TY - JOUR A1 - De Angelis, A. A1 - Tatischeff, V. A1 - Grenier, I. A. A1 - McEnery, J. A1 - Mallamaci, Manuela A1 - Tavani, M. A1 - Oberlack, U. A1 - Hanlon, L. A1 - Walter, R. A1 - Argan, A. A1 - Von Ballmoos, P. A1 - Bulgarelli, A. A1 - Bykov, A. A1 - Hernanz, M. A1 - Kanbach, G. A1 - Kuvvetli, I. A1 - Pearce, M. A1 - Zdziarski, A. A1 - Conrad, J. A1 - Ghisellini, G. A1 - Harding, A. A1 - Isern, J. A1 - Leising, M. A1 - Longo, F. A1 - Madejski, G. A1 - Martinez, M. A1 - Mazziotta, Mario Nicola A1 - Paredes, J. M. A1 - Pohl, Martin A1 - Rando, R. A1 - Razzano, M. A1 - Aboudan, A. A1 - Ackermann, M. A1 - Addazi, A. A1 - Ajello, M. A1 - Albertus, C. A1 - Alvarez, J. M. A1 - Ambrosi, G. A1 - Anton, S. A1 - Antonelli, L. A. A1 - Babic, A. A1 - Baibussinov, B. A1 - Balbom, M. A1 - Baldini, L. A1 - Balman, S. A1 - Bambi, C. A1 - Barres de Almeida, U. A1 - Barrio, J. A. A1 - Bartels, R. A1 - Bastieri, D. A1 - Bednarek, W. A1 - Bernard, D. A1 - Bernardini, E. A1 - Bernasconi, T. A1 - Bertucci, B. A1 - Biland, A. A1 - Bissaldi, E. A1 - Boettcher, M. A1 - Bonvicini, V. A1 - Bosch-Ramon, V. A1 - Bottacini, E. A1 - Bozhilov, V. A1 - Bretz, T. A1 - Branchesi, M. A1 - Brdar, V. A1 - Bringmann, T. A1 - Brogna, A. A1 - Jorgensen, C. Budtz A1 - Busetto, G. A1 - Buson, S. A1 - Busso, M. A1 - Caccianiga, A. A1 - Camera, S. A1 - Campana, R. A1 - Caraveo, P. A1 - Cardillo, M. A1 - Carlson, P. A1 - Celestin, S. A1 - Cermeno, M. A1 - Chen, A. A1 - Cheung, C. C. A1 - Churazov, E. A1 - Ciprini, S. A1 - Coc, A. A1 - Colafrancesco, S. A1 - Coleiro, A. A1 - Collmar, W. A1 - Coppi, P. A1 - Curado da Silva, R. A1 - Cutini, S. A1 - De Lotto, B. A1 - de Martino, D. A1 - De Rosa, A. A1 - Del Santo, M. A1 - Delgado, L. A1 - Diehl, R. A1 - Dietrich, S. A1 - Dolgov, A. D. A1 - Dominguez, A. A1 - Prester, D. Dominis A1 - Donnarumma, I. A1 - Dorner, D. A1 - Doro, M. A1 - Dutra, M. A1 - Elsaesser, D. A1 - Fabrizio, M. A1 - Fernandez-Barral, A. A1 - Fioretti, V. A1 - Foffano, L. A1 - Formato, V. A1 - Fornengo, N. A1 - Foschini, L. A1 - Franceschini, A. A1 - Franckowiak, A. A1 - Funk, S. A1 - Fuschino, F. A1 - Gaggero, D. A1 - Galanti, G. A1 - Gargano, F. A1 - Gasparrini, D. A1 - Gehrz, R. A1 - Giammaria, P. A1 - Giglietto, N. A1 - Giommi, P. A1 - Giordano, F. A1 - Giroletti, M. A1 - Ghirlanda, G. A1 - Godinovic, N. A1 - Gouiffes, C. A1 - Grove, J. E. A1 - Hamadache, C. A1 - Hartmann, D. H. A1 - Hayashida, M. A1 - Hryczuk, A. A1 - Jean, P. A1 - Johnson, T. A1 - Jose, J. A1 - Kaufmann, S. A1 - Khelifi, B. A1 - Kiener, J. A1 - Knodlseder, J. A1 - Kolem, M. A1 - Kopp, J. A1 - Kozhuharov, V. A1 - Labanti, C. A1 - Lalkovski, S. A1 - Laurent, P. A1 - Limousin, O. A1 - Linares, M. A1 - Lindfors, E. A1 - Lindner, M. A1 - Liu, J. A1 - Lombardi, S. A1 - Loparco, F. A1 - Lopez-Coto, R. A1 - Lopez Moya, M. A1 - Lott, B. A1 - Lubrano, P. A1 - Malyshev, D. A1 - Mankuzhiyil, N. A1 - Mannheim, K. A1 - Marcha, M. J. A1 - Marciano, A. A1 - Marcote, B. A1 - Mariotti, M. A1 - Marisaldi, M. A1 - McBreen, S. A1 - Mereghetti, S. A1 - Merle, A. A1 - Mignani, R. A1 - Minervini, G. A1 - Moiseev, A. A1 - Morselli, A. A1 - Moura, F. A1 - Nakazawa, K. A1 - Nava, L. A1 - Nieto, D. A1 - Orienti, M. A1 - Orio, M. A1 - Orlando, E. A1 - Orleanski, P. A1 - Paiano, S. A1 - Paoletti, R. A1 - Papitto, A. A1 - Pasquato, M. A1 - Patricelli, B. A1 - Perez-Garcia, M. A. A1 - Persic, M. A1 - Piano, G. A1 - Pichel, A. A1 - Pimenta, M. A1 - Pittori, C. A1 - Porter, T. A1 - Poutanen, J. A1 - Prandini, E. A1 - Prantzos, N. A1 - Produit, N. A1 - Profumo, S. A1 - Queiroz, F. S. A1 - Raino, S. A1 - Raklev, A. A1 - Regis, M. A1 - Reichardt, I. A1 - Rephaeli, Y. A1 - Rico, J. A1 - Rodejohann, W. A1 - Fernandez, G. Rodriguez A1 - Roncadelli, M. A1 - Roso, L. A1 - Rovero, A. A1 - Ruffini, R. A1 - Sala, G. A1 - Sanchez-Conde, M. A. A1 - Santangelo, Andrea A1 - Parkinson, P. Saz A1 - Sbarrato, T. A1 - Shearer, A. A1 - Shellard, R. A1 - Short, K. A1 - Siegert, T. A1 - Siqueira, C. A1 - Spinelli, P. A1 - Stamerra, A. A1 - Starrfield, S. A1 - Strong, A. A1 - Strumke, I. A1 - Tavecchio, F. A1 - Taverna, R. A1 - Terzic, T. A1 - Thompson, D. J. A1 - Tibolla, O. A1 - Torres, D. F. A1 - Turolla, R. A1 - Ulyanov, A. A1 - Ursi, A. A1 - Vacchi, A. A1 - Van den Abeele, J. A1 - Vankova-Kirilovai, G. A1 - Venter, C. A1 - Verrecchia, F. A1 - Vincent, P. A1 - Wang, X. A1 - Weniger, C. A1 - Wu, X. A1 - Zaharijas, G. A1 - Zampieri, L. A1 - Zane, S. A1 - Zimmer, S. A1 - Zoglauer, A. T1 - Science with e-ASTROGAM A space mission for MeV-GeV gamma-ray astrophysics JF - Journal of High Energy Astrophysics Y1 - 2018 U6 - https://doi.org/10.1016/j.jheap.2018.07.001 SN - 2214-4048 SN - 2214-4056 VL - 19 SP - 1 EP - 106 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Cheng, X. A1 - Ding, M. D. A1 - Zhang, J. A1 - Sun, X. D. A1 - Guo, Y. A1 - Wang, Yi-Ming A1 - Kliem, Bernhard A1 - Deng, Y. Y. T1 - Formation of a double-decker magnetic flux rope in the sigmoidal solar active region 11520 JF - The astrophysical journal : an international review of spectroscopy and astronomical physics N2 - In this paper, we address the formation of a magnetic flux rope (MFR) that erupted on 2012 July 12 and caused a strong geomagnetic storm event on July 15. Through analyzing the long-term evolution of the associated active region observed by the Atmospheric Imaging Assembly and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, it is found that the twisted field of an MFR, indicated by a continuous S-shaped sigmoid, is built up from two groups of sheared arcades near the main polarity inversion line a half day before the eruption. The temperature within the twisted field and sheared arcades is higher than that of the ambient volume, suggesting that magnetic reconnection most likely works there. The driver behind the reconnection is attributed to shearing and converging motions at magnetic footpoints with velocities in the range of 0.1-0.6 km s(-1). The rotation of the preceding sunspot also contributes to the MFR buildup. Extrapolated three-dimensional non-linear force-free field structures further reveal the locations of the reconnection to be in a bald-patch region and in a hyperbolic flux tube. About 2 hr before the eruption, indications of a second MFR in the form of an S-shaped hot channel are seen. It lies above the original MFR that continuously exists and includes a filament. The whole structure thus makes up a stable double-decker MFR system for hours prior to the eruption. Eventually, after entering the domain of instability, the high-lying MFR impulsively erupts to generate a fast coronal mass ejection and X-class flare; while the low-lying MFR remains behind and continuously maintains the sigmoidicity of the active region. KW - Sun: corona KW - Sun: coronal mass ejections (CMEs) KW - Sun: filaments, prominences KW - Sun: magnetic fields Y1 - 2014 U6 - https://doi.org/10.1088/0004-637X/789/2/93 SN - 0004-637X SN - 1538-4357 VL - 789 IS - 2 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Wolf, Thomas J. A. A1 - Sanchez, David M. A1 - Yang, J. A1 - Parrish, R. M. A1 - Nunes, J. P. F. A1 - Centurion, M. A1 - Coffee, R. A1 - Cryan, J. P. A1 - Gühr, Markus A1 - Hegazy, Kareem A1 - Kirrander, Adam A1 - Li, R. K. A1 - Ruddock, J. A1 - Shen, Xiaozhe A1 - Vecchione, T. A1 - Weathersby, S. P. A1 - Weber, Peter M. A1 - Wilkin, K. A1 - Yong, Haiwang A1 - Zheng, Q. A1 - Wang, X. J. A1 - Minitti, Michael P. A1 - Martinez, Todd J. T1 - The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction JF - Nature chemistry N2 - The ultrafast photoinduced ring-opening of 1,3-cyclohexadiene constitutes a textbook example of electrocyclic reactions in organic chemistry and a model for photobiological reactions in vitamin D synthesis. Although the relaxation from the photoexcited electronic state during the ring-opening has been investigated in numerous studies, the accompanying changes in atomic distance have not been resolved. Here we present a direct and unambiguous observation of the ring-opening reaction path on the femtosecond timescale and subangstrom length scale using megaelectronvolt ultrafast electron diffraction. We followed the carbon-carbon bond dissociation and the structural opening of the 1,3-cyclohexadiene ring by the direct measurement of time-dependent changes in the distribution of interatomic distances. We observed a substantial acceleration of the ring-opening motion after internal conversion to the ground state due to a steepening of the electronic potential gradient towards the product minima. The ring-opening motion transforms into rotation of the terminal ethylene groups in the photoproduct 1,3,5-hexatriene on the subpicosecond timescale. KW - Organic chemistry KW - Photochemistry KW - Physical chemistry KW - Theoretical chemistry Y1 - 2019 U6 - https://doi.org/10.1038/s41557-019-0252-7 SN - 1755-4330 SN - 1755-4349 VL - 11 IS - 6 SP - 504 EP - 509 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Tiegs, Scott D. A1 - Costello, David M. A1 - Isken, Mark W. A1 - Woodward, Guy A1 - McIntyre, Peter B. A1 - Gessner, Mark O. A1 - Chauvet, Eric A1 - Griffiths, Natalie A. A1 - Flecker, Alex S. A1 - Acuna, Vicenc A1 - Albarino, Ricardo A1 - Allen, Daniel C. A1 - Alonso, Cecilia A1 - Andino, Patricio A1 - Arango, Clay A1 - Aroviita, Jukka A1 - Barbosa, Marcus V. M. A1 - Barmuta, Leon A. A1 - Baxter, Colden V. A1 - Bell, Thomas D. C. A1 - Bellinger, Brent A1 - Boyero, Luz A1 - Brown, Lee E. A1 - Bruder, Andreas A1 - Bruesewitz, Denise A. A1 - Burdon, Francis J. A1 - Callisto, Marcos A1 - Canhoto, Cristina A1 - Capps, Krista A. A1 - Castillo, Maria M. A1 - Clapcott, Joanne A1 - Colas, Fanny A1 - Colon-Gaud, Checo A1 - Cornut, Julien A1 - Crespo-Perez, Veronica A1 - Cross, Wyatt F. A1 - Culp, Joseph M. A1 - Danger, Michael A1 - Dangles, Olivier A1 - de Eyto, Elvira A1 - Derry, Alison M. A1 - Diaz Villanueva, Veronica A1 - Douglas, Michael M. A1 - Elosegi, Arturo A1 - Encalada, Andrea C. A1 - Entrekin, Sally A1 - Espinosa, Rodrigo A1 - Ethaiya, Diana A1 - Ferreira, Veronica A1 - Ferriol, Carmen A1 - Flanagan, Kyla M. A1 - Fleituch, Tadeusz A1 - Shah, Jennifer J. Follstad A1 - Frainer, Andre A1 - Friberg, Nikolai A1 - Frost, Paul C. A1 - Garcia, Erica A. A1 - Lago, Liliana Garcia A1 - Garcia Soto, Pavel Ernesto A1 - Ghate, Sudeep A1 - Giling, Darren P. A1 - Gilmer, Alan A1 - Goncalves, Jose Francisco A1 - Gonzales, Rosario Karina A1 - Graca, Manuel A. S. A1 - Grace, Mike A1 - Grossart, Hans-Peter A1 - Guerold, Francois A1 - Gulis, Vlad A1 - Hepp, Luiz U. A1 - Higgins, Scott A1 - Hishi, Takuo A1 - Huddart, Joseph A1 - Hudson, John A1 - Imberger, Samantha A1 - Iniguez-Armijos, Carlos A1 - Iwata, Tomoya A1 - Janetski, David J. A1 - Jennings, Eleanor A1 - Kirkwood, Andrea E. A1 - Koning, Aaron A. A1 - Kosten, Sarian A1 - Kuehn, Kevin A. A1 - Laudon, Hjalmar A1 - Leavitt, Peter R. A1 - Lemes da Silva, Aurea L. A1 - Leroux, Shawn J. A1 - Leroy, Carri J. A1 - Lisi, Peter J. A1 - MacKenzie, Richard A1 - Marcarelli, Amy M. A1 - Masese, Frank O. A1 - Mckie, Brendan G. A1 - Oliveira Medeiros, Adriana A1 - Meissner, Kristian A1 - Milisa, Marko A1 - Mishra, Shailendra A1 - Miyake, Yo A1 - Moerke, Ashley A1 - Mombrikotb, Shorok A1 - Mooney, Rob A1 - Moulton, Tim A1 - Muotka, Timo A1 - Negishi, Junjiro N. A1 - Neres-Lima, Vinicius A1 - Nieminen, Mika L. A1 - Nimptsch, Jorge A1 - Ondruch, Jakub A1 - Paavola, Riku A1 - Pardo, Isabel A1 - Patrick, Christopher J. A1 - Peeters, Edwin T. H. M. A1 - Pozo, Jesus A1 - Pringle, Catherine A1 - Prussian, Aaron A1 - Quenta, Estefania A1 - Quesada, Antonio A1 - Reid, Brian A1 - Richardson, John S. A1 - Rigosi, Anna A1 - Rincon, Jose A1 - Risnoveanu, Geta A1 - Robinson, Christopher T. A1 - Rodriguez-Gallego, Lorena A1 - Royer, Todd V. A1 - Rusak, James A. A1 - Santamans, Anna C. A1 - Selmeczy, Geza B. A1 - Simiyu, Gelas A1 - Skuja, Agnija A1 - Smykla, Jerzy A1 - Sridhar, Kandikere R. A1 - Sponseller, Ryan A1 - Stoler, Aaron A1 - Swan, Christopher M. A1 - Szlag, David A1 - Teixeira-de Mello, Franco A1 - Tonkin, Jonathan D. A1 - Uusheimo, Sari A1 - Veach, Allison M. A1 - Vilbaste, Sirje A1 - Vought, Lena B. M. A1 - Wang, Chiao-Ping A1 - Webster, Jackson R. A1 - Wilson, Paul B. A1 - Woelfl, Stefan A1 - Xenopoulos, Marguerite A. A1 - Yates, Adam G. A1 - Yoshimura, Chihiro A1 - Yule, Catherine M. A1 - Zhang, Yixin X. A1 - Zwart, Jacob A. T1 - Global patterns and drivers of ecosystem functioning in rivers and riparian zones JF - Science Advances N2 - River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented “next-generation biomonitoring” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale. Y1 - 2019 U6 - https://doi.org/10.1126/sciadv.aav0486 SN - 2375-2548 VL - 5 IS - 1 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Wang, E. A1 - Kirby, E. A1 - Furlong, K. P. A1 - van Soest, M. A1 - Xu, G. A1 - Shi, X. A1 - Kamp, P. J. J. A1 - Hodges, K. V. T1 - Two-phase growth of high topography in eastern Tibet during the Cenozoic JF - NATURE GEOSCIENCE N2 - High topography in eastern Tibet is thought to have formed when deep crust beneath the central Tibetan Plateau flowed towards the plateau margin, causing crustal thickening and surface uplift(1,2). Rapid exhumation starting about 10-15 million years ago is inferred to mark the onset of surface uplift and fluvial incision(3-6). Although geophysical data are consistent with weak crust capable of flow(7,8), it is unclear how the timing(9) and amount of deformation adjacent to the Sichuan Basin during the Cenozoic era can be explained in this way(10,11). Here we use thermochronology to measure the cooling histories of rocks exposed in a section that stretches vertically over 3 km adjacent to the Sichuan Basin. Our thermal models of exhumation-driven cooling show that these rocks, and hence the plateau margin, were subject to slow, steady exhumation during early Cenozoic time, followed by two pulses of rapid exhumation, one beginning 30-25 million years ago and a second 10-15 million years ago that continues to present. Our findings imply that significant topographic relief existed adjacent to the Sichuan Basin before the Indo-Asian collision. Furthermore, the onset of Cenozoic mountain building probably pre-dated development of the weak lower crust, implying that early topography was instead formed during thickening of the upper crust along faults. We suggest that episodes of mountain building may reflect distinct geodynamic mechanisms of crustal thickening. Y1 - 2012 U6 - https://doi.org/10.1038/NGEO1538 SN - 1752-0894 VL - 5 IS - 9 SP - 640 EP - 645 PB - NATURE PUBLISHING GROUP CY - NEW YORK ER -