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  • 1
    Publication Date: 2018-10-25
    Description: The projected long-term drying of the southwest (SW) United States in response to climate warming raises a sobering alarm for this already water-limited region, yet the climatic controls on moisture availability over longer time scales remain a topic of debate. Here, we present a 350,000-year record of past water table fluctuations in Devils Hole 2 cave that are driven by variations in recharge amount to the local groundwater flow system. Because of the unprecedented length and precision of our record, we can observe variations in regional moisture availability over the last three glacial-interglacial cycles at a millennial-scale resolution. The timing of past water table rises and falls (〉9 m in amplitude) closely coincides with the expansion and reduction of Northern Hemisphere ice volume, which in turn influences the position and intensity of westerly winter storms on orbital time scales. Superimposed on this long-term trend are millennial-scale highstands recorded during the last glaciation that coincide with North Atlantic Heinrich events. Earlier millennial-scale highstands provide the first evidence of multiple short-lived wet periods in the SW United States linked to coeval cooling intervals in the North Atlantic during marine isotope stages 6 and 8. The Devils Hole 2 water table record is currently the longest independently dated paleomoisture record in the SW United States and thus provides a critical testbed to examine the controls on regional moisture availability over larger time scales.
    Electronic ISSN: 2375-2548
    Topics: Natural Sciences in General
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  • 2
    Publication Date: 2018-12-14
    Description: Paired measurements of 14 C/ 12 C and 230 Th ages from two Hulu Cave stalagmites complete a precise record of atmospheric 14 C covering the full range of the 14 C dating method (~54,000 years). Over the last glacial period, atmospheric 14 C/ 12 C ranges from values similar to modern values to values 1.70 times higher (42,000 to 39,000 years ago). The latter correspond to 14 C ages 5200 years less than calibrated ages and correlate with the Laschamp geomagnetic excursion followed by Heinrich Stadial 4. Millennial-scale variations are largely attributable to Earth’s magnetic field changes and in part to climate-related changes in the oceanic carbon cycle. A progressive shift to lower 14 C/ 12 C values between 25,000 and 11,000 years ago is likely related, in part, to progressively increasing ocean ventilation rates.
    Keywords: Atmospheric Science, Geochemistry, Geophysics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 3
    Publication Date: 2014-05-31
    Description: The polarizing optical microscope has been used since the 19th century to study the structural anisotropy of materials, based on the phenomenon of optical birefringence. In contrast, the phenomenon of x-ray birefringence has been demonstrated only recently and has been shown to be a sensitive probe of the orientational properties of individual molecules and/or bonds in anisotropic solids. Here, we report a technique-x-ray birefringence imaging (XBI)-that enables spatially resolved mapping of x-ray birefringence of materials, representing the x-ray analog of the polarizing optical microscope. Our results demonstrate the utility and potential of XBI as a sensitive technique for imaging the local orientational properties of anisotropic materials, including characterization of changes in molecular orientational ordering associated with solid-state phase transitions and identification of the size, spatial distribution, and temperature dependence of domain structures.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Palmer, Benjamin A -- Edwards-Gau, Gregory R -- Kariuki, Benson M -- Harris, Kenneth D M -- Dolbnya, Igor P -- Collins, Stephen P -- New York, N.Y. -- Science. 2014 May 30;344(6187):1013-6. doi: 10.1126/science.1253537.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales. ; School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales. harriskdm@cardiff.ac.uk. ; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, England.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24876494" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 4
    Publication Date: 2015-03-31
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Searchinger, T -- Edwards, R -- Mulligan, D -- Heimlich, R -- Plevin, R -- New York, N.Y. -- Science. 2015 Mar 27;347(6229):1420-2. doi: 10.1126/science.1261221. Epub 2015 Mar 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ 08544, USA. tsearchi@princeton.edu robert.edwards@jrc.it. ; Joint Research Centre, European Commission, Ispra 21027, Italy. tsearchi@princeton.edu robert.edwards@jrc.it. ; Joint Research Centre, European Commission, Ispra 21027, Italy. ; Agricultural Conservation Economics, Laurel, MD 20723, USA. ; Institute of Transportation Studies, University of California at Davis, Davis, CA 95616, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25814570" target="_blank"〉PubMed〈/a〉
    Keywords: Biofuels/*utilization ; Caloric Restriction ; *Crops, Agricultural ; *Food Supply ; *Greenhouse Effect ; Humans ; Models, Economic ; Policy
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 5
    Publication Date: 2015-08-01
    Description: 〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692367/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692367/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Akbari, Omar S -- Bellen, Hugo J -- Bier, Ethan -- Bullock, Simon L -- Burt, Austin -- Church, George M -- Cook, Kevin R -- Duchek, Peter -- Edwards, Owain R -- Esvelt, Kevin M -- Gantz, Valentino M -- Golic, Kent G -- Gratz, Scott J -- Harrison, Melissa M -- Hayes, Keith R -- James, Anthony A -- Kaufman, Thomas C -- Knoblich, Juergen -- Malik, Harmit S -- Matthews, Kathy A -- O'Connor-Giles, Kate M -- Parks, Annette L -- Perrimon, Norbert -- Port, Fillip -- Russell, Steven -- Ueda, Ryu -- Wildonger, Jill -- R01 AI070654/AI/NIAID NIH HHS/ -- R01 AI110713/AI/NIAID NIH HHS/ -- T32 GM007133/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2015 Aug 28;349(6251):927-9. doi: 10.1126/science.aac7932. Epub 2015 Jul 30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Entomology, Univ. of California, Riverside, CA 92507, USA. Center for Disease Vector Research, Institute for Integrative Genome Biology, Univ. of California, Riverside, CA 92507, USA. ; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA. Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA. ; Section of Cell and Developmental Biology, Univ. of California, San Diego, La Jolla, CA 92095, USA. kevin.esvelt@wyss.harvard.edu ebier@ucsd.edu. ; Division of Cell Biology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK. ; Department of Life Sciences, Imperial College London, Silwood Park, Ascot, Berks SL5 7PY, UK. ; Wyss Institute for Biologically Inspired Engineering, Harvard Medical School, Boston, MA 02115, USA. Department of Genetics, Harvard Medical School, Boston, MA 02115, USA. ; Bloomington Drosophila Stock Center, Department of Biology, Indiana Univ., Bloomington, IN 47405, USA. ; Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030 Vienna, Austria. ; CSIRO Centre for Environment and Life Sciences, Underwood Avenue, Floreat, WA 6014, Australia. ; Wyss Institute for Biologically Inspired Engineering, Harvard Medical School, Boston, MA 02115, USA. kevin.esvelt@wyss.harvard.edu ebier@ucsd.edu. ; Section of Cell and Developmental Biology, Univ. of California, San Diego, La Jolla, CA 92095, USA. ; Department of Biology, Univ. of Utah, Salt Lake City, UT 84112, USA. ; Laboratory of Genetics, Univ. of Wisconsin-Madison, Madison, WI 53706, USA. ; Department of Biomolecular Chemistry, Univ. of Wisconsin-Madison, Madison, WI 53706, USA. ; CSIRO Biosecurity Flagship, General Post Of ce Box 1538, Hobart, Tasmania, 7001, Australia. ; Departments of Microbiology & Molecular Genetics and Molecular Biology & Biochemistry, Univ. of California at Irvine, Irvine, CA 92697, USA. ; Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. ; Laboratory of Genetics, Univ. of Wisconsin-Madison, Madison, WI 53706, USA. Laboratory of Cell and Molecular Biology, Univ. of Wisconsin-Madison, Madison, WI 53706, USA. ; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA. Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA. ; Department of Genetics, Univ. of Cambridge, Cambridge, Cambridgeshire CB2 3EH, UK. ; Department of Genetics, Graduate Univ. for Advanced Studies, Mishima, Shizuoka 411-8540, Japan. NIG-Fly Stock Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan. ; Department of Biochemistry, Univ. of Wisconsin-Madison, Madison, WI 53706, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26229113" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; CRISPR-Cas Systems ; *Clustered Regularly Interspaced Short Palindromic Repeats ; *Containment of Biohazards ; Endonucleases/metabolism ; *Genetic Engineering ; *Genetic Research ; Genome ; *Organisms, Genetically Modified ; *Safety
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 6
    Publication Date: 2018-04-06
    Description: Cross-coupling chemistry is widely applied to carbon-carbon bond formation in the synthesis of medicines, agrochemicals, and other functional materials. Recently, single-electron–induced variants of this reaction class have proven particularly useful in the formation of C(sp 2 )–C(sp 3 ) linkages, although certain compound classes have remained a challenge. Here, we report the use of sulfones to activate the alkyl coupling partner in nickel-catalyzed radical cross-coupling with aryl zinc reagents. This method’s tolerance of fluoroalkyl substituents proved particularly advantageous for the streamlined preparation of pharmaceutically oriented fluorinated scaffolds that previously required multiple steps, toxic reagents, and nonmodular retrosynthetic blueprints. Five specific sulfone reagents facilitate the rapid assembly of a vast set of compounds, many of which contain challenging fluorination patterns.
    Keywords: Chemistry
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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