Now showing items 36945-36964 of 37101

    • X-RAY SPECTRAL VARIABILITY IN NGC 3783 

      Reis, R. C.; Fabian, Andrew C.; Reynolds, C. S.; Brenneman, Laura W.; Walton, D. J.; e.a. (IOP Publishing, 2012-01)
      NGC 3783 was observed for approximately 210 ks by Suzaku and in this time showed significant spectral and flux variability at both short (20 ks) and long (100 ks) timescales. The full observation is found to consist of ...
    • X-Ray Spectroscopy of II Pegasi: Coronal Temperature Structure, Abundances, and Variability 

      Huenemoerder, David P.; Canizares, Claude R.; Schulz, Norbert S. (IOP Publishing, 2001-10)
      We have obtained high-resolution X-ray spectra of the coronally active binary II Pegasi (HD 224085), covering the wavelength range of 1.5-25 Å. For the first half of our 44 ks observation, the source was in a quiescent ...
    • THE X-RAY SPECTRUM OF A PLANETARY NEBULA AT HIGH RESOLUTION: 

      Yu, Young Sam; Nordon, Raanan; Kastner, Joel H.; Houck, John C.; Behar, Ehud; e.a. (Institute of Physics/American Astronomical Society, 2009-01)
      We present the results of the first X-ray gratings spectroscopy observations of a planetary nebula (PN)—the X-ray-bright, young BD +30°3639. We observed BD +30°3639 for a total of ~300 ks with the Chandra X-ray Observatory's ...
    • X-ray structure and mechanism of RNA polymerase II stalled at an antineoplastic monofunctional platinum-DNA adduct 

      Zhu, Guangyu; Lippard, Stephen J.; Wang, Dong; Huang, Xuhui (National Academy of Sciences (U.S.), 2010-05)
      DNA is a major target of anticancer drugs. The resulting adducts interfere with key cellular processes, such as transcription, to trigger downstream events responsible for drug activity. cis-Diammine(pyridine)chloroplatinum(II), ...
    • X-ray structure of an AdoMet radical activase reveals an anaerobic solution for formylglycine posttranslational modification 

      Goldman, Peter J.; McLaughlin, Martin I.; Drennan, Catherine L.; Grove, Tyler L.; Sites, Lauren A.; e.a. (National Academy of Sciences (U.S.), 2013-05)
      Arylsulfatases require a maturating enzyme to perform a co- or posttranslational modification to form a catalytically essential formylglycine (FGly) residue. In organisms that live aerobically, molecular oxygen is used ...
    • X-Ray Variability in the Young Massive Triple θ2 Orionis A 

      Schulz, Norbert S.; Testa, Paola; Huenemoerder, David P.; Ishibashi, Kazunori; Canizares, Claude R. (IOP Publishing, 2006-08)
      Massive stars rarely show intrinsic X-ray variability. One exception is θ[superscript 2] Ori A, which has shown strong variability over the last 5 years. We observed a large outburst of the X-ray source with the High Energy ...
    • AN X-RAY VIEW OF THE JET CYCLE IN THE RADIO-LOUD AGN 3C120 

      Lohfink, Anne M.; Reynolds, Christopher S.; Jorstad, Svetlana G.; Marscher, Alan P.; Miller, Eric D.; e.a. (IOP Publishing, 2013-07)
      We present a study of the central engine in the broad-line radio galaxy 3C120 using a multi-epoch analysis of a deep XMM-Newton observation and two deep Suzaku pointings (in 2012). In order to place our spectral data into ...
    • X-RAYING THE INTERGALACTIC O VI ABSORBERS 

      Yao, Y.; Tripp, T. M.; Wang, Q. D.; Danforth, Charles W.; Canizares, Claude R.; e.a. (American Astronomical Society, 2009-05)
      The observed intergalactic O vi absorbers at z > 0 have been regarded as a significant reservoir of the “missing baryons.” However, to fully understand how these absorbers contribute to the baryon inventory, it is crucial ...
    • X-Vision: An Augmented Vision Tool with Real-Time Sensing Ability in Tagged Environments 

      Sun, Yongbin; Kantareddy, Sai Nithin R.; Bhattacharyya, Rahul; Sarma, Sanjay E (Institute of Electrical and Electronics Engineers (IEEE), 2018-12)
      We present the concept of X-Vision, an enhanced Augmented Reality (AR)-based visualization tool, with the realtime sensing capability in a tagged environment. We envision that this type of a tool will enhance the ...
    • XBP-1 regulates signal transduction, transcription factors and bone marrow colonization in B cells 

      Hu, Chih-Chi Andrew; Dougan, Stephanie K.; McGehee, Annette M.; Love, J. Christopher; Ploegh, Hidde (Nature Publishing Group, 2009-04)
      XBP-1, a transcription factor that drives the unfolded protein response (UPR), is activated in B cells when they differentiate to plasma cells. Here, we show that in the B cells, whose capacity to secrete IgM has been ...
    • XBP1s activation can globally remodel N-glycan structure distribution patterns 

      Wong, Madeline Y.; Dewal, Mahender; Taylor, Rebecca J.; Whittaker, Charles A.; Phyo, Pyae; e.a. (Proceedings of the National Academy of Sciences, 2018-10)
      Classically, the unfolded protein response (UPR) safeguards secretory pathway proteostasis. The most ancient arm of the UPR, the IRE1-activated spliced X-box binding protein 1 (XBP1s)-mediated response, has roles in secretory ...
    • XBP1s Links the Unfolded Protein Response to the Molecular Architecture of Mature N-Glycans 

      Antonopoulos, Aristotelis; Haslam, Stuart M.; Dell, Anne; Dewal, Mahender; DiChiara, Andrew Stephen; e.a. (Elsevier, 2015-10)
      The molecular architecture of the mature N-glycome is dynamic, with consequences for both normal and pathologic processes. Elucidating cellular mechanisms that modulate the N-linked glycome is, therefore, crucial. The ...
    • XCone: N-jettiness as an exclusive cone jet algorithm 

      Thaler, Jesse; Tackmann, Frank J.; Vermilion, Christopher K.; Wilkason, Thomas F.; Stewart, Iain (Springer Berlin Heidelberg, 2015-11)
      We introduce a new jet algorithm called XCone, for eXclusive Cone, which is based on minimizing the event shape N -jettiness. Because N -jettiness partitions every event into N jet regions and a beam region, XCone is an ...
    • Xenon Hydrate as an Analog of Methane Hydrate in Geologic Systems Out of Thermodynamic Equilibrium 

      Fu, Xiaojing; Waite, William F.; Cueto-Felgueroso Landeira, Luis; Juanes, Ruben (American Geophysical Union (AGU), 2019-05)
      Methane hydrate occurs naturally under pressure and temperature conditions that are not straightforward to replicate experimentally. Xenon has emerged as an attractive laboratory alternative to methane for studying hydrate ...
    • Xenoprotein engineering via synthetic libraries 

      Gates, Zachary P; Vinogradov, Alexander Alexandrovich; Quartararo, Anthony James; Bandyopadhyay, Anupam; Choo, Zi-Ning; e.a. (National Academy of Sciences (U.S.), 2018-05)
      Chemical methods have enabled the total synthesis of protein molecules of ever-increasing size and complexity. However, methods to engineer synthetic proteins comprising noncanonical amino acids have not kept pace, even ...
    • Xerophonics: Copying Machine Music (Slight Return) 

      Helmreich, Stefan; Downey, Walker (MIT Press, 2019-05)
    • XFe4Ge2(X=Y,Lu) and Mn3Pt: filling-enforced magnetic topological metals 

      Wang, Di; Tang, Feng; Po, Hoi Chun; Vishwanath, Ashvin; Wan, Xiangang (American Physical Society, 2020-03)
      Magnetism, coupled with nontrivial band topology, can bring about many interesting and exotic phenomena, so that magnetic topological materials have attracted persistent research interest. However, compared with nonmagnetic ...
    • XIPE: the x-ray imaging polarimetry explorer 

      Grinberg, Victoria; Linares Alegret, Manuel; Marshall, Herman; Schulz, Norbert S. (SPIE, 2016-06)
      XIPE, the X-ray Imaging Polarimetry Explorer, is a mission dedicated to X-ray Astronomy. At the time of writing XIPE is in a competitive phase A as fourth medium size mission of ESA (M4). It promises to reopen the polarimetry ...
    • The Xist lncRNA Exploits Three-Dimensional Genome Architecture to Spread Across the X Chromosome 

      Engreitz, Jesse Michael; Lander, Eric S.; Pandya-Jones, Amy; McDonel, Patrick; Shishkin, Alexander; e.a. (American Association for the Advancement of Science (AAAS), 2013-07)
      Many large noncoding RNAs (lncRNAs) regulate chromatin, but the mechanisms by which they localize to genomic targets remain unexplored. We investigated the localization mechanisms of the Xist lncRNA during X-chromosome ...
    • The Xist lncRNA interacts directly with SHARP to silence transcription through HDAC3 

      McHugh, Colleen A.; Chen, Chun-Kan; Chow, Amy; Surka, Christine F.; Tran, Christina; e.a. (Nature Publishing Group, 2015-04)
      Many long non-coding RNAs (lncRNAs) affect gene expression, but the mechanisms by which they act are still largely unknown. One of the best-studied lncRNAs is Xist, which is required for transcriptional silencing of one X ...