ALBERT

Description: The Pluto system was recently explored by NASA's New Horizons spacecraft, making closest approach on 14 July 2015. Pluto's surface displays diverse landforms, terrain ages, albedos, colors, and composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto's atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto's diverse surface geology and long-term activity raise fundamental questions about how small planets remain active many billions of years after formation. Pluto's large moon Charon displays tectonics and evidence for a heterogeneous crustal composition; its north pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stern, S A -- Bagenal, F -- Ennico, K -- Gladstone, G R -- Grundy, W M -- McKinnon, W B -- Moore, J M -- Olkin, C B -- Spencer, J R -- Weaver, H A -- Young, L A -- Andert, T -- Andrews, J -- Banks, M -- Bauer, B -- Bauman, J -- Barnouin, O S -- Bedini, P -- Beisser, K -- Beyer, R A -- Bhaskaran, S -- Binzel, R P -- Birath, E -- Bird, M -- Bogan, D J -- Bowman, A -- Bray, V J -- Brozovic, M -- Bryan, C -- Buckley, M R -- Buie, M W -- Buratti, B J -- Bushman, S S -- Calloway, A -- Carcich, B -- Cheng, A F -- Conard, S -- Conrad, C A -- Cook, J C -- Cruikshank, D P -- Custodio, O S -- Dalle Ore, C M -- Deboy, C -- Dischner, Z J B -- Dumont, P -- Earle, A M -- Elliott, H A -- Ercol, J -- Ernst, C M -- Finley, T -- Flanigan, S H -- Fountain, G -- Freeze, M J -- Greathouse, T -- Green, J L -- Guo, Y -- Hahn, M -- Hamilton, D P -- Hamilton, S A -- Hanley, J -- Harch, A -- Hart, H M -- Hersman, C B -- Hill, A -- Hill, M E -- Hinson, D P -- Holdridge, M E -- Horanyi, M -- Howard, A D -- Howett, C J A -- Jackman, C -- Jacobson, R A -- Jennings, D E -- Kammer, J A -- Kang, H K -- Kaufmann, D E -- Kollmann, P -- Krimigis, S M -- Kusnierkiewicz, D -- Lauer, T R -- Lee, J E -- Lindstrom, K L -- Linscott, I R -- Lisse, C M -- Lunsford, A W -- Mallder, V A -- Martin, N -- McComas, D J -- McNutt, R L Jr -- Mehoke, D -- Mehoke, T -- Melin, E D -- Mutchler, M -- Nelson, D -- Nimmo, F -- Nunez, J I -- Ocampo, A -- Owen, W M -- Paetzold, M -- Page, B -- Parker, A H -- Parker, J W -- Pelletier, F -- Peterson, J -- Pinkine, N -- Piquette, M -- Porter, S B -- Protopapa, S -- Redfern, J -- Reitsema, H J -- Reuter, D C -- Roberts, J H -- Robbins, S J -- Rogers, G -- Rose, D -- Runyon, K -- Retherford, K D -- Ryschkewitsch, M G -- Schenk, P -- Schindhelm, E -- Sepan, B -- Showalter, M R -- Singer, K N -- Soluri, M -- Stanbridge, D -- Steffl, A J -- Strobel, D F -- Stryk, T -- Summers, M E -- Szalay, J R -- Tapley, M -- Taylor, A -- Taylor, H -- Throop, H B -- Tsang, C C C -- Tyler, G L -- Umurhan, O M -- Verbiscer, A J -- Versteeg, M H -- Vincent, M -- Webbert, R -- Weidner, S -- Weigle, G E 2nd -- White, O L -- Whittenburg, K -- Williams, B G -- Williams, K -- Williams, S -- Woods, W W -- Zangari, A M -- Zirnstein, E -- New York, N.Y. -- Science. 2015 Oct 16;350(6258):aad1815. doi: 10.1126/science.aad1815.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Southwest Research Institute, Boulder, CO 80302, USA. astern@boulder.swri.edu. ; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA. ; National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA. ; Southwest Research Institute, San Antonio, TX 28510, USA. ; Lowell Observatory, Flagstaff, AZ 86001, USA. ; Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA. ; Southwest Research Institute, Boulder, CO 80302, USA. ; Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. ; Universitat der Bundeswehr Munchen, Neubiberg 85577, Germany. ; Planetary Science Institute, Tucson, AZ 85719, USA. ; KinetX Aerospace, Tempe, AZ 85284, USA. ; NASA Jet Propulsion Laboratory, La Canada Flintridge, CA 91011, USA. ; Massachusetts Institute of Technology, Cambridge, MA 02139, USA. ; University of Bonn, Bonn D-53113, Germany. ; NASA Headquarters (retired), Washington, DC 20546, USA. ; University of Arizona, Tucson, AZ 85721, USA. ; Cornell University, Ithaca, NY 14853, USA. ; NASA Headquarters, Washington, DC 20546, USA. ; Rheinisches Institut fur Umweltforschung an der Universitat zu Koln, Cologne 50931, Germany. ; Department of Astronomy, University of Maryland, College Park, MD 20742, USA. ; Search for Extraterrestrial Intelligence Institute, Mountain View, CA 94043, USA. ; Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA. ; NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. ; National Optical Astronomy Observatory, Tucson, AZ 26732, USA. ; NASA Marshall Space Flight Center, Huntsville, AL 35812, USA. ; Stanford University, Stanford, CA 94305, USA. ; Space Telescope Science Institute, Baltimore, MD 21218, USA. ; University of California, Santa Cruz, CA 95064, USA. ; Lunar and Planetary Institute, Houston, TX 77058, USA. ; Michael Soluri Photography, New York, NY 10014, USA. ; Johns Hopkins University, Baltimore, MD 21218, USA. ; Roane State Community College, Jamestown, TN 38556, USA. ; George Mason University, Fairfax, VA 22030, USA. ; Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26472913" target="_blank"〉PubMed〈/a〉

Description: tert -Butyldimethylsilyl (TBDMS) and tert -butyldiphenylsilyl (TBDPS) are alcohol protecting groups widely employed in organic synthesis in view of their compatibility with a wide range of conditions. Their regioselective installation on polyols generally requires lengthy reactions and the use of high boiling solvents. In the first part of this paper we demonstrate that regioselective silylation of sugar polyols can be conducted in short times with the requisite silyl chloride and a very limited excess of pyridine (2–3 equivalents). Under these conditions, that can be regarded as solvent-free conditions in view of the insolubility of the polyol substrates, the reactions are faster than in most examples reported in the literature, and can even be further accelerated with a catalytic amount of tetrabutylammonium bromide (TBAB). The strategy proved also useful for either the selective TBDMS protection of secondary alcohols or the fast per- O -trimethylsilylation of saccharide polyols. In the second part of the paper the scope of the silylation approach was significantly extended with the development of unprecedented “one-pot” and “solvent-free” sequences allowing the regioselective silylation/alkylation (or the reverse sequence) of saccharide polyols in short times. The developed methodologies represent a very useful and experimentally simple tool for the straightforward access to saccharide building-blocks useful in organic synthesis. Beilstein J. Org. Chem. 2016, 12, 2748–2756. doi:10.3762/bjoc.12.271

Description: 〈p〉Ancient Rome was the capital of an empire of ~70 million inhabitants, but little is known about the genetics of ancient Romans. Here we present 127 genomes from 29 archaeological sites in and around Rome, spanning the past 12,000 years. We observe two major prehistoric ancestry transitions: one with the introduction of farming and another prior to the Iron Age. By the founding of Rome, the genetic composition of the region approximated that of modern Mediterranean populations. During the Imperial period, Rome’s population received net immigration from the Near East, followed by an increase in genetic contributions from Europe. These ancestry shifts mirrored the geopolitical affiliations of Rome and were accompanied by marked interindividual diversity, reflecting gene flow from across the Mediterranean, Europe, and North Africa.〈/p〉

Description: tert-Butyldimethylsilyl (TBDMS) and tert-butyldiphenylsilyl (TBDPS) are alcohol protecting groups widely employed in organic synthesis in view of their compatibility with a wide range of conditions. Their regioselective installation on polyols generally requires lengthy reactions and the use of high boiling solvents. In the first part of this paper we demonstrate that regioselective silylation of sugar polyols can be conducted in short times with the requisite silyl chloride and a very limited excess of pyridine (2–3 equivalents). Under these conditions, that can be regarded as solvent-free conditions in view of the insolubility of the polyol substrates, the reactions are faster than in most examples reported in the literature, and can even be further accelerated with a catalytic amount of tetrabutylammonium bromide (TBAB). The strategy proved also useful for either the selective TBDMS protection of secondary alcohols or the fast per-O-trimethylsilylation of saccharide polyols. In the second part of the paper the scope of the silylation approach was significantly extended with the development of unprecedented “one-pot” and “solvent-free” sequences allowing the regioselective silylation/alkylation (or the reverse sequence) of saccharide polyols in short times. The developed methodologies represent a very useful and experimentally simple tool for the straightforward access to saccharide building-blocks useful in organic synthesis.