). No elements other than H(I) were detected in the stellar photosphere.

  7. A 'no-fault' cerebral palsy pension scheme would benefit all Australians.

    PubMed

    MacLennan, Alastair H

    2011-12-01

    The Australian Federal Productivity Commission is proposing two new schemes to better support those with major disability. The main National Disability Insurance Scheme (NDIS) will provide long-term care and support for the disabled. A smaller scheme, the National Injury Insurance Scheme (NIIS), will provide 'no-fault 'support for those following an accident or 'medical injury'. It is proposed that cerebral palsy (CP) is part of the NIIS. While this brings quicker and more equitable benefits to CP families, the scheme labels CP as a 'medical accident' and infers preventability. Obstetricians will fund much of the system. Despite being labelled a 'no-fault' system, maternity staff can still be litigated for extensive 'head of damages', eg loss of earning capacity. An additional option is for federal/state legislation to introduce a true 'no-fault' lifetime pension specifically for all children on CP registers. This pension would be graded by degree of disability and dependent on waiving civil litigation. Savings in medico-legal costs and potentially a 7% reduction in caesarean delivery would cover the estimated annual cost of $50 000 per annum indexed life pension for severe CP cases and the total annual cost of AUD $93 million for Australia. This pension and the NDIS would help cover the needs of children with CP without recourse to prolonged litigation and without detriment to the maternity services of Australia, caused by defensive obstetrics and maternity hospital closure because of CP litigation.

  8. The Long-Term Care Insurance Program in Israel: solidarity with the elderly in a changing society

    PubMed Central

    2013-01-01

    The Long-Term Care Insurance Program (LTCIP) in Israel is a social security program administered by the National Insurance Institute (NII) since 1988. LTCIP focuses on home-based personal care services. Differently from most other programs under the responsibility of the NII, LTCIP benefits are in-kind benefits and are delivered via multiple for-profit and not-for-profit organizations. In recent years LTCIP has been the target of various legal amendments and numerous administrative changes. While many of these changes may have had significant effects on individuals, they have not altered the fundamental principles of the program. Thus, many of the characteristics of beneficiaries have remained quite stable over the years; other characteristics of the population of beneficiaries have changed over the years reflecting the aging of Israeli society. A central issue related to LTCIP is whether benefits are adequate to meet the needs of the growing elderly population of Israel. While the generosity of LTCIP benefits is questionable, economic and political struggles have limited the scope of changes introduced thus far. PMID:23343104

  9. Resolved line profiles of PNe in NGC6822.

    NASA Astrophysics Data System (ADS)

    Flores-Duran, S.; Peña, M.; Hernández-Martínez, L.; García-Rojas, J.; Ruiz, M. T.

    2014-04-01

    "Using high resolution spectroscopic data obtained with Magellan Inamori Kyocera Echelle (MIKE) at the Magellan telescope at Las Campanas Observatory it was possible to resolve the emission line profiles of [OIII] 5007, Ha and [NII] 6583 in two planetary nebulae belonging to the Local Group galaxy NGC 6822 (Flores-Durán et al. submitted). The two PNe, called PN4 and PN7 were identified after Leisy et al. (2005, A&A, x436, 437). In the case of PN4, it presents wide lines that show a structure with three components. The [NII] 6583 line profile clearly shows a central component surrounded by what appears to be a shell with an expantion velocity of 25 km s-1. For PN7, the [OIII] emission lines present two very close components differing in velocity by about 15 km s-1 and, in the [N II] 6583 profile a faint very-wide component is apparent. This latter component represents a sort of bipolar outflow at high velocities (about 140 km s-1) as the case of the galactic M1-32, M3-15 and others (Medina et al. 2006, RMAA, 42, 53; Akras & López 2012, MNRAS, 425, 2197; Rechy-García et al., this meeting)."

  10. Government Services Information Infrastructure Management

    SciTech Connect

    Cavallini, J.S.; Aiken, R.J.

    1995-04-01

    The Government Services Information Infrastructure (GSII) is that portion of the NII used to link Government and its services, enables virtual agency concepts, protects privacy, and supports emergency preparedness needs. The GSII is comprised of the supporting telecommunications technologies, network and information services infrastructure and the applications that use these. The GSII is an enlightened attempt by the Clinton/Gore Administration to form a virtual government crossing agency boundaries to interoperate more closely with industry and with the public to greatly improve the delivery of government services. The GSII and other private sector efforts, will have a significant impact on the design, development, and deployment of the NII, even if only through the procurement of such services. The Federal Government must adopt new mechanisms and new paradigms for the management of the GSII, including improved acquisition and operation of GSII components in order to maximize benefits. Government requirements and applications will continue to evolv. The requirements from government services and users of form affinity groups that more accurately and effectively define these common requirements, that drive the adoption and use of industry standards, and that provide a significant technology marketplace.

  11. Spectroscopic study in the visible and near infrared wavelength of an Hα-selected sample of star-forming galaxies at z = 0.84

    NASA Astrophysics Data System (ADS)

    Sánchez de Miguel, A.; Gallego, J.; Villar, V.; Pérez-González, P. G.; Zamorano, J.; Cardiel, N.; Acosta Pulido, J. A.

    2013-05-01

    In this work we study the physical properties of star-forming galaxies selected in an Hα near-infrared narrow-band survey tuned for redshift z=0.84 (Villar et al. 2008, 2011). Also, we present a sample at z˜1 with mass greater than 10^{10} M_{⊙} with Hα emission. The observations were carried out with WHT/LIRIS (see Sánchez de Miguel et al. 2011, in Highlights of Spanish Astrophysics VI). The rest of the data from the spectra archive of the RAINBOW Cosmological Survey database (Pérez-González et al. 2005, 2008; Barro et al. 2011ab). According to the redshift distribution of these galaxies, 65% of the galaxies are in a redshift range of 0.005. This velocity range corresponds to less than 25% of the effective volume. Which could be indicative of the presence of substructure. A total of 48 galaxies have detected Hα emission and other 12 show [NII]6584. To complete our multi-wavelength sample we found 23 galaxies with Hβ, [OIII]5007 or [OII]3727 detections. Using this photometry from ancillary data we will calculate nebular and stellar extinctions. We have calculated metallicities using the [NII]/Hα ratio and the Pettini & Pagel (2004) calibrations. The metallicity of samples are compatible with the local galaxies. We found that in all the diagnostic diagrams galaxies have similar properties to the local ones, except they are intrinsically brighter for the same equivalent width [OII]3727.

  12. A comparison of FUV dayglows measured by STSAT-1/FIMS with the AURIC model in a geomagnetic quiet condition

    NASA Astrophysics Data System (ADS)

    Kam, Hosik; Kim, Yong Ha; Hong, Jun-Seok; Lee, Joon-Chan; Choi, Yeon-Ju; Min, Kyung Wook

    2014-09-01

    The Korea scientific microsatellite, STSAT-1 (Science and Technology Satellite-1), was launched in 2003 and observed far ultraviolet (FUV) airglow from the upper atmosphere with a Far-ultraviolet IMaging Spectrograph (FIMS) at an altitude of 690 km. The FIMS consists of a dual-band imaging spectrograph of 900-1150 Å (S-band) and 1340-1715 Å (L-band). Limb scanning observations were performed only at the S-band, resulting in intensity profiles of OI 989 Å, OI 1026 Å, NII 1085 Å and NI 1134 Å emission lines near the horizon. We compare these emission intensities with those computed by using a theoretical model, the AURIC (Atmospheric Ultraviolet Radiance Integrated Code). The intensities of the OI 1026 Å, NII 1085 Å and NI 1134 Å emissions measured by using the FIMS are overall consistent with the values computed by using AURIC under the thermospheric and solar activity conditions on August 6, 1984, which is close to the FIMS's observation condition. We find that the FIMS dayglow intensity profiles match reasonably well with AURIC intensity profiles for the MSIS90 oxygen atom density profiles within factors of 0.5 and 2. However, the FIMS intensities of the OI 989 Å line are about 2 ˜ 4 times stronger than the AURIC intensities, which is expected because AURIC does not properly simulate resonance scattering of airglow and solar photons at 989 Å by atomic oxygen in the thermosphere. We also find that the maximum tangential altitudes of the oxygen bearing dayglows (OI 989 Å, OI 1026 Å) are higher than those of the nitrogen-bearing dayglows (NII 1085 Å, NI 1134 Å), which is confirmed by using AURIC model calculations. This is expected because the oxygen atoms are distributed at higher altitudes in the thermosphere than the nitrogen molecules. Validations of the qualities of both the FIMS instrument and the AURIC model indicate that AURIC should be updated with improved thermospheric models and with measured solar FUV spectra for better agreement with the

  13. Alternative diagnostic diagrams and the `forgotten' population of weak line galaxies in the SDSS

    NASA Astrophysics Data System (ADS)

    Cid Fernandes, R.; Stasińska, G.; Schlickmann, M. S.; Mateus, A.; Vale Asari, N.; Schoenell, W.; Sodré, L.

    2010-04-01

    A numerous population of weak line galaxies (WLGs) is often left out of statistical studies on emission-line galaxies (ELGs) due to the absence of an adequate classification scheme, since classical diagnostic diagrams, such as [OIII]/Hβ versus [NII]/Hα (the BPT diagram), require the measurement of at least four emission lines. This paper aims to remedy this situation by transposing the usual divisory lines between star-forming (SF) galaxies and active galactic nuclei (AGN) hosts and between Seyferts and LINERs to diagrams that are more economical in terms of line quality requirements. By doing this, we rescue from the classification limbo a substantial number of sources and modify the global census of ELGs. More specifically, (1) we use the Sloan Digital Sky Survey Data Release 7 to constitute a suitable sample of 280000 ELGs, one-third of which are WLGs. (2) Galaxies with strong emission lines are classified using the widely applied criteria of Kewley et al., Kauffmann et al. and Stasińska et al. to distinguish SF galaxies and AGN hosts and Kewley et al. to distinguish Seyferts from LINERs. (3) We transpose these classification schemes to alternative diagrams keeping [NII]/Hα as a horizontal axis, but replacing Hβ by a stronger line (Hα or [OII]), or substituting the ionization-level sensitive [OIII]/Hβ ratio with the equivalent width of Hα (WHα). Optimized equations for the transposed divisory lines are provided. (4) We show that nothing significant is lost in the translation, but that the new diagrams allow one to classify up to 50 per cent more ELGs. (5) Introducing WLGs in the census of galaxies in the local Universe increases the proportion of metal-rich SF galaxies and especially LINERs. In the course of this analysis, we were led to make the following points. (i) The Kewley et al. BPT line for galaxy classification is generally ill-used. (ii) Replacing [OIII]/Hβ by WHα in the classification introduces a change in the philosophy of the distinction

  14. Hα imaging of the Herschel Reference Survey. The star formation properties of a volume-limited, K-band-selected sample of nearby late-type galaxies

    NASA Astrophysics Data System (ADS)

    Boselli, A.; Fossati, M.; Gavazzi, G.; Ciesla, L.; Buat, V.; Boissier, S.; Hughes, T. M.

    2015-07-01

    We present new Hα+[NII] imaging data of late-type galaxies in the Herschel Reference Survey aimed at studying the star formation properties of a K-band-selected, volume-limited sample of nearby galaxies. The Hα+[NII] data are corrected for [NII] contamination and dust attenuation using different recipes based on the Balmer decrement and the 24 μm luminosities. We show that the Hα luminosities derived with different corrections give consistent results only whenever the uncertainty on the estimate of the Balmer decrement is σ [C(Hβ)] ≤ 0.1. We used these data to derive the star formation rate of the late-type galaxies of the sample and compare these estimates to those determined using independent monochromatic tracers (far-UV, radio continuum) or the output of spectral energy distribution (SED) fitting codes. This comparison suggests that the 24 μm based dust extinction correction for the Hα data might not be universal and that it should be used with caution in all objects with a low star formation activity, where dust heating can be dominated by the old stellar population. Furthermore, because of the sudden truncation of the star formation activity of cluster galaxies occurring after their interaction with the surrounding environment, the stationarity conditions required to transform monochromatic fluxes into star formation rates might not always be satisfied in tracers other than the Hα luminosity. In a similar way, the parametrisation of the star formation history generally used in SED fitting codes might not be adequate for these recently interacting systems. We then use the derived star formation rates to study the star formation rate luminosity distribution and the typical scaling relations of the late-type galaxies of the HRS. We observe a systematic decrease of the specific star formation rate with increasing stellar mass, stellar mass surface density, and metallicity. We also observe an increase of the asymmetry and smoothness parameters measured

  15. Nearby early-type galaxies with ionized gas. IV. Origin and powering mechanism of the ionized gas

    NASA Astrophysics Data System (ADS)

    Annibali, F.; Bressan, A.; Rampazzo, R.; Zeilinger, W. W.; Vega, O.; Panuzzo, P.

    2010-09-01

    Aims: A significant fraction of early-type galaxies (ETGs) exhibit emission lines in their optical spectra. We attempt to identify the producing the emission mechanism and the ionized gas in ETGs, and its connection with the host galaxy evolution. Methods: We analyzed intermediate-resolution optical spectra of 65 ETGs, mostly located in low density environments and exhibiting spectros-copic diagnostic lines of ISM from which we had previously derived stellar population properties. To extract the emission lines from the galaxy spectra, we developed a new fitting procedure that accurately subtracts the underlying stellar continuum, and accounts for the uncertainties caused by the age-metallicity degeneracy. Results: Optical emission lines are detected in 89% of the sample. The incidence and strength of emission correlate with neither the E/S0 classification, nor the fast/slow rotator classification. By means of the classical [OIII]/Hβ versus [NII]/Hα diagnostic diagram, the nuclear galaxy activity is classified such that 72% of the galaxies with emission are LINERs, 9% are Seyferts, 12% are composite/transition objects, and 7% are non-classified. Seyferts have young luminostiy-weighted ages (≲5 Gyr), and appear, on average, significantly younger than LINERs and composites. Excluding the Seyferts from our sample, we find that the spread in the ([OIII], Hα, or [NII]) emission strength increases with the galaxy central velocity dispersion σ_c. Furthermore, the [NII]/Hα ratio tends to increase with σ_c. The [NII]/Hα ratio decreases with increasing galactocentric distance, indicative of either a decrease in the nebular metallicity, or a progressive “softening” of the ionizing spectrum. The average nebular oxygen abundance is slightly less than solar, and a comparison with the results obtained in Paper III from Lick indices shows that it is ≈0.2 dex lower than that of stars. Conclusions: The nuclear (r < re/16) emission can be attributed to photoionization

  16. Evolution of In-Situ Generated Reinforcement Precipitates in Metal Matrix Composites

    NASA Technical Reports Server (NTRS)

    Sen, S.; Kar, S. K.; Catalina, A. V.; Stefanescu, D. M.; Dhindaw, B. K.

    2004-01-01

    Due to certain inherent advantages, in-situ production of Metal Matrix Composites (MMCs) have received considerable attention in the recent past. ln-situ techniques typically involve a chemical reaction that results in precipitation of a ceramic reinforcement phase. The size and spatial distribution of these precipitates ultimately determine the mechanical properties of these MMCs. In this paper we will investigate the validity of using classical growth laws and analytical expressions to describe the interaction between a precipitate and a solid-liquid interface (SLI) to predict the size and spatial evolution of the in-situ generated precipitates. Measurements made on size and distribution of Tic precipitates in a Ni&I matrix will be presented to test the validity of such an approach.

  17. Lidar observation of marine mixed layer

    NASA Technical Reports Server (NTRS)

    Yamagishi, Susumu; Yamanouchi, Hiroshi; Tsuchiya, Masayuki

    1992-01-01

    Marine mixed layer is known to play an important role in the transportation of pollution exiting ship funnels. The application of a diffusion model is critically dependent upon a reliable estimate of a lid. However, the processes that form lids are not well understood, though considerable progress toward marine boundary layer has been achieved. This report describes observations of the marine mixed layer from the course Ise-wan to Nii-jima with the intention of gaining a better understanding of their structure by a shipboard lidar. These observations were made in the summer of 1991. One interesting feature of the observations was that the multiple layers of aerosols, which is rarely numerically modeled, was encountered. No attempt is yet made to present a systematic analysis of all the data collected. Instead we focus on observations that seem to be directly relevant to the structure of the mixed layer.

  18. PdBI high-resolution high-sensitivity imaging of a strongly lensed submillimeter source at z=5.24

    NASA Astrophysics Data System (ADS)

    Boone, F.; Combes, F.; Krips, M.; Richard, J.; Rawle, T.; Egami, E.; Kneib, J.-P.; Schaerer, D.; Dessauges-Zavadsky, M.; Pello, R.; Clément, B.

    2014-12-01

    We have obtained Plateau de Bure Interferometer observations of HLSJ091828.6+514223 (z=5.24) at six different frequencies to cover the CO(6-5), CO(7-6), CI, H_20_{p}(2,0,2-1,1,1), [NII] and [CII] lines. The high resolution and high sensitivity of these multi-configuration observations allow us to detect the various line velocity components as well as the continuum and to resolve spatially their emission. This wealth of information is used to tackle the problem of lens and source modeling. A methodology is implemented to produce image plane maps, optimize the lens model, and finally inverse the PdBI data in the source plane. The image plane and source plane maps are constructed by fitting directly the pixels to the PdBI visibilities with the non-negative least square method. The preliminary results thus obtained are presented.

  19. Computational Insight into Nickel-Catalyzed Carbon-Carbon versus Carbon-Boron Coupling Reactions of Primary, Secondary, and Tertiary Alkyl Bromides.

    PubMed

    Cheung, Man Sing; Sheong, Fu Kit; Marder, Todd B; Lin, Zhenyang

    2015-05-11

    The nickel-catalyzed alkyl-alkyl cross-coupling (C-C bond formation) and borylation (C-B bond formation) of unactivated alkyl halides reported in the literature show completely opposite reactivity orders in the reactions of primary, secondary, and tertiary alkyl bromides. The proposed Ni(I) /Ni(III) catalytic cycles for these two types of bond-formation reactions were studied computationally by means of DFT calculations at the B3LYP level. These calculations indicate that the rate-determining step for alkyl-alkyl cross-coupling is the reductive elimination step, whereas for borylation the rate is determined mainly by the atom-transfer step. In borylation reactions, the boryl ligand involved has an empty p orbital, which strongly facilitates the reductive elimination step. The inability of unactivated tertiary alkyl halides to undergo alkyl-alkyl cross-coupling is mainly due to the moderately high reductive elimination barrier.

  20. Information Infrastructure Technology and Applications (IITA) Program: Annual K-12 Workshop

    NASA Technical Reports Server (NTRS)

    Hunter, Paul; Likens, William; Leon, Mark

    1995-01-01

    The purpose of the K-12 workshop is to stimulate a cross pollination of inter-center activity and introduce the regional centers to curing edge K-1 activities. The format of the workshop consists of project presentations, working groups, and working group reports, all contained in a three day period. The agenda is aggressive and demanding. The K-12 Education Project is a multi-center activity managed by the Information Infrastructure Technology and Applications (IITA)/K-12 Project Office at the NASA Ames Research Center (ARC). this workshop is conducted in support of executing the K-12 Education element of the IITA Project The IITA/K-12 Project funds activities that use the National Information Infrastructure (NII) (e.g., the Internet) to foster reform and restructuring in mathematics, science, computing, engineering, and technical education.

  1. Role of Communications Satellites in the National and Global Information Infrastructure

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Early in 1995, the Satellite Industry Task Force (SITF) was initiated by executives of the satellite industry to define the role for communication satellites in the National and Global Information Infrastructure (NII/GII). Satellites are essential to this information network because they offer ubiquitous coverage and less time to market. SITF, which was chaired by Dr. Thomas Brackey of the Hughes Space and Communication Division, grew out of a series of workshops held during the summer of 1994 by the communication industry, NASA, and the Defense Information Systems Agency (DISA). Experts were convened from 20 companies representing satellite and terrestrial network builders, operators, and users. For 8 months they worked to identify challenges for the satellite industry to play a pivotal role in the National and Global Information Infrastructure. NASA Lewis Research Center personnel helped out with technical and policy matters.

  2. The warm ISM in the Sgr A region: mid-J CO, atomic carbon, ionized atomic carbon, and ionized nitrogen line observations with the Herschel/HIFI and NANTEN2/SMART Telescopes

    NASA Astrophysics Data System (ADS)

    García, Pablo; Simon, Robert; Stutzki, Jürgen; Requena-Torres, Miguel; Güsten, Rolf; Fukui, Yasuo; Yamamoto, Hiroaki; Bertoldi, Frank; Burton, Michael; Bronfman, Leonardo; Ogawa, Hideo

    2014-05-01

    We present Herschel/HIFI sub-mm atomic carbon ([Ci] 3 P 1 - 3 P 0 and [Ci] 3 P 2 - 3 P 1), ionized carbon ([Cii] 2 P 3/2 - 2 P 1/2), and ionized nitrogen ([Nii] 3 P 1 - 3 P 0) line observations obtained in the frame of the Herschel Guaranteed Time HEXGAL (Herschel EXtraGALactic) key program (P. I. Rolf Güsten, MPIfR), and NANTEN2/SMART carbon monoxide (CO(J = 4 - 3)) observations of the warm gas around the Sgr A region. The spectrally resolved emission from all lines, and the corresponding line intensity ratios, show a very complex morphology. The determination of spatial and spectral (anti)correlation with known sources in the Sgr A region such as the Arched Filaments, NTF filaments, the Sickle, Quintuplet cluster, CND clouds, is ongoing work.

  3. Dust and ionized gas in active radio elliptical galaxies

    NASA Technical Reports Server (NTRS)

    Forbes, D. A.; Sparks, W. B.; Macchetto, F. D.

    1990-01-01

    The authors present broad and narrow bandwidth imaging of three southern elliptical galaxies which have flat-spectrum active radio cores (NGC 1052, IC 1459 and NGC 6958). All three contain dust and extended low excitation optical line emission, particularly extensive in the case of NGC 1052 which has a large H alpha + (NII) luminosity. Both NGC 1052 and IC 1459 have a spiral morphology in emission-line images. All three display independent strong evidence that a merger or infall event has recently occurred, i.e., extensive and infalling HI gas in NGC 1052, a counter-rotating core in IC 1459 and Malin-Carter shells in NGC 6958. This infall event is the most likely origin for the emission-line gas and dust, and the authors are currently investigating possible excitation mechanisms (Sparks et al. 1990).

  4. The Hawaii Imaging Fabry-Perot Interferometer (HIFI)

    NASA Technical Reports Server (NTRS)

    Bland, Jonathan; Cecil, Gerald; Tully, Brent

    1990-01-01

    At Mauna Kea Observatory, researchers conducted optical, imaging spectrophotometric studies of selected active galaxies using both the Canada-France-Hawaii 3.6m and University of Hawaii 2.2m telecopes (Tully, Bland and Cecil 1988). To maximize spatial resolution, researchers select galaxies independent of luminosity but known to possess interesting morphologies or high-velocity, extranuclear ionized gas (Walker 1968; Rubin and Ford 1968). They study both the large-scale patterns produced in IR-luminous, starburst systems (e.g., M82, NGC 253, NGC 6240) and those with compact, but spatially extended, circumnuclear, narrow line regions (e.g., M51, NGC 1068, NGC 4151). Current studies are restricted to the optical (SII), (NII) and (OIII) lines and the brightest Balmer recombination lines. These lines are, in principle, sufficient to constrain the dynamical structure and dominant excitation mechanism of the ionized component.

  5. Microvariability of line profiles in the spectra of OB stars: III. The supergiant ρ LEO

    NASA Astrophysics Data System (ADS)

    Kholtygin, A. F.; Fabrika, S. N.; Burlakova, T. E.; Valyavin, G. G.; Chuntonov, G. A.; Kudryavtsev, D. O.; Kang, D.; Yushkin, M. V.; Galazutdinov, G. A.

    2007-11-01

    We observed the bright supergiant ρ Leo (B1 lab) in January-February 2004 using the 6-m telescope of the Special Astrophysical Observatory (Russia) and the 1.8-m telescope of the Bohyunsan Optical Astronomy Observatory (South Korea). 47 spectra with high time resolution (4-10 min), signal-to-noise ratios 300-1000, and spectral resolutions 45 000-60 000 were obtained. We detected variability in the HeI, SiII, SiIII, and NII line profiles, which may be due to rotational modulation of the profiles and photospheric pulsations of ρ Leo. The possible influence of the stellar magnetic field on the line-profile variations is discussed.

  6. On-Board Switching and Routing Advanced Technology Study

    NASA Technical Reports Server (NTRS)

    Yegenoglu, F.; Inukai, T.; Kaplan, T.; Redman, W.; Mitchell, C.

    1998-01-01

    Future satellite communications is expected to be fully integrated into National and Global Information Infrastructures (NII/GII). These infrastructures will carry multi gigabit-per-second data rates, with integral switching and routing of constituent data elements. The satellite portion of these infrastructures must, therefore, be more than pipes through the sky. The satellite portion will also be required to perform very high speed routing and switching of these data elements to enable efficient broad area coverage to many home and corporate users. The technology to achieve the on-board switching and routing must be selected and developed specifically for satellite application within the next few years. This report presents evaluation of potential technologies for on-board switching and routing applications.

  7. The radical mechanism of biological methane synthesis by methyl-coenzyme M reductase.

    PubMed

    Wongnate, Thanyaporn; Sliwa, Dariusz; Ginovska, Bojana; Smith, Dayle; Wolf, Matthew W; Lehnert, Nicolai; Raugei, Simone; Ragsdale, Stephen W

    2016-05-20

    Methyl-coenzyme M reductase, the rate-limiting enzyme in methanogenesis and anaerobic methane oxidation, is responsible for the biological production of more than 1 billion tons of methane per year. The mechanism of methane synthesis is thought to involve either methyl-nickel(III) or methyl radical/Ni(II)-thiolate intermediates. We employed transient kinetic, spectroscopic, and computational approaches to study the reaction between the active Ni(I) enzyme and substrates. Consistent with the methyl radical-based mechanism, there was no evidence for a methyl-Ni(III) species; furthermore, magnetic circular dichroism spectroscopy identified the Ni(II)-thiolate intermediate. Temperature-dependent transient kinetics also closely matched density functional theory predictions of the methyl radical mechanism. Identifying the key intermediate in methanogenesis provides fundamental insights to develop better catalysts for producing and activating an important fuel and potent greenhouse gas.

  8. Laser operation by dissociation of metal complexes. II - New transitions in Cd, Fe, Ni, Se, Sn, Te, V, and Zn

    NASA Technical Reports Server (NTRS)

    Chou, M. S.; Cool, T. A.

    1977-01-01

    The reported investigation is a continuation of a study conducted by Chou and Cool (1976). The experimental results discussed are partly related to laser transitions in Cd(I), Cd(II), and Zn(II). Laser transitions in Fe(I), Ni(I), Sn(I), Te(I), and V(I) are also considered along with the observation of a laser pulse with two peaks in connection with the study of laser transitions in Se(I). Experiments related to prospective visible laser operation in thallium at 6550 and 6714 are also discussed, giving attention to spontaneous emission measurements at 6550 and 5350 A, the effects of additive molecules, and laser cavity experiments at 6550 and 6714 A.

  9. A line of defense approach to fissile material control

    SciTech Connect

    Holloway, S.P.; Holloway, N.J.

    1995-12-31

    A crucial element of the safety policy of the UK Atomic Weapons Establishment (AWE) is that concerned with the safe control of fissile material in order to minimize the potential for unplanned criticality. The principles by which AWE controls fissile material advocate a simple Line of Defense (LOD) approach to assessing criticality-safety related aspects of fissile operations. An LOD assessment provides a measure of the depth of defense available to prevent general types of criticality accident and can be used to demonstrate compliance with the risk-based Basic Safety Limits (BSLs) and Objectives (BSOs) used by the UK Nuclear Installations Inspectorate (NII) to judge the safety of operations in accordance with its Safety Assessment Principles (SAPs) for Nuclear Plants. This paper discusses the LOD concept, the basis of LOD assessment and describes LODs specific to criticality control.

  10. Synthesis and structural characterization of two half-sandwich nickel(II) complexes with the scorpionate ligands

    NASA Astrophysics Data System (ADS)

    Wang, G.-F.; Zhang, X.; Sun, S.-W.; Sun, H.; Ma, H.-X.

    2015-12-01

    The synthesis and characterization of two new halfsandwich mononuclear nickel(II) complexes with the scorpionate ligands, [ k 3- N, N', N''- Tp t-Bu, Me NiI] ( 1) and [ k 3- N, N', N''- Tp t-Bu, Me NiNO3] ( 2), are reported. These complexes have been fully characterized by elemental analyses and infrared spectra. Their molecular structures were determined by single crystal X-ray diffraction. The nickel(II) ion of complex 1 is in a four-coordinate environment, in which the donor atoms are provided by three nitrogen atoms of a hydrotris(pyrazolyl) borate ligand and one iodide atom, while that of complex 2 is in a five-coordinate environment with three nitrogen atoms from a hydrotris(pyrazolyl)borate ligand and two oxygen atoms from a nitrate ion.

  11. Biochemistry of methyl-coenzyme M reductase: the nickel metalloenzyme that catalyzes the final step in synthesis and the first step in anaerobic oxidation of the greenhouse gas methane.

    PubMed

    Ragsdale, Stephen W

    2014-01-01

    Methane, the major component of natural gas, has been in use in human civilization since ancient times as a source of fuel and light. Methanogens are responsible for synthesis of most of the methane found on Earth. The enzyme responsible for catalyzing the chemical step of methanogenesis is methyl-coenzyme M reductase (MCR), a nickel enzyme that contains a tetrapyrrole cofactor called coenzyme F430, which can traverse the Ni(I), (II), and (III) oxidation states. MCR and methanogens are also involved in anaerobic methane oxidation. This review describes structural, kinetic, and computational studies aimed at elucidating the mechanism of MCR. Such studies are expected to impact the many ramifications of methane in our society and environment, including energy production and greenhouse gas warming.

  12. The radical mechanism of biological methane synthesis by methyl-coenzyme M reductase.

    PubMed

    Wongnate, Thanyaporn; Sliwa, Dariusz; Ginovska, Bojana; Smith, Dayle; Wolf, Matthew W; Lehnert, Nicolai; Raugei, Simone; Ragsdale, Stephen W

    2016-05-20

    Methyl-coenzyme M reductase, the rate-limiting enzyme in methanogenesis and anaerobic methane oxidation, is responsible for the biological production of more than 1 billion tons of methane per year. The mechanism of methane synthesis is thought to involve either methyl-nickel(III) or methyl radical/Ni(II)-thiolate intermediates. We employed transient kinetic, spectroscopic, and computational approaches to study the reaction between the active Ni(I) enzyme and substrates. Consistent with the methyl radical-based mechanism, there was no evidence for a methyl-Ni(III) species; furthermore, magnetic circular dichroism spectroscopy identified the Ni(II)-thiolate intermediate. Temperature-dependent transient kinetics also closely matched density functional theory predictions of the methyl radical mechanism. Identifying the key intermediate in methanogenesis provides fundamental insights to develop better catalysts for producing and activating an important fuel and potent greenhouse gas. PMID:27199421

  13. Spectroscopic pilot study in the near infrared of a sample of star-forming galaxies at z = 2

    NASA Astrophysics Data System (ADS)

    Gallego, J.; Sánchez de Miguel, A.; Zamorano, J.; Pérez-González, P. G.; Cardiel, N.; Barro, G.

    2011-11-01

    In this work we present the results of the spectroscopic analysis inthe near-infrared K band of a sample of 12 active star forminggalaxies at z ˜ 2. The sample was selected by using photometricredshifts, blue colors and large fluxes in the 24 μ m band ofMIPS/Spitzer. To analyze their physical properties we have computedtheir sizes, colors, stellar masses, extinctions and other parametersavailable in literature and in the "Rainbow" database. We computeHα luminosities and star formation rates for all galaxies atthat redshift. We were able to estimate metallicities from [NII]6584for a sub sample of the objects. In particular the dependence of the metallicitywith the stellar mass has been studied and compared with the results of other samples ofgalaxies at several redshifts. For a fixed mass, the metallicities ofour galaxies are compatible than those similar at the corresponding redshift, following the general trend of lower metallicities for higher redshifts.

  14. Liquefied Noble Gas (LNG) detectors for detection of nuclear materials

    NASA Astrophysics Data System (ADS)

    Nikkel, J. A.; Gozani, T.; Brown, C.; Kwong, J.; McKinsey, D. N.; Shin, Y.; Kane, S.; Gary, C.; Firestone, M.

    2012-03-01

    Liquefied-noble-gas (LNG) detectors offer, in principle, very good energy resolution for both neutrons and gamma rays, fast response time (hence high-count-rate capabilities), excellent discrimination between neutrons and gamma rays, and scalability to large volumes. They do, however, need cryogenics. LNG detectors in sizes of interest for fissionable material detection in cargo are reaching a certain level of maturity because of the ongoing extensive R&}D effort in high-energy physics regarding their use in the search for dark matter and neutrinoless double beta decay. The unique properties of LNG detectors, especially those using Liquid Argon (LAr) and Liquid Xenon (LXe), call for a study to determine their suitability for Non-Intrusive Inspection (NII) for Special Nuclear Materials (SNM) and possibly for other threats in cargo. Rapiscan Systems Laboratory, Yale University Physics Department, and Adelphi Technology are collaborating in the investigation of the suitability of LAr as a scintillation material for large size inspection systems for air and maritime containers and trucks. This program studies their suitability for NII, determines their potential uses, determines what improvements in performance they offer and recommends changes to their design to further enhance their suitability. An existing 3.1 liter LAr detector (microCLEAN) at Yale University, developed for R&}D on the detection of weakly interacting massive particles (WIMPs) was employed for testing. A larger version of this detector (15 liters), more suitable for the detection of higher energy gamma rays and neutrons is being built for experimental evaluation. Results of measurements and simulations of gamma ray and neutron detection in microCLEAN and a larger detector (326 liter CL38) are presented.

  15. The Conditions Underpinning Extreme Star Formation in ULIRGs and LIRGs as Revealed by Herschel Far-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Vasquez, Gabriel A.; Ashby, Matthew; Smith, Howard Alan; McTier, Moiya; Melendez, Marcio

    2016-01-01

    We present a systematic survey of molecular and atomic line fluxes in all star-forming galaxies observed by the Herschel PACs instrument with detectable OH lines that also contain Herschel SPIRE FTS spectra, to determine how physical conditions vary as a function of star formation rate. Specifically, we measured selected CO, H2O, [CI], and [NII] integrated line fluxes in a sample of 145 star-forming galaxies covering a range of far-infrared luminosities ranging from 109 to above 1012 LSun . Thus, our sample includes typical, quiescent galaxies as well as Luminous Infrared Galaxies (LIRGs) and Ultra Luminous Infrared Galaxies (ULIRGs), known to be creating stars extremely rapidly. We find evidence suggesting that ULIRGs with far-infrared luminosities of LFIR> 1012 LSun require an additional heating mechanism other than UV heating from star formation, while LIRGs and less luminous star-forming galaxies may be heated primarily by their star formation. We also find that the [NII] 3P1 - 3P0 fine structure line flux and those of the CO J=5-4, CO J=7-6, and CO J=8-7 transitions are generally weaker for ULIRGs compared to LIRGs and less luminous star-forming galaxies, while we find the CO J=11-10, CO J=12-11, and CO J=13-12 transitions are generally stronger. In all these respects, ULIRGs are shown to differ significantly from other galaxies undergoing less extreme star formation. This work was supported in part by the NSF REU and DoD ASSURE programs under NSF grant no. 1262851 and by the Smithsonian Institution.

  16. Role of information systems in controlling costs: the electronic medical record (EMR) and the high-performance computing and communications (HPCC) efforts

    NASA Astrophysics Data System (ADS)

    Kun, Luis G.

    1994-12-01

    On October 18, 1991, the IEEE-USA produced an entity statement which endorsed the vital importance of the High Performance Computer and Communications Act of 1991 (HPCC) and called for the rapid implementation of all its elements. Efforts are now underway to develop a Computer Based Patient Record (CBPR), the National Information Infrastructure (NII) as part of the HPCC, and the so-called `Patient Card'. Multiple legislative initiatives which address these and related information technology issues are pending in Congress. Clearly, a national information system will greatly affect the way health care delivery is provided to the United States public. Timely and reliable information represents a critical element in any initiative to reform the health care system as well as to protect and improve the health of every person. Appropriately used, information technologies offer a vital means of improving the quality of patient care, increasing access to universal care and lowering overall costs within a national health care program. Health care reform legislation should reflect increased budgetary support and a legal mandate for the creation of a national health care information system by: (1) constructing a National Information Infrastructure; (2) building a Computer Based Patient Record System; (3) bringing the collective resources of our National Laboratories to bear in developing and implementing the NII and CBPR, as well as a security system with which to safeguard the privacy rights of patients and the physician-patient privilege; and (4) utilizing Government (e.g. DOD, DOE) capabilities (technology and human resources) to maximize resource utilization, create new jobs and accelerate technology transfer to address health care issues.

  17. Perfis de temperatura eletrônica em regiões HII

    NASA Astrophysics Data System (ADS)

    Copetti, M. V. F.

    2003-08-01

    As flutuações de temperatura eletrônica em regiões HII, inicialmente propostas para explicar as discrepâncias entre os valores de temperatura obtidos por diferentes métodos, têm sido apontadas como a causa mais provável das enormes diferenças encontradas entre as abundâncias químicas medidas através de linhas excitadas colisionalmente e de linhas de recombinação. Recentemente têm sido reportadas tentativas de detecção e quantificação diretas das flutuações de temperatura eletrônica através de medidas ponto a ponto, obtidas por meio de espectroscopia de fenda longa, das razões de linhas [OIII]l4263/l5007 e [NII]l5755/l6584, principais sensores de temperatura. Neste trabalho, utilizamos o código numérico de fotoionização Cloudy para avaliar a confiabilidade desse procedimento. Concluímos que, para valores de densidade eletrônica e de temperatura efetiva da estrela ionizante típicos das regiões HII, os perfis superficiais de temperatura obtidos via medidas do sensor [OIII]l4263/l5007 são bons traçadores dos gradientes internos de temperatura eletrônica. Já os perfis de temperatura eletrônica medidos por meio da razão [NII]l5755/l6584 não reproduzem os gradientes verdadeiros de temperatura.

  18. Constraining the structure of the Narrow-Line Region of nearby QSO2s

    NASA Astrophysics Data System (ADS)

    Storchi-Bergmann, Thaisa

    2014-10-01

    The Narrow-Line Region (NLR) of Active Galactic Nuclei (AGN) is the only resolved region of AGN, observed via high excitation ionized gas emission that extends from hundred to kiloparsec scales in the host galaxies. In nearby AGN (z<0.03), the NLR is known to present an elongated or cone-like morphology seen in type 2 AGN, and circular morphology in type 1 AGN, supporting the Unified Model. Nevertheless, at somewhat higher z's (~ 0.5) recent ground-based studies have found mostly circular morphologies in observations of QSO2s (obscured QSOs). But at the corresponding distances of these objects, ground-based observations lack the necessary angular resolution to fully resolve the NLRs. It is not clear if the intrinsic NLR morphology changes for more luminous AGN or this is an effect of the atmospheric seeing. Only with HST we will be able to resolve the NLR morphology down to a few hundred parsec scales in the galaxy. We thus propose a "mini-survey" of the NLRs by obtaining narrow-band images in [OIII] and Halpha+[NII] of a sample of nearby QSO2s spanning the redshift range 0.05NII] images will be used to calculate the gas masses and constrain the nature of the emission, providing also a census of the presence of recent star formation in the host galaxies.

  19. Decommissioning at AWE

    SciTech Connect

    Biles, K.; Hedges, M.; Campbell, C

    2008-07-01

    AWE (A) has been at the heart of the UK Nuclear deterrent since it was established in the early 1950's. It is a nuclear licensed site and is governed by the United Kingdoms Nuclear Installation Inspectorate (NII). AWE plc on behalf of the Ministry of Defence (MOD) manages the AWE (A) site and all undertakings including decommissioning. Therefore under NII license condition 35 'Decommissioning', AWE plc is accountable to make and implement adequate arrangements for the decommissioning of any plant or process, which may affect safety. The majority of decommissioning projects currently being undertaken are to do with Hazard category 3, 4 or 5 facilities, systems or plant that have reached the end of their operational span and have undergone Post-Operational Clean-Out (POCO). They were either built for the production of fissile components, for supporting the early reactor fuels programmes or for processing facility waste arisings. They either contain redundant contaminated gloveboxes associated process areas, process plant or systems or a combination of all. In parallel with decommissioning project AWE (A) are undertaking investigation into new technologies to aid decommissioning projects; to remove the operative from hands on operations; to develop and implement modifications to existing process and techniques used. AWE (A) is currently going thorough a sustained phase of upgrading its facilities to enhance its scientific capability, with older facilities, systems and plant being replaced, making decommissioning a growth area. It is therefore important to the company to reduce these hazards progressively and safety over the coming years, making decommissioning an important feature of the overall legacy management aspects of AWE PLC's business. This paper outlines the current undertakings and progress of Nuclear decommissioning on the AWE (A) site. (authors)

  20. Identification of Hypoxia-Inducible Target Genes of Aspergillus fumigatus by Transcriptome Analysis Reveals Cellular Respiration as an Important Contributor to Hypoxic Survival

    PubMed Central

    Kroll, Kristin; Pähtz, Vera; Hillmann, Falk; Vaknin, Yakir; Schmidt-Heck, Wolfgang; Roth, Martin; Jacobsen, Ilse D.; Osherov, Nir; Brakhage, Axel A.

    2014-01-01

    Aspergillus fumigatus is an opportunistic, airborne pathogen that causes invasive aspergillosis in immunocompromised patients. During the infection process, A. fumigatus is challenged by hypoxic microenvironments occurring in inflammatory, necrotic tissue. To gain further insights into the adaptation mechanism, A. fumigatus was cultivated in an oxygen-controlled chemostat under hypoxic and normoxic conditions. Transcriptome analysis revealed a significant increase in transcripts associated with cell wall polysaccharide metabolism, amino acid and metal ion transport, nitrogen metabolism, and glycolysis. A concomitant reduction in transcript levels was observed with cellular trafficking and G-protein-coupled signaling. To learn more about the functional roles of hypoxia-induced transcripts, we deleted A. fumigatus genes putatively involved in reactive nitrogen species detoxification (fhpA), NAD+ regeneration (frdA and osmA), nitrogen metabolism (niaD and niiA), and respiration (rcfB). We show that the nitric oxygen (NO)-detoxifying flavohemoprotein gene fhpA is strongly induced by hypoxia independent of the nitrogen source but is dispensable for hypoxic survival. By deleting the nitrate reductase gene niaD, the nitrite reductase gene niiA, and the two fumarate reductase genes frdA and osmA, we found that alternative electron acceptors, such as nitrate and fumarate, do not have a significant impact on growth of A. fumigatus during hypoxia, but functional mitochondrial respiratory chain complexes are essential under these conditions. Inhibition studies indicated that primarily complexes III and IV play a crucial role in the hypoxic growth of A. fumigatus. PMID:25084861

  1. Identification of hypoxia-inducible target genes of Aspergillus fumigatus by transcriptome analysis reveals cellular respiration as an important contributor to hypoxic survival.

    PubMed

    Kroll, Kristin; Pähtz, Vera; Hillmann, Falk; Vaknin, Yakir; Schmidt-Heck, Wolfgang; Roth, Martin; Jacobsen, Ilse D; Osherov, Nir; Brakhage, Axel A; Kniemeyer, Olaf

    2014-09-01

    Aspergillus fumigatus is an opportunistic, airborne pathogen that causes invasive aspergillosis in immunocompromised patients. During the infection process, A. fumigatus is challenged by hypoxic microenvironments occurring in inflammatory, necrotic tissue. To gain further insights into the adaptation mechanism, A. fumigatus was cultivated in an oxygen-controlled chemostat under hypoxic and normoxic conditions. Transcriptome analysis revealed a significant increase in transcripts associated with cell wall polysaccharide metabolism, amino acid and metal ion transport, nitrogen metabolism, and glycolysis. A concomitant reduction in transcript levels was observed with cellular trafficking and G-protein-coupled signaling. To learn more about the functional roles of hypoxia-induced transcripts, we deleted A. fumigatus genes putatively involved in reactive nitrogen species detoxification (fhpA), NAD(+) regeneration (frdA and osmA), nitrogen metabolism (niaD and niiA), and respiration (rcfB). We show that the nitric oxygen (NO)-detoxifying flavohemoprotein gene fhpA is strongly induced by hypoxia independent of the nitrogen source but is dispensable for hypoxic survival. By deleting the nitrate reductase gene niaD, the nitrite reductase gene niiA, and the two fumarate reductase genes frdA and osmA, we found that alternative electron acceptors, such as nitrate and fumarate, do not have a significant impact on growth of A. fumigatus during hypoxia, but functional mitochondrial respiratory chain complexes are essential under these conditions. Inhibition studies indicated that primarily complexes III and IV play a crucial role in the hypoxic growth of A. fumigatus.

  2. Metabolic engineering of the morphology of Aspergillus oryzae by altering chitin synthesis.

    PubMed

    Müller, Christian; McIntyre, Mhairi; Hansen, Kim; Nielsen, Jens

    2002-04-01

    Morphology and alpha-amylase production during submerged cultivation were examined in a wild-type strain (A1560) and in strains of Aspergillus oryzae in which chitin synthase B (chsB) and chitin synthesis myosin A (csmA) have been disrupted (ChsB/G and CM101). In a flowthrough cell, the growth of submerged hyphal elements was studied online, making it possible to examine the growth kinetics of the three strains. The average tip extension rates of the CM101 and ChsB/G strains were 25 and 88% lower, respectively, than that of the wild type. The branching intensity in the CM101 strain was 25% lower than that in the wild type, whereas that in the ChsB/G strain was 188% higher. During batch cultivation, inseparable clumps were formed in the wild-type strain, while no or fewer large inseparable clumps existed in the cultivations of the ChsB/G and CM101 strains. The alpha-amylase productivity was not significantly different in the three strains. A strain in which the transcription of chsB could be controlled by the nitrogen source-regulated promoter niiA (NiiA1) was examined during chemostat cultivation, and it was found that the branching intensity could be regulated by regulating the promoter, signifying an important role for chsB in branching. However, the pattern of branching responded very slowly to the change in transcription, and increased branching did not affect alpha-amylase productivity. alpha-Amylase residing in the cell wall was stained by immunofluorescence, and the relationship between tip number and enzyme secretion is discussed.

  3. Fundamental studies and development of nickel-catalyzed trifluoromethylthiolation of aryl chlorides: active catalytic species and key roles of ligand and traceless MeCN additive revealed.

    PubMed

    Yin, Guoyin; Kalvet, Indrek; Englert, Ulli; Schoenebeck, Franziska

    2015-04-01

    A catalytic protocol to convert aryl and heteroaryl chlorides to the corresponding trifluoromethyl sulfides is reported herein. It relies on a relatively inexpensive Ni(cod)2/dppf (cod = 1,5-cyclooctadiene; dppf = 1,1'-bis(diphenylphosphino)ferrocene) catalyst system and the readily accessible coupling reagent (Me4N)SCF3. Our computational and experimental mechanistic data are consistent with a Ni(0)/Ni(II) cycle and inconsistent with Ni(I) as the reactive species. The relevant intermediates were prepared, characterized by X-ray crystallography, and tested for their catalytic competence. This revealed that a monomeric tricoordinate Ni(I) complex is favored for dppf and Cl whose role was unambiguously assigned as being an off-cycle catalyst deactivation product. Only bidentate ligands with wide bite angles (e.g., dppf) are effective. These bulky ligands render the catalyst resting state as [(P-P)Ni(cod)]. The latter is more reactive than Ni(P-P)2, which was found to be the resting state for ligands with smaller bite angles and suffers from an initial high-energy dissociation of one ligand prior to oxidative addition, rendering the system unreactive. The key to effective catalysis is hence the presence of a labile auxiliary ligand in the catalyst resting state. For more challenging substrates, high conversions were achieved via the employment of MeCN as a traceless additive. Mechanistic data suggest that its beneficial role lies in decreasing the energetic span, therefore accelerating product formation. Finally, the methodology has been applied to synthetic targets of pharmaceutical relevance. PMID:25790253

  4. Ultrafast Excited State Relaxation of a Metalloporphyrin Revealed by Femtosecond X-ray Absorption Spectroscopy.

    PubMed

    Shelby, Megan L; Lestrange, Patrick J; Jackson, Nicholas E; Haldrup, Kristoffer; Mara, Michael W; Stickrath, Andrew B; Zhu, Diling; Lemke, Henrik T; Chollet, Matthieu; Hoffman, Brian M; Li, Xiaosong; Chen, Lin X

    2016-07-20

    Photoexcited Nickel(II) tetramesitylporphyrin (NiTMP), like many open-shell metalloporphyrins, relaxes rapidly through multiple electronic states following an initial porphyrin-based excitation, some involving metal centered electronic configuration changes that could be harnessed catalytically before excited state relaxation. While a NiTMP excited state present at 100 ps was previously identified by X-ray transient absorption (XTA) spectroscopy at a synchrotron source as a relaxed (d,d) state, the lowest energy excited state (J. Am. Chem. Soc., 2007, 129, 9616 and Chem. Sci., 2010, 1, 642), structural dynamics before thermalization were not resolved due to the ∼100 ps duration of the available X-ray probe pulse. Using the femtosecond (fs) X-ray pulses of the Linac Coherent Light Source (LCLS), the Ni center electronic configuration from the initial excited state to the relaxed (d,d) state has been obtained via ultrafast Ni K-edge XANES (X-ray absorption near edge structure) on a time scale from hundreds of femtoseconds to 100 ps. This enabled the identification of a short-lived Ni(I) species aided by time-dependent density functional theory (TDDFT) methods. Computed electronic and nuclear structure for critical excited electronic states in the relaxation pathway characterize the dependence of the complex's geometry on the electron occupation of the 3d orbitals. Calculated XANES transitions for these excited states assign a short-lived transient signal to the spectroscopic signature of the Ni(I) species, resulting from intramolecular charge transfer on a time scale that has eluded previous synchrotron studies. These combined results enable us to examine the excited state structural dynamics of NiTMP prior to thermal relaxation and to capture intermediates of potential photocatalytic significance.

  5. Warm ISM in the Sagittarius A Complex. I. Mid-J CO, atomic carbon, ionized atomic carbon, and ionized nitrogen sub-mm/FIR line observations with the Herschel-HIFI and NANTEN2/SMART telescopes

    NASA Astrophysics Data System (ADS)

    García, P.; Simon, R.; Stutzki, J.; Güsten, R.; Requena-Torres, M. A.; Higgins, R.

    2016-04-01

    Aims: We investigate the spatial and spectral distribution of the local standard of rest (LSR) velocity resolved submillimetre emission from the warm (25-90 K) gas in the Sgr A Complex, located in the Galactic centre. Methods: We present large-scale submillimetre heterodyne observations towards the Sgr A Complex covering ~300 arcmin2. These data were obtained in the frame of the Herschel EXtraGALactic guaranteed time key program (HEXGAL) with the Herschel-HIFI satellite and are complemented with submillimetre observations obtained with the NANTEN2/SMART telescope as part of the NANTEN2/SMART Central Nuclear Zone Survey. The observed species are CO(J = 4-3) at 461.0 GHz observed with the NANTEN2/SMART telescope, and [CI] 3P1-3P0 at 492.2 GHz, [CI] 3P2-3P1 at 809.3 GHz, [NII] 3P1-3P0 at 1461.1 GHz, and [CII] 2P3/2-2P1/2 at 1900.5 GHz observed with the Herschel-HIFI satellite. The observations are presented in a 1 km s-1 spectral resolution and a spatial resolution ranging from 46 arcsec to 28 arcsec. The spectral coverage of the three lower frequency lines is ±200 km s-1, while in the two high frequency lines, the upper LSR velocity limit is +94 km s-1 and +145 km s-1 for the [NII] and [CII] lines, respectively. Results: The spatial distribution of the emission in all lines is very widespread. The bulk of the carbon monoxide emission is found towards Galactic latitudes below the Galactic plane, and all the known molecular clouds are identified. Both neutral atomic carbon lines have their brightest emission associated with the +50 km s-1 cloud. Their spatial distribution at this LSR velocity describes a crescent-shape structure, which is probably the result of interaction with the energetic event (one or several supernovae explosions) that gave origin to the non-thermal Sgr A-East source. The [CII] and [NII] emissions have most of their flux associated with the thermal arched-filaments and the H region and bright spots in [CII] emission towards the central nuclear

  6. Ionized gas characteristics in the cavities of the gas and dust disc of the spiral galaxy NGC 6946

    NASA Astrophysics Data System (ADS)

    Efremov, Yu. N.; Afanasiev, V. L.; Egorov, O. V.

    2011-07-01

    The parameters of the ionized gas in NGC 6946 (in the [NII] λλ6548, 6583, H α and [SII] λλ6717, 6731 lines) are investigated with the SAO RAS BTA telescope along three positions of the long slit of the SCORPIO focal reducer, passing through a number of large and small cavities of the gaseous disc of the galaxy. These cavities correspond exactly to the cavities in warm dust, visible at 5 - 8µm. We found that everywhere in the direction of NGC 6946 the lines of ionized gas are decomposed into two Gaussians, one of which shows almost constant [SII]/H α and [NII]/H α ratios, as well as an almost constant radial velocity within the measurement errors (about -35… - 50 km/s). This component is in fact the foreground radiation from the diffuse ionized gas of our Galaxy, which is not surprising, given the low (12°) latitude of NGC 6946; a similar component is also present in the emission of neutral hydrogen. The analysis of the component of ionized gas, occurring inNGC 6946, has revealed that it shows signs of shock excitation in the cavities of the gaseous disc of the galaxy. This shock excitation is as well typical for the extraplanar diffuse ionized gas (EDIG), observed in a number of spiral galaxies at their high Z-coordinates. This can most likely be explained by low density of the gas in the NGC 6946 disc (with the usual photoionization) inside the cavities, due to what we see the spectral features of the EDIG gas of NGC 6946, projected onto them, and located outside the plane of the galaxy. In the absence of separation of ionized gas into two components by radial velocities, there is an increasing contribution to the integral line parameters by the EDIG of our Galaxy when the gas density in NGC 6946 decreases, which explains some strange results, obtained in the previous studies. Themorphology of warmdust, visible in the infrared range and HI is almost the same (except for the peripheral parts of the galaxy, where there are no sources of dust heating

  7. An irradiated jet in M 17

    NASA Astrophysics Data System (ADS)

    Comerón, F.; Pasquali, A.; Alves de Oliveira, C.

    2013-04-01

    Context. M 17 is one of the best studied giant HII regions in our galactic neighborhood. It should also provide a suitable environment for the class of fully ionized jets externally irradiated by the presence of nearby hot stars. However, no such jets have been observed thus far in M 17. Aims: We report on a visible imaging survey of the M 17 nebula with the goal of identifying likely shock-excited nebulosities. Methods: We imaged M 17 through narrow-band filters centered on the most intense visible lines of [OIII], Hα+[NII], [SII], and Hβ. We obtained follow-up spectroscopy of the only jet-like structure identified in the images. We also used published X-ray observations of M 17 obtained with the Chandra X-ray Observatory, as well as infrared data obtained with the Very Large Telescope and with the Spitzer Space Telescope, to look for evidence of a jet-driving source. Results: We have detected what appears to be the first jet identified in M 17 visible HII region. The jet is composed of a set of knots, two of which have significant radial velocities with respect to the HII region, and a distant arc-like bright nebulosity that may represent an early episode of intense mass loss by the jet-driving source. The follow-up spectra of the structures composing the jet, including the arc, support this interpretation by revealing intense forbidden lines of [NII] and [SII] due to enhanced collisional excitation in shocks. The presence of a X-ray source, most likely a young stellar object, at a position where the jet launching source should be expected to lie reinforces the interpretation. We identify a tentative near-infrared counterpart of the X-ray source, although it is offset by 1".9 from the nominal position of the X-ray source, which is almost three times the radius of its positional uncertainty. The very weak [OI] emission in the spectra of the jet knots and the arc suggests that they are nearly fully ionized, in agreement with the environment in which the jet is

  8. Spectroscopic and Computational Studies of Reduction of the Metal versus the Tetrapyrrole Ring of Coenzyme F430 from Methyl-Coenzyme M Reductase†

    PubMed Central

    Dey, Mishtu; Kunz, Ryan; Van Heuvelen, Katherine M.; Craft, Jennifer L.; Horng, Yih-Chern; Tang, Qun; Bocian, David F.; George, Simon J.; Brunold, Thomas C.; Ragsdale, Stephen W.

    2008-01-01

    Methyl-Coenzyme M reductase (MCR) catalyzes the final step in methane biosynthesis by methanogenic archaea and contains a redox-active nickel tetrahydrocorphin, Coenzyme F430, at its active site. Spectroscopic and computational methods have been used to study a novel form of the Coenzyme, called F330, which is obtained by reducing F430 with sodium borohydride (NaBH4). F330 exhibits a prominent absorption peak at 330 nm, which is blue shifted by 100 nm relative to F430. Mass spectrometric studies demonstrate that the tetrapyrrole ring in F330 has undergone reduction, based on the incorporation of protium (or deuterium), upon treatment of F430 with NaBH4 (or NaBD4). One- and two-dimensional NMR studies show that the site of reduction is the exocyclic ketone group of the tetrahydrocorphin. Resonance Raman studies indicate that elimination of this π-bond increases the overall π-bond order in the conjugative framework. X-ray absorption, magnetic circular dichroism, and computational results show that F330 contains low-spin Ni(II). Thus, conversion of F430 to F330 reduces the hydrocorphin ring but not the metal. Conversely, reduction of F430 with Ti(III) citrate to generate F380 (corresponding to the active MCRred1 state) reduces the Ni(II) to Ni(I), but does not reduce the tetrapyrrole ring system, which is consistent with other studies (Piskorski, R. and Jaun, B. (2003) J. Am. Chem. Soc. 125:13120-5 and Craft, J. L. et al. (2004) J. Biol. Inorg. Chem. 9:77-89). The distinct origins of the absorption band shifts associated with the formation of F330 and F380 are discussed within the framework of our computational results. These studies on the nature of the product(s) of reduction of F430 are of interest in the context of the mechanism of methane formation by MCR and in relation to the chemistry of hydroporphinoid systems in general. The spectroscopic and time dependent DFT calculations add important insight into the electronic structure of the Ni-hydrocorphinate in

  9. Mono- and dinuclear nickel(II) complexes of resolved Schiff-base ligands with extended quinoline substituents.

    PubMed

    Prema, Dipesh; Oshin, Kayode; Desper, John; Levy, Christopher J

    2012-04-28

    The coordination chemistry of four enantiopure tetradentate bis(iminoquinoline) ligands with nickel(II) salts is reported. The previously reported ligands CBQ, CPQ, BBQ, and BPQ result from the condensation of (1R,2R)-cyclohexyldiamine or (R)-BINAM with two equivalents of 2-formylbenzo[h]quinoline or 8-isopropyl-2-quinolinecarboxaldehyde {CBQ = (1R,2R)-cyclohexanediamine-N,N'-bis(benzo[h]quinoline-2-ylmethylene), CPQ = (1R,2R)-cyclohexanediamine-N,N'-bis[[(8-isopropyl)-2-quinolinyl]methylene], BBQ = [(R)-1,1'-binaphthalene]-2,2'-diamine-N,N'-bis(benzo[h]quinoline-2-ylmethylene), BPQ = [(R)-1,1'-binaphthalene]-2,2'-diamine-N,N'-bis[[(8-isopropyl)-2-quinolinyl]methylene]}. Reaction of NiI(2) with the (1R,2R)-cyclohexyl ligands gives the mononuclear distorted trigonal-bipyramidal (TBP) complexes [Ni(N(3)-CBQ)I(2)] and [Ni(N(3)-CPQ)I(2)]. Incomplete iodide abstraction from [Ni(N(3)-CPQ)I(2)] with AgOTf leads to partial replacement of the iodide with hydroxide from adventitious water to give [Ni(N(3)-CPQ)I(1.6)(OH)(0.4)] (distorted TBP). The corresponding reaction with [Ni(N(3)-CBQ)I(2)] again fails to remove all of the iodide, resulting instead in conversion to the syn dinuclear [Ni(2)(CBQ)(μ-X)(2)I(2)] (X = Cl(0.925)I(0.075)) complex, where chloride abstraction from the solvent (CH(2)Cl(2)) has resulted in a mixed halide system and the metal centers are square-pyramidal. Reaction of Ni(OTf)(2) with CBQ leads to the isolation of the octahedral cation [Ni(CMBQ)(2)](2+), with CMBQ [(1R,2R)-cyclohexanediamine-mono-N-(benzo[h]quinoline-2-ylmethylene)] being the partial hydrolysis product of CBQ. [Ni(CMBQ)(2)][OTf](2) crystallizes as a 1:1 mixture of P and M helical diastereomers. The coordination of NiI(2) with the (R)-BINAM derived ligands yields the anti dinuclear P-helical complexes [Ni(2)(BBQ)(μ-I)(2)I(2)] and [Ni(2)(BPQ)(μ-I)(2)I(2)]: one nickel ion is coordinated in each bidentate iminoquinoline pocket and the geometry at the metal centers is distorted square

  10. VizieR Online Data Catalog: NGC 891 Herschel PACS and SPIRE spectroscopy (Hughes+, 2015)

    NASA Astrophysics Data System (ADS)

    Hughes, T. M.; Foyle, K.; Schirm, M. R. P.; Parkin, T. J.; de Looze, I.; Wilson, C. D.; Bendo, G. J.; Baes, M.; Fritz, J.; Boselli, A.; Cooray, A.; Cormier, D.; Karczewski, O. L.; Lebouteiller, V.; Lu, N.; Madden, S. C.; Spinoglio, L.; Viaene, S.

    2014-10-01

    We present Herschel PACS spectroscopic observations of the [CII] 158, [NII] 122, [OI] 63, 145, and [OIII] 88 micron fine-structure lines in NGC 891 taken has part of the Very Nearby Galaxy Survey (P.I.: C. Wilson). Observations were taken on the 28th February and 1st March, 2011, using the unchopped grating scan mode. They were processed from Level 0 to Level 1 using the Herschel Interactive Processing Environment (HIPE) v.9.2 with calibration files FM,41, following the standard pipeline reduction steps for the unchopped observing mode. Level 1 cubes were exported to PACSman v.3.5.2 (Lebouteiller, 2012A&A...548A..91L), where each individual spaxel's spectrum is fit with a Gaussian function and second order polynomial for the line and continuum baseline, respectively. Intensity maps of the integrated flux are created from the individual rasters, also using PACSman, by projecting the rasters onto a common, over-sampled grid with a 3.133 arcsec pixel size. Complete details on the data reduction may be found in the paper. Our data files are summarised in cubes.dat. Each file is a FITS cube with 8 planes, where each plane contains the following maps: (1.) integrated intensity map in units of W/m2/sr, (2.) integrated intensity error map in units of W/m2/sr, (3.) velocity map in units of km/s, (4.) velocity error map in units of km/s, (5.) full-width at half-maximum map of the line fit in units of km/s, (6.) full-width at half-maximum error map in units of km/s, (7.) continuum map in Jy, and (8.) continuum error map in units of Jy. Please note that the observations consist of raster maps and strips for the [CII], [NII] and [OI] 63 micron lines, and only strips for the remaining lines. The raw data can be retrieved from the Herschel Science Archive (ESA) with the stated OBSIDs. (2 data files).

  11. Diel vertical distribution and migration of a euphausiid Euphausia pacifica in the Southern Yellow Sea

    NASA Astrophysics Data System (ADS)

    Liu, Hui-Lian; Sun, Song

    2010-04-01

    Stage-specific differences in the diel vertical distribution and migration of a euphausiid, Euphausia pacifica, were studied at a single station (E2, 70 m water depth) in the South Yellow Sea, by sampling with a conical closing net from five discrete strata, every 3 h, for 24 h, on 2-3 May 2001. Environmental data were collected simultaneously with the net sampling. Results showed that eggs contributed a large proportion of the numerical abundance of the Euphausia pacifica population throughout the investigation. They were mainly distributed below 20 m depth, and concentrated in the 30-50 m strata throughout the day and night. Nauplius stage I (NI) was distributed below 10 m, and seldom occurred in the upper 10 m. Nauplius stage II (NII) and Metanauplius stage (MN) extended their distribution to nearly the whole water column; however, the MN resided somewhat shallower than NII. The majority of calyptopis stages I to III (CI to CIII ) and early furcilia stages I to III (FI to FIII) were restricted to the upper 30 m throughout the day. The weighted mean depth tended to increase as the stage progressed from stage FI onward. Calyptopis stages showed a weak or moderate diel vertical migration behavior, and the onset of an obvious diel vertical migration took place in FII stage. The amplitude of the diel vertical migration varied with developmental stages. Stages after FIV were often absent from samples during the investigation, but from the limited available data, DVM occurred from stages FIV-VI and female adults. However, the male adults showed a somewhat different migration behavior. In summary, an ontogenetic migration pattern is obvious from this high-frequency sampling: spawning took place at 20-50 m depth, hatched nauplii sank a little, metanauplius began moving toward the surface, and calyptopis larvae reached the uppermost layer. Furcilia larvae began DVM and deepened their daytime residence depth with age. The vertical distribution of Euphausia pacifica seemed

  12. Non-invasive pneumococcal serotypes and antimicrobial susceptibilities in a paediatric hospital in the era of conjugate vaccines.

    PubMed

    McElligott, Martha; Vickers, Imelda; Cafferkey, Mary; Cunney, Robert; Humphreys, Hilary

    2014-06-12

    To evaluate the effects of 7-valent pneumococcal conjugate vaccine (PCV7) introduction to the routine childhood immunisation schedule in 2008 and its replacement by PCV13 in 2010 in Ireland, we surveyed the serotypes and antimicrobial susceptibilities of 339 pneumococci associated with carriage and non-invasive infection (NII) in a Dublin paediatric hospital from 2009 to 2012. Furthermore, we compared the distribution of pneumococcal serotypes collected from 2009 to 2012 to 105 NII pneumococci isolated in 2007, the year before conjugate vaccine introduction. PCV7 serotypes declined from 2007 to 2012 as follows: carriage, 67-23% (p=0.0004); conjunctivitis, 58-0% (p<0.0001); non-bacteraemic lower respiratory tract infection, 50-19% (p=0.0363) and otitis media 54-27%. Notably, antimicrobial resistant (AMR) PCV7 serotypes showed a significant decrease by the end of the study period (i.e. 2012) (p<0.0001). Compared with 2007 the overall occurrence of serotype 19A increased from 1.9 to 10% in 2010 (p=0.0132) and to 15% in 2011 (p=0.0005). Importantly, serotype 19A declined significantly from 2011 levels to an overall prevalence of 4.8% in 2012 (p=0.0243). Most striking was the significant reduction of AMR 19A (p=0.0195). Conversely, increases were observed in non-vaccine type (NVT) pneumococci in 2009-2012, of which serotypes 11A (n=30), 15B/C (n=17), 22F (n=14), 35Bn=13), non-typeable pneumococci (n=13) and 23A (n=12) were the most prevalent. Moreover, an increase in NVT non-susceptible to at least one antimicrobial in 2009-2012 was noted, attributable to serotypes 35B (n=10) and 15A (n=7). In summary, this study has shown that PCV7 and PCV13 introduction has had a positive impact on their target serotypes and antimicrobial resistance amongst pneumococci within a paediatric hospital within a short time period. However, the increase in NVT prevalence highlights the need for continued surveillance. PMID:24795223

  13. Spectral classification of emission-line galaxies from the Sloan Digital Sky Survey. I. An improved classification for high-redshift galaxies

    NASA Astrophysics Data System (ADS)

    Lamareille, F.

    2010-01-01

    Aims: We study the spectral classification of emission-line galaxies as starforming galaxies or active galactic nuclei (AGNs). With the high-quality data from the Sloan Digital Sky Survey (SDSS) we define an improved classification to be used for high-redshift galaxies. Methods: We classify emission-line galaxies of the SDSS according to the latest standard recipe using [Oiii]λ5007, [Nii]λ6584, [Sii]λ6717+6731, Hα, and Hβ emission lines. We obtain four classes: starforming galaxies, Seyfert 2, LINERs, and composites. We then examine where these galaxies fall in the blue diagram used at high redshift (i.e. log([Oiii]λ5007/Hβ) vs. log([Oii]λλ3726+3729/Hβ). Results: We define new improved boundaries in the blue diagram for starforming galaxies, Seyfert 2, LINERs, SF/Sy2, and SF-LIN/comp classes. We maximize the success rate to 99.7% for the detection of starforming galaxies to 86% for the Seyfert 2 (including the SF/Sy2 region) and to 91% for the LINERs. We also minimize the contamination to 16% in the region of starforming galaxies. We cannot reliably separate composites from starforming galaxies and LINERs, but we define an SF-LIN/comp region where most of them fall (64%).

  14. The Sunrise project: An R&D project for a national information infrastructure prototype

    SciTech Connect

    Lee, Juhnyoung

    1995-02-01

    Sunrise is a Los Alamos National Laboratory (LANL) project started in October 1993. It is intended to a prototype National Information Infrastructure (NII) development project. A main focus of Sunrise is to tie together enabling technologies (networking, object-oriented distributed computing, graphical interfaces, security, multimedia technologies, and data mining technologies) with several specific applications. A diverse set of application areas was chosen to ensure that the solutions developed in the project are as generic as possible. Some of the application areas are materials modeling, medical records and image analysis, transportation simulations, and education. This paper provides a description of Sunrise and a view of the architecture and objectives of this evolving project. The primary objectives of Sunrise are three-fold: (1) To develop common information-enabling tools for advanced scientific research and its applications to industry; (2) To enhance the capabilities of important research programs at the Laboratory; and (3) To define a new way of collaboration between computer science and industrially relevant research.

  15. Development of a polarization resolved spectroscopic diagnostic for measurements of the magnetic field in the Caltech coaxial magnetized plasma jet experiment

    NASA Astrophysics Data System (ADS)

    Shikama, Taiichi; Bellan, Paul M.

    2011-11-01

    Measurements of the magnetic field strength in current-carrying magnetically confined plasmas are necessary for understanding the underlying physics governing the dynamical behavior. Such a measurement would be particularly useful in the Caltech coaxial magnetized plasma gun, an experiment used for fundamental studies relevant to spheromak formation, astrophysical jet formation/propagation, solar coronal physics, and the general behavior of twisted magnetic flux tubes that intercept a boundary. In order to measure the field strength in the Caltech experiment, a non-perturbing spectroscopic method is being implemented to observe the Zeeman splitting in the emission spectra. The method is based on polarization-resolving spectroscopy of the Zeeman-split σ components, a technique previously used in both solar and laboratory plasmas. We have designed and constructed an optical system that can simultaneously detect left- and right-circularly polarized emission with both high throughput and small extinction ratio. The system will be used on the 489.5 nm NII line, chosen because of its simple Zeeman structure and minimal Stark broadening.

  16. Spectroscopy of planetary nebulae in the region of Canis Major

    NASA Astrophysics Data System (ADS)

    Kniazev, A. Yu.

    2012-11-01

    We present the results of a pilot project of spectroscopic observations for planetary nebulae (PNe) and PN candidates in Canis Major, a sky region where the remnant of a disrupted dwarf galaxy cannibalized by the Milky Way may be located. The spectra of seven objects were taken while testing the SALT spectrograph (South African Astronomical Observatory). All elemental abundances have been obtained by the T e method, where the electron temperature is calculated directly using the measured weak auroral [OIII] λ 4363 Å and/or [NII] λ 5755 Å lines. We have measured the intensities of all the detected emission lines and determined the abundances of oxygen and several other elements (N, Ne, S, Cl, C, and He) in all PNe. The radial velocity for one PN has been measured for the first time and the velocities for all of the remaining PNe have been measured with a considerably better accuracy than that of the previously published ones. The elemental abundances for three PNe have been calculated for the first time and the accuracies of determining the abundances for three others have been improved. The measured heavy-element abundance ratios (S/O, Ne/O, Cl/O) are in good agreement with their typical values for HII regions. Among the PNe studied, ESO 428-05 is the first and so far the most likely candidate for belonging to the remnants of a possible dwarf galaxy disrupted by the tidal interaction with the Milky Way.

  17. Probing Star Formation in the Early Universe with Far-IR Spectroscopy using ZEUS-2

    NASA Astrophysics Data System (ADS)

    Vishwas, Amit; Ferkinhoff, Carl; Nikola, Thomas; Parshley, Stephen; Schoenwald, Justin Paul; Stacey, Gordon J.; Higdon, James L.; Higdon, Sarah; Brisbin, Drew; Verma, Aprajita; Riechers, Dominik A.; Hailey-Dunsheath, Steve; Menten, Karl; Güsten, Rolf; Weiss, Axel; Irwin, Kent; Cho, Hsiao-Mei; Niemack, Michael D.; Halpern, Mark; Amiri, Mandana; Hasselfield, Matthew; Wiebe, Donald V.; Ade, Peter A. R.; Tucker, Carole E.

    2015-01-01

    ZEUS-2 is a long slit, direct detection, grating spectrometer for submillimeter wavelengths between 200-850 μm. At present, ZEUS-2 employs a single TES bolometer array that addresses only the 350 and 450 μm windows. Here we report the first science obtained with this array on the Atacama Pathfinder Experiment (APEX) telescope, and our progress towards implementing a second TES array that will open up the 200, 230, 640, 850 μm windows for direct detection spectroscopy on APEX.Our investigations focus on detecting faint and broad far-infrared (FIR) fine structure lines of ionized carbon [CII] at 158 μm, nitrogen [NII] at 122 and 205 μm and doubly ionized oxygen [OIII] at 52 and 88 μm from distant galaxies as the lines are redshifted into the submm telluric windows. We are primarily interested in the redshift 1 to 4 interval which encompasses the epoch of maximum star formation rate per unit co-moving volume in the Universe. These far infrared lines are important gas coolants, and powerful probes of the physical conditions of the interstellar medium and the starlight that heats the gas. Here we report detections of the [CII] and [OIII] 88 μm lines from sources at redshift 1.8 to 4.3, and show how the lines can be used to trace both the spatial extent of the star formation and the hardness of the ambient radiation fields.

  18. Observing Nearby Galaxies with CCAT

    NASA Astrophysics Data System (ADS)

    Armus, Lee; Stacey, G. J.; Wilson, C.; Bolatto, A. D.; Rangwala, N.; Nikola, T.; Kauffmann, J.; Bertoldi, F.; Glenn, J.; CCAT Team

    2013-01-01

    CCAT, with its 25m primary, advanced detectors and fast mapping speed will be extremely adept at deep, large-scale surveys for distant, dusty galaxies in the early Universe, and the most deeply buried star-forming complexes in the Milky Way. However, since it will also be sensitive to low surface brightness emission from diffuse dust, and the key far-infrared and mm cooling lines of the ISM, CCAT will also be a superb telescope for studying nearby galaxies in exquisite detail. For the nearest systems (e.g. M83), CCAT will be able to produce diffraction-limited maps in the mid-J CO rotational lines, and the [CI] and [NII] fine-structure lines on physical scales approaching those of individual molecular clouds. For samples of luminous starburst galaxies out to 0.3-0.5, CCAT will offer unprecedented sensitivity and spatial resolution in the high-J CO lines which are critical for pinpointing X-ray dissociation regions heated by AGN. Here, we will outline the strong scientific case for using CCAT to map the cold dust, the molecular gas and the ionized and atomic interstellar medium in local galaxies.

  19. Development of the 2nd Generation Redshift(z) and Early Universe Spectrometer and the Detailed Study of Far-IR Fine-Structure Lines in High-z Galaxies

    NASA Astrophysics Data System (ADS)

    Ferkinhoff, Carl; Brisbin, D.; Nikola, T.; Parshley, S.; Stacey, G. J.; Hailey-Dunsheath, S. J.; Irwin, K. D.; Cho, H.; Niemack, M.; Benford, D. J.; Staguhn, J.; Phillips, T. G.; Falgarone, E.

    2013-01-01

    The 2nd generation Redshift(z) and Early Universe Spectrometer (ZEUS-2), is a long-slit echelle grating spectrometer ( 1000) for observations at submillimeter wavelengths from 200 to 850 μm. Its design is optimized for the detection of redshifted far-infrared spectral lines from galaxies in the early universe. Combined with its exquisite sensitivity, broad wavelength coverage, and large 2.5%) instantaneous bandwidth, ZEUS-2 is uniquely suited for studying galaxies between 0.2 and 5—spanning the peaks in both the star formation rate and AGN activity in the universe. ZEUS-2 saw first light at the Caltech Submillimeter Observatory (CSO) in the spring of 2012 and was commissioned on the Atacama Pathfinder Experiment (APEX) this past November. Here we report on the instrument development and performance as well as initial scientific results from the APEX commissioning. We also discuss our ZEUS-1 (the first generation Redshift(z) and Early Universe Spectrometer) detections of the [NII] 122 μm and [OIII] 88 μm lines from starburst galaxies at redshifts between ~2.5 and 4. These are the first high-z detections of these lines and they are examples of work we plan to continue with ZEUS-2. As such, they demonstrate the potential of ZEUS-2 for increasing our understanding of galaxies and galaxy evolution over cosmic time.

  20. Measuring the Relative Contributions of Viscous Accretion and Photoevaporation to the Dispersal of Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Simon, M. N.; Pascucci, I.; Rigliaco, E.; Gorti, U.; Hollenbach, D.

    2014-03-01

    Models of protoplanetary disk evolution suggest that photoevaporation driven by the central star and viscous evolution via gas accretion onto the star are the main mechanisms that drive disk dispersal. Viscous evolution has the ability to smoothly decrease the disk surface density, but photoevaporation can drastically change it by creating gaps in planet-forming regions that widen quickly over time. This quick gas dispersal can stop the migration of giant planets whose location affects the final delivery of volatiles (including water) to terrestrial planets. We selected a sample of twenty protoplanetary disks around T. Tauri stars in the Taurus region spanning all three main disk evolutionary stages, with a range of mass accretion rates. For this sample we have acquired high-resolution optical spectra with Keck/HIRES covering gas lines that trace both accretion and photoevaporation. We will present an analysis of the forbidden OI, SII, and NII lines and provide empirically determined mass loss rates as a function of disk evolutionary stage and mass accretion rate. This will enhance our understanding of the disk stage at which photoevaporation starts to dominate over viscous accretion.

  1. Metallicity in the GRB100316D/SN 2010bh Host Complex

    NASA Astrophysics Data System (ADS)

    Levesque, Emily M.; Berger, E.; Soderberg, A. M.; Chornock, R.

    2012-01-01

    The recent long-duration GRB 100316D, associated with supernova SN 2010bh and detected by Swift, is one of the nearest GRB-SNe ever observed (z = 0.059). This provides us with a unique opportunity to study the explosion environment on kpc scale in relation to the host galaxy complex. Here we present spatially-resolved spectrophotometry of the host galaxy, focusing on both the explosion site and the brightest star-forming regions. Using these data, we extract the spatial profiles of the relevant emission features (H-alpha, H-beta, [OIII] 5007A, and [NII] 6584A), and use these profiles to examine variations in metallicity and star formation rate as a function of position in the host galaxy. We conclude that GRB 100316D/SN2010bh occurred in a low-metallicity host galaxy, and that the GRB-SN explosion site corresponds to the region with the lowest metallicity and highest star formation rate sampled by our observations. Combining our work with other recent spatially-resolved studies of nearby GRB host galaxies, these results have compelling implications for larger-scale studies of LGRB host environments at higher redshifts. This research was supported in part by NASA through an Einstein Postdoctoral Fellowship.

  2. Kinematics of the Ionized Gas in Dwarf Irregular Galaxies

    NASA Astrophysics Data System (ADS)

    Valdez-Gutiérrez, Margarita; Rosado, Margarita

    2007-05-01

    Introduction: Some preliminary results focused on the kinematics and dynamics of the ionized gas in the local group dwarf irregular galaxy IC10 are presented. Method: Scanning Fabry-Perot interferometry was performed in the Hα, [SII], [NII] and [OIII] lines. The dedicated ADHOC package was used in the reduction process. Results: On galactic scales the radial velocity field in this galaxy is relatively well behaved, however, the rotation curve has been difficult to obtain. On local scales the kinematics reflects the superposition of shells, filaments, SNRs and diffuse gas. At many of these locations the velocity widths are supersonic and many times larger than those found in the adjacent HII regions. Discussion: This is the first time that the kinematics of the ionized gas in the dwarf irregular IC10 is studied in great detail, literally pixel to pixel with moderate spectral and spatial resolutions. From these preliminary results a very complex behavior of the ionized gas is unveiled, as has been the case for the dwarf irregulars IC1613 and NGC4449, previously studied by our group of collaborators. Further analysis is being carried out.

  3. A belt transect setting strategy for mark-recapture experiments to evaluate the 1D diffusion coefficient of beached litter in the cross-shore direction.

    PubMed

    Hinata, Hirofumi; Kataoka, Tomoya

    2016-08-15

    We propose a belt transect setting strategy for mark-recapture experiments (MREs) to evaluate the time-independent 1D diffusion coefficient (〈Dp0〉) of marine litter in the cross-shore direction that determines the backwashing flux of the litter, based on two-year MREs for plastic floats (PFs) on Wadahama Beach, Nii-jima Island, Japan. When the alongshore width of the belt transect (Lt) was of the order of, or longer than, the length scale of wave-induced nearshore current circulation (Lc), the PFs were rarely transported alongshore across the selected transects prior to being backwashed offshore. Thus, the transect residence time became longer and showed a much weaker dependence on the transect position, in contrast to when Lt was even shorter than Lc. We therefore obtained the diffusion coefficients close to the value of (〈Dp0〉) when we set Lt to the order of, or longer than, Lc. PMID:27263978

  4. Geoengineering and seismological aspects of the Niigata-Ken Chuetsu-Oki earthquake of 16 July 2007

    USGS Publications Warehouse

    Kayen, R.; Brandenberg, S.J.; CoIlins, B.D.; Dickenson, S.; Ashford, S.; Kawamata, Y.; Tanaka, Y.; Koumoto, H.; Abrahamson, N.; Cluff, L.; Tokimatsu, K.

    2009-01-01

    The M6.6 Niigata-Ken Chuetsu-Oki earthquake of 16 July 2007 occurred off the west coast of Japan with a focal depth of 10 km, immediately west of Kashiwazaki City and Kariwa Village in southern Niigata Prefecture. Peak horizontal ground accelerations of 0.68 g were measured in Kashiwazaki City, as well as at the reactor floor level of the world's largest nuclear reactor, located on the coast at Kariwa Village. Liquefaction of historic and modern river deposits, aeolian dune sand, and manmade fill was widespread in the coastal region nearest the epicenter and caused ground deformations that damaged bridges, embankments, roadways, buildings, ports, railways and utilities. Landslides along the coast of southern Niigata Prefecture and in mountainous regions inland of Kashiwazaki were also widespread affecting transportation infrastructure. Liquefaction and a landslide also damaged the nuclear power plant sites. This paper, along with a companion digital map database available at http://walrus.wr.usgs.gOv/infobank/n/nii07jp/html/n-ii-07-jp.sites.kmz, describes the seismological and geo-engineering aspects of the event. ?? 2009, Earthquake Engineering Research Institute.

  5. Production and application of chemical fibers with special properties for manufacturing composite materials and goods of different usage

    NASA Technical Reports Server (NTRS)

    Levit, R.

    1993-01-01

    The development of modern technologies demands the creation of new nonmetallic, fibrous materials with specific properties. The fibers and materials developed by NII 'Chimvolokno', St. Petersburg, can be divided into two groups. The first group includes heat-resistant fibers, fire-resistant fibers, thermotropic fibers, fibers for medical application, and textile structures. The second group contains refractory fibers, chemoresistant and antifriction fibers, fibers on the basis of polyvinyl alcohol, microfiltering films, and paperlike and nonwoven materials. In cooperation with NPO 'Chimvolokno' MYTITSHI, we developed and started producing heat-resistant high-strength fibers on the base of polyhetarearilin and aromatic polyimides (SVM and terlon); heat-resistant fibers on the base of polyemede (aramid); fire-retardant fibers (togilen); chemoresistant and antifriction fibers on the basis of homo and copolymers of polytetrafluoroethylene (polyfen and ftorin); and water soluble, acetylated, and high-modulus fibers from polyvinyl alcohol (vylen). Separate reports will deal with textile structures and thermotropic fibers, as well as with medical fibers. One of the groups of refractory fibers carbon fibers (CF) and the corresponding paperlike nonwoven materials are discussed in detail. Also, composite materials (CM) and their base, which is the subject of the author's research since 1968, is discussed.

  6. Visual Communications for Heterogeneous Networks/Visually Optimized Scalable Image Compression. Final Report for September 1, 1995 - February 28, 2002

    SciTech Connect

    Hemami, S. S.

    2003-06-03

    The authors developed image and video compression algorithms that provide scalability, reconstructibility, and network adaptivity, and developed compression and quantization strategies that are visually optimal at all bit rates. The goal of this research is to enable reliable ''universal access'' to visual communications over the National Information Infrastructure (NII). All users, regardless of their individual network connection bandwidths, qualities-of-service, or terminal capabilities, should have the ability to access still images, video clips, and multimedia information services, and to use interactive visual communications services. To do so requires special capabilities for image and video compression algorithms: scalability, reconstructibility, and network adaptivity. Scalability allows an information service to provide visual information at many rates, without requiring additional compression or storage after the stream has been compressed the first time. Reconstructibility allows reliable visual communications over an imperfect network. Network adaptivity permits real-time modification of compression parameters to adjust to changing network conditions. Furthermore, to optimize the efficiency of the compression algorithms, they should be visually optimal, where each bit expended reduces the visual distortion. Visual optimality is achieved through first extensive experimentation to quantify human sensitivity to supra-threshold compression artifacts and then incorporation of these experimental results into quantization strategies and compression algorithms.

  7. Star-forming galaxies in low-redshift clusters: comparison of integrated properties of cluster and field galaxies

    NASA Astrophysics Data System (ADS)

    Bretherton, C. F.; James, P. A.; Moss, C.; Whittle, M.

    2010-12-01

    Aims: We investigate the effect of the cluster environment on the star formation properties of galaxies in 8 nearby Abell clusters. Methods: Star formation properties are determined for individual galaxies using the equivalent width of Hα+[Nii] line emission from narrow-band imaging. Equivalent width distributions are derived for each galaxy type in each of 3 environments - cluster, supercluster (outside the cluster virial radius) and field. The effects of morphological disturbance on star formation are also investigated. Results: We identify a population of early-type disk galaxies in the cluster population with enhanced star formation compared to their field counterparts. The enhanced cluster galaxies frequently show evidence of disturbance, and the disturbed galaxies show marginal evidence for a higher velocity dispersion, possibly indicative of an infalling population. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias; and with the Jacobus Kapteyn Telescope, which was operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

  8. Physical Parameters of the Pre-WN Candidate HD326823

    NASA Astrophysics Data System (ADS)

    de Araujo, F. X.; Marcolino, W. L. F.; Borges Fernándes, M.

    2006-06-01

    HD326823 is a massive and luminous star characterized mainly by the presence of very intense HeI emission lines. From qualitative spectroscopic studies it was proposed by Lopes et al. (1992, A&A, 261, 482) and Borges Fernándes et al. (2001, ApJS, 136, 747) that this interesting object is in a pre-WN stage of evolution. In the present work we reinforce this conclusion, thanks to the estimate of its physical parameters like mass loss rate and especially chemical abundances. The data analysed by us were obtained at ESO 2.2-m telescope, with the spectrograph FEROS (R=48000) on April, 2005. The method employed to obtain the parameters is the fitting of HI, HeI and NII emission lines. In order to do this we have used the CMFGEN code, developed by J. Hilliers and colaborators (see, for instance, Hiller & Miller 1998, ApJ, 496, 407). This code is adequate for the modelling of lines produced in an expanding atmosphere and it includes important effects like line-blanketting and clumping. Preliminary results indicate a mass loss rate in the range and a clear overabundance of helium. As nitrogen abundance is concerned, it also indicates a tendency of increased abundance, but the result is not so firm in this case.

  9. Spin tuning of electron-doped metal-phthalocyanine layers.

    PubMed

    Stepanow, Sebastian; Lodi Rizzini, Alberto; Krull, Cornelius; Kavich, Jerald; Cezar, Julio C; Yakhou-Harris, Flora; Sheverdyaeva, Polina M; Moras, Paolo; Carbone, Carlo; Ceballos, Gustavo; Mugarza, Aitor; Gambardella, Pietro

    2014-04-01

    The spin state of organic-based magnets at interfaces is to a great extent determined by the organic environment and the nature of the spin-carrying metal center, which is further subject to modifications by the adsorbate-substrate coupling. Direct chemical doping offers an additional route for tailoring the electronic and magnetic characteristics of molecular magnets. Here we present a systematic investigation of the effects of alkali metal doping on the charge state and crystal field of 3d metal ions in Cu, Ni, Fe, and Mn phthalocyanine (Pc) monolayers adsorbed on Ag. Combined X-ray absorption spectroscopy and ligand field multiplet calculations show that Cu(II), Ni(II), and Fe(II) ions reduce to Cu(I), Ni(I), and Fe(I) upon alkali metal adsorption, whereas Mn maintains its formal oxidation state. The strength of the crystal field at the Ni, Fe, and Mn sites is strongly reduced upon doping. The combined effect of these changes is that the magnetic moment of high- and low-spin ions such as Cu and Ni can be entirely turned off or on, respectively, whereas the magnetic configuration of MnPc can be changed from intermediate (3/2) to high (5/2) spin. In the case of FePc a 10-fold increase of the orbital magnetic moment accompanies charge transfer and a transition to a high-spin state.

  10. Dielectric and electrophoretic properties of wax dispersions in the presence of pour depressants

    SciTech Connect

    Agaev, S.G.; Taranova, L.V.

    1987-05-01

    It appeared to be of interest to evaluate the depressant efficiency of additives on the basis of results obtained in studying electrophoretic and dielectric properties of wax-containing systems when these additives are present. The electrical properties of dispersion of a petroleum paraffin wax (mp 56/sup 0/C) in n-heptane were investigated in the presence of the commercial pour depressants PMD D (specification TU 01-270-68) (a polymethyacrylate) and AzNII (GOST (All-Union State Standard) 8443-57) (condensation product from chlorinated wax and naphthalene), and two ester-type additives synthesized in the laboratory: TyumII 79, which is bis(diacylpentarythritol 4-nitrophthalate) and TyumII 222, which is bis(diacylpentarythritol succinate). The pour depressants TyumII 79 and TyumII 222 are products obtained by condensation of C/sub 21/-C/sub 26/ synthetic fatty acids, pentaerythritol, and a dicarboxylic acid (4-nitrophthalic acid or succinic acid), with component ratio 2.1:1:1 and 2.1:1:0.55, respectively.

  11. Quasar feedback at the peak of the galaxy formation epoch

    NASA Astrophysics Data System (ADS)

    Alexandroff, Rachael; Zakamska, Nadia; Liu, Guilin; Greene, Jenny; Strauss, Michael

    2014-08-01

    Feedback from accreting supermassive black holes is now a standard ingredient in galaxy formation models. It is seen as necessary for limiting the maximal masses of galaxies and for establishing the black- hole / bulge correlations. Using Gemini GMOS, we demonstrated that powerful ionized gas winds are a ubiquitous feature in luminous obscured z=0.5 quasars. We now propose to extend this discovery to the epoch of peak galaxy formation and quasar activity - to the era at which feedback was most prominent and the galaxy / black hole correlations were established. We request 4.5 hours of Gemini-NIFS LGS adaptive- optics observations of an extremely luminous moderately obscured quasar at z=2.3 to map the morphology and kinematics of the ionized gas and to determine whether it exhibits the signs of black hole feedback in the form of an unbound ionized gas outflow. We will observe H(beta) and [OIII](lambda)5007Ain the H-band and H(alpha) and [NII](lambda)(lambda)6548,6583Ain the K-band on sub-galactic and galaxy-wide scales (spatial resolution 0.8 kpc, field of view 24 kpc). Obscured quasars likely constitute the majority of the quasar population and may represent the relatively early enshrouded phase of the black hole growth; thus, luminous obscured quasars are the most likely sites of quasar feedback, in agreement with our findings at low redshift.

  12. The federal role in the health information infrastructure: a debate of the pros and cons of government intervention.

    PubMed

    Shortliffe, E H; Bleich, H L; Caine, C G; Masys, D R; Simborg, D W

    1996-01-01

    Some observers feel that the federal government should play a more active leadership role in educating the medical community and in coordinating and encouraging a more rapid and effective implementation of clinically relevant applications of wide-area networking. Other people argue that the private sector is recognizing the importance of these issues and will, when the market demands it, adopt and enhance the telecommunications systems that are needed to produce effective uses of the National Information Infrastructure (NII) by the healthcare community. This debate identifies five areas for possible government involvement: convening groups for the development of standards; providing funding for research and development; ensuring the equitable distribution of resources, particularly to places and people considered by private enterprise to provide low opportunities for profit; protecting rights of privacy, intellectual property, and security; and overcoming the jurisdictional barriers to cooperation, particularly when states offer conflicting regulations. Arguments against government involvement include the likely emergence of an adequate infrastructure under free market forces, the often stifling effect of regulation, and the need to avoid a common-and-control mentality in an infrastructure that is best promoted collaboratively.

  13. [Frontotemporal dementia (FTD) and genetic mutations including progranulin gene].

    PubMed

    Arai, Tetsuaki; Hasegawa, Masato; Nishihara, Masugi; Nonaka, Takashi; Kametani, Fuyuki; Yoshida, Mari; Hashizume, Yoshio; Beach, Thomas G; Morita, Mitsuya; Nakano, Imaharu; Oda, Tatsuro; Tsuchiya, Kuniaki; Akiyama, Haruhiko

    2008-11-01

    Research on familial frontotemporal lobar degeneration (FTLD) has led to the discovery of disease-causing genes: microtubule-associated protein tau (MAPT), progranulin (PGRN) and valosin-containing protein (VCP). TAR DNA-binding protein of 43 kDa (TDP-43) has been identified as a major component of tau-negative ubiquitin-positive inclusions in familial and sporadic FTLD and amyotrophic lateral sclerosis (ALS), which are now referred to as TDP-43 proteinopathy. Recent findings of mutations in TDP-43 gene in familial and sporadic ALS cases confirm the pathogenetic role for TDP-43 in neurodegeneration. TDP-43 proteinopathies have been classified into 4 pathological subtypes. Type 1 is characterized by numerous dystrophic neurites (DNs), Type 2 has numerous neuronal cytoplasmic inclusions (NCIs), Type 3 has NCIs and DNs and Type 4 has neuronal intranuclear inclusions (NIIs) and DNs. There is a close relationship between such pathological subtypes of TDP-43 proteinopathy and the immunoblot pattern of C-terminal fragments of accumulated TDP-43. These results parallel our earlier findings of differing C-terminal tau fragments in progressive supranuclear palsy and corticobasal degeneration, despite identical composition of tau isoforms. Taken together, these results suggest that elucidating the mechanism of C-terminal fragment origination may shed light on the pathogenesis of several neurodegenerative disorders involving TDP-43 proteinopathy and tauopathy. PMID:19198141

  14. Chemical composition of nebulosities in the magellanic clouds.

    PubMed

    Aller, L H; Czyzak, S J; Keyes, C D; Boeshaar, G

    1974-11-01

    From photoelectric spectrophotometric data secured at Cerro Tololo Interamerican Observatory we have attempted to derive electron densities and temperatures, ionic concentrations, and chemical abundances of He, C, N, O, Ne, S, and Ar in nebulosities in the Magellanic Clouds. Although 10 distinct nebulosities were observed in the Small Cloud and 20 such objects in the Large Cloud, the most detailed observations were secured only for the brighter objects. Results for 30 Doradus are in harmony with those published previously and recent work by Peimbert and Torres-Peimbert. Nitrogen and heavier elements appear to be less abundant in the Small Cloud than in the Large Cloud, in accordance with the conclusions of Dufour. A comparison with the Orion nebula suggests He, N, Ne, O, and S may all be less abundant in the Megellanic Clouds, although adequate evaluations will require construction of detailed models. For example, if we postulate that the [NII], [OII], and [SII] radiations originate primarily in regions with electron temperatures near 8000 degrees K, while the [OIII], [NeIII], [ArIII], and H radiations are produced primarily in regions with T(epsilon) = 10,000 degrees K, the derived chemical abundances in the clouds are enhanced.

  15. Structural models of the bimetallic subunit at the A-cluster of acetyl coenzyme a synthase/CO dehydrogenase: binuclear sulfur-bridged Ni-Cu and Ni-Ni complexes and their reactions with CO.

    PubMed

    Harrop, Todd C; Olmstead, Marilyn M; Mascharak, Pradip K

    2004-11-17

    The Ni(II)-dicarboxamido-dithiolato complexes (Et4N)2[Ni(NpPepS)] (1) and (Et4N)2[Ni(PhPepS)] (2) were used as Nid metallosynthons in the construction of higher nuclearity dinuclear Ni-Cu and Ni-Ni species to model the bimetallic Mp-Nid site of the A-cluster of acetyl coenzyme A synthase/CO dehydrogenase (ACS/CODH). Reaction of 1 with [Cu(neo)Cl] and [Ni(terpy)Cl2] in MeCN affords the dinuclear complexes (Et4N)[Cu(neo)Ni(NpPepS)] (3) and [Ni(terpy)Ni(NpPepS)] (4), respectively. Reaction of 2 with [Ni(dppe)Cl2] in MeCN yields [Ni(dppe)Ni(PhPepS)] (6). The Ni-Cu complex 3 exhibits no redox chemistry at the Nid site and no reaction with CO. In contrast, the Nip sites in 4 and 6 are readily reduced (characterized by their Ni(I) EPR spectra) and bind CO, exhibiting nuco bands at 2044 and 1997 cm-1, respectively, indicating terminal CO binding. The present Ni-Ni systems replicate the structural and chemical properties of the A-cluster site in ACS/CODH and support the presence of Ni at Mp in the catalytically active enzyme.

  16. Herbal medicine (Danggui Shaoyao San) for treating primary dysmenorrhea: A systematic review and meta-analysis of randomized controlled trials.

    PubMed

    Lee, Hye Won; Jun, Ji Hee; Kil, Ki-Jung; Ko, Byong-Seob; Lee, Choong Hwan; Lee, Myeong Soo

    2016-03-01

    Danggui Shaoyao San (DSS), a traditional herbal prescription, has long been used to treat menopause-related symptoms, including dysmenorrhea. We conducted a systematic review of randomized controlled trials to evaluate the efficacy of DSS for dysmenorrhea. We searched the following electronic databases through October 2015: PubMed; EMBASE; the Cochrane Library; AMED; five Korean databases (KoreaMed, DBPIA, OASIS, RISS, and KISS); three Chinese databases (CNKI, Wan Fang Database, and VIP), and one Japanese database (CiNii). The Cochrane criteria were used to assess the risk of bias for the individual studies. All randomized clinical trials (RCTs) of DSS or modified DSS were included. Data from all articles were extracted by two independent reviewers. Meta-analysis was used to pool the data. A total of 746 potentially relevant studies were identified, and four RCTs met our inclusion criteria. All of the included RCTs had a high risk of bias across their domains. Three RCTs showed favourable effects of DSS on response rate compared with conventional medicine, and a meta-analysis showed that DSS had superior effects compared to analgesics (RR: 1.31, 95%CI, 1.06-1.63, I(2)=73%). One RCT showed a beneficial effect of DSS on pain compared with placebo control. Our systematic review and meta-analysis provided suggestive evidence of the superiority of DSS over analgesics or placebo for dysmenorrhea. The quality of evidence for this finding was low to moderate because of a high risk of bias. PMID:26857875

  17. The coordination chemistry of "[BP3]NiX" platforms: targeting low-valent nickel sources as promising candidates to L3Ni=E and L3Ni(triple bond)E linkages.

    PubMed

    MacBeth, Cora E; Thomas, J Christopher; Betley, Theodore A; Peters, Jonas C

    2004-07-26

    A series of divalent, monovalent, and zerovalent nickel complexes supported by the electron-releasing, monoanionic tris(phosphino)borate ligands [PhBP3] and [PhBPiPr3] ([PhBP3] = [PhB(CH2PPh2)3]-, [PhBPiPr3] = [PhB(CH2PiPr2)3]-) have been synthesized to explore fundamental aspects of their coordination chemistry. The pseudotetrahedral, divalent halide complexes [PhBP3]NiCl (1), [PhBP3]NiI (2), and [PhBPiPr3]NiCl (3) were prepared by the metalation of [PhBP3]Tl or [PhBPiPr3]Tl with (Ph3P)2NiCl2, NiI2, and (DME)NiCl2 (DME = 1,2-dimethoxyethane), respectively. Complex 1 is a versatile precursor to a series of complexes accessible via substitution reactions including [PhBP3]Ni(N3) (4), [PhBP3]Ni(OSiPh3) (5), [PhBP3]Ni(O-p-tBu-Ph) (6), and [PhBP3]Ni(S-p-tBu-Ph) (7). Complexes 2-5 and 7 have been characterized by X-ray diffraction (XRD) and are pseudotetrahedral monomers in the solid state. Complex 1 reacts readily with oxygen to form the four-electron-oxidation product, [[PhB(CH2POPh2)2(CH2PPh2)]NiCl] (8A or 8B), which features a solid-state structure that is dependent on its method of crystallization. Chemical reduction of 1 using Na/Hg or other potential 1-electron reductants generates a product that arises from partial ligand degradation, [PhBP3]Ni(eta2-CH2PPh2) (9). The more sterically hindered chloride 3 reacts with Li(dbabh) (Hdbabh = 2,3:5,6-dibenzo-7-azabicyclo[2.2.1]hepta-2,5-diene) to provide the three-coordinate complex [kappa2-PhBPiPr3]Ni(dbabh) (11), also characterized by XRD. Chemical reduction of complex 1 in the presence of L-type donors produces the tetrahedral Ni(I) complexes [PhBP3]Ni(PPh3) (12) and [PhBP3]Ni(CNtBu) (13). Reduction of 3 following the addition of PMe3 or tert-butyl isocyanide affords the Ni(I) complexes [PhBPiPr3]Ni(PMe3) (14) and [PhBPiPr3]Ni(CNtBu) (15), respectively. The reactivity of these [PhBP3]NiIL and [PhBPiPr3]NiIL complexes with respect to oxidative group transfer reactions from organic azides and diazoalkanes is discussed

  18. The Far Infrared Spectroscopic Explorer (FIRSPEX): probing the lifecycle of the ISM in the universe

    NASA Astrophysics Data System (ADS)

    Rigopoulou, D.; Caldwell, M.; Ellison, B.; Pearson, C.; Caux, E.; Cooray, A.; Gallego, J. D.; Gerin, M.; Goicoechea, J. R.; Goldsmith, P.; Kramer, C.; Lis, D. C.; Molinari, S.; Ossenkopf-Okada, V.; Savini, G.; Tan, B. K.; Tielens, X.; Viti, S.; Wiedner, M.; Yassin, G.

    2016-07-01

    The Far Infrared Spectroscopic Explorer (FIRSPEX) is a novel European-led astronomy mission concept developed to enable large area ultra high spectroscopic resolution surveys in the THz regime. FIRSPEX opens up a relatively unexplored spectral and spatial parameter space that will produce an enormously significant scientific legacy by focusing on the properties of the multi-phase ISM, the assembly of molecular clouds in our Galaxy and the onset of star formation; topics which are fundamental to our understanding of galaxy evolution. The mission uses a heterodyne instrument and a ~1.2 m primary antenna to scan large areas of the sky in a number of discreet spectroscopic channels from L2. The FIRSPEX bands centered at [CI] 809 GHz, [NII]1460 GHz, [CII]1900 GHz and [OI]4700 GHz have been carefully selected to target key atomic and ionic fine structure transitions difficult or impossible to access from the ground but fundamental to the study of the multi-phase ISM in the Universe. The need for state-of-the-art sensitivity dictates the use of superconducting mixers configured either as tunnel junctions or hot electron bolometers. This technology requires cooling to low temperatures, approaching 4K, in order to operate. The receivers will operate in double sideband configuration providing a total of 7 pixels on the sky. FIRSPEX will operate from L2 in both survey and pointed mode enabling velocity resolved spectroscopy of large areas of sky as well as targeted observations.

  19. Beyond telecommuting: A new paradigm for the effect of telecommunications on travel

    NASA Astrophysics Data System (ADS)

    Niles, J. S.

    1994-09-01

    Conventional wisdom about social and economic behavior holds that the use of telecommunications is a natural substitute for transportation. For example, telephone calls can replace travel to meetings, and facsimile or electronic-mail transmission of documents substitutes for courier or postal delivery. The moving of information can replace the moving of people and goods. Vehicle traffic on the national transportation infrastructure can be replaced by digital traffic on what is now called the national information infrastructure (NII). A leading example is telecommuting. This means using telecommunications to replace commuting between home and work. Telecommuting is an optional way of expanding employees' work locations in those circumstances where it yields both improved organizational performance and employee satisfaction. Telecommuting accounts for 7.6 million U.S. workers as of early 1993, up 15% from the 6.6 million counted in 1992. The growth of telecommuting has been strong for the past five years. No one has identified any reasons to suggest that this growth will abate in the forseeable future.

  20. Differential Toxicities of Nickel Salts to the Nematode Caenorhabditis elegans.

    PubMed

    Meyer, Dean; Birdsey, Jennifer M; Wendolowski, Mark A; Dobbin, Kevin K; Williams, Phillip L

    2016-08-01

    This study focused on assessing whether nickel (Ni) toxicity to the nematode Caenorhabditis elegans was affected by the molecular structure of the Ni salt used. Nematodes were exposed to seven Ni salts [Ni sulfate hexahydrate (NiSO4·6H2O), Ni chloride hexahydrate (NiCl2·6H2O), Ni acetate tetrahydrate (Ni(OCOCH3)2·4H2O), Ni nitrate hexahydrate (N2NiO6·6H2O), anhydrous Ni iodide (NiI2), Ni sulfamate hydrate (Ni(SO3NH2)2·H2O), and Ni fluoride tetrahydrate (NiF2·4H2O)] in an aquatic medium for 24 h, and lethality curves were generated and analyzed. Ni fluoride, Ni iodide, and Ni chloride were most toxic to C. elegans, followed by Ni nitrate, Ni sulfamate, Ni acetate, and Ni sulfate. The LC50 values of the halogen-containing salts were statistically different from the corresponding value of the least toxic salt, Ni sulfate. This finding is consistent with the expected high bioavailability of free Ni ions in halide solutions. We recommend that the halide salts be used in future Ni testing involving aquatic invertebrates. PMID:27278637

  1. Publicly available database for spectral line measurements of SDSS DR7 galaxies

    NASA Astrophysics Data System (ADS)

    Oh, Kyuseok; Sarzi, Marc; Schawinski, Kevin; Yi, Sukyoung K.

    2012-08-01

    We present a new database of absorption and emission-line measurements based on the Sloan Digital Sky Survey (SDSS) 7th data release of galaxies within a redshift of 0.2. Using the publicly available penalized pixel-fitting (pPXF) and gas and absorption line fitting (gandalf) codes, our work improve the existing measurements for stellar kinematics, the strength of various absorption line features, and the flux and width of the emissions from different species of ionised gas. Most notable of our work is that, we provide quality of the fit to assess reliability of the measurements. The quality assessment can be highly effective for finding new classes of objects. For example, based on the quality assessment around the Ha and [NII] nebular lines, we found approximately 1% of the SDSS spectra which classified as galaxies by the SDSS pipeline are in fact type I Seyfert AGN. This paper presents a summary of the recent paper, Oh et al.(2011). The database is publicly available at http://gem.yonsei.ac.kr/ossy/.

  2. National Information Infrastructure Education Forum: A summary report

    SciTech Connect

    Tonn, B.E.; Oliver, C.E.

    1994-05-01

    The National Information Infrastructure (NII) Education Forum was held on October 6-8, 1993, in Arlington, Virginia. The Forum was sponsored by the Office of Scientific Computing, U.S. Department of Energy (DOE). Its purpose was to discuss technology for K-12 education and what role DOE and its national laboratories could play in developing, disseminating, and using technology for K-12. The Forum brought together over 120 people from across the nation. Participants represented six groups: national laboratories; education research institutions; K-12 teachers and administrators; industry; federal agencies; and other institutions. The Forum consisted of a series of structured presentations from each of these six groups; technology demonstrations; and open, small group discussions. The presentations covered the following: important K-12 education and computing issues, national laboratory capabilities, other federal sector initiatives, and industry perspectives. The demonstration room had over 20 computers networked to the Internet. Workshop participants were shown (1) how to use the Internet to access resources anywhere in the world, (2) state-of-the-art network video teleconferencing technology, (3) multi-media technology, and (4) various other educational software systems.

  3. OT2_anoriega_2: SABER: Spectral Analysis of the Bowshock Emission in a Runaway

    NASA Astrophysics Data System (ADS)

    Noriega-Crespo, A.

    2011-09-01

    Bowshocks around runaway OB stars are some of the most spectacular objects in the mid/far infrared, covering in some cases as much as half a degree across the sky. The bowshocks are essentially enormous gas shells contained by ram pressure where the dust trapped in their interiors reprocesses the UV flux from the parent OB stars and re-radiates it in the infrared. The pressure balance between the stellar wind and the ISM, also implies a tight relationship between their physical properties, and therefore, bowshocks from runaway stars provide a powerful tool to probe the interstellar medium and/or the properties of the OB stellar wind. The formation of these shells requires very efficient cooling that is expected to take place through the emission of a wealth of atomic fine structure lines, like [OI] 63.2 or [NII] 205.2 micron. Because the diffuse nature of these shells it has been very difficult to confirm this expectation using spectroscopic observations. In this project we propose to use the PACS spectrometer to observe the zeta Oph bowshock in order to better understand and constrain the physical conditions of its gas shell, its dust properties, its turbulence, and in such a way that will allow to use zeta Oph as a template to make sense of the physical properties of the many more runaway bowshocks are continuously being discovered.

  4. The federal role in the health information infrastructure: a debate of the pros and cons of government intervention.

    PubMed Central

    Shortliffe, E H; Bleich, H L; Caine, C G; Masys, D R; Simborg, D W

    1996-01-01

    Some observers feel that the federal government should play a more active leadership role in educating the medical community and in coordinating and encouraging a more rapid and effective implementation of clinically relevant applications of wide-area networking. Other people argue that the private sector is recognizing the importance of these issues and will, when the market demands it, adopt and enhance the telecommunications systems that are needed to produce effective uses of the National Information Infrastructure (NII) by the healthcare community. This debate identifies five areas for possible government involvement: convening groups for the development of standards; providing funding for research and development; ensuring the equitable distribution of resources, particularly to places and people considered by private enterprise to provide low opportunities for profit; protecting rights of privacy, intellectual property, and security; and overcoming the jurisdictional barriers to cooperation, particularly when states offer conflicting regulations. Arguments against government involvement include the likely emergence of an adequate infrastructure under free market forces, the often stifling effect of regulation, and the need to avoid a common-and-control mentality in an infrastructure that is best promoted collaboratively. PMID:8816347

  5. Sharing lattice QCD data over a widely distributed file system

    NASA Astrophysics Data System (ADS)

    Amagasa, T.; Aoki, S.; Aoki, Y.; Aoyama, T.; Doi, T.; Fukumura, K.; Ishii, N.; Ishikawa, K.-I.; Jitsumoto, H.; Kamano, H.; Konno, Y.; Matsufuru, H.; Mikami, Y.; Miura, K.; Sato, M.; Takeda, S.; Tatebe, O.; Togawa, H.; Ukawa, A.; Ukita, N.; Watanabe, Y.; Yamazaki, T.; Yoshie, T.

    2015-12-01

    JLDG is a data-grid for the lattice QCD (LQCD) community in Japan. Several large research groups in Japan have been working on lattice QCD simulations using supercomputers distributed over distant sites. The JLDG provides such collaborations with an efficient method of data management and sharing. File servers installed on 9 sites are connected to the NII SINET VPN and are bound into a single file system with the GFarm. The file system looks the same from any sites, so that users can do analyses on a supercomputer on a site, using data generated and stored in the JLDG at a different site. We present a brief description of hardware and software of the JLDG, including a recently developed subsystem for cooperating with the HPCI shared storage, and report performance and statistics of the JLDG. As of April 2015, 15 research groups (61 users) store their daily research data of 4.7PB including replica and 68 million files in total. Number of publications for works which used the JLDG is 98. The large number of publications and recent rapid increase of disk usage convince us that the JLDG has grown up into a useful infrastructure for LQCD community in Japan.

  6. Discovery in IC10 of the farthest known symbiotic star

    NASA Astrophysics Data System (ADS)

    Gonçalves, Denise R.; Magrini, Laura; Munari, Ulisse; Corradi, Romano L. M.; Costa, Roberto D. D.

    2008-11-01

    We report the discovery of the first known symbiotic star in IC10, a starburst galaxy belonging to the Local Group, at a distance of ~750 kpc. The symbiotic star was identified during a survey of emission-line objects. It shines at V = 24.62 +/- 0.04,V - RC = 2.77 +/- 0.05 and RC - IC = 2.39 +/- 0.02, and suffers from EB- V = 0.85 +/- 0.05 reddening. The spectrum of the cool component well matches that of solar neighbourhood M8III giants. The observed emission lines belong to Balmer series, [SII], [NII] and [OIII]. They suggest a low electronic density, negligible optical depth effects and 35000 < Teff < 90000 K for the ionizing source. The spectrum of the new symbiotic star in IC10 is an almost perfect copy of that of Hen 2-147, a well-known Galactic symbiotic star and Mira. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership. We also retrieved UBVRI images of the `Survey of Local Group Galaxies Currently Forming Stars', Massey et al. (2007). E-mail: denise@ov.ufrj.br

  7. Cognitive Behavioral Therapy in Psychiatric Nursing in Japan

    PubMed Central

    Yoshinaga, Naoki; Nosaki, Akiko; Hayashi, Yuta; Tanoue, Hiroki; Shimizu, Eiji; Kunikata, Hiroko; Okada, Yoshie; Shiraishi, Yuko

    2015-01-01

    Psychiatric nurses have played a significant role in disseminating cognitive behavioral therapy (CBT) in Western countries; however, in Japan, the application, practice, efficiency, and quality control of CBT in the psychiatric nursing field are unclear. This study conducted a literature review to assess the current status of CBT practice and research in psychiatric nursing in Japan. Three English databases (MEDLINE, CINAHL, and PsycINFO) and two Japanese databases (Ichushi-Web and CiNii) were searched with predetermined keywords. Fifty-five articles met eligibility criteria: 46 case studies and 9 comparative studies. It was found that CBT took place primarily in inpatient settings and targeted schizophrenia and mood disorders. Although there were only a few comparative studies, each concluded that CBT was effective. However, CBT recipients and outcome measures were diverse, and nurses were not the only CBT practitioners in most reports. Only a few articles included the description of CBT training and supervision. This literature review clarified the current status of CBT in psychiatric nursing in Japan and identified important implications for future practice and research: performing CBT in a variety of settings and for a wide range of psychiatric disorders, conducting randomized controlled trials, and establishing pre- and postqualification training system. PMID:26798512

  8. Analysis of a beach as a time-invariant linear input/output system of marine litter.

    PubMed

    Kataoka, Tomoya; Hinata, Hirofumi; Kato, Shigeru

    2013-12-15

    The exponential decay of the amount of new litter on Wadahama Beach, Nii-jima Island, Japan revealed by 20-month mark-recapture experiments demonstrates a linear response of the beach to the input of target items. Here we show the amplitude and phase characteristics of the beach as a time-invariant linear input/output system and discuss the hydrodynamic and geomorphological factors that would determine the characteristics with the aid of a diffusion equation. The characteristics are fully determined by the residence time of the items (τ(r)=209 days) and can be described as functions of the ratio of τ(r) to the period of input variability. The decay is reproduced well by the analytical solution of the equation with a constant diffusion coefficient (D), whose order was estimated by τ(r) and the backshore width. Generally, D would depend on hydrodynamical statistics and beach geomorphology as well as the dimensions and density of the items. PMID:24143956

  9. National Security Science and Technology Initiative: Air Cargo Screening, Final Report for CRADA Number NFE-07-01081

    SciTech Connect

    Bingham, Philip; Bush, John; Bowerman, Biays; Cespedes, Ernesto; White, Timothy

    2004-12-01

    The non-intrusive inspection (NII) of consolidated air cargo carried on commercial passenger aircraft continues to be a technically challenging, high-priority requirement of the Department of Homeland Security’s Science and Technology Directorate (DHS S&T), the Transportation Security Agency and the Federal Aviation Administration. The goal of deploying a screening system that can reliably and cost-effectively detect explosive threats in consolidated cargo without adversely affecting the flow of commerce will require significant technical advances that will take years to develop. To address this critical National Security need, the Battelle Memorial Institute (Battelle), under a Cooperative Research and Development Agreement (CRADA) with four of its associated US Department of Energy (DOE) National Laboratories (Oak Ridge, Pacific Northwest, Idaho, and Brookhaven), conducted a research and development initiative focused on identifying, evaluating, and integrating technologies for screening consolidated air cargo for the presence of explosive threats. Battelle invested $8.5M of internal research and development funds during fiscal years 2007 through 2009.

  10. Analysis of a beach as a time-invariant linear input/output system of marine litter.

    PubMed

    Kataoka, Tomoya; Hinata, Hirofumi; Kato, Shigeru

    2013-12-15

    The exponential decay of the amount of new litter on Wadahama Beach, Nii-jima Island, Japan revealed by 20-month mark-recapture experiments demonstrates a linear response of the beach to the input of target items. Here we show the amplitude and phase characteristics of the beach as a time-invariant linear input/output system and discuss the hydrodynamic and geomorphological factors that would determine the characteristics with the aid of a diffusion equation. The characteristics are fully determined by the residence time of the items (τ(r)=209 days) and can be described as functions of the ratio of τ(r) to the period of input variability. The decay is reproduced well by the analytical solution of the equation with a constant diffusion coefficient (D), whose order was estimated by τ(r) and the backshore width. Generally, D would depend on hydrodynamical statistics and beach geomorphology as well as the dimensions and density of the items.

  11. Hot Post-AGB Stars

    NASA Astrophysics Data System (ADS)

    Parthasarathy, M.; Gauba, G.; Fujii, T.; Nakada, Y.

    2001-08-01

    From the study of IRAS sources with far-IR colors similar to planetary nebulae (PNe), several proto-planetary nebulae with hot (OB) post-AGB central stars have been detected. These stars form an evolutionary link between the cooler G,F,A supergiant stars that have evolved off the Asymptotic Giant Branch (AGB) and the hot (OB) central stars of PNe. The optical spectra of these objects show strong Balmer emission lines and in some cases low excitation nebular emission lines such as [NII] and [SII] superposed on the OB stellar continuum. The absence of of [OIII] 5007Å line and the presence of low excitation nebular emission lines indicate that photoionisation has just started. The UV(IUE) spectra of some of these objects revealed violet shifted stellar wind P-Cygni profiles of CIV, SiIV and NV, indicating hot and fast stellar wind and post-AGB mass loss. These objects appear to be rapildy evolving into the early stages of PNe similar to that observed in the case of Hen1357 IRAS 17119-5926 (Stingray Nebula) and IRAS 18062+2410 SAO85766.

  12. novPTMenzy: a database for enzymes involved in novel post-translational modifications.

    PubMed

    Khater, Shradha; Mohanty, Debasisa

    2015-01-01

    With the recent discoveries of novel post-translational modifications (PTMs) which play important roles in signaling and biosynthetic pathways, identification of such PTM catalyzing enzymes by genome mining has been an area of major interest. Unlike well-known PTMs like phosphorylation, glycosylation, SUMOylation, no bioinformatics resources are available for enzymes associated with novel and unusual PTMs. Therefore, we have developed the novPTMenzy database which catalogs information on the sequence, structure, active site and genomic neighborhood of experimentally characterized enzymes involved in five novel PTMs, namely AMPylation, Eliminylation, Sulfation, Hydroxylation and Deamidation. Based on a comprehensive analysis of the sequence and structural features of these known PTM catalyzing enzymes, we have created Hidden Markov Model profiles for the identification of similar PTM catalyzing enzymatic domains in genomic sequences. We have also created predictive rules for grouping them into functional subfamilies and deciphering their mechanistic details by structure-based analysis of their active site pockets. These analytical modules have been made available as user friendly search interfaces of novPTMenzy database. It also has a specialized analysis interface for some PTMs like AMPylation and Eliminylation. The novPTMenzy database is a unique resource that can aid in discovery of unusual PTM catalyzing enzymes in newly sequenced genomes. Database URL: http://www.nii.ac.in/novptmenzy.html

  13. Defining information security education, training, and awareness needs using electronic meeting space

    NASA Astrophysics Data System (ADS)

    Schou, Corey D.; Frost, James; Wingert, Nathan; Maconachy, W. V.

    1999-01-01

    The United States is at target. For those of us who grew up curing the cold war this is not news; however, the threat is different than it has been in the past. Now it may be another super power or it may be a teenage child with a personal computer. Both government and civilian entities are potential targets. The national information infrastructure (NII) is the real target. The determined hacker can bring down not only government systems, but the power-grid, the financial system, or the air traffic control system as well. All organizations must be aware of the threat and be prepared to react appropriately. Of course, the federal government has begun to protect their critical systems. However, many American corporations have not yet fully protected their systems. Since there is a common threat, common standards for countermeasures are applicable. This paper reports on the use of an electronic meeting room technology by government, industry, and academia to establish a national training standard. If you are a CIO or advise one about security matters, these standards are important.

  14. Control of spoilage fungi by protective lactic acid bacteria displaying probiotic properties.

    PubMed

    Varsha, Kontham Kulangara; Priya, Sulochana; Devendra, Leena; Nampoothiri, Kesavan Madhavan

    2014-04-01

    Thirty-six lactic acid bacteria belong to Lactococcus, Lactobacillus, Enterococcus, and Pediococcus were isolated, and the spectrum of antifungal activity was verified against Fusarium oxysporum (KACC 42109), Aspergillus niger (KACC 42589), Fusarium moniliforme (KACC 08141), Penicillium chrysogenum (NII 08137), and the yeast Candida albicans (MTCC 3017). Three isolates, identified as Pediococcus pentosaceus (TG2), Lactobacillus casei (DY2), and Lactococcus (BSN) were selected further, and their antifungal compounds were identified by ESI-MS and HPLC analysis as a range of carboxylic acids along with some unidentified, higher molecular weight compounds. An attempt to check out the shelf life extension of wheat bread without fungal spoilage was performed by fermenting the dough with the Lactococcus isolate. Apart from growth in low pH and tolerance to bile salts, probiotic potential of these three isolates was further substantiated by in vitro screening methods that include transit tolerance to the conditions in the upper human gastrointestinal tract and bacterial adhesion capacity to human intestinal cell lines.

  15. Curva de rotación de la Galaxia Eso 321-25

    NASA Astrophysics Data System (ADS)

    Díaz, R.; Carranza, G.; Ahumada, J.; Arreguine, V.

    Se presenta la curva de rotación de esta galaxia, generada a partir de espectros obtenidos con el Espectrógrafo Multifunción del telescopio de 1.54 m de Bosque Alegre. El análisis de las curvas de velocidad radial obtenidas muestra que el núcleo no coincide con el centro de simetría de las mismas, lo que es consistente con el aspecto morfológico exhibido por la galaxia en imágenes de banda ancha. En estas últimas, el núcleo muestra una estructura peculiar y no coincidiría con el centro geométrico del disco aparente. Los flujos relativos de líneas (Hα /[NII]λ 6583 y [SII]λ 6731/λ 6716) indicarían niveles de excitación y densidad electrónica normales en regiones HII, aún en la zona nuclear. Este trabajo forma parte de un programa de estudio de cinemática, excitación y densidad electrónica del gas ionizado en galaxias peculiares del Atlas de Galaxias Australes de Sérsic.

  16. Magnetic and structural phase transitions of multiferroic boracites M3B7O13X (M =3 d transition metal Cr-Zn or Mg; X =halogen Cl, Br, I)

    NASA Astrophysics Data System (ADS)

    Schnelle, Walter; Schmid, Hans

    2015-05-01

    The specific heat capacity of mostly single-crystalline samples of 21 boracite compounds M3B7O13X with M a 3 d transition metal (Cr, Mn, Fe, Co, Ni, Cu, Zn) or Mg and X a halogen (Cl, Br, I) is determined. In combination with magnetic susceptibility data the magnetic ordering of the M2 + ions at TN is investigated in detail. The fully ferroelectric/fully ferroelastic structural phase transitions at higher temperatures are measured by differential scanning calorimetry. In the Cr-Br, Cr-I, Cu-Cl, and Cu-Br compounds, previously unknown magnetic phases were found. Magnetic order in the boracites is characterized by the quantum and classical spin states of the M2 + ions, a variable degree of structural distortion, orbital effects, and competing exchange interactions. The Cu-Cl, Cu-Br, and Ni-Cl boracites exhibit broad maxima of magnetic specific heat and of magnetic susceptibility above TN caused by low-dimensional or frustrated magnetic interactions. Co boracites display additional broad anomalies below TN originating from continuous spin reorientations and effective S =1 /2 ground states. Indications for spin reorientations are also observed for Fe boracites. New phases appear in high magnetic fields for some Co and Fe boracites, which is not the case for the Mn compounds. Stronger magnetic frustration is deduced for the cubic Cr compounds. For the latter compounds and Ni-I boracite magnetostructural phase transitions are observed.

  17. Acupuncture for treating sciatica: a systematic review protocol

    PubMed Central

    Qin, Zongshi; Liu, Xiaoxu; Yao, Qin; Zhai, Yanbing; Liu, Zhishun

    2015-01-01

    Introduction This systematic review aims to assess the effectiveness and safety of acupuncture for treating sciatica. Methods The following nine databases will be searched from their inception to 30 October 2014: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the Chinese Biomedical Literature Database (CBM), the Chinese Medical Current Content (CMCC), the Chinese Scientific Journal Database (VIP database), the Wan-Fang Database, the China National Knowledge Infrastructure (CNKI) and Citation Information by National Institute of Informatics (CiNii). Randomised controlled trials (RCTs) of acupuncture for sciatica in English, Chinese or Japanese without restriction of publication status will be included. Two researchers will independently undertake study selection, extraction of data and assessment of study quality. Meta-analysis will be conducted after screening of studies. Data will be analysed using risk ratio for dichotomous data, and standardised mean difference or weighted mean difference for continuous data. Dissemination This systematic review will be disseminated electronically through a peer-reviewed publication or conference presentations. Trial registration number PROSPERO CRD42014015001. PMID:25922105

  18. Dust In Hell: Discovery Of Dust In Hot Gas Around Group-Centered Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Temi, Pasquale; Brighenti, F.; Mathews, W. G.

    2007-05-01

    Observations with the Spitzer infrared telescope reveal extended internally produced dust in the hot gas (KT 1 KeV) atmospheres surrounding two optically normal galaxies, NGC 5044 and NGC 4636. We interpret this as a dusty buoyant outflow resulting from energy released by gas accretion onto supermassive black holes in the galaxy cores. Both galaxies have highly disturbed, transient activities in the hot gas and contain strong dust emission at 70 and 160 microns in excess of what expected from normal stellar mass loss. The 70 micron image is clearly extended. The lifetime of dust in hot (KT=1KeV) interstellar gas to destruction by sputtering (ion impacts), 10 million years, establishes the time when the dust first entered the hot gas. Remarkably, in NGC 5044 we observe interstellar PAH dust-molecular emission at 8 microns out to about 5 Kpc that is spatially coincident with extended Halpha+[NII] emission from warm gas. We propose that this dust comes from the destruction and heating of dusty disks in the nuclei of these galaxies, followed by buoyant transport. A simple calculation shows that dust-assisted cooling in outflowing buoyant gas in NGC 5044 can cool the gas within a few Kpc in about 10 million years, explaining the optical line emission observed.

  19. Long-Slit Spectroscopy of Parsec-Scale Jets from DG Tauri

    NASA Astrophysics Data System (ADS)

    Oh, Heeyoung; Pyo, Tae-Soo; Yuk, In-Soo; Park, Byeong-Gon

    2015-04-01

    We present the observational results from optical long-slit spectroscopy of parsec-scale jets of DG Tau. From HH 158 and HH 702, the optical emission lines of Hα, OI λλ6300, 6363, NII λλ6548, 6584, and SII λλ6716, 6731 were obtained. The kinematics and physical properties (electron density, electron temperature, ionization fraction, and mass-loss rate) are investigated along the blueshifted jet up to 650 arcsec distance from the source. For the HH 158, the radial velocity range is -50 to -250 km s^{-1}. The proper motion of knots is 0.196 - 0.272 arcsec yr^{-1}. The electron density is ˜10^{4} cm^{-3} close to the star and decreases to ˜10^{2} cm^{-3} at 14 arcsec away from the star. Ionization fraction indicates that the gas is almost neutral in the vicinity of the source. It increases up to over 0.4 along the distance. The HH 702 is located at 650 arcsec from the source. It shows ˜ -80 km s^{-1} in the radial velccity. Its line ratios are similar to those at knot C of HH 158. The mass-loss rate is estimated about ˜ 10^{-7} M_{⊙} yr^{-1}, which is similar with the values from previous studies.

  20. Propiedades físicas del gas en regiones de formación estelar multiples en galaxias BCDs: IIZw33 y Mrk600

    NASA Astrophysics Data System (ADS)

    Campuzano-Castro, F.; Hagele, G.; Cardaci, M.; Bosch, G.; Firpo, V.

    2015-08-01

    In this work we perform a detailed analysis of the spectra of the ionized gas belonging to 9 giant HII regions with violent star formation in two Blue Compact Dwarf galaxies. We have measured a large number of recombination and forbidden lines taking into account the underlying stellar population (defining a pseudo continuum for the hydrogen and helium emission lines). The physical properties of the gas have been estimated using the methodology proposed by our group. For the star forming knots, depending on the data available, we derived: (i) the reddening constant from the hydrogen recombination lines in all the regions, (ii) the electron density in the low excitation zone from the sulphur once ionized [SII]6717 and 6731 emission lines ratio, (iii) the electron temperatures using the auroral lines present in the spectra of several of our regions and applying the direct method or empirical relations and photo ionization models: T([OII]), T([OIII]), T([SII]), T([SIII])], and T([NII]) depending on the quality of the spectra, (iv) ionic abundances of He, O, O, S, S, N, Ne, Ar and Ar in most of the knots, except the last one that could only be measured for one object, (v) the total chemical abundances of O, S, N, Ne and Ar, (vi) the ionization degree from the softness parameter .

  1. Measurement of Water Distribution in through-plane Direction in a PEFC using a Neutron Image Intensifier

    NASA Astrophysics Data System (ADS)

    Sugimoto, K.; Murakawa, H.; Miyata, K.; Asano, H.; Takenaka, N.; Yasuda, R.

    Hydrogen gas and air are supplied to a polymer electrolyte fuel cell (PEFC). The air and the hydrogen form water and condensation may occur in the cathode side. The generated water may affect the fuel cell performance because of blocking the oxygen from reaching cathode reaction area. An imaging system with a neutron image intensifier (NII) was used for visualizing the water behaviour in the PEFC. The water distributions in the proton exchange membrane (PEM) and the gas diffusion layers (GDL) were measured by the imaging system. Visualization experiments were performed during the PEFC operation in order to clarify the water distributions in the experiments with different utilization. The generated water was discharged into the channel after the amount of water thickness in the GDL increased to a certain value of about 600 μm in thickness in the through-plane direction. The discharged water formed water drops in the channel. The effects of the water drops in the channel on the fuel cell performance could be observed clearly. It was shown that the cell voltage increased when the water was evacuated.

  2. Beyond telecommuting: A new paradigm for the effect of telecommunications on travel

    SciTech Connect

    Niles, J.S.

    1994-09-01

    Conventional wisdom about social and economic behavior holds that the use of telecommunications is a natural substitute for transportation. For example, telephone calls can replace travel to meetings, and facsimile or electronic-mail transmission of documents substitutes for courier or postal delivery. The moving of information can replace the moving of period and goods. Vehicle traffic on the national transportation infrastructure can be replaced by digital traffic on what is now called the National Information Infrastructure (NII). A leading example is telecommuting. This means using telecommunications to replace commuting between home and work. Telecommuting is an optional way of expanding employees` work locations in those circumstances where it yields both improved organizational performance and employee satisfication. Telecommuting accounts for 7.6 million U.S. workers as of early 1993, up 15% from the 6.6 million counted in 1992. The growth of telecommuting has been strong for the past five years. No one has identified any reasons to suggest that this growth will abate in the forseeable future.

  3. Medium-resolution studies of extreme ultraviolet emission from N2 by electron impact - Vibrational perturbations and cross sections of the c4-prime 1Sigma(+)u and b-prime 1Sigma(+)u states

    NASA Technical Reports Server (NTRS)

    Ajello, Joseph M.; James, Geoffrey K.; Franklin, Brian O.; Shemansky, Donald E.

    1989-01-01

    In a crossed-beam experiment the electron-impact-induced fluorescence spectrum of N2 in the extreme ultraviolet is studied at a spectral resolution of up to 0.03 nm. The optically thin experiment obtained the highest-resolution electron-impact emission spectrum of the Rydberg and valence states of N2. The spectral measurements provide the emission cross sections of each of the vibrational transitions of the Carroll-Yoshino and the Birge-Hopfield-II band systems. Laboratory vibrational-excitation cross sections arising from the mutual perturbation of the c4-prime 1Sigma(+)u and b-prime 1Sigma(+)u states by homogeneous configuration interactions are measured from 10 to 400 eV, and a modified Born approximation analytic model is given for them. The analysis leads to accurate band-system oscillator strengths. The relative emission and excitation cross sections each of the vibrational levels are compared. In addition, low-resolution measurements of the cross section of the atomic dissociation fragments (NI, NII, NIII) from 40 to 102 nm are made, and medium-resolution measurements are made of the emission cross section of the c4 1Pi(u), c5-prime 1Sigma(+)u, c5 1Pi(u), and c6-prime 1Sigma(+)u to X 1Sigma(+)g (0,0) transitions.

  4. Spectrophotometric study in the near-IR of a sample of H alpha-selected galaxies with active star formation at z = 0.84

    NASA Astrophysics Data System (ADS)

    Sánchez de Miguel, A.; Gallego, J.; Villar, V.; Zamorano, J.; Acosta, J.; Pérez-Gonzalez, P. G.; Barro, G.

    2011-11-01

    In this work we present the results of the spectroscopic analysis in the near-infrared J band of a sample of 48 star forming galaxies at z = 0.84. Half of the sample was selected by a narrow-band filter tuned to Hα at that redshift and the other half was selected by photometric redshifts at the same redshift. We provide Hα luminosities and star formation rates for all galaxies at that redshift. We were able to estimate metallicities from [NII]6584 Å for a sub sample of eight galaxies, two of the galaxies were from neckband selection. To analyze their physical properties we have computed their sizes, colors, stellar masses, extinctions and other parameters available in literature and in the Rainbow database. In particular the dependence of the stellar mass with the specific star formation rate and metallicity have been studied and compared with the results of other samples of galaxies at several redshifts. For a fixed mass, the metallicities of our galaxies are compatible than those similar at the local Universe, although with higher dispersion. This fact implies that selection in Hα is less biased than a selection in UV, since it includes galaxies with more evolved populations besides objects dominated by star formation. The comparison of the observed properties with models of evolution leads us to think that z = 0.8 star-forming galaxies have already undergone significant changes and begin to developed in a more passive way.

  5. Broadband Satellite Technologies and Markets Assessed

    NASA Technical Reports Server (NTRS)

    Wallett, Thomas M.

    1999-01-01

    The current usage of broadband (data rate greater than 64 kilobits per second (kbs)) for multimedia network computer applications is increasing, and the need for network communications technologies and systems to support this use is also growing. Satellite technology will likely be an important part of the National Information Infrastructure (NII) and the Global Information Infrastructure (GII) in the next decade. Several candidate communications technologies that may be used to carry a portion of the increased data traffic have been reviewed, and estimates of the future demand for satellite capacity have been made. A study was conducted by the NASA Lewis Research Center to assess the satellite addressable markets for broadband applications. This study effort included four specific milestones: (1) assess the changing nature of broadband applications and their usage, (2) assess broadband satellite and terrestrial technologies, (3) estimate the size of the global satellite addressable market from 2000 to 2010, and (4) identify how the impact of future technology developments could increase the utility of satellite-based transport to serve this market.

  6. Reflight of the Stratospheric TeraHertz Observatory: STO-2

    NASA Astrophysics Data System (ADS)

    Stark, Antony

    This is the Lead Proposal for the "Reflight of the Stratospheric TeraHertz Observatory: STO-2". STO-2 will address a key problem in modern astrophysics, understanding the Life Cycle of the Interstellar Medium (ISM). STO-2 will survey approximately 1/4 of the Southern Galactic plane in the dominant interstellar cooling line [CII] (158 μm) and the important star formation tracer [NII] (205 μm). With ~1 arcminute angular resolution, STO-2 will spatially resolve atomic, ionic and molecular clouds out to 10 kpc. Taking advantage of its enhanced, extended lifetime cryogenic receivers, the STO-2 survey will be conducted at unparalleled sensitivity levels. STO- 2 will uniquely probe the pivotal formative and disruptive stages in the life cycle of interstellar clouds and the relationship between global star formation rates and the properties of the ISM. Combined with previous HI and CO surveys, STO-2 will create 3-dimensional maps of the structure, dynamics, turbulence, energy balance, and pressure of the Milky Way's ISM, as well as the star formation rate. Once we gain an understanding of the relationship between ISM properties and star formation in the Milky Way, we can better interpret observations of nearby galaxies and the distant universe. The mission goals for these surveys are to: 1) Determine the life cycle of Galactic interstellar gas, 2) Study the creation and disruption of star-forming clouds in the Galaxy, 3) Determine the parameters that affect the star formation rate in the galaxy, and 4) Provide templates for star formation and stellar/interstellar feedback in other galaxies. STO-2 will re-use the 80cm telescope, gondola, and subsystems from STO-1. For the STO-2 flight, STO-1 s high spectral resolution (<1 km/s) heterodyne receiver system will be upgraded for extended cryogenic lifetime, enhanced sensitivity, and greater reliability. The flight receiver has eight, cryogenic HEB mixers; four optimized for the [CII] line and four for the [NII] line. STO-2

  7. Reflight of the Stratospheric TeraHertz Observatory: STO-2

    NASA Astrophysics Data System (ADS)

    Hollenbach, David

    This is the Lead Proposal for the "Reflight of the Stratospheric TeraHertz Observatory: STO-2". STO-2 will address a key problem in modern astrophysics, understanding the Life Cycle of the Interstellar Medium (ISM). STO-2 will survey approximately 1&/ of the Southern Galactic plane in the dominant interstellar cooling line [CII] (158 μm) and the important star formation tracer [NII] (205 μm). With ~1 arcminute angular resolution, STO-2 will spatially resolve atomic, ionic and molecular clouds out to 10 kpc. Taking advantage of its enhanced, extended lifetime cryogenic receivers, the STO-2 survey will be conducted at unparalleled sensitivity levels. STO- 2 will uniquely probe the pivotal formative and disruptive stages in the life cycle of interstellar clouds and the relationship between global star formation rates and the properties of the ISM. Combined with previous HI and CO surveys, STO-2 will create 3-dimensional maps of the structure, dynamics, turbulence, energy balance, and pressure of the Milky Way's ISM, as well as the star formation rate. Once we gain an understanding of the relationship between ISM properties and star formation in the Milky Way, we can better interpret observations of nearby galaxies and the distant universe. The mission goals for these surveys are to: 1) Determine the life cycle of Galactic interstellar gas, 2) Study the creation and disruption of star-forming clouds in the Galaxy, 3) Determine the parameters that affect the star formation rate in the galaxy, and 4) Provide templates for star formation and stellar/interstellar feedback in other galaxies. STO-2 will re-use the 80cm telescope, gondola, and subsystems from STO-1. For the STO-2 flight, STO-1 s high spectral resolution (<1 km/s) heterodyne receiver system will be upgraded for extended cryogenic lifetime, enhanced sensitivity, and greater reliability. The flight receiver has eight, cryogenic HEB mixers; four optimized for the [CII] line and four for the [NII] line. STO-2

  8. Insights into gas heating and cooling in the disc of NGC 891 from Herschel far-infrared spectroscopy⋆⋆⋆

    NASA Astrophysics Data System (ADS)

    Hughes, T. M.; Foyle, K.; Schirm, M. R. P.; Parkin, T. J.; De Looze, I.; Wilson, C. D.; Bendo, G. J.; Baes, M.; Fritz, J.; Boselli, A.; Cooray, A.; Cormier, D.; Karczewski, O. Ł.; Lebouteiller, V.; Lu, N.; Madden, S. C.; Spinoglio, L.; Viaene, S.

    2015-03-01

    We present Herschel PACS and SPIRE spectroscopy of the most important far-infrared cooling lines in the nearby, edge-on spiral galaxy, NGC 891: [Cii] 158 μm, [Nii] 122, 205 μm, [Oi] 63, 145 μm, and [Oiii] 88 μm. We find that the photoelectric heating efficiency of the gas, traced via the ([Cii]+[Oi]63)/FTIR ratio, varies from a mean of 3.5 × 10-3 in the centre up to 8 × 10-3 at increasing radial and vertical distances in the disc. A decrease in ([Cii]+[Oi]63)/FTIR but constant ([Cii]+[Oi]63)/FPAH with increasing FIR colour suggests that polycyclic aromatic hydrocarbons (PAHs) may become important for gas heating in the central regions. We compare the observed flux of the FIR cooling lines and total IR emission with the predicted flux from a PDR model to determine the gas density, surface temperature and the strength of the incident far-ultraviolet (FUV) radiation field, G0. Resolving details on physical scales of ~0.6 kpc, a pixel-by-pixel analysis reveals that the majority of the PDRs in NGC 891's disc have hydrogen densities of 1 < log (n/ cm-3) < 3.5 experiencing an incident FUV radiation field with strengths of 1.7 < log G0< 3. Although these values we derive for most of the disc are consistent with the gas properties found in PDRs in the spiral arms and inter-arm regions of M 51, observed radial trends in n and G0 are shown to be sensitive to varying optical thickness in the lines, demonstrating the importance of accurately accounting for optical depth effects when interpreting observations of high inclination systems. Increasing the coverage of our analysis by using an empirical relationship between the MIPS 24 μm and [Nii] 205 μm emission, we estimate an enhancement of the FUV radiation field strength in the far north-eastern side of the disc relative to the rest of the disc that coincides with the above-average star formation rate surface densities and gas-to-dust ratios. However, an accurate interpretation remains difficult due to optical depth

  9. Nature of the crust-mantle transition layer during the crustal growth along the Izu-Bonin island arc deduced from the seismic amplitude modeling

    NASA Astrophysics Data System (ADS)

    Sato, T.; Kodaira, S.; Takahashi, N.; Miura, S.; Kaneda, Y.

    2008-12-01

    by a finite difference wave propagation program code (Larsen and Grieger, 1998). Along this island arc, the top of this transition layer has a velocity contrast value of about 0.4 km/s from Kurose hall to Kaitoku Seamount, except for the area ranging from Nii-jima to Kurose hall (0.25 km/s). On the other hand, the velocity contrast value at the bottom of this transition layer is large (>0.4 km/s) between Nii-jima and Kurose hall, and small (0.2 km/s) from Kurose hall southward. Especially, this value at the bottom of this layer ranging from Kayo Seamount to Nishi-no-shima is almost 0 km/s. From these results of this study and the petrological study (e.g., Tatsumi et al., 2008), this transition layer beneath the volcanic front along this arc is a mixture of the mafic residues and olivine cumulates formed during the crustal growth. In addition, the no velocity contrast value at the bottom of this transition layer implies that this transition layer highly consists of olivine cumulates, so that the area from Kayo Seamount to Nishi-no-shima may show the infant stage during the crustal growth. The Moho along the volcanic front in the oceanic island arc probably has a complex signature, as suggested by the crust-mantle transition layer composed of mixture of mafic residues and olivine cumulates.

  10. Influence of mixed thiolate/thioether versus dithiolate coordination on the accessibility of the uncommon +I and +III oxidation states for the nickel ion: an experimental and computational study.

    PubMed

    Gennari, Marcello; Orio, Maylis; Pécaut, Jacques; Bothe, Eberhard; Neese, Frank; Collomb, Marie-Noëlle; Duboc, Carole

    2011-04-18

    Sulfur-rich nickel metalloenzymes are capable of stabilizing Ni(I) and Ni(III) oxidation states in catalytically relevant species. In an effort to better understand the structural and electronic features that allow the stabilization of such species, we have investigated the electrochemical properties of two mononuclear N(2)S(2) Ni(II) complexes that differ in their sulfur environment. Complex 1 features aliphatic dithiolate coordination ([NiL], 1), and complex 2I is characterized by mixed thiolate/thioether coordination ([NiL(Me)]I, 2I). The latter results from the methylation of a single sulfur of 1. The X-ray structure of 2I reveals a distorted square planar geometry around the Ni(II) ion, similar to what was previously reported by us for 1. The electrochemical investigation of 1 and 2(+) shows that the addition of a methyl group shifts the potentials of both redox Ni(II)/Ni(I) and Ni(III)/Ni(II) redox couples by about 0.7 and 0.6 V to more positive values. Through bulk electrolyses, only the mononuclear dithiolate [Ni(I)L](-) (1(-)) and the mixed thiolate/thioether [Ni(III)L(Me)](2+) (2(2+)) complexes were generated, and their electronic properties were investigated by UV-vis and EPR spectroscopy. For 1(-) (Ni(I), d(9) configuration) the EPR data are consistent with a d(x(2))(-)(y(2)) based singly occupied molecular orbitals (SOMOs). However, DFT calculations suggest that there is also pronounced radical character. This is consistent with the small g-anisotropy observed in the EPR experiments. The spin population (Mulliken analysis) analysis of 1(-) reveals that the main contribution to the SOMO (64%) is due to the bipyridine unit. Time dependent density functional theory (TD-DFT) calculations attribute the most prominent features observed in the electronic absorption spectrum of 1(-) to metal to ligand charge transfer (MLCT) transitions. Concerning 2(2+), the EPR spectrum displays a rhombic signal with g(x) = 2.236, g(y) = 2.180, and g(z) = 2.039 in CH(3)CN

  11. L'CO/LFIR Relations with CO Rotational Ladders of Galaxies Across the Herschel SPIRE Archive

    NASA Technical Reports Server (NTRS)

    Kamenetzky, J.; Rangwala, N.; Glenn, J.; Maloney, P. R.; Conley, A.

    2015-01-01

    We present a catalog of all CO (carbon monoxide) (J (total angular momentum quantum number) equals 1-0 through J equals 13-12), [CI], and [NII] lines available from extragalactic spectra from the Herschel SPIRE (Spectral and Photometric Imaging Receiver) Fourier Transform Spectrometer (FTS) archive combined with observations of the low-J CO lines from the literature and from the Arizona Radio Observatory. This work examines the relationships between L (sub FIR (Far Infra Red)), L prime (sub CO), and L (sub CO) / L (sub CO, 1-0). We also present a new method for estimating probability distribution functions (PDFs) from marginal signal-to-noise ratio Herschel FTS spectra, which takes into account the instrumental "ringing" and the resulting highly correlated nature of the spectra. The slopes of Log (L (sub FIR)) versus Log (L prime (sub CO)) are linear for all mid- to high-J CO lines. The mid- to high-J CO luminosity relative to CO J equals 1-0 increases with increasing L (sub FIR), indicating higher excitement of the molecular gas, though these ratios do not exceed approximately 100. The luminosities relative to CO J equals 1-0 remain relatively at from J equals 6-5 through J equals13-2, across many orders of magnitude of L (sub FIR). Qualitative comparisons to current theoretical models do not match these flat SLED (spectral line energy distributions) shapes, indicating the need for more comprehensive modeling of the excitation processes of warm molecular gas in nearby galaxies.

  12. Studies of a Series of [Ni(P R₂N{sup Ph}₂)₂(CH₃CN)]2+ Complexes as Electrocatalysts for H₂ Production. Substituent Variation at the Phosphorus Atom of the P₂N₂ Ligand

    SciTech Connect

    Kilgore, Uriah J.; Stewart, Michael P.; Helm, Monte L.; Dougherty, William G.; Kassel, W. Scott; DuBois, M. Rakowski; DuBois, Daniel L.; Bullock, R. Morris

    2011-10-14

    A series of [Ni(P{sup R}₂N{sup Ph}₂)₂(CH₃CN)](BF₄)₂ complexes containing the cyclic diphosphine ligands [PR₂NPh₂ = 1,5-diaza-3,7-diphosphacyclooctane; R = benzyl (Bn), n-butyl (n-Bu), 2-phenylethyl (PE), 2,4,4-trimethylpentyl (TP), and cyclohexyl (Cy)] have been synthesized and characterized. X-ray diffraction studies reveal that the cations of [Ni(PBn₂NPh₂)₂(CH₃CN)](BF₄)₂ and [Ni(Pn-Bu₂NPh₂)₂(CH₃CN)](BF₄)₂ have distorted trigonal bipyramidal geometries. The Ni(0) complex [Ni(P Bn₂N{sup Ph}₂)₂] was also synthesized and characterized by X-ray diffraction studies and shown to have a distorted tetrahedral structure. These complexes, with the exception of [Ni(PCy₂NPh₂)₂(CH₃CN)](BF₄)₂, all exhibit reversible electron transfer processes for both the Ni(II/I) and Ni(I/0) couples and are electrocatalysts for the production of H₂ in acidic acetonitrile solutions. The heterolytic cleavage of H₂ by [Ni(PR₂NPh₂)₂(CH₃CN)](BF₄)₂ complexes in the presence of p-anisidine or p-bromoaniline was used to determine the hydride donor abilities of the corresponding [HNi(PR₂NPh₂)₂](BF₄) complexes. However, for the catalysts with the most bulky R groups, the turnover frequencies do not parallel the driving force for elimination of H₂, suggesting that steric interactions between the alkyl substituents on phosphorus and the nitrogen atom of the pendant amines play an important role in determining the overall catalytic rate.

  13. Application of bimodal distribution to the detection of changes in uranium concentration in drinking water collected by random daytime sampling method from a large water supply zone.

    PubMed

    Garboś, Sławomir; Święcicka, Dorota

    2015-11-01

    The random daytime (RDT) sampling method was used for the first time in the assessment of average weekly exposure to uranium through drinking water in a large water supply zone. Data set of uranium concentrations determined in 106 RDT samples collected in three runs from the water supply zone in Wroclaw (Poland), cannot be simply described by normal or log-normal distributions. Therefore, a numerical method designed for the detection and calculation of bimodal distribution was applied. The extracted two distributions containing data from the summer season of 2011 and the winter season of 2012 (nI=72) and from the summer season of 2013 (nII=34) allowed to estimate means of U concentrations in drinking water: 0.947 μg/L and 1.23 μg/L, respectively. As the removal efficiency of uranium during applied treatment process is negligible, the effect of increase in uranium concentration can be explained by higher U concentration in the surface-infiltration water used for the production of drinking water. During the summer season of 2013, heavy rains were observed in Lower Silesia region, causing floods over the territory of the entire region. Fluctuations in uranium concentrations in surface-infiltration water can be attributed to releases of uranium from specific sources - migration from phosphate fertilizers and leaching from mineral deposits. Thus, exposure to uranium through drinking water may increase during extreme rainfall events. The average chronic weekly intakes of uranium through drinking water, estimated on the basis of central values of the extracted normal distributions, accounted for 3.2% and 4.1% of tolerable weekly intake.

  14. FIFI-LS [OIII] Spectrosopy of Nearby Infrared Bright Galaxies: Tracing Stellar Populations, the O/N Abundance Ratio, and absolute abundances

    NASA Astrophysics Data System (ADS)

    Stacey, Gordon

    We propose to map the [OIII] 52 um line emission from the central regions of five infrared bright, nearby star forming galaxies, NGC 1808, NGC 1365, NGC 3256, NGC 4945, and Arp 299. These data will be used together with publically available [OIII] 88 um, [NII] 122 um, and [NIII] 57 um line detections from Herschel/PACS and H radio recombination line interferometric observations to constrain the ionized gas density and mass, the hardness of the stellar radiation fields (hence most massive star on the main sequence), the O/N ratio (reflecting the numbers of cycles for star formation) and the ionized gas phase N/H and O/H abundances which measure the star formation efficiency integrated over time. We will also use the Herschel archival [OI] 63 and 146 um, and [CII] 158 um imaging to characterize the neutral ISM and the strength of the FUV (6-13.6 eV) stellar radiation fields. Together we will have a continuous measure of the stellar UV radiation fields from 6 to 54 eV thereby constraining the numbers of upper main sequence stars. The proposed FIFI-LS [OIII] 52 um line observations are the lynch-pin that holds the technique together. These measurements provide a local benchmark for our line-ratio techniques that can be applied to similar studies of high-z galaxies where it is expected that stellar radiation fields will be harder, and the O/N radio will be larger for the lowest metallicity galaxies. Therefore, the proposed observations are fundamentally important to our understanding of the star formation process over cosmic time.

  15. Two Pathways for Electrocatalytic Oxidation of Hydrogen by a Nickel Bis(diphosphine) Complex with Pendant Amines in the Second Coordination Sphere

    SciTech Connect

    Yang, Jenny Y.; Smith, Stuart E.; Liu, Tianbiao L.; Dougherty, William G.; Hoffert, Wesley A.; Kassel, W. S.; Rakowski DuBois, Mary; DuBois, Daniel L.; Bullock, R. Morris

    2013-07-03

    A nickel bis(diphosphine) complex containing pendant amines in the second coordination sphere, [Ni(PCy2Nt-Bu2)2](BF4)2 (PCy2Nt-Bu2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane), is an electrocatalyst for hydrogen oxidation. Under 1.0 atm H2 using NEt3 as a base and with added water, a turnover frequency of 45 s-1 is observed at 23 °C; this is the fastest observed for a molecular catalyst. The addition of hydrogen to the NiII complex gives thee isomers of the doubly protonated Ni0 complex [Ni(PCy2HNt-Bu2)2](BF4)2; these complexes have been studied by 1H and 31P NMR spectroscopy, and for one isomer, an X-ray diffraction study. Using the pKa values and NiII/I and NiI/0 redox potentials in a thermochemical cycle, the free energy of hydrogen addition to [Ni(PCy2Nt-Bu2)2]2+ was determined to be -7.9 kcal mol-1. The catalytic rate observed in dry acetonitrile for the oxidation of H2 at the NiII/I couple depends on base size, with larger bases (NEt3, tert-BuNH2) resulting in slower catalysis than n-BuNH2. Addition of water accelerates the rate of catalysis, especially for the larger bases. The results of these studies provide important insights into the design of catalysts for hydrogen oxidation that facilitate proton movement and operate at moderate potentials. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  16. Spectral variability of the IR source IRAS 01005+7910 optical component

    NASA Astrophysics Data System (ADS)

    Klochkova, V. G.; Chentsov, E. L.; Panchuk, V. E.; Sendzikas, E. G.; Yushkin, M. V.

    2014-10-01

    High-resolution optical spectra of the IR source IRAS01005+7910 are used to determine the spectral type of its central star, B1.5±0.3, identify the spectral features, and analyze their profile and radial-velocity variations. The systemic velocity V sys = -50.5 km s-1 is determined from the positions of the symmetric and stable profiles of the forbidden [NI], [N II], [OI], [S II], and [Fe II] emission lines. The presence of the [NII] and [SII] forbidden emissions indicates the onset of the ionization of the circumstellar envelope and the fact that the star is very close to undergoing the planetary nebula stage. The broad range of radial velocity V r estimates based on the line cores, which amounts to about 34 km s-1, is partly due to the deformations of the profiles caused by variable emissions. The variations of the V r in the line wings are smaller, about 23 km s-1, and may be due to pulsations and/or hidden binarity of the star. The deformations of the profiles of absorption-emission lines may result from variations of their absorption components caused by the variations of the geometry and kinematics in the wind base. The H α lines exhibit PCyg III type wind profiles. Deviations of the wind from spherical symmetry are shown to be small. The relatively low wind velocity (27-74 km s-1 from different observations) and the strong intensity of the red emission (it exceeds the continuum level by up to a factor of seven) are typical for hypergiants rather than the classical supergiants. IRAS01005 is an example of spectral mimicry of a low-mass post-AGB star masquerading as a massive hypergiant.

  17. The great East Japan earthquake disaster: a compilation of published literature on health needs and relief activities, march 2011-september 2012.

    PubMed

    Ochi, Sae; Murray, Virginia; Hodgson, Susan

    2013-05-13

    Objective To provide an overview of the health needs following the Great East Japan Earthquake Disaster and the lessons identified. Methods The relevant of peer review and grey literature articles in English and Japanese, and books in Japanese, published from March 2011 to September 2012 were searched. Medline, Embase, PsycINFO, and HMIC were searched for journal articles in English, CiNii for those in Japanese, and Amazon.co.jp. for books. Descriptions of the health needs at the time of the disaster were identified using search terms and relevant articles were reviewed. Findings 85 English articles, 246 Japanese articles and 13 books were identified, the majority of which were experience/activity reports. Regarding health care needs, chronic conditions such as hypertension and diabetes were reported to be the greatest burden from the early stages of the disaster. Loss of medication and medical records appeared to worsen the situation. Many sub-acute symptoms were attributed to the contaminated sludge of the tsunamis and the poor living environment at the evacuation centres. Particularly vulnerable groups were identified as the elderly, those with mental health illnesses and the disabled. Although the response of the rescue activities was prompt, it sometimes failed to meet the on-site needs due to the lack of communication and coordination. Conclusion The lessons identified from this mega-disaster highlighted the specific health needs of the vulnerable populations, particularly the elderly and those with non-communicable diseases. Further research is needed so that the lessons identified can be incorporated into future contingency plans in Japan and elsewhere.

  18. Studies on Anthropogenic Impact on Water Quality in Hilo (Hawaii) Bay and Mapping the Study Stations Using Geospatial Technologies

    NASA Astrophysics Data System (ADS)

    Cartier, A. J.; Williams, M. S.; Adolf, J.; Sriharan, S.

    2015-12-01

    Hilo Bay has uncharacteristically brown waters compared to other waters found in Hawai'i. The majority of the freshwater entering Hilo Bay is from storm and surface water runoff. The anthropogenic impact on water quality at Hilo Bay is due to sediment entrance, cesspools (Bacteria), and invasive species (Albizia). This poster presentation will focus on the water quality and phytoplankton collected on a weekly basis at a buoy positioned one meter from the shore of Hilo Bay, preserving the phytoplankton intact, concentrating and dehydrating the sample with ethanol, and viewing the phytoplankton with a scanning electron microscope (Hitachi S-3400NII). The GPS (Global Positioning System) points were collected at the sampling stations. Three transects on three separate dates were performed in Hilo Bay with salinity, percent dissolved oxygen, turbidity, secchi depth, temperature, and chlorophyll fluorescence data collected at each sampling station. A consistent trend observed in all transects was as distance from the river increased turbidity decreased and salinity increased. The GPS data on June 30, 2015 showed a major correlation between stations and their distance from shore. There is a decrease in the turbidity but not the temperature for these stations. The GPS points collected on July 7, 2015 at thirteen stations starting with station one being at the shore to the water, showed that the salinity concentration fluctuate noticeably at the first 6 stations. As we proceed further away from the shore, the salinity concentration increases from stations seven through thirteen. The water temperature shows little variation throughout the thirteen stations. The turbidity level was high at the shore and shows a noticeable drop at station thirteen.

  19. The kinematics of the quadrupolar nebula M 1-75 and the identification of its central star

    NASA Astrophysics Data System (ADS)

    Santander-García, M.; Rodríguez-Gil, P.; Hernandez, O.; Corradi, R. L. M.; Jones, D.; Giammanco, C.; Beckman, J. E.; Carignan, C.; Fathi, K.; Rubio-Díez, M. M.; Jiménez-Luján, F.; Benn, C. R.

    2010-09-01

    Context. The link between how bipolar planetary nebulae are shaped and their central stars is still poorly understood. Aims: This paper investigates the kinematics and shaping of the multipolar nebula M 1-75, and briefly discusses the location and nature of its central star. Methods: Fabry-Perot data from GHαFAS on the WHT that samples the Doppler shift of the [Nii] 658.3 nm line are used to study the dynamics of the nebula by means of a detailed 3D spatio-kinematical model. Multi-wavelength images and spectra from the WFC and IDS on the INT, as well as from ACAM on the WHT, allowed us to constrain the parameters of the central star. Results: The two pairs of lobes, angularly separated by ~22°, were ejected simultaneously approx. ~3500-5000 years ago, at the adopted distance range from 3.5 to 5.0 kpc. The larger lobes show a slight degree of point symmetry. The formation of the nebula could be explained by wind interaction in a system consisting of a post-AGB star surrounded by a disc warped by radiative instabilities. This requires the system to be a close binary or a single star that engulfed a planet as it died. On the other hand, we present broad- and narrow-band images and a low S/N optical spectrum of the highly-reddened, previously unnoticed star that is likely the nebular progenitor. Its estimated V-I colour allows us to derive a rough estimate of the parameters and nature of the central star. Based on observations made with the 4.2 m William Herschel Telescope and the 2.5 m Isaac Newton Telescope, both operated on the island of la Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

  20. The Reaction Mechanism of Methyl-Coenzyme M Reductase

    PubMed Central

    Wongnate, Thanyaporn; Ragsdale, Stephen W.

    2015-01-01

    Methyl-coenzyme M reductase (MCR) is a nickel tetrahydrocorphinoid (coenzyme F430) containing enzyme involved in the biological synthesis and anaerobic oxidation of methane. MCR catalyzes the conversion of methyl-2-mercaptoethanesulfonate (methyl-SCoM) and N-7-mercaptoheptanoylthreonine phosphate (CoB7SH) to CH4 and the mixed disulfide CoBS-SCoM. In this study, the reaction of MCR from Methanothermobacter marburgensis, with its native substrates was investigated using static binding, chemical quench, and stopped-flow techniques. Rate constants were measured for each step in this strictly ordered ternary complex catalytic mechanism. Surprisingly, in the absence of the other substrate, MCR can bind either substrate; however, only one binary complex (MCR·methyl-SCoM) is productive whereas the other (MCR·CoB7SH) is inhibitory. Moreover, the kinetic data demonstrate that binding of methyl-SCoM to the inhibitory MCR·CoB7SH complex is highly disfavored (Kd = 56 mm). However, binding of CoB7SH to the productive MCR·methyl-SCoM complex to form the active ternary complex (CoB7SH·MCR(NiI)·CH3SCoM) is highly favored (Kd = 79 μm). Only then can the chemical reaction occur (kobs = 20 s−1 at 25 °C), leading to rapid formation and dissociation of CH4 leaving the binary product complex (MCR(NiII)·CoB7S−·SCoM), which undergoes electron transfer to regenerate Ni(I) and the final product CoBS-SCoM. This first rapid kinetics study of MCR with its natural substrates describes how an enzyme can enforce a strictly ordered ternary complex mechanism and serves as a template for identification of the reaction intermediates. PMID:25691570

  1. Japan Data Exchange Network JDXnet and Cloud-type Data Relay Server for Earthquake Observation Data

    NASA Astrophysics Data System (ADS)

    Takano, K.; Urabe, T.; Tsuruoka, H.; Nakagawa, S.

    2015-12-01

    In Japan, high-sensitive seismic observation and broad-band seismic observation are carried out by several organization such as Japan Meteorological Agency (JMA) , National Research Institute for Earth Science and Disaster Prevention (NIED), nine National Universities, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) , etc. The total number of the observation station is about 1400 points. The total volume of the seismic waveform data collected from all these observation station is about 1MByte for 1 second (about 8 to 10Mbps) by using the WIN system(Urabe 1991). JDXnet is the Japan Data eXchange network for earthquake observation data. JDXnet was started from 2007 by cooperation of the researchers of each organization. All the seismic waveform data are available at the all organizations in real-time. The core of JDXnet is the broadcast type real-time data exchange by using the nationwide L2-VPN service offered in JGN-X of NICT and SINET4 of NII. Before the Tohoku earthquake, the nine national universities had collected seismic data to each data center and then exchanged with other universities and institutions by JDXnet. However, in this case, if the center of the university was stopped, all data of the university could not use even though there are some alive observation stations. Because of this problem, we have prepared the data relay server in the data center of SINET4 ie the cloud center. This data relay server collects data directly from the observation stations of the universities and delivers data to all universities and institutions by JDXnet. By using the relay server on cloud center, even if some universities are affected by a large disaster, it is eliminated that the data of the living station is lost. If the researchers set up seismometers and send data to the relay server, then data are available to all researchers. This mechanism promotes the joint use of the seismometers and joint research activities in nationwide researchers.

  2. EPR Spectroscopy of catalytic systems based on nickel complexes of 1,4-diaza-1,3-butadiene (α-diimine) ligands in hydrogenation and polymerization reactions

    NASA Astrophysics Data System (ADS)

    Titova, Yu. Yu.; Belykh, L. B.; Schmidt, F. K.

    2015-01-01

    EPR spectroscopy is used to study catalytic hydration and polymerization reaction systems based on α-diimine complexes of Ni(0) and Ni(II) with the general formula NiBr2(DAD-R) (R = -C3H7 or -CH3) or Ni(DAD-CH3)2 (DAD(-C3H7) = 1,4-bis(2,6-diiso-propylphenyl)-2,3-(dimethyl-1,4-diazabuta-1,3-diene, DAD(-CH3) = 1,4-bis(2,6-dimethylphenyl)-2,3-dimethyl-1,4-diazabuta-1,3-diene)), in combination with Lewis acids (AlEt3, AlEt2Cl, AlEtCl2, B(F5C6)3, BF3.OEt2). Ni(I) complexes of the form (DAD-R)NiX2AlX'y(C2H5)3-y composition (an aluminum atom can be replaced by a boron atom) were identified, where R = -CH3 or -C3H7, X = Br, and X' = Cl or -C2H5 and α-diimine anion radicals are included in derivatives of aluminum or boron. Oxidation reactions of the Ni(DAD-CH3)2 complex with aluminum alkyl halides and boron derivatives with formation of paramagnetic nickel complexes are observed. It is found that there is no direct relationship between the polymerization activity of ethylene or hydration of the alkenes and the concentration of paramagnetic particles.

  3. In vivo activation of methyl-coenzyme M reductase by carbon monoxide

    PubMed Central

    Zhou, Yuzhen; Dorchak, Alexandria E.; Ragsdale, Stephen W.

    2013-01-01

    Methyl-coenzyme M reductase (MCR) from methanogenic archaea catalyzes the rate-limiting and final step in methane biosynthesis. Using coenzyme B as the two-electron donor, MCR reduces methyl-coenzyme M (CH3-SCoM) to methane and the mixed disulfide, CoBS-SCoM. MCR contains an essential redox-active nickel tetrahydrocorphinoid cofactor, Coenzyme F430, at its active site. The active form of the enzyme (MCRred1) contains Ni(I)-F430. Rapid and efficient conversion of MCR to MCRred1 is important for elucidating the enzymatic mechanism, yet this reduction is difficult because the Ni(I) state is subject to oxidative inactivation. Furthermore, no in vitro methods have yet been described to convert Ni(II) forms into MCRred1. Since 1991, it has been known that MCRred1 from Methanothermobacter marburgensis can be generated in vivo when cells are purged with 100% H2. Here we show that purging cells or cell extracts with CO can also activate MCR. The rate of in vivo activation by CO is about 15 times faster than by H2 (130 and 8 min-1, respectively) and CO leads to twofold higher MCRred1 than H2. Unlike H2-dependent activation, which exhibits a 10-h lag time, there is no lag for CO-dependent activation. Based on cyanide inhibition experiments, carbon monoxide dehydrogenase is required for the CO-dependent activation. Formate, which also is a strong reductant, cannot activate MCR in M. marburgensis in vivo. PMID:23554601

  4. Retrieval Success from a 1950's UK Fuel Storage Pond: Blazing a Trail for Early Hazard Reduction

    SciTech Connect

    Bruce, S.

    2006-07-01

    Work has begun to tackle one of the biggest challenges in the UK nuclear cleanup program: the retrieval of spent nuclear fuel from the First Generation Magnox Fuel Storage Pond at Sellafield. The UK Government regulatory body, Nuclear Installations Inspectorate (NII) considers this pond to be the country's highest priority in terms of Hazard Reduction, a view supported by the facility owner, UK Government's Nuclear Decommissioning Authority (NDA). Remotely operated submersible vehicles (ROV's) were used by British Nuclear Group to assess the condition of stored fuel in First Generation Magnox Storage Ponds (1945-60's build). The ROV survey showed fuel condition was better than expected, and engineers were able to prototype retrieval on a selected skip (container) of fuel. The retrieval and subsequent export to the Fuel Handling Plant (FHP) was executed in November 2005 and was completely successful. The next stage is to reprocess the fuel using the Magnox Reprocessing Plant. If this is successful the prototype retrieval will have demonstrated that: - British Nuclear Group can safely retrieve fuel from its legacy ponds; - British Nuclear Group can safely transport retrieved legacy fuel between facilities; - British Nuclear Group can eliminate the hazard presented by this legacy fuel by use of existing on-site reprocessing facilities. This in turn enables the option to commence larger-scale fuel retrievals from these legacy ponds years ahead of the current plan which assumes new plants to be available to handle all arisings from the legacy ponds in 2015. This hazard reduction could commence as early as 2008. (authors)

  5. Temperature dependence of methyl-coenzyme M reductase activity and of the formation of the methyl-coenzyme M reductase red2 state induced by coenzyme B.

    PubMed

    Goenrich, Meike; Duin, Evert C; Mahlert, Felix; Thauer, Rudolf K

    2005-06-01

    Methyl-coenzyme M reductase (MCR) catalyses the formation of methane from methyl-coenzyme M (CH(3)-S-CoM) and coenzyme B (HS-CoB) in methanogenic archaea. The enzyme has an alpha(2)beta(2)gamma(2) subunit structure forming two structurally interlinked active sites each with a molecule F(430) as a prosthetic group. The nickel porphinoid must be in the Ni(I) oxidation state for the enzyme to be active. The active enzyme exhibits an axial Ni(I)-based electron paramagnetic resonance (EPR) signal and a UV-vis spectrum with an absorption maximum at 385 nm. This state is called the MCR-red1 state. In the presence of coenzyme M (HS-CoM) and coenzyme B the MCR-red1 state is in part converted reversibly into the MCR-red2 state, which shows a rhombic Ni(I)-based EPR signal and a UV-vis spectrum with an absorption maximum at 420 nm. We report here for MCR from Methanothermobacter marburgensis that the MCR-red2 state is also induced by several coenzyme B analogues and that the degree of induction by coenzyme B is temperature-dependent. When the temperature was lowered below 20 degrees C the percentage of MCR in the red2 state decreased and that in the red1 state increased. These changes with temperature were fully reversible. It was found that at most 50% of the enzyme was converted to the MCR-red2 state under all experimental conditions. These findings indicate that in the presence of both coenzyme M and coenzyme B only one of the two active sites of MCR can be in the red2 state (half-of-the-sites reactivity). On the basis of this interpretation a two-stroke engine mechanism for MCR is proposed.

  6. p62 positive, TDP-43 negative, neuronal cytoplasmic and intranuclear inclusions in the cerebellum and hippocampus define the pathology of C9orf72-linked FTLD and MND/ALS.

    PubMed

    Al-Sarraj, Safa; King, Andrew; Troakes, Claire; Smith, Bradley; Maekawa, Satomi; Bodi, Istvan; Rogelj, Boris; Al-Chalabi, Ammar; Hortobágyi, Tibor; Shaw, Christopher E

    2011-12-01

    Neuronal cytoplasmic inclusions (NCIs) containing phosphorylated TDP-43 (p-TDP-43) are the pathological hallmarks of motor neuron disease/amyotrophic lateral sclerosis (MND/ALS) and FTLD-TDP. The vast majority of NCIs in the brain and spinal cord also label for ubiquitin and p62, however, we have previously reported a subset of TDP-43 proteinopathy patients who have unusual and abundant p62 positive, TDP-43 negative inclusions in the cerebellum and hippocampus. Here we sought to determine whether these cases carry the hexanucleotide repeat expansion in C9orf72. Repeat primer PCR was performed in 36 MND/ALS, FTLD-MND/ALS and FTLD-TDP cases and four controls. Fourteen individuals with the repeat expansion were detected. In all the 14 expansion mutation cases there were abundant globular and star-shaped p62 positive NCIs in the pyramidal cell layer of the hippocampus, the vast majority of which were p-TDP-43 negative. p62 positive NCIs were also abundant in the cerebellar granular and molecular layers in all cases and in Purkinje cells in 12/14 cases but they were only positive for p-TDP-43 in the granular layer of one case. Abundant p62 positive, p-TDP-43 negative neuronal intranuclear inclusions (NIIs) were seen in 12/14 cases in the pyramidal cell layer of the hippocampus and in 6/14 cases in the cerebellar granular layer. This unusual combination of inclusions appears pathognomonic for C9orf72 repeat expansion positive MND/ALS and FTLD-TDP which we believe form a pathologically distinct subset of TDP-43 proteinopathies. Our results suggest that proteins other than TDP-43 are binding p62 and aggregating in response to the mutation which may play a mechanistic role in neurodegeneration. PMID:22101323

  7. Dust and ionized gas in elliptical galaxies: Signatures of merging collisions

    NASA Technical Reports Server (NTRS)

    Goudfrooij, Paul; Dejong, Teije

    1993-01-01

    Traditionally elliptical galaxies were thought to be essentially devoid of interstellar matter. However, recent advances in instrumental sensitivity have caused a renaissance of interest in dust and gas in - or associated with - elliptical galaxies. In particular, the technique of co-adding IRAS survey scans has led to the detection of more than half of all ellipticals with BT less than 11 mag. in the Revised Shapley-Ames catalog, indicating the presence of 10(exp 7) - 10(exp 8) solar mass of cold interstellar matter (Jura et al. 1987). In addition, CCD multi-color surface photometry shows dust patches in about 30 percent of the cases studied to date (e.g., Veron-Cetty & Veron 1988). Thorough study of the gas and dust in ellipticals is important to (1) determine its origin (mass-loss from late-type stars, merging collisions with other galaxies or accretion inflows from cooling X-ray gas), and (2) investigate the 3-D shape of ellipticals, as can be derived from the orientation of the dust lanes and the 2-D velocity field of the gas. An important result of our comprehensive CCD imaging program is that a relevant fraction (approximately 40 percent) of the sample objects exhibits dust patches within extended H-alpha+(NII) line-emitting filaments. This common occurrence can be easily accounted for if the dust and gas have an external origin, i.e., mergers or interactions with gas-rich galaxies. Evidence supporting this suggestion: (1) the ionized gas is usually dynamically decoupled from the stellar velocity field (see, e.g., Sharples et al. 1983, Bertola & Bettoni 1988); (2) it is shown in a companion paper (Goudfrooij et al. 1992) that internal stellar mass loss alone can not account for the dust content of elliptical galaxies.

  8. Cometary Knots Around A Dying Star

    NASA Technical Reports Server (NTRS)

    1994-01-01

    These gigantic, tadpole-shaped objects are probably the result of a dying star's last gasps. Dubbed 'cometary knots' because their glowing heads and gossamer tails resemble comets, the gaseous objects probably were formed during a star's final stages of life. Hubble astronomer C. Robert O'Dell and graduate student Kerry P. Handron of Rice University in Houston, Texas discovered thousands of these knots with the Hubble Space Telescope while exploring the Helix nebula, the closest planetary nebula to Earth at 450 light-years away in the constellation Aquarius. Although ground-based telescopes have revealed such objects, astronomers have never seen so many of them. The most visible knots all lie along the inner edge of the doomed star's ring, trillions of miles away from the star's nucleus. Although these gaseous knots appear small, they're actually huge. Each gaseous head is at least twice the size of our solar system; each tail stretches for 100 billion miles, about 1,000 times the distance between the Earth and the Sun. Astronomers theorize that the doomed star spews hot, lower-density gas from its surface, which collides with cooler, higher-density gas that had been ejected 10,000 years before. The crash fragments the smooth cloud surrounding the star into smaller, denser finger-like droplets, like dripping paint. This image was taken in August, 1994 with Hubble's Wide Field Planetary Camera 2. The red light depicts nitrogen emission ([NII] 6584A); green, hydrogen (H-alpha, 6563A); and blue, oxygen (5007A).

  9. Herschel SPIRE-FTS observations of RCW 120

    NASA Astrophysics Data System (ADS)

    Rodón, J. A.; Zavagno, A.; Baluteau, J.-P.; Habart, E.; Köhler, M.; Le Bourlot, J.; Le Petit, F.; Abergel, A.

    2015-07-01

    Context. The expansion of Galactic H ii regions can trigger the formation of a new generation of stars. However, little is know about the physical conditions that prevail in these regions. Aims: We study the physical conditions that prevail in specific zones towards expanding H ii regions that trace representative media such as the photodissociation region, the ionized region, and condensations with and without ongoing star formation. Methods: We use the SPIRE Fourier Transform Spectrometer (FTS) on board Herschel to observe the H ii region RCW 120. Continuum and lines are observed in the 190-670μm range. Line intensities and line ratios are obtained and used as physical diagnostics of the gas. We used the Meudon PDR code and the RADEX code to derive the gas density and the radiation field at nine distinct positions including the PDR surface and regions with and without star-formation activity. Results: For the different regions we detect the atomic lines [NII] at 205μm and [CI] at 370 and 609μm, the 12CO ladder between the J = 4 and J = 13 levels and the 13CO ladder between the J = 5 and J = 14 levels, as well as CH+ in absorption. We find gas temperatures in the range 45-250 K for densities of 104-106 cm-3, and a high column density on the order of NH ~ 1022 cm-2 that is in agreement with dust analysis. The ubiquitousness of the atomic and CH+ emission suggests the presence of a low-density PDR throughout RCW 120. High-excitation lines of CO indicate the presence of irradiated dense structures or small dense clumps containing young stellar objects, while we also find a less dense medium (NH ~ 1020 cm-2) with high temperatures (80-200 K). Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  10. The great East Japan earthquake disaster: a compilation of published literature on health needs and relief activities, march 2011-september 2012.

    PubMed

    Ochi, Sae; Murray, Virginia; Hodgson, Susan

    2013-01-01

    Objective To provide an overview of the health needs following the Great East Japan Earthquake Disaster and the lessons identified. Methods The relevant of peer review and grey literature articles in English and Japanese, and books in Japanese, published from March 2011 to September 2012 were searched. Medline, Embase, PsycINFO, and HMIC were searched for journal articles in English, CiNii for those in Japanese, and Amazon.co.jp. for books. Descriptions of the health needs at the time of the disaster were identified using search terms and relevant articles were reviewed. Findings 85 English articles, 246 Japanese articles and 13 books were identified, the majority of which were experience/activity reports. Regarding health care needs, chronic conditions such as hypertension and diabetes were reported to be the greatest burden from the early stages of the disaster. Loss of medication and medical records appeared to worsen the situation. Many sub-acute symptoms were attributed to the contaminated sludge of the tsunamis and the poor living environment at the evacuation centres. Particularly vulnerable groups were identified as the elderly, those with mental health illnesses and the disabled. Although the response of the rescue activities was prompt, it sometimes failed to meet the on-site needs due to the lack of communication and coordination. Conclusion The lessons identified from this mega-disaster highlighted the specific health needs of the vulnerable populations, particularly the elderly and those with non-communicable diseases. Further research is needed so that the lessons identified can be incorporated into future contingency plans in Japan and elsewhere. PMID:23787732

  11. Mapping of the physicochemical conditions of the planetary nebula Menzel 1

    NASA Astrophysics Data System (ADS)

    Santos, P.; Monteiro, H.

    2014-10-01

    We prensent a study of the physicochemical conditions of the planetary nebula Menzel 1 using the method of spatially resolved spectrophotometric mapping. The data used in this study were collected in the Cerro Tololo Inter-American Observatory (CTIO) 0.9 m telescope. Observations were made with traditional long-slit spectroscopy with exposures taken for multiple parallel positions along the object in order to map it. The separation of the 4" slits were of 4". Initially, a data cube was created with the spectra obtained for each position of the slit. We used MPFIT - a software package that aims to find parameters that best fit the data to a function - to fit gaussians to the emission lines observed in each pixel of the spatial direction, for each slit in the data cube. We then reconstructed the image of the nebula for each a given emission line extracted from the data cube, interpolating between observed slit positions. With these maps, we obtained the interstellar extinction from the Hα Hβ ratio pixel by pixel. We obtained the density map from the [SII]671.7nm/673.1nm ratio and the temperature map from the [NII](654.8+658.4)nm/575.5nm ratio. Using the code NEAT (Nebular Empirical Analysis Tool), the maps of the chemical abundance were calculated from the flux maps. These maps provide a spatially resolved overview of the physicochemical conditions found in this object. From the maps, we calculated mean values for the main diagnostics, which compared well with values from the literature, showing that we retrieved results from observations without spatial resolution. This method allows the study of planetary nebulae in more detail than conventional methods.

  12. Mechanistic enzymology of CO dehydrogenase from Clostridium thermoaceticum. Progress report, March 25, 1993--March 24, 1994

    SciTech Connect

    Ragsdale, S.W.

    1994-04-01

    Anaerobic acetogenic bacteria can convert carbon dioxide and carbon monoxide to cell carbon by a pathway which is called the acetyl-CoA pathway. With this pathway they convert monosaccharides and the methoxy group of lignin derived aromatics into acetic acid. The acetic acid is then used by a number of organisms, including methanogens, as a carbon and energy source. Therefore, the acetyl-CoA pathway links the biodegradation of complex macromolecules like cellulose and lignin to the utilization of simple two carbon units. The final steps in acetyl-CoA biosynthesis by anaerobic bacteria are performed by carbon monoxide dehydrogenase (CODH), a nickel/iron-sulfur protein. We have previously demonstrate that the conversion of CH{sub 3}-H{sub 4} folate, CO and CoA to acetyl-CoA involves enzyme-bound intermediates that the one- and two-carbon precursors of acetyl-CoA are organometallic complexes, and that the site for assembly of acetyl-CoA is a novel Ni-Fe-S cluster which binds CO as a terminal carbonyl, i.e., M-C {equivalent_to} O. In the past year we have shown that the activities for CO oxidation and acetyl-CoA synthesis sites occur at separate sites, that it is a Fe, not a Ni, site in the Ni-Fe-S cluster which binds CO for acetyl-CoA synthesis, and that carbon disulfide (CS2) reacts with CODH at the Ni-Fe-S site to generate an isolated Ni(I) species. We also determined that CS{sub 2} is competitive with CO at the acetyl-CoA synthesis site and does not bind to the CO oxidation/CO{sub 2} reduction site.

  13. Describing the Gas Kinematics and Excitation of the Inner Kiloparsec of the Post-Starburst Quasar SDSS J170328.95+614109.9

    NASA Astrophysics Data System (ADS)

    Pinto, Pamela Soto; Sanmartim, David

    2016-01-01

    Post-Starburst Quasars (PSQs) are hypothesized to represent a stage in the evolution of massive galaxies in which both star formation and nuclear activity have been triggered and are visible simultaneously before one or the other fades. We present preliminary results for the study of the kinematics and excitation of the gas present in the PSQ J1703+6141 in order to understand which are the excitation mechanisms in the central region of this object (starburst or/and AGN?). For this purpose we have used optical Integral Field Spectroscopy (IFS) obtained with the GMOS-IFU at Gemini North telescope and performed IDL codes to analyze the spectra. We have found that the [OIII] emission line can be observed all around the object and that it presents a higher blueshift to the South West direction. On the other hand, the Hβ line is better observed around the nucleus and it presents an apparent rotation. Also, the ratio between these two emission lines is typical of a Seyfert galaxy according to the BPT diagram and typical of an AGN based on the study of Lamareille et al. 2004, that uses the ratio between [OII]3727 and Hβ for the study instead of [NII]/Hα like the BPT diagram does. Ionization models are necessary to analyze the gas excitation and to distinguish what are the main mechanisms working in the central region of this PSQ. Also, further studies will be conducted to analyze the stellar kinematics and the history of star formation in the central kpc of this PSQ.

  14. Design and Analysis Tools for Concurrent Blackboard Systems

    NASA Technical Reports Server (NTRS)

    McManus, John W.

    1991-01-01

    A blackboard system consists of a set of knowledge sources, a blackboard data structure, and a control strategy used to activate the knowledge sources. The blackboard model of problem solving is best described by Dr. H. Penny Nii of the Stanford University AI Laboratory: "A Blackboard System can be viewed as a collection of intelligent agents who are gathered around a blackboard, looking at pieces of information written on it, thinking about the current state of the solution, and writing their conclusions on the blackboard as they generate them. " The blackboard is a centralized global data structure, often partitioned in a hierarchical manner, used to represent the problem domain. The blackboard is also used to allow inter-knowledge source communication and acts as a shared memory visible to all of the knowledge sources. A knowledge source is a highly specialized, highly independent process that takes inputs from the blackboard data structure, performs a computation, and places the results of the computation in the blackboard data structure. This design allows for an opportunistic control strategy. The opportunistic problem-solving technique allows a knowledge source to contribute towards the solution of the current problem without knowing which of the other knowledge sources will use the information. The use of opportunistic problem-solving allows the data transfers on the blackboard to determine which processes are active at a given time. Designing and developing blackboard systems is a difficult process. The designer is trying to balance several conflicting goals and achieve a high degree of concurrent knowledge source execution while maintaining both knowledge and semantic consistency on the blackboard. Blackboard systems have not attained their apparent potential because there are no established tools or methods to guide in their construction or analyze their performance.

  15. The Great East Japan Earthquake Disaster: a Compilation of Published Literature on Health Needs and Relief Activities, March 2011-September 2012

    PubMed Central

    Ochi, Sae; Murray, Virginia; Hodgson, Susan

    2013-01-01

    Objective To provide an overview of the health needs following the Great East Japan Earthquake Disaster and the lessons identified. Methods The relevant of peer review and grey literature articles in English and Japanese, and books in Japanese, published from March 2011 to September 2012 were searched. Medline, Embase, PsycINFO, and HMIC were searched for journal articles in English, CiNii for those in Japanese, and Amazon.co.jp. for books. Descriptions of the health needs at the time of the disaster were identified using search terms and relevant articles were reviewed. Findings 85 English articles, 246 Japanese articles and 13 books were identified, the majority of which were experience/activity reports. Regarding health care needs, chronic conditions such as hypertension and diabetes were reported to be the greatest burden from the early stages of the disaster. Loss of medication and medical records appeared to worsen the situation. Many sub-acute symptoms were attributed to the contaminated sludge of the tsunamis and the poor living environment at the evacuation centres. Particularly vulnerable groups were identified as the elderly, those with mental health illnesses and the disabled. Although the response of the rescue activities was prompt, it sometimes failed to meet the on-site needs due to the lack of communication and coordination. Conclusion The lessons identified from this mega-disaster highlighted the specific health needs of the vulnerable populations, particularly the elderly and those with non-communicable diseases. Further research is needed so that the lessons identified can be incorporated into future contingency plans in Japan and elsewhere. PMID:23787732

  16. [Effects of mixed decomposition of Populus simonii and other tree species leaf litters on soil properties in Loess Plateau].

    PubMed

    Li, Qian; Liu, Zeng-Wen; Du, Liang-Zhen

    2012-03-01

    In this study, the leaf litters of Populus simonii and other 11 tree species were put into soil separately or in mixture after grinding, and incubated in laboratory to analyze the effects of their decomposition on soil properties and the interactions between the litters decomposition. The decomposition of each kind of the leaf litters in soil increased the soil urease, dehydrogenase, and phosphatase activities and the soil organic matter and available N contents markedly, but had greater differences in the effects on the soil available P content and CEC. The decomposition of the leaf litters of Caragana microphylla and of Amorpha fruticosa showed obvious effects in improving soil properties. The decomposition of the mixed leaf litters of P. simonii and Pinus tabulaeformis, Platycladus orientalis, Robinia pseudoacacia, or Ulmus pumila showed interactive promotion effects on the abundance of soil microbes, and that of the mixed leaf litters of P. simonii and P. orientalis or C. microphylla showed interactive promotion effects on the soil organic matter, available P, and available K contents and soil CEC but interactive inhibition effects on the activities of most of the soil enzymes tested. The decomposition of the mixed leaf litters of P. simonii and Larix principis-rupprechtii showed interactive promotion effects on the activities of most of the soil enzymes and soil nutrient contents, while that of the mixed leaf litters of P. simonii and P. sylvestris var. mongolica showed interactive inhibition effects. Overall, the decomposition of the mixed leaf litters of P. simo- nii and U. pumila, P. tabulaeformis, L. principis-rupprechtii, or R. pseudoacacia could improve soil quality, but the mixed leaf litters of P. simonii and P. orientalis, C. microphylla, P. sylvestris var. mongolica, Hippophae rhamnoides, or A. fruticosa showed an interactive inhibition effect during their decomposition.

  17. Hot interstellar gas and ionization of embedded clouds

    NASA Technical Reports Server (NTRS)

    Cheng, K.-P.; Bruhweiler, F.

    1990-01-01

    Researchers present detailed photoionization calculations for the instellar cloud in which the Sun is embedded. They consider the EUV radiation field with contribution from discrete stellar sources and from a thermal bremsstrahlung-radiative recombination spectrum emitted from the surrounding 10 to the 6th power k coronal substrate. They establish lower limits to the fractional ionization of hydrogen and helium of 0.17 and 0.29 respectively. The high He ionization fraction results primarily from very strong line emission below 500 A originating in the surrounding coronal substrate while the H ionization is dominated by the EUV radiation from the discrete stellar sources. The dual effects of thermal conduction and the EUV spectrum of the 10 to the 6th k plasma on ionization in the cloud skin are explored. The EUV radiation field and Auger ionization have insignificant effects on the resulting ionic column densities of Si IV, C IV, N V and O VI through the cloud skin. Calculations show that the abundances of these species are dominated by collisional ionization in the thermal conduction front. Because of a low charge exchange rate with hydrogen, the ionic column density ratios of N (CIII)/N (CII) and N (NII)/N (NI) are dominated by the EUV radiation field in the local interstellar medium. These ratios should be important diagnostics for the EUV radiation field and serve as surrogate indicators of the interstellar He and H ionization fraction respectively. Spacecraft such as Lyman which is designed to obtain high resolution spectral data down to the Lyman limit at 912 A could sample interstellar lines of these ions.

  18. ISM Properties of Local Luminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Diaz-Santos, Tanio; Armus, Lee; Stierwalt, Sabrina; Elbaz, David; Malhotra, Sangeeta

    2015-08-01

    Luminous and Ultra-luminous Infrared Galaxies ((U)LIRGs) represent the most important galaxy population at redshifts z > 1 as they account for more than 50% of all star formation produced in the Universe at those epochs; and encompass what it is called the main-sequence (MS) of star-forming galaxies. Investigating their local counterparts -low luminosity LIRGs- is therefore key to understand the physical properties and phases of their inter-stellar medium (ISM) - a task that is rather challenging in the distant Universe. On the other hand, high-z star-bursting (out of the MS) systems, although small in number, account for a modest yet still significant fraction of the total energy production. Here I present far-IR line emission observations ([CII]158μm, [OI]63μm, [OIII]88μm and [NII]122μm) obtained with Herschel for two large samples of nearby LIRGs: The Great Observatories All-sky LIRG Survey (GOALS), a sample of more than 240 relatively cold LIRGs, and a survey of 30 LIRGs selected to have very warm mid- to far-IR colors, suggestive of an ongoing intense nuclear starburst and/or an AGN. Using photo-dissociation region (PDR) models we derive the basic characteristics of the ISM (ionization intensity and density) for both samples and study differences among systems as a function of AGN activity, merger stage, dust temperature, and compactness of the starburst - parameters that are thought to control the life cycle of galaxies moving in and out of the MS, locally and at high-z.

  19. Potential-Dependent Electrocatalytic Pathways: Controlling Reactivity with pKa for Mechanistic Investigation of a Nickel-Based Hydrogen Evolution Catalyst.

    PubMed

    Rountree, Eric S; Dempsey, Jillian L

    2015-10-21

    A detailed mechanistic analysis is presented for the hydrogen evolution catalyst [Ni(P2(Ph)N2(Ph))2(CH2CN)][BF4]2 in acetonitrile (P2(Ph)N2(Ph) = 1,3,5,7-tetraphenyl-1,5-diaza-3,7-diphosphacyclooctane). This complex has a Ni(II/I) redox couple at −0.83 V and a Ni(I/0) redox couple at −1.03 V versus Fc(+/0). These two closely spaced redox events both promote proton reduction catalysis, each via a distinct mechanism: an electrochemical ECEC pathway and an EECC route. The EECC mechanism, operative at more negative potentials, was isolated through use of a weak acid (anilinium, pKa = 10.6 in CH3CN) to avert protonation of the singly reduced species. Electroanalytical methods and time-resolved spectroscopy were used to analyze the kinetics of the elementary steps of hydrogen evolution catalysis. The rate constant for the formation of a nickel(II)–hydride intermediate was determined via measurements of peak shift (k1 = 1.2 × 106 M(-1) s(-1)) and through foot-of-the-wave analysis (k1 = 6.5 × 106 M(-1) s(-1)). Reactivity of the isolated hydride with acid to release hydrogen and regenerate the nickel(II) complex was monitored by stopped-flow spectroscopy. Kinetics obtained from stopped-flow measurements are corroborated by current plateau analysis of the catalytic cyclic voltammograms. These kinetic data suggest the presence of an off-cycle intermediate in the reaction.

  20. Continuous Emission Monitor for Toxic Metals in the Off-Gases of Thermal Treatment Facilities

    SciTech Connect

    Gary Loge

    1998-12-01

    Self-calibration procedures for continuous monitoring of toxic metals in the off-gases of thermal treatment facilities using laser-induced breakdown spectroscopy (LIBS) were tested. The tests were performed using a heated aerosol/gas flow system that generated simulated off-gas conditions with calibrated amounts of metal in an optical cell. Calibration curves of LIBS signal for metal concentration in the cell were obtained for various gas and optical conditions. Gas conditions that were varied include water in either vapor and condensed aerosol droplet form, the presence of easily ionizable elements (i. e., potassium), speciation of the metal analyte, and the gas temperature. In addition, laser pulse energy, focal length, and detector alignment were independently varied. Two different sets of calibration curves were obtained, one set with Mn(II) and N(II) emission obtained simultaneously and a second set with Cd(I) and Cd(II) emission obtained simultaneously with N(I) emission obtained in a sequential manner. For both sets of data, calibration curves were obtained using 1) single line intensities, 2) the ratio of metal single line intensity to nitrogen single line intensity, and 3) the ratio of total metal emission to total nitrogen emission obtained using the temperature and electron density. Results show that correction using the ratio of metal single line intensity to nitrogen single line intensity does help in maintaining a constant slope of calibration curves for various conditions. However, the total emission self-calibration procedure shows better performance in most cases.

  1. Two pathways for electrocatalytic oxidation of hydrogen by a nickel bis(diphosphine) complex with pendant amines in the second coordination sphere.

    PubMed

    Yang, Jenny Y; Smith, Stuart E; Liu, Tianbiao; Dougherty, William G; Hoffert, Wesley A; Kassel, W Scott; Rakowski DuBois, M; DuBois, Daniel L; Bullock, R Morris

    2013-07-01

    A nickel bis(diphosphine) complex containing pendant amines in the second coordination sphere, [Ni(P(Cy)2N(t-Bu)2)2](BF4)2 (P(Cy)2N(t-Bu)2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane), is an electrocatalyst for hydrogen oxidation. The addition of hydrogen to the Ni(II) complex gives three isomers of the doubly protonated Ni(0) complex [Ni(P(Cy)2N(t-Bu)2H)2](BF4)2. Using the pKa values and Ni(II/I) and Ni(I/0) redox potentials in a thermochemical cycle, the free energy of hydrogen addition to [Ni(P(Cy)2N(t-Bu)2)2](2+) was determined to be -7.9 kcal mol(-1). The catalytic rate observed in dry acetonitrile for the oxidation of H2 depends on base size, with larger bases (NEt3, t-BuNH2) resulting in much slower catalysis than n-BuNH2. The addition of water accelerates the rate of catalysis by facilitating deprotonation of the hydrogen addition product before oxidation, especially for the larger bases NEt3 and t-BuNH2. This catalytic pathway, where deprotonation occurs prior to oxidation, leads to an overpotential that is 0.38 V lower compared to the pathway where oxidation precedes proton movement. Under the optimal conditions of 1.0 atm H2 using n-BuNH2 as a base and with added water, a turnover frequency of 58 s(-1) is observed at 23 °C.

  2. Education in nuclear decommissioning in the north of Scotland

    SciTech Connect

    Catlow, F.; Reeves, G.M.

    2007-07-01

    This paper describes the work covered and experience gained in the first two years of operation of DERC, a Centre for Decommissioning and Environmental Remediation in the Highlands of Scotland. The Centre is a unique development which was set up to teach nuclear decommissioning as a separate discipline, address the problem of a declining skills base in the field of nuclear technologies and to take advantage of the unique and exceptional innovative, technical and research opportunities offered through the decommissioning of Britain's fast reactor site at Dounreay. The Centre is an offshoot from North Highland College which is a member of UHI, the University in embryo of the Highlands and Islands. The Centre currently supports ten PhD students completing various diverse projects mainly in the field of nuclear environmental remediation. In addition there area number of full and part time MSc students who participate in NTEC (Nuclear Technology Education Consortium) a consortium of British Universities set up specifically to engender interest and skills in nuclear technology at postgraduate level. At undergraduate level, courses are offered in Nuclear Decommissioning and related subjects as part of Electrical and Mechanical degree courses. In addition to our relationship with the United Kingdom Atomic Energy Authority (UKAEA) the Dounreay site licensee, we have links with Rolls-Royce and the Ministry of Defence who also share the Dounreay site and with other stakeholders such as, the UK regulator (HSE/NII), the Scottish Environmental Protection Agency (SEPA), local and international contractors and we liaise with the newly formed Nuclear Decommissioning Authority (NDA), who provide some sponsorship and support. We possess our own equipment and laboratories for taking and analysing soil samples and for conducting environmental surveys. Recently we commissioned an aerial survey of contamination in the locality from natural sources, other background levels such as

  3. Virtual collaborative environments: programming and controlling robotic devices remotely

    NASA Astrophysics Data System (ADS)

    Davies, Brady R.; McDonald, Michael J., Jr.; Harrigan, Raymond W.

    1995-12-01

    This paper describes a technology for remote sharing of intelligent electro-mechanical devices. An architecture and actual system have been developed and tested, based on the proposed National Information Infrastructure (NII) or Information Highway, to facilitate programming and control of intelligent programmable machines (like robots, machine tools, etc.). Using appropriate geometric models, integrated sensors, video systems, and computing hardware; computer controlled resources owned and operated by different (in a geographic sense as well as legal sense) entities can be individually or simultaneously programmed and controlled from one or more remote locations. Remote programming and control of intelligent machines will create significant opportunities for sharing of expensive capital equipment. Using the technology described in this paper, university researchers, manufacturing entities, automation consultants, design entities, and others can directly access robotic and machining facilities located across the country. Disparate electro-mechanical resources will be shared in a manner similar to the way supercomputers are accessed by multiple users. Using this technology, it will be possible for researchers developing new robot control algorithms to validate models and algorithms right from their university labs without ever owning a robot. Manufacturers will be able to model, simulate, and measure the performance of prospective robots before selecting robot hardware optimally suited for their intended application. Designers will be able to access CNC machining centers across the country to fabricate prototypic parts during product design validation. An existing prototype architecture and system has been developed and proven. Programming and control of a large gantry robot located at Sandia National Laboratories in Albuquerque, New Mexico, was demonstrated from such remote locations as Washington D.C., Washington State, and Southern California.

  4. Biosensing and bioremediation of Cr(VI) by cell free extract of Enterobacter aerogenes T2.

    PubMed

    Panda, Jigisha; Sarkar, Priyabrata

    2014-01-01

    Hexavalent chromium or Cr(VI) enters the environment through several anthropogenic activities and it is highly toxic and carcinogenic. Hence it is required to be detected and remediated from the environment. In this study, low-cost and environment-friendly methods of biosensing and bioremediation of Cr(VI) have been proposed. Crude cell free extract (CFE) of previously isolated Enterobacter aerogenes T2 (GU265554; NII 1111) was prepared and exploited to develop a stable biosensor for direct estimation of Cr(VI) in waste water, by using three electrodes via cyclic voltammetry. For bioremediation studies, a homogeneous solution of commercially available sodium alginate and CFE was added dropwise in a continuously stirred calcium chloride solution. Biologically modified calcium alginate beads were produced and these were further utilized for bioremediation studies. The proposed sensor showed linear response in the range of 10-40 μg L(-1) Cr(VI) and the limit of detection was found to be 6.6 μg L(-1) Cr(VI). No interference was observed in presence of metal ions, e.g., lead, cadmium, arsenic, tin etc., except for insignificant interference with molybdenum and manganese. In bioremediation studies, modified calcium alginate beads showed encouraging removal rate 900 mg Cr(VI)/m(3) water per day with a removal efficiency of 90%, much above than reported in literature. The proposed sensing system could be a viable alternative to costly measurement procedures. Calcium alginate beads, modified with CFE of E. aerogenes, could be used in bioremediation of Cr(VI) since it could work in real conditions with extraordinarily high capacity.

  5. A study of the trace sulfide mineral assemblages in the Stillwater Complex, Montana, USA

    NASA Astrophysics Data System (ADS)

    Aird, Hannah M.; Ferguson, Katherine M.; Lehrer, Malia L.; Boudreau, Alan E.

    2016-07-01

    The sulfide assemblages of the Stillwater Complex away from the well-studied ore zones are composed mainly of variable proportions of pyrrhotite, chalcopyrite, pentlandite, and ±pyrite. Excluding vein assemblages and those affected by greenschist and lower temperature alteration, the majority can be classified into two broad assemblages, defined here as pristine (multiphase, often globular in shape) or volatile-bearing (multiphase, high-temperature, volatile-rich minerals such as biotite, hornblende, or an unmixed calcite-dolomite assemblage). The volatile-bearing assemblages are mainly found within and below the J-M reef, where native copper and sphalerite are also locally present. Pristine sulfides are found throughout the stratigraphy. Both groups can be affected by apparent S loss in the form of pyrite being converted to magnetite and chalcopyrite to a Cu-Fe-oxide (delafossite), with little to no silicate alteration. An upward trend from pentlandite-rich to pyrrhotite-rich to pyrite-rich assemblages is observed in the footwall rocks in upper GN-I, and the same trend repeats from just below the reef and continues into the overlying N-II and GN-II. Modeling suggests that the sulfide Ni in the Peridotite Zone is largely controlled by silicate Ni. When taken together, observations are most readily explained by the remobilization of selected elements by a high-temperature fluid with the apparent loss of S > Cu > Ni. This could concentrate ore metals by vapor refining, eventually producing a platinum group element-enriched sulfide ore zone, such as the J-M reef.

  6. Preparation for Retrievals from Sellafield Legacy Ponds Installation of the Gantry Refurbishment System

    SciTech Connect

    Ellison, M.

    2008-07-01

    Retrieval of sludge and fuel from the First Generation Magnox Fuel Storage Pond, and its safe long term storage is one of the NDA's top priorities in the UK clean up programme. The plant is currently undergoing a series of major modifications in preparation for the retrievals operations. The most visible example of these modifications is the Gantry Refurbishment System (GRS), a major work platform which has recently been lifted onto the pond long travel girders used by the Skip Handler. This paper describes the design, manufacture, works test, and site installation of this major piece of equipment. The installation lift, involving the use of an 800Te crane was one of the largest lifts undertaken at Sellafield. The GRS is a mobile platform structure which is designed to be pushed or pulled along the long travel girders by the Skip Handler. Its principle function is to provide a safe and shielded working platform from which to undertake refurbishment of the Skip Handler long travel girders and support structure. The potential hazards and consequences resulting from the modification were fully understood and controls were put in place to ensure that the risk of carrying out the work was as low as reasonably practicable. The work was authorised by the NII, Sellafield Nuclear Safety Committee and an independent readiness review panel. Despite less than perfect weather in the run up to the lift, the GRS was successfully and safely lifted onto the pond on 18 October 2006, the culmination of three years of planning, engineering and construction. (authors)

  7. Infrared mergers and infrared quasi-stellar objects with galactic winds - III. Mrk 231: an exploding young quasi-stellar object with composite outflow/broad absorption lines (and multiple expanding superbubbles)

    NASA Astrophysics Data System (ADS)

    Lípari, S.; Terlevich, R.; Zheng, W.; Garcia-Lorenzo, B.; Sanchez, S. F.; Bergmann, M.

    2005-06-01

    We present a study of outflow (OF) and broad absorption line (BAL) systems in Mrk 231, and in similar infrared (IR) quasi-stellar objects (QSOs). This study is based mainly on one-dimensional and two-dimensional spectroscopy (obtained at La Palma/William Herschel Telescope, Hubble Space Telescope, International Ultraviolet Explorer, European Southern Observatory/New Technology Telescope, Kitt Peak National Observatory, Apache Point Observatory and Complejo Astronomico El Leoncito observatories) plus Hubble Space Telescope images. For Mrk 231, we report evidence that the extreme nuclear OF process has at least three main components on different scales, which are probably associated with: (i) the radio jet, at parsec scale; (ii) the extreme starburst at parsec and kiloparsec scale. This OF has generated at least four concentric expanding superbubbles and the BAL systems. Specifically, inside and very close to the nucleus the two-dimensional spectra show the presence of an OF emission bump in the blend Hα+[NII], with a peak at the same velocity of the main BAL-I system (VEjectionBAL-I~-4700 km s-1). This bump was more clearly detected in the area located at 0.6-1.5 arcsec (490-1220 pc), to the south-west of the nucleus core, showing a strong and broad peak. In addition, in the same direction [at position angle (PA) ~-120°, i.e. close to the PA of the small-scale radio jet] at 1.7-2.5 arcsec, we also detected multiple narrow emission-line components, with `greatly' enhanced [NII]/Hα ratio (very similar to the spectra of jets bow shocks). These results suggest that the BAL-I system is generated in OF clouds associated with the parsec-scale jet. The Hubble Space Telescope images show four (or possibly five) nuclear superbubbles or shells with radii r~ 2.9, 1.5, 1.0, 0.6 and 0.2 kpc. For these bubbles, the two-dimensional Hα velocity field map and two-dimensional spectra show the following. (i) At the border of the more extended bubble (S1), a clear expansion of the

  8. Natural 'background' soil water repellency in conifer forests: its prediction and relationship to wildfire occurrence

    NASA Astrophysics Data System (ADS)

    Doerr, Stefan; Woods, Scott; Martin, Deborah; Casimiro, Marta

    2013-04-01

    Soils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites (n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by col- lecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were fur- ther analyzed for repellency using WDPT and contact angle (hsl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species (Pinus ponderosa, Pinus contorta, Picea engelma- nii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long- unburnt conifer forest soils of the north-western USA is

  9. Stabilization of Nickel Complexes with Ni0•••H-N Bonding Interactions Using Sterically Demanding Cyclic Diphosphine Ligands

    SciTech Connect

    Wiedner, Eric S.; Yang, Jenny Y.; Chen, Shentan; Raugei, Simone; Dougherty, William G.; Kassel, W. S.; Helm, Monte L.; Bullock, R. Morris; Rakowski DuBois, Mary; DuBois, Daniel L.

    2012-01-09

    The series of complexes Ni(P{sub 2}{sup tBu}N{sub 2}{sup R}), [Ni(P{sub 2}{sup tBu}N{sub 2}{sup R}){sub 2}]BF{sub 4}, [HNi(P{sub 2}{sup tBu}N{sub 2}{sup Ph}){sub 2}]BF{sub 4}, and [Co(P{sub 2}{sup tBu}N{sub 2}{sup Ph}){sub 2}]BF{sub 4} (P{sub 2}{sup tBu}N{sub 2}{sup R} = 1,5-dialkyl-3,7-tert-butyl-1,5-diaza-3,7-diphosphacyclooctane; alkyl (R) = phenyl, benzyl) have been synthesized and characterized. Spectroscopic, electrochemical, and X-Ray diffraction studies indicate these complexes are stable as a result of the tetrahedral arrangement of the two diphosphine ligands. Electrochemical oxidation of [HNi(P{sub 2}{sup tBu}N{sub 2}{sup Ph}){sub 2}]BF{sub 4} results in rapid proton transfer from nickel at a rate faster that can be observed on the CV timescale. Double protonation of Ni(P{sub 2}{sup tBu}N{sub 2}{sup BN}){sub 2} forms the endo-endo, endo exo, and exo-exo isomers of [Ni(P{sub 2}{sup tBu}N{sup BN}HN{sup BN}){sub 2}](BF{sub 4}){sub 2}, which were found to be more stable towards loss of H{sub 2} than previously observed for similar complexes. The presence of Ni{sup 0} {hor_ellipsis} HN bonds at the endo-protonation sites of [Ni(P{sub 2}{sup tBu}N{sup Bn}HN{sup BN}){sub 2}](BF{sub 4}){sub 2} results in significant differences in the Ni(I/0) oxidation potentials of each of the isomers. The differences in E{sub 1/2}(I/0) values correspond to bond free energies of 7.4 and 3.7 kcal/mol for the first and second Ni{sup 0} {hor_ellipsis} HN bonds of the endo-exo and endo-endo isomers, respectively. Computational studies of related model complexes reproduce these Ni{sup 0} {hor_ellipsis} HN bonds within 1-2 kcal/mol.

  10. Studies of a Series of [Ni(PR2NPh2)2(CH3CN)]2+ Complexes as Electrocatalysts for H2 Production: Substituent Variation at the Phosphorus Atom of the P2N2 Ligand

    SciTech Connect

    Kilgore, Uriah J.; Stewart, Michael P.; Helm, Monte L.; Dougherty, William G.; Kassel, W. S.; Rakowski DuBois, Mary; DuBois, Daniel L.; Bullock, R. Morris

    2011-11-07

    A series of [Ni(PR2NPh2)2(CH3CN)](BF4)2 complexes containing the cyclic diphosphine ligands (PR2NPh2 = 1,5-diaza-3,7-diphosphacyclooctane; R = benzyl (Bn), n-butyl (n-Bu), 2-phenylethyl (PE), 2,4,4-trimethylpentyl (TP), and cyclohexyl (Cy)) have been synthesized and characterized. X-ray diffraction studies reveal that the cations of [Ni(PBn2NPh2)2(CH3CN)](BF4)2 and [Ni(Pn-Bu2NPh2)2(CH3CN)](BF4)2 have distorted trigonal bipyramidal geometries. The Ni(0) complex [Ni(PBn2NPh2)2 (CH3CN)] was also synthesized and characterized by X-ray diffraction studies and shown to have a distorted tetrahedral structure. These complexes, with the exception of [Ni(PCy2NPh2)2(CH3CN)](BF4)2, all exhibit reversible electron transfer processes for both the Ni(II/I) and Ni(I/0) couples and are electrocatalysts for the production of H2 in acidic acetonitrile solutions. The heterolytic cleavage of H2 by [Ni(PR2NPh2)2(CH3CN)](BF4)2 complexes in the presence of p-anisidine or p-bromoaniline was used to determine the hydride donor abilities of the corresponding [HNi(PR2NPh2)2](BF4) complexes. However, the failure to observe a strong correlation between the turnover frequencies for H2 production and the hydride donor abilities, along with structural features of [Ni(PBn2NPh2)2(CH3CN)], suggest that steric interactions between the alkyl substituents on phosphorus and the nitrogen atom of the pendant amines play an important role in determining the overall catalytic rate. This material is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences.

  11. Stabilization of Nickel Complexes with Ni 0 ···H–N Bonding Interactions Using Sterically Demanding Cyclic Diphosphine Ligands

    SciTech Connect

    Wiedner, Eric S.; Yang, Jenny Y.; Chen, Shentan; Raugei, Simone; Dougherty, William G.; Kassel, W. Scott; Helm, Monte L.; Bullock, R. Morris; Rakowski DuBois, M.; DuBois, Daniel L.

    2012-01-09

    The series of complexes Ni(PtBu₂NR₂)₂, [Ni(PtBu₂NR₂)₂]BF₄, [HNi(PtBu₂NR₂)₂]BF₄, and [Co(PtBu₂NPh₂)₂]BF₄ (PtBu₂NR₂ = 1,5-dialkyl-3,7-tert-butyl-1,5-diaza-3,7-diphosphacyclooctane; alkyl = phenyl, benzyl) have been synthesized and characterized. Spectroscopic, electrochemical, and X-ray diffraction studies indicate these complexes are stable as a result of the tetrahedral arrangement of the two diphosphine ligands. Electrochemical oxidation of [HNi(PtBu₂NPh₂)₂]BF₄ results in rapid proton transfer from nickel at a rate faster than can be observed on the CV time scale. Double protonation of Ni(PtBu₂NBn₂)₂ forms the endo-endo, endo-exo, and exo-exo isomers of [Ni(PtBu₂NBnHNBn)₂](BF₄)₂, which were found to be more stable toward loss of H₂ than previously observed for similar complexes. The presence of Ni⁰···HN hydrogen bonds at the endo protonation sites of [Ni(PtBu₂NBnHNBn)₂](BF₄)₂ results in significant differences in the Ni(I/0) oxidation potentials of each of the isomers. The differences in E1/2(I/0) values correspond to bond free energies of 7.4 and 3.7 kcal/mol for the first and second Ni⁰···HN hydrogen bonds of the endo-exo and endo-endo isomers, respectively. Computational studies give bond dissociation energies of the Ni⁰···HN bonds that are within 1–2 kcal/mol of the experimentally determined values.

  12. HAWC+: A Detector, Polarimetry, and Narrow-Band Imaging Upgrade to SOFIA's Far-Infrared Facility Camera

    NASA Astrophysics Data System (ADS)

    Dowell, C. D.; Staguhn, J.; Harper, D. A.; Ames, T. J.; Benford, D. J.; Berthoud, M.; Chapman, N. L.; Chuss, D. T.; Dotson, J. L.; Irwin, K. D.; Jhabvala, C. A.; Kovacs, A.; Looney, L.; Novak, G.; Stacey, G. J.; Vaillancourt, J. E.; HAWC+ Science Collaboration

    2013-01-01

    HAWC, the High-resolution Airborne Widebandwidth Camera, is the facility far-infrared camera for SOFIA, providing continuum imaging from 50 to 250 microns wavelength. As a result of NASA selection as a SOFIA Second Generation Instruments upgrade investigation, HAWC will be upgraded with enhanced capability for addressing current problems in star formation and interstellar medium physics prior to commissioning in early 2015. We describe the capabilities of the upgraded HAWC+, as well as our initial science program. The mapping speed of HAWC is increased by a factor of 9, accomplished by using NASA/Goddard's Backshort-Under-Grid bolometer detectors in a 64x40 format. Two arrays are used in a dual-beam polarimeter format, and the full complement of 5120 transition-edge detectors is read using NIST SQUID multiplexers and U.B.C. Multi-Channel Electronics. A multi-band polarimeter is added to the HAWC opto-mechanical system, at the cryogenic pupil image, employing rotating quartz half-wave plates. Six new filters are added to HAWC+, bringing the full set to 53, 63, 89, 155, and 216 microns at R = 5 resolution and 52, 63, 88, 158, and 205 microns at R = 300 resolution. The latter filters are fixed-tuned to key fine-structure emission lines from [OIII], [OI], [CII], and [NII]. Polarimetry can be performed in any of the filter bands. The first-light science program with HAWC+ emphasizes polarimetry for the purpose of mapping magnetic fields in Galactic clouds. The strength and character of magnetic fields in molecular clouds before, during, and after the star formation phase are largely unknown, despite pioneering efforts on the KAO and ground-based telescopes. SOFIA and HAWC+ provide significant new capability: sensitivity to extended dust emission (to A_V ~ 1) which is unmatched, ~10 arcsec angular resolution combined with wide-field mapping which allows statistical estimates of magnetic field strength, and wavelength coverage spanning the peak of the far

  13. New insights on Stephan's Quintet: exploring the shock in three dimensions

    NASA Astrophysics Data System (ADS)

    Iglesias-Páramo, J.; López-Martín, L.; Vílchez, J. M.; Petropoulou, V.; Sulentic, J. W.

    2012-03-01

    Aims: We study the ionized gas emission from the large scale shock region of Stephan's Quintet (SQ). Methods: We carried out integral field unit (IFU) optical spectroscopy on three pointings in and near the SQ shock. We used Potsdam MultiAperture Spectrometer (PMAS) on the 3.5 m Calar Alto telescope to obtain measures of emission lines that provide insight into physical properties of the gas. Severe blending of Hα and [Nii]λ6548, 6583 Å emission lines in many spaxels required the assumption of at least two kinematical components to extract fluxes for the individual lines. Results: The main results from our study include (a) detection of discrete emission features in the new intruder velocity range 5400-6000 km s-1 showing properties consistent with Hii regions, (b) detection of a low-velocity component spanning the range 5800-6300 km s-1 with properties resembling a solar-metallicity shocked gas and (c) detection of a high-velocity component at ≈6600 km s-1 with properties consistent with those of a low-metallicity shocked gas. Conclusions: The two shocked components are interpreted as products of a collision between NGC 7318b new intruder and a debris field in its path. This has given rise to a complex structure of ionized gas where several components with different kinematical and physical properties coexist, although part of the original interstellar medium (ISM) associated with NGC 7318b is still present and remains unaltered. Our observations suggest that the low-velocity ionized component might have existed before the new intruder collision and could be associated with the NW-LV Hi component. The high-velocity ionized component might fill the gap between the Hi complexes observed in SQ-A and NGC 7319's tidal filament (NW-HV, Arc-N and Arc-S in Williams et al. 2002, AJ, 123, 2417). Based on observations taken at the 3.5 m telescope at Calar Alto Observatory.Tables 1-5, Figs. 12-19 and Appendix A are available in electronic form at http://www.aanda.org

  14. Abundâncias espectroscópicas de simbióticas amarelas

    NASA Astrophysics Data System (ADS)

    Calbo, S. R.; Costa, R. D. D.

    2003-08-01

    Este trabalho consiste no estudo de uma amostra de estrelas simbióticas amarelas cujas componentes frias apresentam tipos espectrais G ou K. Uma amostra de 20 estrelas foi usada, o que corresponde ao conjunto completo de estrelas simbióticas amarelas visíveis no hemisfério sul presentes no catálogo de Belczynski et al (2000 A&A Suppl. 146, 407). Os espectros estelares foram obtidos por observações usando os telescópios de 1,6 m do LNA e 1,52 m do ESO e os dados fornecidos pelo satélite IUE (International Ultraviolet Explorer) e posteriormente reduzidos no IAG. Os fluxos das linhas medidas de cada espectro foram calibrados em fluxo (com as correções de avermelhamento baseados no trabalho de Pacheco e Costa 1992, A&A 257, 619), e os parâmetros físicos (temperatura e densidade eletrônica) das nebulosas que envolvem os sistemas simbióticos determinados, usando-se fluxos medidos de OIII e NII da parte visível do espectro. Para a determinação das razões de abundâncias de C/N e O/N aplicou-se o método de Nussbaumer et al. (1988, A&A 198, 179). As razões de abundâncias foram derivadas das linhas de emissão (NIV, CIV, OIII, NIII e CIII) dos espectros IUE. Numa última fase plotou-se o diagrama C/N-O/N onde comparou-se a abundância química das simbióticas amarelas obtidas neste trabalho com as de gigantes normais. Os resultados mostram abundâncias compatíveis com aquelas derivadas para nebulosas planetárias do bojo, indicando que o material nebular é originado das gigantes vermelhas de cada sistema, e não da fonte quente. (FAPESP, CNPq)

  15. Metallic abundances of the 2002 Leonid

    NASA Astrophysics Data System (ADS)

    Kasuga, T.; Yamamoto, T.; Watanabe, J.; Yano, H.

    The Leonid meteor shower is caused by the Earth's encountering dust trails ejected from Comet 55P/Tempel-Tuttle. After the return of this comet in 1998, a theoretical calculation predicted that the peak activities could go up to a `storm' level in next five years. From the latest study of comets, the measurements of the HDO/H2O ratio imply the possibility of delivering volatile materials to the Earth by cometary dust grains. To explore the possibility of delivering water and pre-biotic organics to the Earth, we developed a HDTV spectroscopic observational system. The system was focused on the near - ultraviolet wavelength range (300 nm - 600 nm) by combining reflective grating, UV lens (f=30 mm, F1.4), Image Intensifier (I.I.), and High Definition TV camera (HDTV). The field of view (FOV) was 23° × 13°, and the observable wavelength range was in 300 nm - 900 nm, with resolution of 1.0 - 1.5 nm. By using this system, we carried out spectroscopic observations at the SUBARU Telescope site and the Nobeyama Radio observatory site in 2001. In 2002, we participated in NASA's Leonid Multi - Instrument Aircraft Campaign (Leonid MAC), which had started since 1998. This campaign concept is to bring together world-wide scientists from different disciplines and cooperatively observe the Leonid meteors using a wide range of techniques. Scientists were divided into two airplanes. The one was the NASA DC-8 Airborne Laboratory, and the other one was FISTA. The route of the both aircrafts was from Torrejon, Spain to Offutt, Nebraska in order to encounter two predicted peaks. This observation also could decrease air extinction and Rayleigh scattering in the ultraviolet region. The High-Definition TV spectra in the visual--ultraviolet region were obtained during the 2002 Leonid aircraft campaign. The ultraviolet wavelengths of between 300--600 nm were observed, and the metallic atoms were identified, mainly MgI, MgII, FeI, CaI, CaII, NiI, NaI and MnI. From the analysis of the

  16. Functional Characterization of Aspergillus nidulans ypkA, a Homologue of the Mammalian Kinase SGK

    PubMed Central

    Colabardini, Ana Cristina; Brown, Neil Andrew; Savoldi, Marcela; Goldman, Maria Helena S.; Goldman, Gustavo Henrique

    2013-01-01

    The serum- and glucocorticoid-regulated protein kinase (SGK) is an AGC kinase involved in signal cascades regulated by glucocorticoid hormones and serum in mammals. The Saccharomyces cerevisiae ypk1 and ypk2 genes were identified as SGK homologues and Ypk1 was shown to regulate the balance of sphingolipids between the inner and outer plasma membrane. This investigation characterized the Aspergillus nidulans YPK1 homologue, YpkA, representing the first filamentous fungal YPK1 homologue. Two conditional mutant strains were constructed by replacing the endogenous ypk1 promoter with two different regulatable promoters, alcA (from the alcohol dehydrogenase gene) and niiA (from the nitrate reductase gene). Both constructs confirmed that ypkA was an essential gene in A. nidulans. Repression of ypkA caused decreased radial growth, a delay in conidial germination, deficient polar axis establishment, intense branching during late stages of growth, a lack of asexual spores, and a terminal phenotype. Membrane lipid polarization, endocytosis, eisosomes and vacuolar distribution were also affected by ypkA repression, suggesting that YpkA plays a role in hyphal morphogenesis via coordinating the delivery of cell membrane and wall constituents to the hyphal apex. The A. nidulans Pkh1 homologue pkhA was also shown to be an essential gene, and preliminary genetic analysis suggested that the ypkA gene is not directly downstream of pkhA or epistatic to pkhA, rather, ypkA and pkhA are genetically independent or in parallel. BarA is a homologue of the yeast Lag1 acyl-CoA-dependent ceramide synthase, which catalyzes the condensation of phytosphingosine with a fatty acyl-CoA to form phytoceramide. When barA was absent, ypkA repression was lethal to the cell. Therefore, there appears to be a genetic interaction between ypkA, barA, and the sphingolipid synthesis. Transcriptional profiling of ypkA overexpression and down-regulation revealed several putative YpkA targets associated with the

  17. The diffuse ionized interstellar medium perpendicular to the plane of NGC 891

    NASA Technical Reports Server (NTRS)

    Dettmar, Ralf-Juergen; Keppel, Jean; Roberts, Morton S.; Gallagher, John S., III

    1990-01-01

    In an attempt to study the structure and the properties of the diffuse ionized interstellar medium perpendicular to the plane of disk galaxies researchers obtained H alpha images and spectra of NGC 891. Perhaps the most remarkable property of the H alpha emission line in NGC 891 is its extension out of the plane of the galaxy: researchers are able to measure the H alpha line out to more than 30 seconds (1.4 kpc) from the midplane. This means that the ionized hydrogen extends at least four times higher than the neutral hydrogen layer. An anomalously large scale-height for the ionized gas of approx. equals 1 kpc is also found in the Milky Way. The echelle spectra show a changing ratio of NII to H alpha. This excludes the possibility that the large scaleheight of the emission is due to scattering of disk emission by dust high above the plane. The z-extent of the H alpha emission is confirmed by the imaging result. The large z-extent of the ionized gas is confined to the inner half of the visible disk. In this inner region the H alpha distribution also shows a filamentary structure of the diffuse ionized medium. These filaments, sticking out of the plane, originate in HII regions in the plane. The H alpha image also shows a large scale asymmetry if the NE and SW parts of the disk are compared. The NE part is more prominent and extended in H alpha. The same asymmetry is also seen in the radio continuum distribution. This correlation between the diffuse ionized medium and the distribution of relativistic electrons is one example of a relation between star formation processes in the disk and the various components of the halo. Thermal filaments or spurs which are related to HII regions are also known in the Galaxy. These filamentary structures perpendicular to the galactic planes may represent the chimneys which result in the supernova dominated model of the Interstellar Medium by Norman and Ikeuchi (1989).

  18. Intense accretion and mass loss of a very low mass young stellar object

    NASA Astrophysics Data System (ADS)

    Fernández, M.; Comerón, F.

    2001-12-01

    We present visible and near-infrared photometry and spectroscopy of LS-RCrA 1, a faint, very late-type object (M 6.5-M 7) seen in the direction of the R Coronae Australis star forming complex. While its emission spectrum shows prominent features of accretion and mass loss typical of young stellar objects, its underlying continuum and photometric properties are puzzling when trying to derive a mass and age based on pre-main sequence evolutionary tracks: the object appears to be far too faint for a young member of the R Coronae Australis complex of its spectral type. We speculate that this may be due to either its evolution along pre-main sequence tracks being substantially altered by the intense accretion, or to a combination of partial blocking and scattering of the light of the object by a nearly edge-on circumstellar disk. The rich emission line spectrum superimposed on the stellar continuum is well explained by an intense accretion process: the Halpha , CaII infrared triplet, and HeI 6678 lines show equivalent widths typical of very active classical T Tauri stars. The near-infrared observations show anomalously weak spectral features and no significant excess emission in the K band, which we tentatively interpret as indicating line filling due to emission in a magnetic accretion funnel flow. At the same time, numerous, strong forbidden optical lines ([OI], [NII] and [SII]) and H2 emission at 2.12 mu m suggest that the object is simultaneously undergoing mass loss, providing another example that shows that mass loss and accretion are closely related processes. Such an intense accretion and mass loss activity is observed for the first time in a young stellar object in the transition region between low mass stars and brown dwarfs, and provides a valuable observational test on the effects of accretion on the evolution of objects with such low masses. Based on observations collected at the European Southern Observatory in La Silla and Cerro Paranal (Chile), in

  19. Spectroscopic and computational studies of reduction of the metalversus the tetrapyrrole ring of coenzyme F-430 from methyl-coenzyme Mreductase

    SciTech Connect

    Dey, Mishtu; Kunz, Ryan C.; van Heuvelen, Katherine M.; Craft,Jennifer L.; Horng, Yih-Chern; Tang, Qun; Bocian, David F.; George, SimonJ.; Brunold, Thomas C.; Ragsdale, Stephen W.

    2006-06-30

    Methyl-coenzyme M reductase (MCR) catalyzes the final stepin methane biosynthesis by methanogenic archaea and contains aredox-active nickel tetrahydrocorphin, coenzyme F430, at its active site.Spectroscopic and computational methods have been used to study a novelform of the coenzyme, called F330, which is obtained by reducing F430with sodium borohydride (NaBH4). F330 exhibits a prominent absorptionpeak at 330 nm, which is blue shifted by 100 nm relative to F430. Massspectrometric studies demonstrate that the tetrapyrrole ring in F330 hasundergone reduction, on the basis of the incorporation of protium (ordeuterium), upon treatment of F430 with NaBH4 (or NaBD4). One- andtwo-dimensional NMR studies show that the site of reduction is theexocyclic ketone group of the tetrahydrocorphin. Resonance Raman studiesindicate that elimination of this pibond increases the overall pi-bondorder in the conjugative framework. X-ray absorption, magnetic circulardichroism, and computational results show that F330 contains low-spinNi(II). Thus, conversion of F430 to F330 reduces the hydrocorphin ringbut not the metal. Conversely, reduction of F430 with Ti(III) citrate togenerate F380 (corresponding to the active MCRred1 state) reduces theNi(II) to Ni(I) but does not reduce the tetrapyrrole ring system, whichis consistent with other studies [Piskorski, R., and Jaun, B. (2003) J.Am. Chem. Soc. 125, 13120-13125; Craft, J. L., et al. (2004) J. Biol.Inorg. Chem. 9, 77-89]. The distinct origins of the absorption bandshifts associated with the formation of F330 and F380 are discussedwithin the framework of our computational results. These studies on thenature of the product(s) of reduction of F430 are of interest in thecontext of the mechanism of methane formation by MCR and in relation tothe chemistry of hydroporphinoid systems in general. The spectroscopicand time-dependent DFT calculations add important insight into theelectronic structure of the nickel hydrocorphinate in its Ni(II) and

  20. Long-slit spectrophotometry of the multiple knots of the polar ring galaxy IIZw71

    NASA Astrophysics Data System (ADS)

    Pérez-Montero, E.; García-Benito, R.; Díaz, A. I.; Pérez, E.; Kehrig, C.

    2009-04-01

    Aims: The blue compact dwarf galaxy IIZw71 is catalogued as a probable polar-ring galaxy, and along its long axis it has several very luminous knots showing recent episodes of star formation. Our main aim is to study the physical properties, the stellar content, and the kinematics in the brightest knots of the polar ring. Methods: We carried out long-slit spectroscopic observations of the polar ring in the spectral range 3500-10 000 Å taken with the William Herschel Telescope (WHT). The spectroscopic observations complemented by the available photometry of the galaxy in narrow Hα filters. Results: We measured the rotation curve of the ring, from which we infer a ratio M/LB ≈ 3.9 inside the star-forming ring. We measured the auroral [Oiii] line in the two brightest knots, allowing us to measure oxygen, sulphur, nitrogen, argon, and neon chemical abundances following the direct method. Different empirical calibrators were used to estimate the oxygen abundance in the two faintest knots where the temperature sensitive lines could not be measured. The metallicities obtained are very similar for all the knots, but lower than previously reported in the literature from integrated spectra. The N/O abundance, as derived from the N2O2 parameter (the ratio of the [Nii] and [Oii] intensities), is remarkably constant over the ring, indicating that local polution processes are not conspicuous. Using synthetic stellar populations (SSPs) calculated with the code STARLIGHT, we studied the age distribution of the stellar populations in each knot, finding that in all of them there is a combination of a very young population with less than 10 Myr, responsible for the ionisation of the gas, with other populations older than 100 Myr, probably responsible for the chemical evolution of the knots. The small differences in metallicity and the age distributions among the different knots are indicative of a common chemical evolution, probably related to the process of interaction with the

  1. Homogeneous Electrocatalytic Reduction of Carbon Dioxide to Carbon Monoxide by Ni(cyclam)

    NASA Astrophysics Data System (ADS)

    Froehlich, Jesse Dan

    The homogeneous electrochemical reduction of CO2 by the molecular catalyst [Ni(cyclam)]2+ was studied by electrochemistry and infrared spectroelectrochemistry. This catalyst has been previously shown to have increased CO2 reduction activity when adsorbed on a mercury electrode. The homogeneous reactivity, without a mercury electrode, was often ignored in the literature. Ni(cyclam) was found to efficiently and selectively produce CO at moderate overpotentials in both aqueous and mixed organic solvent systems in a homogenous fashion at an inert glassy carbon electrode. Methylated analogs of Ni(cyclam) were also studied and observed to have more positive reduction potentials and attenuated CO2 reduction activity. The electrochemical kinetics were probed by varying CO2 substrate and proton concentrations. Products of CO2 reduction are observed in infrared spectra obtained from spectroelectrochemical experiments. The two major species observed were a Ni(I) carbonyl, [Ni(cyclam)(CO)]+, and a Ni(II) coordinated bicarbonate, [Ni(cyclam)(CO2OH)] +. The rate-limiting step during electrocatalysis was determined to be CO loss from the deactivated species, [Ni(cyclam)(CO)]+, to produce the active catalyst, [Ni(cyclam)]+. Another macrocyclic complex, [Ni(TMC)]+, was deployed as a CO scavenger in order to inhibit the deactivation of [Ni(cyclam)] + by CO. Addition of the CO scavenger was shown to dramatically increase the catalytic current observed for CO2 reduction by [Ni(cyclam)] +. Evidence for the [Ni(TMC)]+ acting as a CO scavenger includes the observation of [Ni(TMC)(CO)]+ by IR. Density functional theory calculations, probing the optimized geometry of the [Ni(cyclam)(CO)] + species, are also presented. These findings have implications on the increased activity for CO2 reduction when [Ni(cyclam)] + is adsorbed on a mercury electrode. The [Ni(cyclam)(CO)] + structure has significant distortion of the Ni center out of the plane of the cyclam nitrogens. This distortion

  2. Solid state NMR studies of photoinduced polarization in photosynthetic reaction centers: mechanism and simulations.

    PubMed

    McDermott, A; Zysmilich, M G; Polenova, T

    1998-03-01

    We simulate Photo-Chemically Induced Dynamic Nuclear Polarization in the 15N-solid-state NMR of 15N-labeled photosynthetic reaction centers using a Radical Pair Mechanism (RPM). According to the experimental data, the directly polarized nuclei include all eight nitrogens in the ground state of the bacteriochlorophyll special pair (P), and N-II in the bacteriopheophytin acceptor (H) [M.G. Zysmilich, A.E. McDermott, J. Am. Chem. Soc., 116 (1994) 8362-8363.] [M.G. Zysmilich, A. McDermott, J. Am. Chem. Soc., 118 (1996) 5867-5873.] [M.G. Zysmilich, A. McDermott, Proc. Natl. Acad. Sci. U.S.A., 93 (1996) 6857-6860.]; other signals are polarized in nonspecifically labeled samples, but the polarization apparently results from magnetization exchange with neighboring polarized nitrogens, and these are not treated in this work. Two quantitative models for the polarization associated with the RPM are presented and are used to test the validity of the proposal that this mechanism is cooperative in the reaction centers. The kinetic models can treat the steady state polarizations as well as the approach to steady state, and in principle could be expanded to include anisotropic effects, or pulse-probe experiments. Several features of the detailed simulations of the steady-state amplitudes and the kinetics of the approach to steady-state are compared with our data, including the signs and approximate absolute magnitudes of the polarization on the nitrogen nuclei in P and H(L), and the changes in the relative amplitudes with the change in the lifetime of the molecular triplet, photoaccumulation time, nuclear relaxation rate and illumination intensity. The simulations demonstrate that the polarization intensities are in qualitative agreement with those predicted for the RPM, including the curious observation of strong polariza-tion on the pheophytin acceptor for certain experimental conditions. However, this agreement requires efficient relaxation of the nitrogens on H(L) by 3P, due

  3. The First Detection of Diffuse Interstellar [OII] Emission from the Milky Way using Spatial Heterodyne Spectroscopy

    NASA Astrophysics Data System (ADS)

    Mierkiewicz, E. J.; Roesler, F. L.; Harlander, J. M.; Reynolds, R. J.; Jaehnig, K. P.

    2004-12-01

    Using a newly developed Spatial Heterodyne Spectrometer (SHS), we have achieved the first detection of diffuse [OII] 372.6 nm and 372.9 nm emission lines from the warm (10,000 K), low density (0.1 cm-3) ionized component of our Galaxy's interstellar medium (WIM). These [OII] lines are a principal coolant for this wide spread, photoionized gas and are a potential tracer of variations in the gas temperature resulting from unidentified interstellar heating processes that appear to be acting within the Galaxy's disk and halo. We have also detected numerous, weak airglow lines, including terrestrial [OII] emission. In our SHS system, Fizeau fringes of wavenumber-dependent spatial frequency are produced by a Michelson interferometer modified by replacing the return mirrors with diffraction gratings. These fringes are recorded on a position sensitive detector and Fourier transformed to recover a spectrum over a limited range centered at the grating Littrow wavenumber. SHS combines interferometric and field-widening gains to achieve sensitivities much larger than conventional grating instruments of similar size and resolving power, and comparable to the Wisconsin Hα Mapper (WHAM) Fabry-Perot, but in the near UV where WHAM cannot observe. Our early results confirm the superb performance of the SHS technique for measurements of spatially extended faint emissions, including the first detection of [OII] emission lines extending out to 20 degrees from the Galactic equator in the longitude range of 110 to 150 degrees. [OII] intensities range from tens of Rayleighs near the Galactic plane to less than one Rayleigh at high Galactic latitudes. The [OII] line profiles clearly show structure indicating emission along the lines of sight from both local interstellar gas and more distant gas in the Perseus spiral arm. Preliminary line ratio comparisons with WHAM [NII] (658.4 nm) and Hα (656.3 nm) observations confirm the utility of the [OII] observations as a temperature diagnostic

  4. Evaluation of simulated strategies for reducing nitrate-nitrogen losses through subsurface drainage systems.

    PubMed

    Ale, Srinivasulu; Bowling, Laura C; Youssef, Mohamed A; Brouder, Sylvie M

    2012-01-01

    The nitrates (NO(3)-N) lost through subsurface drainage in the Midwest often exceed concentrations that cause deleterious effects on the receiving streams and lead to hypoxic conditions in the northern Gulf of Mexico. The use of drainage and water quality models along with observed data analysis may provide new insight into the water and nutrient balance in drained agricultural lands and enable evaluation of appropriate measures for reducing NO(3)-N losses. DRAINMOD-NII, a carbon (C) and nitrogen (N) simulation model, was field tested for the high organic matter Drummer soil in Indiana and used to predict the effects of fertilizer application rate and drainage water management (DWM) on NO-N losses through subsurface drainage. The model was calibrated and validated for continuous corn (Zea mays L.) (CC) and corn-soybean [Glycine max (L.) Merr.] (CS) rotation treatments separately using 7 yr of drain flow and NO(3)-N concentration data. Among the treatments, the Nash-Sutcliffe efficiency of the monthly NO(3)-N loss predictions ranged from 0.30 to 0.86, and the percent error varied from -19 to 9%. The medians of the observed and predicted monthly NO(3)-N losses were not significantly different. When the fertilizer application rate was reduced ~20%, the predicted NO(3)-N losses in drain flow from the CC treatments was reduced 17% (95% confidence interval [CI], 11-25), while losses from the CS treatment were reduced by 10% (95% CI, 1-15). With DWM, the predicted average annual drain flow was reduced by about 56% (95% CI, 49-67), while the average annual NO(3)-N losses through drain flow were reduced by about 46% (95% CI, 32-57) for both tested crop rotations. However, the simulated NO(3)-N losses in surface runoff increased by about 3 to 4 kg ha(-1) with DWM. For the simulated conditions at the study site, implementing DWM along with reduced fertilizer application rates would be the best strategy to achieve the highest NO(3)-N loss reductions to surface water. The

  5. Competitive Mg2+ block of a large-conductance, Ca(2+)-activated K+ channel in rat skeletal muscle. Ca2+, Sr2+, and Ni2+ also block

    PubMed Central

    1991-01-01

    The patch-clamp technique was used to investigate the effect of intracellular Mg2+ (Mgi2+) on the conductance of the large-conductance, Ca(2+)-activated K+ channel in cultured rat skeletal muscle. Measurements of single-channel current amplitudes indicated that Mgi2+ decreased the K+ currents in a concentration-dependent manner. Increasing Mgi2+ from 0 to 5, 10, 20, and 50 mM decreased channel currents by 34%, 44%, 56%, and 73%, respectively, at +50 mV. The magnitude of the Mgi2+ block increased with depolarization. For membrane potentials of -50, +50, and +90 mV, 20 mM Mgi2+ reduced the currents 22%, 56%, and 70%, respectively. Mgi2+ did not change the reversal potential, indicating that Mg2+ does not permeate the channel. The magnitude of the Mgi2+ block decreased as the concentration of K+ was increased. At a membrane potential of +50 mv, 20 mM Mgi2+ reduced the currents 71%, 56%, and 25% for Ki+ of 75, 150, and 500 mM. These effects of Mgi2+, voltage, and K+ were totally reversible. Although the Woodhull blocking model could approximate the voltage and concentration effects of the Mgi2+ block (Kd approximately 30 mM with 150 mM symmetrical K+; electrical distance approximately 0.22 from the inner surface), the Woodhull model could not account for the effects of K+. Double reciprocal plots of 1/single channel current vs. 1/[K+] in the presence and absence of Mgi2+, indicated that the Mgi2+ block is consistent with apparent competitive inhibition between Mgi2+ and Ki+. Cai2+, Nii2+, and Sri2+ were found to have concentration- and voltage- dependent blocking effects similar, but not identical, to those of Mgi2+. These observations suggest the blocking by Mgi2+ of the large- conductance, Ca(2+)-activated K+ channel is mainly nonspecific, competitive with K+, and at least partially electrostatic in nature. PMID:1940847

  6. Systematic Review of Acupuncture for Chronic Prostatitis/Chronic Pelvic Pain Syndrome

    PubMed Central

    Qin, Zongshi; Wu, Jiani; Zhou, Jing; Liu, Zhishun

    2016-01-01

    Abstract Acupuncture is a promising therapy for relieving symptoms in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), which affects >15% of adult men worldwide. The aim of the study was to assess the effects and safety of the use of acupuncture for CP/CPPS. MEDLINE, EMBASE, CENTRAL, Web of Science, CBM, CNKI, Wang-Fang Database, JCRM, and CiNii were searched from their inception through 30 November 2015. Grey literature databases and websites were also searched. No language limits were applied. Only randomized controlled trials (RCTs) with CP/CPPS treated by acupuncture were included. Two reviewers extracted data and assessed the risk of bias of RCTs using the Cochrane Risk of Bias Tools, respectively. Seven trials were included, involving 471 participants. The result of meta-analysis indicated that compared with sham acupuncture (MD: −6.09 [95%CI: −8.12 to −5.68]) and medicine (Levofloxacinand, Ibuprofen, and Tamsulosin) (MD: −4.57 [95%CI: −7.58 to −1.56]), acupuncture was more effective at decreasing the total NIH-CPSI score. Real acupuncture was superior to sham acupuncture in improving symptoms (pain, voiding) and quality of life (Qof) domain subscores. Compared to sham acupuncture and medicine, acupuncture appears to be more effective at improving the global assessment. Two trials found that there is no significant difference between acupuncture and sham acupuncture in decreasing the IPSS score. Acupuncture failed to show more favorable effects in improving both symptoms and the Qof domain compared with medicine. Overall, current evidence supports acupuncture as an effective treatment for CP/CPPS-induced symptoms, particularly in relieving pain. Based on the meta-analysis, acupuncture is superior to sham acupuncture in improving symptoms and Qof. Acupuncture might be similar to medicine (Levofloxacinand, Ibuprofen, and Tamsulosin) in its long-term effects, but evidence was limited due to high ROB among included trials as well as

  7. Is computerised CBT really helpful for adult depression?-A meta-analytic re-evaluation of CCBT for adult depression in terms of clinical implementation and methodological validity

    PubMed Central

    2013-01-01

    Background Depression is a major cause of disability worldwide, and computerised cognitive behavioural therapy (CCBT) is expected to be a more augmentative and efficient treatment. According to previous meta-analyses of CCBT, there is a need for a meta-analytic revaluation of the short-term effectiveness of this therapy and for an evaluation of its long-term effects, functional improvement and dropout. Methods Five databases were used (MEDLINE, PsycINFO, EMBASE, CENTRAL and CiNii). We included all RCTs with proper concealment and blinding of outcome assessment for the clinical effectiveness of CCBT in adults (aged 18 and over) with depression. Using Cohen’s method, the standard mean difference (SMD) for the overall pooled effects across the included studies was estimated with a random effect model. The main outcome measure and the relative risk of dropout were included in the meta-analysis. Results Fourteen trials met the inclusion criteria, and sixteen comparisons from these were used for the largest meta-analysis ever. All research used appropriate random sequence generation and Intention-to-Treat analyses (ITT), and employed self-reported measures as the primary outcome. For the sixteen comparisons (2807 participants) comparing CCBT and control conditions, the pooled SMD was −0.48 [95% IC −0.63 to −0.33], suggesting similar effect to the past reviews. Also, there was no significant clinical effect at long follow-up and no improvement of function found. Furthermore, a significantly higher drop-out rate was found for CCBT than for controls. When including studies without BDI as a rating scale and with only modern imputation as sensitivity analysis, the pooled SMD remained significant despite the reduction from a moderate to a small effect. Significant publication bias was found in a funnel plot and on two tests (Begg’s p = 0.09; Egger’s p = 0.01). Using a trim and fill analysis, the SMD was −0.32 [95% CI −0.49 to −0.16]. Conclusion

  8. A Multiwavelength Study of the OH Megamaser Galaxy IRAS16399-0937

    NASA Astrophysics Data System (ADS)

    Sales, D.

    2015-09-01

    We present a multiwavelength study of the morphology and spectral energy distribution (SED) of the OH Megamaser galaxy (OHMG) IRAS16399- 0937, based on new HST ACS broad band (F814W) and emission line (Halpha+[NII]) images and archive data from HST, 2MASS, Spitzer, Herschel and the VLA (Fig. 1). This system has a double nucleus, whose northern (IRAS16399N) and southern (IRAS16399S) components have a projected separation of 6" (3.4 kpc) and have previously been optically identified as a Low Ionization Nuclear Emission Line Region (LINER) and Starburst (SB) nucleus, respectively. The nuclei are embedded in a tidally distorted common envelope, in which star formation activity is widespread, but mostly heavily obscured (Fig. 1). The infrared spectrum is dominated by strong polycyclic aromatic hydrocarbon (PAH) features, but deep silicate absorption and absorption features due to water ice and hydrogenated amorphous carbon grains are also present, and are strongest in the IRAS16399N nucleus (Fig. 2 and 3). The radio emission, including the compact component associated with the IRAS16399N nucleus, is generally consistent with star formation. The global star formation rate (SFR) is 20M(sun)/yr, with the two nuclei accounting for 40% of the total (Table 2). The 0.435 - 500 micron SED was fitted with a model including stellar, dusty+PAH ISM and AGN torus components using our new Markov Chain Monte Carlo code, clumpyDREAM (Fig. 4). The results indicate that the IRAS16399N nucleus contains an AGN of bolometric luminosity (Lbol 10^{44} ergs/s), which is deeply embedded in a quasi-spherical distribution of optically thick clumps with a covering fraction 1 (Table 1). We suggest that these clumps are the source of the OH megamaser emission in IRAS16399-0937. The high torus covering fraction precludes AGN photoionization as the origin of the LINER spectrum, however, the spectrum is consistent with shocks of velocity 100 - 200 km/s. The SED fits indicate SFRs of 2.9 and 2.4 M

  9. Anthropogenic heavy metals in the environment of Eurasian Arctic Nature Reserves

    NASA Astrophysics Data System (ADS)

    Vinogradova, Anna; Ivanova, Yulia; Karpov, Alexey

    2014-05-01

    The Russian Arctic Nature Reserves are situated far from the main industrial regions. In spite of this, there are anthropogenic constituents (for example, heavy metals - HM) in the environmental objects (air, water, etc.) and in food chains (plants, birds, and so on). We studied the long-range atmospheric transport of some heavy metals (such as nickel, copper, lead, arsenic, and so on) to four Nature Reserves situated near the shore of the Arctic Ocean - in the Deltas of the Pechora River (Nenets reserve), the Ob River (Gydansky reserve), the Lena River (Ust-Lensky reserve), and at Wrangel Island. The air mass trajectories to each reserve were calculated with the help of the site (www.arl.noaa.gov/ready) for each day of January, April, July, and October for the period of 2001-2010. Analyzing the spatial distributions of these trajectories we studied seasonal variations in air transport of pollution to different Russian Arctic points. Modeling the HM transport in the atmosphere was as in [1]. The main assumption is that HM are transported with submicron aerosol particles. The annual source emissions for the last decade are generalized from the data published by Roshydromet of Russia (http://www.nii-atmosphere.ru/files/PUBL/Eg_2008.doc). The main important source-regions were found for each point. Mean anthropogenic HM concentrations in air and precipitations, as well as HM fluxes onto the surface were estimated at different arctic regions. The spatial distributions of so called "potential function of pollution" were calculated and presented on the maps. These results allow to analyze the role of a real pollution source or of a planned source for each reserve. So, the influence of northern oil and gas industry may be of great importance because of its proximity to the reserves under investigation. The work was partly supported by RFBR, grant No. 14-05-00059. Authors thank the NOAA service for possibility to use their data and products. ________________ 1. Vinogradova

  10. A multiwavelength study of the remnant of nova GK Persei

    NASA Astrophysics Data System (ADS)

    Anupama, G. C.; Kantharia, N. G.

    2005-05-01

    We present new observations of the nebular remnant of the old nova GK Persei 1901 in the optical using the Himalayan Chandra Telescope (HCT) and at low radio frequencies using the Giant Metrewave Radio Telescope (GMRT). The dimensions of the shell in the optical emission lines of [NII], [OIII] and [OII] are 108× 94 arcsec2, 104× 94 arcsec2 and 99× 87 arcsec2, respectively. The evolution of the nova remnant indicates shock interaction with the ambient medium, especially in the southwest quadrant. Application of a simple model for the shock and its evolution to determine the time dependence of the radius of the shell in the southwest quadrant indicates that the shell is now expanding into an ambient medium that has a density of 0.12 cm-3, compared to the density of the ambient medium of 0.8 cm-3 ahead of the shock in 1987. There are indications of a recent interaction of the nova remnant with the ambient medium in the northeast quadrant. There is a distinct flattening of the shell, as well as an increase in the number and brightness of the knots in the region. The brightest optical knots in this region are also detected in the radio images. The nova remnant of GK Per is detected at all the observed radio frequencies and is of a similar extent to the optical remnant. Putting together our radio observations with VLA archival data on GK Per from 1997, we obtain three interesting results: 1. the spectrum above 1.4 GHz follows a power law with an index -0.7 (S∝ να) and below 1.4 GHz follows a power law with an index ˜ -0.85. This could be due to the presence of at least two populations of electrons dominating the global emission at different frequencies; 2. we record an annual secular decrease of 2.1% in the flux density of the nova remnant at 1.4 and 4.9 GHz between 1984 and 1997 which has left the spectral index unchanged at -0.7. No such decrease is observed in the flux densities below 1 GHz; 3. we record an increase in the flux density at 0.33 GHz compared to

  11. MUSE discovers perpendicular arcs in the inner filament of Centaurus A

    NASA Astrophysics Data System (ADS)

    Hamer, S.; Salomé, P.; Combes, F.; Salomé, Q.

    2015-03-01

    Context. Evidence of active galactic nuclei (AGN) interaction with the intergalactic medium is observed in some galaxies and many cool core clusters. Radio jets are suspected to dig large cavities into the surrounding gas. In most cases, very large optical filaments (several kpc) are also seen all around the central galaxy. The origin of these filaments is still not understood. Star-forming regions are sometimes observed inside the filaments and are interpreted as evidence of positive feedback (AGN-triggered star formation). Aims: Centaurus A is a very nearby galaxy with huge optical filaments aligned with the AGN radio-jet direction. Here, we searched for line ratio variations along the filaments, kinematic evidence of shock-broadend line widths, and large-scale dynamical structures. Methods: We observed a 1' × 1' region around the so-called inner filament of Cen A with the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT) during the Science Verification period. Results: (i) The brightest lines detected are the Hαλ6562.8, [NII]λ6583, [OIII]λ4959+5007 and [SII]λ6716+6731. MUSE shows that the filaments are made of clumpy structures inside a more diffuse medium aligned with the radio-jet axis. We find evidence of shocked shells surrounding the star-forming clumps from the line profiles, suggesting that the star formation is induced by shocks. The clump line ratios are best explained by a composite of shocks and star formation illuminated by a radiation cone from the AGN. (ii) We also report a previously undetected large arc-like structure: three streams running perpendicular to the main filament; they are kinematically, morphologically, and excitationally distinct. The clear difference in the excitation of the arcs and clumps suggests that the arcs are very likely located outside of the radiation cone and match the position of the filament only in projection. The three arcs are thus most consistent with neutral material swept along by a

  12. Ionization processes in a local analogue of distant clumpy galaxies: VLT MUSE IFU spectroscopy and FORS deep images of the TDG NGC 5291N

    NASA Astrophysics Data System (ADS)

    Fensch, J.; Duc, P.-A.; Weilbacher, P. M.; Boquien, M.; Zackrisson, E.

    2016-01-01

    Context. We present Integral Field Unit (IFU) observations with MUSE and deep imaging with FORS of a dwarf galaxy recently formed within the giant collisional HI ring surrounding NGC 5291. This Tidal Dwarf Galaxy (TDG) -like object has the characteristics of typical z = 1-2 gas-rich spiral galaxies: a high gas fraction, a rather turbulent clumpy interstellar medium, the absence of an old stellar population, and a moderate metallicity and star formation efficiency. Aims: The MUSE spectra allow us to determine the physical conditions within the various complex substructures revealed by the deep optical images and to scrutinize the ionization processes at play in this specific medium at unprecedented spatial resolution. Methods: Starburst age, extinction, and metallicity maps of the TDG and the surrounding regions were determined using the strong emission lines Hβ, [OIII], [OI], [NII], Hα, and [SII] combined with empirical diagnostics. Different ionization mechanisms were distinguished using BPT-like diagrams and shock plus photoionization models. Results: In general, the physical conditions within the star-forming regions are homogeneous, in particular with a uniform half-solar oxygen abundance. On small scales, the derived extinction map shows narrow dust lanes. Regions with atypically strong [OI] emission line immediately surround the TDG. The [OI]/ Hα ratio cannot be easily accounted for by the photoionization by young stars or shock models. At greater distances from the main star-foming clumps, a faint diffuse blue continuum emission is observed, both with the deep FORS images and the MUSE data. It does not have a clear counterpart in the UV regime probed by GALEX. A stacked spectrum towards this region does not exhibit any emission line, excluding faint levels of star formation, or stellar absorption lines that might have revealed the presence of old stars. Several hypotheses are discussed for the origin of these intriguing features. Based on observations

  13. X-shooter spectroscopy of the puzzling gamma-ray source 3FGL1603.9-4903/PMN J1603-4904

    NASA Astrophysics Data System (ADS)

    Goldoni, P.; Pita, S.; Boisson, C.; Müller, C.; Dauser, T.; Jung, I.; Krauss, F.; Lenain, J.-P.; Sol, H.

    2016-08-01

    The Fermi/LAT instrument has detected about two thousand extragalactic high energy (E > 100 MeV) gamma-ray sources. 3FGL 1603.9-4903 is a very hard and bright one and it is associated to the radio source PMN J1603-4904. Its nature is not yet clear as it could be either a very peculiar BL Lac or a compact symmetric object radio source which are considered as the early stage of a radio galaxy. The latter, if confirmed, would be the first detection in gamma-rays for this class of objects. A redshift z=0.18 +/- 0.01 has recently been claimed on the basis of the detection of a single X-ray line at 5.44 +/- 0.05 keV which has been interpreted as a 6.4 keV (rest frame) fluorescent line. We observed PMN J1603-4904 with the UV-NIR VLT/X-shooter spectrograph for two hours. We extracted spectra in the visible and NIR range that we calibrated in flux and corrected for telluric absorption. We systematically searched for absorption and emission features. The source was detected starting from ~ 6300 Ang down to 24000 Ang with an intensity similar to that of its 2MASS counterpart and a mostly featureless spectrum. The continuum lacks absorption features and thus is non-stellar in origin and most likely non-thermal. In addition to this spectrum, we detected three emission lines that we interpret as the Halpha-[NII] complex, the [SII] 6716,6731 doublet and the [SIII] 9530 line; we obtain a redshift estimate of z= 0.2321 +/- 0.0004. The line ratios suggest that a LINER/Seyfert nucleus powers the emission. This new redshift measurement implies that the X-ray line previously detected should be interpreted as a 6.7 keV line which is very peculiar but not impossible for this kind of source.

  14. Optical-NIR spectroscopy of the puzzling γ-ray source 3FGL 1603.9-4903/PMN J1603-4904 with X-Shooter

    NASA Astrophysics Data System (ADS)

    Goldoni, P.; Pita, S.; Boisson, C.; Müller, C.; Dauser, T.; Jung, I.; Krauß, F.; Lenain, J.-P.; Sol, H.

    2016-02-01

    Context. The Fermi/LAT instrument has detected about two thousand extragalactic high energy (E ≥ 100 MeV) γ-ray sources. One of the brightest is 3FGL J1603.9-4903; it is associated to the radio source PMN J1603-4904. Its nature is not yet clear, it could be either a very peculiar BL Lac or a compact symmetric object radio source which are considered as the early stage of a radio galaxy. The latter, if confirmed, would be the first detection in γ-rays for this class of objects. A redshift z = 0.18 ± 0.01 has recently been claimed on the basis of the detection of a single X-ray line at 5.44 ± 0.05 keV which has been interpreted as a 6.4 keV (rest frame) fluorescent line. Aims: We aim to investigate the nature of 3FGL J1603.9-4903/PMN J1603-4904 using optical-to near-IR (NIR) spectroscopy. Methods: We observed PMN J1603-4904 with the UV-NIR VLT/X-Shooter spectrograph for two hours. We extracted spectra in the visible and NIR range that we calibrated in flux and corrected for telluric absorption. We systematically searched for absorption and emission features. Results: The source was detected starting from ~6300 Å down to 24 000 Å with an intensity similar to that of its 2MASS counterpart and a mostly featureless spectrum. The continuum lacks absorption features and thus is non-stellar in origin and most likely non-thermal. In addition to this spectrum, we detected three emission lines that we interpret as the Hα-[NII] complex, the [SII]λ,λ6716, 6731 doublet and the [SIII]λ 9530 line; we obtain a redshift estimate of z = 0.2321 ± 0.0004. The line ratios suggest that a LINER/Seyfert nucleus powers the emission. This new redshift measurement implies that the X-ray line previously detected should be interpreted as a 6.7 keV line which is very peculiar. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under program 095.B-0400(A). The raw FITS data files are available in the ESO archive.

  15. Outflows and complex stellar kinematics in SDSS star-forming galaxies

    NASA Astrophysics Data System (ADS)

    Cicone, C.; Maiolino, R.; Marconi, A.

    2016-04-01

    We investigate the properties of star-formation-driven outflows by using a large spectroscopic sample of ~160 000 local "normal" star-forming galaxies drawn from the Sloan digital sky survey (SDSS), spanning a wide range of star formation rates (SFRs) and stellar masses (M∗). The galaxy sample is divided into a fine grid of bins in the M∗-SFR parameter space, for each of which we produced a composite spectrum by stacking the SDSS spectra of the galaxies contained in that bin together. We exploited the high signal-to-noise of the stacked spectra to study the emergence of faint features of optical emission lines that may trace galactic outflows and are otherwise too faint to detect in individual galaxy spectra. We have adopted a novel approach that relies on the comparison between the line-of-sight velocity distribution (LoSVD) of the ionised gas (as traced by the [OIII]λ5007 and Hα+[NII]λλ6548, 6583 emission lines) and the LoSVD of the stars, which are used as a reference for tracing virial motions. Significant deviations in the gas kinematics from the stellar kinematics in the high-velocity tail of the LoSVDs are interpreted as a signature of outflows. Our results suggest that the incidence of ionised outflows increases with SFR and specific SFR. The outflow velocity (vout) is found to correlate tightly with the SFR for SFR> 1 M⊙ yr-1, whereas the dependence of vout on SFR is nearly flat at lower SFRs. The outflow velocity appears to also increase with the stellar velocity dispersion (σ∗), although this relation has a much larger scatter than the one with SFR, and we infer velocities as high as vout ~ (6-8)σ∗. Strikingly, we detect the signature of ionised outflows only in galaxies located above the main sequence (MS) of star-forming galaxies in the M∗-SFR diagram, and the incidence of such outflows increases sharply with the offset from the MS. This result suggests that star-formation-driven outflows may be responsible for shaping the upper

  16. On solving the Diophantine equation x^3+y^3+z^3=k on a vector computer

    NASA Astrophysics Data System (ADS)

    Heath-Brown, D. R.; Lioen, W. M.; Riele, H. J. J. Te

    1993-07-01

    Recently, the first author has proposed a new algorithm for solving the Diophantine equation {x^3} + {y^3} + {z^3} = k , where k is a given nonzero integer. In this paper we present the detailed versions of this algorithm for some values of k given below, and we describe how we have optimized and run the algorithm on a Cyber 205 vector computer. A vectorized version of the Euclidean algorithm was written, which is capable of solving the equations {w_i}{x_i} ≡ 1 bmod {n_i},i = 1,2, ldots , at vector speed. Moreover, the basic double-precision arithmetic operations ( + , - , × ,/) were vectorized. The following cases were implemented and run: k = 3,30,2,20,39 , and 42. For k = 3 a range was searched which includes the cube \\vert x\\vert,\\vert y\\vert,\\vert z\\vert ≤ {10^8} ; this considerably extends an earlier search in the cube \\vert x\\vert,\\vert y\\vert,\\vert z\\vert ≤ {2^{16}} . No solutions were found apart from the known ones (1, 1, 1) and (4,4, - 5) . For k = 30 , which probably is, with k = 3 , the case which has attracted most attention in the literature, no solution was found. It is the smallest case for which no solution is known and for which one has not been able to find a proof that no solution exists. For k = 2 a parametric form solution is known, but we also found one which does not belong to this parametric form, viz., (1214928,3480205, - 3528875) . For k = 20 , several new large solutions were found in addition to several known ones; this case served as a (partial) check of the correctness of our program. Finally, for k = 39 we found the first solution: (134476,117367, - 159380) . Hence, this case can be dropped from the list of values of k (k = 30,33,39,42, ldots ) for which no solution is known (yet).

  17. SWSextantis stars: the dominant population of cataclysmic variables with orbital periods between 3 and 4h

    NASA Astrophysics Data System (ADS)

    Rodríguez-Gil, P.; Gänsicke, B. T.; Hagen, H.-J.; Araujo-Betancor, S.; Aungwerojwit, A.; Allende Prieto, C.; Boyd, D.; Casares, J.; Engels, D.; Giannakis, O.; Harlaftis, E. T.; Kube, J.; Lehto, H.; Martínez-Pais, I. G.; Schwarz, R.; Skidmore, W.; Staude, A.; Torres, M. A. P.

    2007-06-01

    We present time-series optical photometry of five new cataclysmic variables (CVs) identified by the Hamburg Quasar Survey (HQS). The deep eclipses observed in HS 0129+2933 (= TT Tri), HS 0220+0603 and HS 0455+8315 provided very accurate orbital periods of 3.35129827(65), 3.58098501(34) and 3.56937674(26) h, respectively. HS 0805+3822 shows grazing eclipses and has a likely orbital period of 3.2169(2) h. Time-resolved optical spectroscopy of the new CVs (with the exception of HS 0805+3822) is also presented. Radial velocity studies of the Balmer emission lines provided an orbital period of 3.55 h for HS 1813+6122, which allowed us to identify the observed photometric signal at 3.39 h as a negative superhump wave. The spectroscopic behaviour exhibited by all the systems clearly identifies them as new SW Sextantis (SW Sex) stars. HS 0220+0603 shows unusual NII and SiII emission lines suggesting that the donor star may have experienced nuclear evolution via the CNO cycle. These five new additions to the class increase the number of known SW Sex stars to 35. Almost 40 per cent of the total SW Sex population do not show eclipses, invalidating the requirement of eclipses as a defining characteristic of the class and the models based on a high orbital inclination geometry alone. On the other hand, as more SW Sex stars are identified, the predominance of orbital periods in the narrow 3-4.5 h range is becoming more pronounced. In fact, almost half the CVs which populate the 3-4.5 h period interval are definite members of the class. The dominance of SW Sex stars is even stronger in the 2-3 h period gap, where they make up 55 per cent of all known gap CVs. These statistics are confirmed by our results from the HQS CVs. Remarkably, 54 per cent of the Hamburg nova-like variables have been identified as SW Sex stars with orbital periods in the 3-4.5 h range. The observation of this pile-up of systems close to the upper boundary of the period gap is difficult to reconcile with the

  18. Functional characterization of Aspergillus nidulans ypkA, a homologue of the mammalian kinase SGK.

    PubMed

    Colabardini, Ana Cristina; Brown, Neil Andrew; Savoldi, Marcela; Goldman, Maria Helena S; Goldman, Gustavo Henrique

    2013-01-01

    The serum- and glucocorticoid-regulated protein kinase (SGK) is an AGC kinase involved in signal cascades regulated by glucocorticoid hormones and serum in mammals. The Saccharomyces cerevisiae ypk1 and ypk2 genes were identified as SGK homologues and Ypk1 was shown to regulate the balance of sphingolipids between the inner and outer plasma membrane. This investigation characterized the Aspergillus nidulans YPK1 homologue, YpkA, representing the first filamentous fungal YPK1 homologue. Two conditional mutant strains were constructed by replacing the endogenous ypk1 promoter with two different regulatable promoters, alcA (from the alcohol dehydrogenase gene) and niiA (from the nitrate reductase gene). Both constructs confirmed that ypkA was an essential gene in A. nidulans. Repression of ypkA caused decreased radial growth, a delay in conidial germination, deficient polar axis establishment, intense branching during late stages of growth, a lack of asexual spores, and a terminal phenotype. Membrane lipid polarization, endocytosis, eisosomes and vacuolar distribution were also affected by ypkA repression, suggesting that YpkA plays a role in hyphal morphogenesis via coordinating the delivery of cell membrane and wall constituents to the hyphal apex. The A. nidulans Pkh1 homologue pkhA was also shown to be an essential gene, and preliminary genetic analysis suggested that the ypkA gene is not directly downstream of pkhA or epistatic to pkhA, rather, ypkA and pkhA are genetically independent or in parallel. BarA is a homologue of the yeast Lag1 acyl-CoA-dependent ceramide synthase, which catalyzes the condensation of phytosphingosine with a fatty acyl-CoA to form phytoceramide. When barA was absent, ypkA repression was lethal to the cell. Therefore, there appears to be a genetic interaction between ypkA, barA, and the sphingolipid synthesis. Transcriptional profiling of ypkA overexpression and down-regulation revealed several putative YpkA targets associated with the

  19. Planetary Nebulae in the Solar Neighbourhood: Statistics, Distance Scale and Luminosity Function

    NASA Astrophysics Data System (ADS)

    Frew, David J.

    2008-07-01

    An accurate census of the nearest planetary nebulae (PNe) is needed for calculations of the total number, space density, scale height, and birth rate of PNe in the Galaxy, to understand the dynamics of an evolving nebula and its relationship to the cooling history of the central star, and also to provide an unbiased sample to investigate the frequency of binary central stars and their role in the formation and shaping of these objects. This study presents the most refined volume-limited survey of PNe known to date. Integrated H-alpha fluxes for over 400 mostly evolved PNe are presented, based primarily on data from the Southern H-alpha Sky Survey Atlas (SHASSA) and the Virginia Tech Spectral-Line Survey (VTSS). Aperture photometry on the digital images was performed to extract H-alpha+[NII] fluxes. The [NII] contribution was then de-convolved using literature data, new data from slit spectra, or spectrophotometric data from the Wisconsin H-Alpha Mapper (WHAM) also obtained as part of this project. Comparison with previous work shows that the flux scale presented here has no significant zero-point error. The H-alpha fluxes are used to determine new Zanstra temperatures for those PNe with accurate central star photometry, calculating surface-brightness distances for each PN in the sample, and in conjunction with accurate [OIII] fluxes, new absolute PN magnitudes for delineating the faint end of the PN luminosity function. A spectroscopic survey of a range of MASH PNe is also presented. New emission-line intensities for 60 PNe are given, including a preliminary discussion of the chemical abundances of this sample. New distances have been determined for a large number of PNe, by either critically examining the literature, or by deriving new extinction and kinematic distances where suitable. For all PNe not amenable to these approaches, distances were estimated from a new H-alpha surface brightness-radius (SB-r) relation. The Hα SB-r relation covers >6 dex in SB, and

  20. A 2 THz Heterodyne Array Receiver for SOFIA

    NASA Technical Reports Server (NTRS)

    Walker, Christopher K.

    1998-01-01

    We proposed to perform a comprehensive design study of a 16-element heterodyne array receiver for SOFIA. The array was designed to utilize hot-electron bolometers in an efficient, low-cost waveguide mount to achieve low noise performance between approx. 1500 and 2400 GHz. Due to the prevailing physical conditions in the interstellar medium, this frequency range is one of the richest in the FIR portion of the spectrum. An array designed for this wavelength range will make excellent use of the telescope and the available atmospheric transmission, and will provide a new perspective on stellar, chemical, and galaxy evolution in the present as well as past epochs. A few of the most important molecular and atomic species which the instrument will sample are CII, OI, CO, OH, NII, and CH. The system used the most sensitive detectors available in an efficient optical system. The local oscillator was a compact CO2 pumped far-infrared laser currently under development for SOFIA. The backend spectrometer was an array acousto-optic spectrometer (aAOS). The spectrometer utilizes proven hardware and technologies to provide broadband performance (greater than or equal to 1 GHz per AOS channel) and high spectral resolution (1 MHz) with the maximum sensitivity and minimum complexity and cost. The proposed instrument would be the fastest and most sensitive heterodyne receiver ever to operate in the 1.5 - 2.4 THz band. One of the key technologies developed for the proposed instrument is the laser micromachining of waveguide structures. These structures provide both the optical link between the instrument and the telescope (via an array of efficient feedhorns) and the impedance transformation between the detectors and free space. With the assistance of funds provided from this grant, we were able to fabricate and test the world's first laser micromachined feedhorns. Figure 1 is a photograph of the 2 THz double feedhorn structure designed and constructed under the auspices of this grant

  1. Microbial activity and soil organic matter decay in roadside soils polluted with petroleum hydrocarbons

    NASA Astrophysics Data System (ADS)

    Mykhailova, Larysa; Fischer, Thomas; Iurchenko, Valentina

    2015-04-01

    positively correlated with the carbohydrate fraction and negatively correlated with the aliphatic fraction of the soil C, while carbohydrate-C and alkyl-C increased and decreased with distance from the road, respectively. It is proposed that petroleum hydrocarbons supress soil biological activity at concentrations above 1500 mg kg-1, and that soil organic matter priming primarily affects the carbohydrate fraction of soil organic matter. It can be concluded that the abundance of solid carbohydrates (O-alkyl C) is of paramount importance for the hydrocarbon mineralization under natural conditions, compared to more recalcitrant SOM fractions (mainly aromatic and alkyl C). References Mykhailova, L., Fischer, T., Iurchenko, V. (2013) Distribution and fractional composition of petroleum hydrocarbons in roadside soils. Applied and Environmental Soil Science, vol. 2013, Article ID 938703, 6 pages, DOI 10.1155/2013/938703 Mykhailova, L., Fischer, T., Iurchenko, V. (2014) Deposition of petroleum hydrocarbons with sediment trapped in snow in roadside areas. Journal of Environmental Engineering and Landscape Management 22(3):237-244, DOI 10.3846/16486897.2014.889698 Nelson P.N. and Baldock J.A. (2005) Estimating the molecular composition of a diverse range of natural organic materials from solid-state 13C NMR and elemental analyses, 2005, Biogeochemistry (2005) 72: 1-34, DOI 10.1007/s10533-004-0076-3 Zyakun, A., Nii-Annang, S., Franke, G., Fischer, T., Buegger, F., Dilly, O. (2011) Microbial Actvity and 13C/12C Ratio as Evidence of N-Hexadecane and N-Hexadecanoic Acid Biodegradation in Agricultural and Forest Soils. Geomicrobiology Journal 28:632-647, DOI 10.1080/01490451.2010.489922

  2. VizieR Online Data Catalog: Multi-resolution images of M33 (Boquien+, 2015)

    NASA Astrophysics Data System (ADS)

    Boquien, M.; Calzetti, D.; Aalto, S.; Boselli, A.; Braine, J.; Buat, V.; Combes, F.; Israel, F.; Kramer, C.; Lord, S.; Relano, M.; Rosolowsky, E.; Stacey, G.; Tabatabaei, F.; van der Tak, F.; van der Werf, P.; Verley, S.; Xilouris, M.

    2015-02-01

    The FITS file contains maps of the flux in star formation tracing bands, maps of the SFR, maps of the attenuation in star formation tracing bands, and a map of the stellar mass of M33, each from a resolution of 8"/pixel to 512"/pixel. The FUV GALEX data from NGS were obtained directly from the GALEX website through GALEXVIEW. The observation was carried out on 25 November 2003 for a total exposure time of 3334s. Hα+[NII] observations were carried out in November 1995 on the Burrel Schmidt telescope at Kitt Peak National Observatory. The observations and the data processing are analysed in detail in Hoopes & Walterbos (2000ApJ...541..597H). The Spitzer IRAC 8um image sensitive to the emission of Polycyclic Aromatic Hydrocarbons (PAH) and the MIPS 24um image sensitive to the emission of Very Small Grains (VSG) were obtained from the NASA Extragalactic Database and have been analysed by Hinz et al. (2004ApJS..154..259H) and Verley et al. (2007A&A...476.1161V, Cat. J/A+A/476/1161). The PACS data at 70um and 100um, which are sensitive to the warm dust heated by massive stars, come from two different programmes. The 100um image was obtained in the context of the Herschel HerM33es open time key project (Kramer et al., 2010A&A...518L..67K, observation ID 1342189079 and 1342189080). The observation was carried out in parallel mode on 7 January 2010 for a duration of 6.3h. It consisted in 2 orthogonal scans at a speed of 20"/s, with a leg length of 7'. The 70um image was obtained as a follow-up open time cycle 2 programme (OT2mboquien4, observation ID 1342247408 and 1342247409). M33 was scanned on 25 June 2012 at a speed of 20"/s in 2 orthogonal directions over 50' with 5 repetitions of this scheme in order to match the depth of the 100um image. The total duration of the observation was 9.9h. The cube, cube.fits files, contains 16 extensions: * FUV * HALPHA * 8 * 24 * 70 * 100 * SFR_FUV * SFR_HALPHA * SFR_24 * SFR_70 * SFR_100 * SFRFUV24 * SFRHALPHA24 * A_FUV * A

  3. Comparative Spectroscopic Analysis of B[e] Supergiants and LBV

    NASA Astrophysics Data System (ADS)

    Borges Fernandes, M.

    2000-02-01

    The upper HRD is populated by massive stars. These objects have, as a characteristic, a substantial mass loss, due mostly to radiation pressure, throughout their whole lives. However about the evolution of these stars, the only secure informations are that they are B or O type stars in the zero age main sequence and they finish their lifes in a supernova explosion. The difficulties, to ascertain the others evolutive stages of these objects, are that they do not exhibit (in most cases) photosferic absorption lines, due to their complex circumstellar medium, preventing the estimate of the physical parameters. Moreover, these phases are relatively "shorts", and so we have a little sample of objects. Among the "short" phases, we detach the B[e] Supergiant (B[e]sg) and the Luminous Blue Variable (LBV) phases. The stars in these two evolutive stages show similar characteristics in the optical spectrum. They are, the presence in B type stars, of forbidden emission lines of [FeII], [OI] (in the B[e]sg) and [NII] (in the LBV). The presence of strong Balmer emission lines, low excitation permitted emission lines of predominantly low ionization metals, e.g. FeII in the optical spectrum and a strong near or mid-infrared excess due to hot circumstellar dust. In general, the Balmer lines (and sometimes HeI and FeII lines too) show P-Cygni profiles, due to mass loss. In despite of the similarities, the LBV are separated of the B[e]sg, due to strong spectral-photometric variability. Then it is necessary a detailed spectroscopical analysis of some objects, to obtain not only a better classification, like a B[e]sg or LBV, but useful informations to perform in the future a physical model. We have done such analysis for five stars in the Galaxy: HD 87643, HD 89249, HR Car, GG Car and CPD-529243. With our new data, others presented by literature, and a long time monitoring of these stars, we believe that in the near future, it will be possible to determine a correct classification to

  4. Approximate theoretical model for the five electronic states ( Ω = 5/2, 3/2, 3/2, 1/2, 1/2) arising from the ground 3d 9 configuration in nickel halide molecules and for rotational levels of the two Ω = 1/2 states in that manifold

    NASA Astrophysics Data System (ADS)

    Hougen, Jon T.

    2011-05-01

    their difference can vary between -10 B and +10 B. These theoretical results are in good agreement with the two observed p values for both NiF and NiCl. The present formalism should in principle be applicable to NiBr and NiI, and to the halides of palladium, since Pd + has a well isolated 4d 9 electronic ground configuration. Extension to metal halides having d n configurations with n < 9, or to platinum halides may present difficulties, since manifolds from the d n and d n-1s configurations may be heavily mixed, thus requiring "too many" parameters in the electronic part of the problem. Application to linear triatomic molecules may also present problems because of the large number of vibronic perturbations made possible by their four vibrational degrees of freedom.

  5. Spectroscopic aperture biases in inside-out evolving early-type galaxies from CALIFA

    NASA Astrophysics Data System (ADS)

    Gomes, J. M.; Papaderos, P.; Vílchez, J. M.; Kehrig, C.; Iglesias-Páramo, J.; Breda, I.; Lehnert, M. D.; Sánchez, S. F.; Ziegler, B.; Dos Reis, S. N.; Bland-Hawthorn, J.; Galbany, L.; Bomans, D. J.; Rosales-Ortega, F. F.; Walcher, C. J.; García-Benito, R.; Márquez, I.; Del Olmo, A.; Mollá, M.; Marino, R. A.; Catalán-Torrecilla, C.; González Delgado, R. M.; López-Sánchez, Á. R.; Califa Collaboration

    2016-02-01

    Integral field spectroscopy (IFS) studies based on CALIFA survey data have recently revealed ongoing low-level star formation (SF) in the periphery of a small fraction (~10%) of local early-type galaxies (ETGs), witnessing a still ongoing inside-out galaxy growth process. A distinctive property of the nebular component in these ETGs, classified i+, is a structure with two radial zones, the inner of which displays LINER emission with a Hα equivalent width EW(Hα) ≃ 1 Å, the outer (3 Å Nii]/Hα vs. [Oiii]/Hβ emission-line (BPT) ratios consists of a monotonic shift upward and to the right precisely along the upper right wing of the "seagull" distribution on the BPT plane, that is, along the pathway connecting composite SF/Hii galaxies with AGN/LINERs. Motivated by these observational insights, we also investigate theoretically observational biases in aperture-limited studies of inside-out growing galaxies as a function of z. To this end, we devise a simple 1D model that involves an outward-propagating exponentially decreasing SF process since z ~ 10 and reproduces the radial extent and two-zone EW

  6. Spectacular tails of ionized gas in the Virgo cluster galaxy NGC 4569

    NASA Astrophysics Data System (ADS)

    Boselli, A.; Cuillandre, J. C.; Fossati, M.; Boissier, S.; Bomans, D.; Consolandi, G.; Anselmi, G.; Cortese, L.; Côté, P.; Durrell, P.; Ferrarese, L.; Fumagalli, M.; Gavazzi, G.; Gwyn, S.; Hensler, G.; Sun, M.; Toloba, E.

    2016-03-01

    Context. Using MegaCam at the CFHT, we obtained a deep narrow band Hα+[NII] wide-field image of NGC 4569 (M90), the brightest late-type galaxy in the Virgo cluster. The image reveals the presence of long tails of diffuse ionized gas, without any associated stellar component extending from the disc of the galaxy up to ≃80 kpc (projected distance) and with a typical surface brightness of a few 10-18 erg s-1 cm-2 arcsec-2. These features provide direct evidence that NGC 4569 is undergoing a ram-presure stripping event. The image also shows a prominent 8 kpc spur of ionized gas that is associated with the nucleus that spectroscopic data identify as an outflow. With some assumptions on the 3D distribution of the gas, we use the Hα surface brightness of these extended low-surface brightness features to derive the density and the mass of the gas that has been stripped during the interaction of the galaxy with the intracluster medium. The comparison with ad hoc chemo-spectrophotometric models of galaxy evolution indicates that the mass of the Hα emitting gas in the tail is a large fraction of that of the cold phase that has been stripped from the disc, suggesting that the gas is ionized within the tail during the stripping process. The lack of star-forming regions suggests that mechanisms other than photoionization are responsible for the excitation of the gas (shocks, heat conduction, magneto hydrodynamic waves). This analysis indicates that ram pressure stripping is efficient in massive (Mstar ≃ 1010.5 M⊙) galaxies located in intermediate-mass (≃1014 M⊙) clusters under formation. It also shows that the mass of gas expelled by the nuclear outflow is only ~1% than that removed during the ram pressure stripping event.Together these results indicate that ram pressure stripping, rather than starvation through nuclear feedback, can be the dominant mechanism that is responsible for the quenching of the star formation activity of galaxies in high density

  7. Cross-Couplings Using Aryl Ethers via C-O Bond Activation Enabled by Nickel Catalysts.

    PubMed

    Tobisu, Mamoru; Chatani, Naoto

    2015-06-16

    the first Sonogashira-type reaction of anisoles. From a mechanistic perspective, nickel-catalyzed cross-couplings of aryl ethers are at a nascent stage, in particular regarding the mode of activation of C(aryl)-O bonds. Oxidative addition is one plausible pathway, although such a process has not been fully verified experimentally. Nickel-catalyzed reductive cleavage of aryl ethers in the absence of an external reducing agent provides strong support for this oxidative addition process. Several other mechanisms have also been proposed. For example, Martin demonstrated a new possibility of the involvement of a Ni(I) species, which could mediate the cleavage of the C(aryl)-O bond via a redox-neutral pathway. The tolerance of aryl ethers under commonly used synthetic conditions enables alkoxy groups to serve as a platform for late-stage elaboration of complex molecules without any tedious protecting group manipulations. Aryl ethers are therefore not mere economical alternatives to aryl halides but also enable nonclassical synthetic strategies. PMID:26036674

  8. Enhancing the Legacy of Spitzer and Herschel with the MOSFIRE Deep Evolution Field Survey

    NASA Astrophysics Data System (ADS)

    Reddy, Naveen

    The next frontier for comprehensive galaxy surveys is the epoch at z~1.5-3.5, the peak of star formation and black hole activity. Despite the new windows that Spitzer and Herschel have opened up into the stellar and dust emission of distant galaxies and AGN during this key epoch, these studies have been limited by the lack of spectroscopic redshifts and the unknown physical conditions (e.g., metallicities, ionization) within the targeted galaxies. To realize the full potential of Spitzer and Herschel, we require a large spectroscopic survey that will: (a) efficiently assemble spectroscopic redshifts for large samples of galaxies at z=1.4-3.8; (b) yield the physical conditions, including the ionization and metallicities of these galaxies; and (c) easily obtain spectroscopic redshifts even for very dusty/confused galaxies. To this end, our team has been allocated a large program of 47 Keck nights with the multi-object near-IR spectrograph MOSFIRE to carry out the MOSFIRE Deep Evolution Field Survey (MOSDEF) in three of the Hubble CANDELS fields. MOSDEF will obtain rest-optical spectra of ~1500 galaxies at redshifts z=1.4-3.8, targeting many of the optical nebular emission lines and continuum features (e.g., [OII], [OIII], H-beta, H-alpha, [NII], [SII], 4000 Angstrom break, Ca H and K, and Mbg) that until now have been inaccessible for large samples of distant galaxies, but which are routinely used to measure the SFRs, dust attenuation, metal and gas content, and ionization and dynamical properties in nearby galaxies. MOSDEF spectroscopy provides a critical supporting role for the analysis of Spitzer and Herschel observations of distant galaxies. With this transformative dataset, we will perform the following analyses. First, we will use Spitzer and Herschel imaging, aided with spectroscopic redshifts from MOSDEF, to construct individual and mean dust SEDs for galaxies at redshifts 1.4

  9. Investigation of the Nebular Remnants of Novae

    NASA Astrophysics Data System (ADS)

    Ribeiro, Valério A. R. M.

    2011-01-01

    of the F502N filter. This in turn gave valuable information on the spatial orientation of the nebula. The inclination angle was derived to be 39+1-10 degrees, comparable with estimates of the inclination of the central binary. Furthermore, it was also suggested, when comparing two different epochs, that there was evidence for some deceleration of the inner hour glass while the outer dumbbell expanded linearly. This linear expansion is also confirmed with X-ray observations. In the case of V2491 Cyg, V2672 Oph and KT Eri, no resolved imaging was available primarily due to their distances versus time since outburst. The modelling here concentrated on reproducing the Hα line profile at various outburst epochs to derive their true geometry. V2491 Cyg, was explored using the first scientific results for the Liverpool Telescope prototype spectrograph. These were best-fit using a morphology with polar blobs and an equatorial ring with an inclination angle of 80+3-12 degrees and a maximum expansion velocity of the polar blobs of 3100+200-100 km s-1 and for the equatorial ring of 2700+200-100 km s-1. Multi-epoch fitting showed that the line profile at later times consisted of a combination of Hα and [NII] emission. Furthermore, the derived inclination implies that eclipses should be observed for which a search is now underway. In addition, the amplitude versus time of decline from maximum relationship, at the inclination derived, may imply a recurrent nova nature of V2491 Cyg. V2672 Oph's derived nebular morphology was that of polar blobs and an equatorial ring with an underlying prolate structure which seemed to reduce in relative density with time compared to the other components. The inclination of the system was suggested to be 0±6 degrees and a maximum expansion velocity Vexp = 4800+900-800 km s-1. The morphology found here is incompatible with that expected for a fast nova which may again lend support for a recurrent nova nature of V2672 Oph. In KT Eri, optical

  10. National Security Science and Technology Initiative: Air Cargo Screening

    SciTech Connect

    Bingham, Philip R; White, Tim; Cespedes, Ernesto; Bowerman, Biays; Bush, John

    2010-11-01

    The non-intrusive inspection (NII) of consolidated air cargo carried on commercial passenger aircraft continues to be a technically challenging, high-priority requirement of the Department of Homeland Security's Science and Technology Directorate (DHS S&T), the Transportation Security Agency and the Federal Aviation Administration. The goal of deploying a screening system that can reliably and cost-effectively detect explosive threats in consolidated cargo without adversely affecting the flow of commerce will require significant technical advances that will take years to develop. To address this critical National Security need, the Battelle Memorial Institute (Battelle), under a Cooperative Research and Development Agreement (CRADA) with four of its associated US Department of Energy (DOE) National Laboratories (Oak Ridge, Pacific Northwest, Idaho, and Brookhaven), conducted a research and development initiative focused on identifying, evaluating, and integrating technologies for screening consolidated air cargo for the presence of explosive threats. Battelle invested $8.5M of internal research and development funds during fiscal years 2007 through 2009. The primary results of this effort are described in this document and can be summarized as follows: (1) Completed a gap analysis that identified threat signatures and observables, candidate technologies for detection, their current state of development, and provided recommendations for improvements to meet air cargo screening requirements. (2) Defined a Commodity/Threat/Detection matrix that focuses modeling and experimental efforts, identifies technology gaps and game-changing opportunities, and provides a means of summarizing current and emerging capabilities. (3) Defined key properties (e.g., elemental composition, average density, effective atomic weight) for basic commodity and explosive benchmarks, developed virtual models of the physical distributions (pallets) of three commodity types and three explosive

  11. Spectral properties of X-ray selected narrow emission line galaxies

    NASA Astrophysics Data System (ADS)

    Romero-Colmenero, E.

    1998-03-01

    constitute it. Furthermore, by combining both samples of NELGs, I find a tendency for sources at lower fluxes to display harder slopes (95% confidence level), further strengthening the case for NELGs to be major contributors to the XRB at the fainter fluxes. The analysis of optical spectroscopy, obtained on La Palma and Hawaii, shows that NELGs form a very heterogeneous group, made up of a mixture of Seyfert 2, LINER and HII-region like galaxies. Seyfert 2 galaxies are found to possess in general the steepest X-ray slopes. Ways to explain this in the context of the unified model of AGN are discussed. The FWHM of some emission lines (Halpha, Hbeta, [NII]) in the NELGs appears to increase with steepening X-ray spectral slope. In the case of the Balmer lines, this is at variance with what is observed in broad line AGN. The FWHM of the Balmer lines is also correlated to the FWHM of the forbidden lines, indicating that they must originate in regions of similar velocity fields. Unfortunately, the number of sources uniquely classified is not sufficient to investigate these relationships on a source type basis. The optical emission line ratios of a bright RIXOS source (aka Arp 185, NGC 6217), classified as a starburst galaxy in the literature, indicate that this is in fact a weak-[OI] LINER, powered either by emission from hot O stars or by hot stars together with a non-stellar continuum. Spatially resolved spectroscopic analysis suggests that the Balmer emission lines are concentrated in the inner regions of the nucleus, while the forbidden lines arise from a more extended region. Line ratios do not indicate a change in the ionizing continuum of this source with distance from the centre.

  12. New Galactic Planetary Nebulae and the role of Central Star Binarity

    NASA Astrophysics Data System (ADS)

    Miszalski, B.

    2009-09-01

    LIS includes the distribution of neutral clumps of dust and H2 during the CE phase into the orbital plane that are then photo-ionised by winds during the PN phase. If the binary scenario holds then Nitrogen abundances for PNe with LIS would be rendered meaningless since the [NII] emission observed is not a result of enriched stellar material, but rather reflects shocked emission generated with models that assume standard abundances.

  13. UVES Analyses the Universe: A First Portfolio of Most Promising Results

    NASA Astrophysics Data System (ADS)

    2000-04-01

    , Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Y, Ba, La, Ce, Nd and Eu. While earlier photometric studies indicated a metallicity much lower than the solar one, the present spectral analysis found that the overall metallicity of the stars is only two times less than solar. The abundance pattern is essentially solar (no alpha elements or oxygen enhancement), with the noticeable exception of the very heaviest species (Ba to Eu) which are enhanced by a factor that is similar to what is observed in the Magellanic Clouds. This implies that this dwarf galaxy has experienced a higher level of chemical reprocessing on a longer timescale than was previously assumed . The new finding is a clear demonstration of the crucial importance of high-quality spectra for this type of investigation. Future systematic observations with UVES will certainly shed new light on the evolution of these systems. An extensive discussion of these results is given in the paper by Piercarlo Bonifacio , Paolo Molaro , Paolo DiMarcantonio and Paolo Santin (Trieste Astronomical Observatory, Italy), and Vanessa Hill and Luca Pasquini (ESO Garching), submitted to the European research journal Astronomy & Astrophysics . E. Hunting Black Holes in the Nuclei of Galaxies ESO PR Photo 09e/00 ESO PR Photo 09e/00 [Preview - JPEG: 276 x 400 pix - 144k] [Normal - JPEG: 476 x 800 pix - 384k] Caption : ESO PR Photo 09e/00 shows the velocity pattern of the gas in the inner region of the spiral galaxy NGC 7782, as visualized by the [NII] emission line (rest wavelength 658.3 nm). The north and south sides of the galaxy correspond to the left and right of the spectrum. At the distance of this galaxy, 1 arcsec = 1,182 light-years. The original UVES spectrum was exposed during 30 min, with an average seeing of 0.7 arcsec. The full wavelength range is 476 - 684 nm in the red arm of the instrument. The spectrum pixel size is 0.027 Å x 0.18 arcsec (1.2 km/sec x 215 light-years). It is believed that super-massive black