29 research outputs found

    The Distribution, Excitation and Formation of Cometary Molecules: Methanol, Methyl Cyanide and Ethylene Glycol

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    We present an interferometric and single dish study of small organic species toward Comets C/1995 O1 (Hale-Bopp) and C/2002 T7 (LINEAR) using the BIMA interferometer at 3 mm and the ARO 12m telescope at 2 mm. For Comet Hale-Bopp, both the single-dish and interferometer observations of CH3OH indicate an excitation temperature of 105+/-5 K and an average production rate ratio Q(CH3OH)/Q(H2O)~1.3% at ~1 AU. Additionally, the aperture synthesis observations of CH3OH suggest a distribution well described by a spherical outflow and no evidence of significant extended emission. Single-dish observations of CH3CN in Comet Hale-Bopp indicate an excitation temperature of 200+/-10 K and a production rate ratio of Q(CH3CN)/Q(H2O)~0.017% at ~1 AU. The non-detection of a previously claimed transition of cometary (CH2OH)2 toward Comet Hale-Bopp with the 12m telescope indicates a compact distribution of emission, D<9'' (<8500 km). For the single-dish observations of Comet T7 LINEAR, we find an excitation temperature of CH3OH of 35+/-5 K and a CH3OH production rate ratio of Q(CH3OH)/Q(H2O)~1.5% at ~0.3 AU. Our data support current chemical models that CH3OH, CH3CN and (CH2OH)2 are parent nuclear species distributed into the coma via direct sublimation off cometary ices from the nucleus with no evidence of significant production in the outer coma.Comment: accepted for publication in Ap

    The mammalian gene function resource: the International Knockout Mouse Consortium.

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    In 2007, the International Knockout Mouse Consortium (IKMC) made the ambitious promise to generate mutations in virtually every protein-coding gene of the mouse genome in a concerted worldwide action. Now, 5 years later, the IKMC members have developed high-throughput gene trapping and, in particular, gene-targeting pipelines and generated more than 17,400 mutant murine embryonic stem (ES) cell clones and more than 1,700 mutant mouse strains, most of them conditional. A common IKMC web portal (www.knockoutmouse.org) has been established, allowing easy access to this unparalleled biological resource. The IKMC materials considerably enhance functional gene annotation of the mammalian genome and will have a major impact on future biomedical research

    The mammalian gene function resource: The International Knockout Mouse Consortium

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    In 2007, the International Knockout Mouse Consortium (IKMC) made the ambitious promise to generate mutations in virtually every protein-coding gene of the mouse genome in a concerted worldwide action. Now, 5 years later, the IKMC members have developed highthroughput gene trapping and, in particular, gene-targeting pipelines and generated more than 17,400 mutant murine embryonic stem (ES) cell clones and more than 1,700 mutant mouse strains, most of them conditional. A common IKMC web portal (www.knockoutmouse.org) has been established, allowing easy access to this unparalleled biological resource. The IKMC materials considerably enhance functional gene annotation of the mammalian genome and will have a major impact on future biomedical research

    The mammalian gene function resource: the international knockout mouse consortium

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    ATR/Mec1: coordinating fork stability and repair.

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    During S phase, eukaryotic cells unwind and duplicate a tremendous amount of DNA, generating structures that are very sensitive to both endogenous and exogenous insults. The collision of DNA polymerases with damaged DNA or other obstructions to fork progression generates replication stress, which can evolve into fork collapse if the replisome components are not stabilized. To ensure genome integrity, stalled replication forks are recognized by a checkpoint, whose central player is the human kinase ATR or Mec1 in S. cerevisiae. This review will discuss recent findings revealing roles of the ATR/Mec1 kinase: both in stabilizing the replisome directly and in activating the checkpoint response to regulate origin firing, DNA repair, fork restart, and cell cycle progression

    Balancing competing needs for plants that have commercial interests and weed potential

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    Some introduced pasture plants have been very successful at improving Australian livestock production. For example, olive hymenachne (Hymenachne amplexicaulis) is used as a ponded pasture species in tropical Australia and buffel grass (Cenchrus ciliaris) is an important grazing resource in arid and semi-arid regions. Buffel grass can also help to control erosion

    Balancing competing needs for plants that have commercial interests and weed potential

    No full text
    Some introduced pasture plants have been very successful at improving Australian livestock production. For example, olive hymenachne (Hymenachne amplexicaulis) is used as a ponded pasture species in tropical Australia and buffel grass (Cenchrus ciliaris) is an important grazing resource in arid and semi-arid regions. Buffel grass can also help to control erosion

    Policy, institutional and managerial considerations in managing weeds with a commercial value

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    "In Australia, governments spend approximately $116.4 million on weed management, monitoring and research each year. This figure does not include resources provided by volunteers or weed management undertaken as a component of other landcare activities, nor costs incurred by agricultural industries as a result of weeds."--p. 2

    Policy, institutional and managerial considerations in managing weeds with a commercial value

    No full text
    "In Australia, governments spend approximately $116.4 million on weed management, monitoring and research each year. This figure does not include resources provided by volunteers or weed management undertaken as a component of other landcare activities, nor costs incurred by agricultural industries as a result of weeds."--p. 2
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