1,384 research outputs found

    Firm Responses to High-Speed Internet

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    Multipurpose hardened spacecraft insulation

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    A Multipurpose Hardened Spacecraft Multilayer Insulation (MLI) system was developed and implemented to meet diverse survivability and performance requirements. Within the definition and confines of a MLI assembly (blanket), the design: (1) provides environmental protection from natural and induced nuclear, thermal, and electromagnetic radiation; (2) provides adequate electrostatic discharge protection for a geosynchronous satellite; (3) provides adequate shielding to meet radiated emission needs; and (4) will survive ascent differential pressure loads between enclosed volume and space. The MLI design is described which meets these requirements and design evolution and verification is discussed. The application is for MLI blankets which closeout the area between the laser crosslink subsystem (LCS) equipment and the DSP spacecraft cabin. Ancillary needs were implemented to ease installation at launch facility and to survive ascent acoustic and vibration loads. Directional venting accommodations were also incorporated to avoid contamination of LCS telescope, spacecraft sensors, and second surface mirrors (SSMs)

    Recognition of two distinct elements in the RNA substrate by the RNA-binding domain of the T. thermophilus DEAD box helicase Hera

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    DEAD box helicases catalyze the ATP-dependent destabilization of RNA duplexes. Whereas duplex separation is mediated by the helicase core shared by all members of the family, flanking domains often contribute to binding of the RNA substrate. The Thermus thermophilus DEAD-box helicase Hera (for “heat-resistant RNA-binding ATPase”) contains a C-terminal RNA-binding domain (RBD). We have analyzed RNA binding to the Hera RBD by a combination of mutational analyses, nuclear magnetic resonance and X-ray crystallography, and identify residues on helix α1 and the C-terminus as the main determinants for high-affinity RNA binding. A crystal structure of the RBD in complex with a single-stranded RNA resolves the RNA–protein interactions in the RBD core region around helix α1. Differences in RNA binding to the Hera RBD and to the structurally similar RBD of the Bacillus subtilis DEAD box helicase YxiN illustrate the versatility of RNA recognition motifs as RNA-binding platforms. Comparison of chemical shift perturbation patterns elicited by different RNAs, and the effect of sequence changes in the RNA on binding and unwinding show that the RBD binds a single-stranded RNA region at the core and simultaneously contacts double-stranded RNA through its C-terminal tail. The helicase core then unwinds an adjacent RNA duplex. Overall, the mode of RNA binding by Hera is consistent with a possible function as a general RNA chaperone

    Proposition 7: California Daylight Saving Time

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    Untersuchungen zur Verbreitung und Biologie der Cephalopoden im östlichen Weddellmeer

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    Fin de vie paisible à domicile: quelles interventions de soins palliatifs permettent un bon accompagnement ? travail de Bachelor

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    Les soins palliatifs sont devenus depuis quelques années un défi de santé publique. Les demandes augmentent au fil des années mais les places ne croissent pas pour autant à la même vitesse. Ce travail permet de déterminer ce qui est nécessaire au patient en fin de vie pour mourir à domicile dans de bonnes conditions

    Behavioral Profiles of Genetically Selected Aggressive and Nonaggressive Male Wild House Mice in Two Anxiety Tests

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    Artificially selected aggressive (SAL) and non-aggressive (LAL) male house mice were tested in a hexagonal tunnel maze and light–dark preference (LD) box to determine if the bidirectional selection for aggressive behavior leads to a coselection for different levels of trait anxiety. The tunnel maze consists of an open, brightly lit central arena surrounded by a complex system of interconnecting tunnels. As in the LD box, animals which spend less time and are less active in the brightly illuminated section of the maze are considered to have higher anxiety levels. In the tunnel maze, the LAL mice showed more exploration and spent more time in the central arena than the SAL animals, but only during the final 2 min of the 6-min test. This reduced preference for the central arena was not due to general inactivity or a failure of the SAL to find the central arena and indicates a higher level of state anxiety in the aggressive animals. In contrast, no “anxiety-like” differences were found in the LD box, either for the percentage of time spent in the light compartment or for the number of crossings. SAL males actually showed higher levels of moving and rearing, and lower levels of freezing, than did LAL males.
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