Now showing items 17211-17230 of 18256

    • U-manifolds 

      Kumar, Alok; Vafa, Cumrun (Elsevier, 1997)
      We use non-perturbative U-duality symmetries of type II strings to construct new vacuum solutions. In some ways this generalizes the F-theory vacuum constructions. We find the possibilities of new vacuum constructions are ...
    • U.S. Daily Temperatures: The Meaning of Extremes in the Context of Nonnormality 

      Huybers, Peter John; McKinnon, Karen Aline; Rhines, Andrew Nelson; Tingley, M (American Meteorological Society, 2014)
      Variations in extreme daily temperatures are explored in relation to changes in seasonal mean temperature using 1218 high-quality U.S. temperature stations spanning 1900–2012. Extreme temperatures are amplified (or damped) ...
    • U.S. Monetary Policy in an Integrating World: 1960 to 2000 

      Cooper, Richard; Little, Jane Sneddon (Federal Reserve Bank of Boston, 2001)
      This article examines the impact of global developments on the practice of U.S. monetary policy, broadly defined to include regulatory and lender-of-last-resort functions as well as open market, discount, and intervention ...
    • Ubiquitous Presence and Novel Diversity of Anaerobic Alkane Degraders in Cold Marine Sediments 

      Gittel, Antje; Donhauser, Johanna; Røy, Hans; Girguis, Peter R.; Jørgensen, Bo B.; Kjeldsen, Kasper U. (Frontiers Media S.A., 2015)
      Alkanes are major constituents of crude oil and are released to the marine environment by natural seepage and from anthropogenic sources. Due to their chemical inertness, their removal from anoxic marine sediments is ...
    • Ubiquitous Promoter-Localization of Essential Virulence Regulators in Francisella tularensis 

      Ramsey, Kathryn M.; Osborne, Melisa L.; Vvedenskaya, Irina O.; Su, Cathy; Nickels, Bryce E.; Dove, Simon L. (Public Library of Science, 2015)
      Francisella tularensis is a Gram-negative bacterium whose ability to replicate within macrophages and cause disease is strictly dependent upon the coordinate activities of three transcription regulators called MglA, SspA, ...
    • Ubiquitous transgene expression and Cre-based recombination driven by the ubiquitin promoter in zebrafish 

      Mosimann, Christian; Kaufman, Charles Kore; Li, Pulin; Pugach, Emily K.; Tamplin, Owen J.; Zon, Leonard Ira (The Company of Biologists, 2010)
      Molecular genetics approaches in zebrafish research are hampered by the lack of a ubiquitous transgene driver element that is active at all developmental stages. Here, we report the isolation and characterization of the ...
    • Ubiquitylation of the Transducin Βγ Subunit Complex. Regulation by Phosducin 

      Obin, Martin; Lee, Bruce Y.; Meinke, Gretchen; Bohm, Andrew; Lee, Rehwa H.; Gaudet, Rachelle; Hopp, Johnathan A.; Arshavsky, Vadim Y.; Willardson, Barry M.; Taylor, Allen (American Society for Biochemistry and Molecular Biology, 2002)
      G proteins (Galphabetagamma) are essential signaling molecules, which dissociate into Galpha and Gbetagamma upon activation by heptahelical membrane receptors. We have identified the betagamma subunit complex of the ...
    • UBVRILight Curves of 44 Type Ia Supernovae 

      Jha, Saurabh; Kirshner, Robert P.; Challis, Peter; Garnavich, Peter M.; Matheson, Thomas; Soderberg, Alicia M.; Graves, Genevieve J. M.; Hicken, Malcolm; Alves, João F.; Arce, Héctor G.; Balog, Zoltan; Barmby, Pauline; Barton, Elizabeth J.; Berlind, Perry; Bragg, Ann E.; Briceño, César; Brown, Warren R.; Buckley, James H.; Caldwell, Nelson; Calkins, Michael L.; Carter, Barbara J.; Concannon, Kristi Dendy; Donnelly, R. Hank; Eriksen, Kristoffer A.; Fabricant, Daniel G.; Falco, Emilio E.; Fiore, Fabrizio; Garcia, Michael R.; Gómez, Mercedes; Grogin, Norman A.; Groner, Ted; Groot, Paul J.; Haisch, Karl E. Jr.; Hartmann, Lee; Hergenrother, Carl W.; Holman, Matthew J.; Huchra, John P.; Jayawardhana, Ray; Jerius, Diab; Kannappan, Sheila J.; Kim, Dong-Woo; Kleyna, Jan T.; Kochanek, Christopher S.; Koranyi, Daniel M.; Krockenberger, Martin; Lada, Charles J.; Luhman, Kevin L.; Luu, Jane X.; Macri, Lucas M.; Mader, Jeff A.; Mahdavi, Andisheh; Marengo, Massimo; Marsden, Brian G.; McLeod, Brian A.; McNamara, Brian R.; Megeath, S. Thomas; Moraru, Dan; Mossman, Amy E.; Muench, August A.; Muñoz, Jose A.; Muzerolle, James; Naranjo, Orlando; Nelson-Patel, Kristin; Pahre, Michael A.; Patten, Brian M.; Peters, James; Peters, Wayne; Raymond, John C.; Rines, Kenneth; Schild, Rudolph E.; Sobczak, Gregory J.; Spahr, Timothy B.; Stauffer, John R.; Stefanik, Robert P.; Szentgyorgyi, Andrew H.; Tollestrup, Eric V.; Väisänen, Petri; Vikhlinin, Alexey; Wang, Zhong; Willner, S. P.; Wolk, Scott J.; Zajac, Joseph M.; Zhao, Ping; Stanek, Krzysztof Z. (American Astronomical Society, 2006)
      We present UBVRI photometry of 44 Type Ia supernovae (SNe Ia) observed from 1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. ...
    • Ukraine Offers No Easy Lessons for Taiwan 

      Overholt, William (The East Asia Foundation, 2022-06)
      As Russian tanks and troops rolled into Ukraine, speculation about a parallel mainland invasion of Taiwan was predictable. After all, Vladimir Putin and Xi Jinping met in Beijing on the eve of the Winter Olympics — and the ...
    • Ultan Qalası: A Fortified Site in the Sasanian Borderlands (Mughan Steppe, Iranian Azerbaijan) 

      Alizadeh, Karim (British Institute of Persian Studies, 2011)
      Our knowledge of Sasanian imperial strategy continues to grow as a result of a range of projects investigating the frontiers of the Sasanian Empire. Understanding of the north-western fringe of the Empire in particular is ...
    • Ultimately short ballistic vertical graphene Josephson junctions 

      Lee, Gil-Ho; Kim, Sol; Jhi, Seung-Hoon; Lee, Hu-Jong (Nature Pub. Group, 2015)
      Much efforts have been made for the realization of hybrid Josephson junctions incorporating various materials for the fundamental studies of exotic physical phenomena as well as the applications to superconducting quantum ...
    • Ultra-bright Photoactivatable Fluorophores Created by Reductive Caging 

      Vaughan, Joshua C.; Jia, Shu; Zhuang, Xiaowei (2012)
      Sub-diffraction-limit imaging can be achieved by sequential localization of photoactivatable fluorophores, where the image resolution depends on the number of photons detected per localization. Here, we report a strategy ...
    • Ultra-fast intramolecular singlet fission to persistent multiexcitons by molecular design 

      Pun, Andrew; Asadpoordarvish, Amir; Kumarasamy, Elango; Tayebjee, Murad; Niesner, Daniel; McCamey, Dane; Sanders, Samuel; Sfeir, Matthew; Campos, Luis (Springer Science and Business Media LLC, 2019-08-12)
      Singlet fission—that is, the generation of two triplets from a lone singlet state—has recently resurfaced as a promising process for the generation of multiexcitons in organic systems. Although advances in this area have ...
    • Ultra-high-Q TE/TM Dual-Polarized Photonic Crystal Nanocavities 

      Zhang, Yinan; McCutcheon, Murray; Burgess, Ian; Loncar, Marko (Optical Society of America, 2009)
      We demonstrate photonic crystal nanobeam cavities that support both TE- and TM-polarized modes, each with a Quality factor greater than one million and a mode volume on the order of the cubic wavelength. We show that these ...
    • Ultra-low threshold gallium nitride photonic crystal nanobeam laser 

      Niu, Nan; Woolf, Alexander J; Wang, Danqing; Zhu, Tongtong; Quan, Qimin; Oliver, Rachel; Hu, Evelyn (AIP Publishing, 2015)
      We report exceptionally low thresholds (9.1 μJ/cm2) for room temperature lasing at ∼450 nm in optically pumped Gallium Nitride (GaN) nanobeam cavity structures. The nanobeam cavity geometry provides high theoretical Q ...
    • Ultra-Luminous Supernovae as a New Probe of the Interstellar Medium in Distant Galaxies 

      Berger, Edo; Chornock, R; Lunnan, R.; Foley, R.; Czekala, Ian Philip; Rest, A.; Leibler, C.; Soderberg, Alicia M.; Roth, K.; Narayan, G.; Huber, M. E.; Milisavljevic, Danny; Sanders, Nathan Edward; Drout, M.; Margutti, R.; Kirshner, Robert P.; Marion, G. H.; Challis, P. J.; Riess, A. G.; Smartt, S. J.; Burgett, W. S.; Hodapp, K. W.; Heasley, J. N.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E. A.; McCrum, M.; Price, P. A.; Smith, K.; Tonry, J. L.; Wainscoat, R. J. (IOP Publishing, 2012)
      We present the Pan-STARRS1 discovery and light curves, and follow-up MMT and Gemini spectroscopy of an ultra-luminous supernova (ULSN; dubbed PS1-11bam) at a redshift of z = 1.566 with a peak brightness of MUV ≈ −22.3 mag. ...
    • Ultra-sensitive and resilient compliant strain gauges for soft machines 

      Araromi, Oluwaseun A.; Graule, Moritz; Dorsey, Kristen; Castellanos, Samantha; Foster, Jonathan; Hsu, Wen-Hao; Passy, Arthur; Vlassak, Joost; Weaver, James; Walsh, Conor; Wood, Robert (Springer Science and Business Media LLC, 2020-11-11)
      Soft machines are a promising new design paradigm for human-centric devices and systems required to interact gently with their environment. For soft machines to respond intelligently to their surroundings, compliant sensory ...
    • Ultra-thin optical interference coatings on rough and flexible substrates 

      Kats, Mikhail A.; Capasso, Federico (AIP Publishing, 2014)
      Recently demonstrated ultra-thin optical coatings comprising nanometer-thick highly absorbing films on top of reflecting substrates can display strong optical interference effects, resulting in structural colors and ...
    • Ultradiffuse galaxies: the high-spin tail of the abundant dwarf galaxy population 

      Amorisco, Nicola C.; Loeb, Abraham (Oxford University Press (OUP), 2016)
      Recent observations have revealed the existence of an abundant population of faint, low surface brightness (SB) galaxies, which appear to be numerous and ubiquitous in nearby galaxy clusters, including the Virgo, Coma and ...
    • Ultrafast and Fault-Tolerant Quantum Communication across Long Distances 

      Muralidharan, Sreraman; Kim, Jungsang; Lütkenhaus, Norbert; Lukin, Mikhail D.; Jiang, Liang (American Physical Society (APS), 2014)
      Quantum repeaters (QRs) provide a way of enabling long distance quantum communication by establishing entangled qubits between remote locations. In this Letter, we investigate a new approach to QRs in which quantum information ...