TY - JOUR A1 - Abramowski, Attila A1 - Aharonian, Felix A. A1 - Benkhali, Faical Ait A1 - Akhperjanian, A. G. A1 - Angüner, Ekrem Oǧuzhan A1 - Backes, Michael A1 - Balzer, Arnim A1 - Becherini, Yvonne A1 - Tjus, J. Becker A1 - Berge, David A1 - Bernhard, Sabrina A1 - Bernlöhr, K. A1 - Birsin, E. A1 - Blackwell, R. A1 - Boettcher, Markus A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Bregeon, Johan A1 - Brun, Francois A1 - Brun, Pierre A1 - Bryan, Mark A1 - Bulik, Tomasz A1 - Carr, John A1 - Casanova, Sabrina A1 - Chakraborty, N. A1 - Chalme-Calvet, R. A1 - Chaves, Ryan C. G. A1 - Chen, Andrew A1 - Chretien, M. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Conrad, Jan A1 - Couturier, C. A1 - Cui, Y. A1 - Davids, I. D. A1 - Degrange, B. A1 - Deil, C. A1 - deWilt, P. A1 - Djannati-Ata, A. A1 - Domainko, W. A1 - Donath, A. A1 - Dubus, G. A1 - Dutson, K. A1 - Dyks, J. A1 - Dyrda, M. A1 - Edwards, T. A1 - Egberts, Kathrin A1 - Eger, P. A1 - Ernenwein, J-P. A1 - Espigat, P. A1 - Farnier, C. A1 - Fegan, S. A1 - Feinstein, F. A1 - Fernandes, M. V. A1 - Fernandez, D. A1 - Fiasson, A. A1 - Fontaine, G. A1 - Foerster, A. A1 - Fuessling, M. A1 - Gabici, S. A1 - Gajdus, M. A1 - Gallant, Y. A. A1 - Garrigoux, T. A1 - Giavitto, G. A1 - Giebels, B. A1 - Glicenstein, J. F. A1 - Gottschall, D. A1 - Goyal, A. A1 - Grondin, M-H. A1 - Grudzinska, M. A1 - Hadasch, D. A1 - Haeffner, S. A1 - Hahn, J. A1 - Hawkes, J. A1 - Heinzelmann, G. A1 - Henri, G. A1 - Hermann, G. A1 - Hervet, O. A1 - Hillert, A. A1 - Hinton, James Anthony A1 - Hofmann, W. A1 - Hofverberg, P. A1 - Hoischen, Clemens A1 - Holler, M. A1 - Horns, D. A1 - Ivascenko, A. A1 - Jacholkowska, A. A1 - Jamrozy, M. A1 - Janiak, M. A1 - Jankowsky, F. A1 - Jung-Richardt, I. A1 - Kastendieck, M. A. A1 - Katarzynski, K. A1 - Katz, U. A1 - Kerszberg, D. A1 - Khelifi, B. A1 - Kieffer, M. A1 - Klepser, S. A1 - Klochkov, D. A1 - Kluzniak, W. A1 - Kolitzus, D. A1 - Komin, Nu. A1 - Kosack, K. A1 - Krakau, S. A1 - Krayzel, F. A1 - Krueger, P. P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lau, J. A1 - Lefaucheur, J. A1 - Lefranc, V. A1 - Lemiere, A. A1 - Lemoine-Goumard, M. A1 - Lenain, J-P. A1 - Lohse, T. A1 - Lopatin, A. A1 - Lu, C-C. A1 - Lui, R. A1 - Marandon, V. A1 - Marcowith, Alexandre A1 - Mariaud, C. A1 - Marx, R. A1 - Maurin, G. A1 - Maxted, N. A1 - Mayer, M. A1 - Meintjes, P. J. A1 - Menzler, U. A1 - Meyer, M. A1 - Mitchell, A. M. W. A1 - Moderski, R. A1 - Mohamed, M. A1 - Mora, K. A1 - Moulin, Emmanuel A1 - Murach, T. A1 - de Naurois, M. A1 - Niemiec, J. A1 - Oakes, L. A1 - Odaka, H. A1 - Oettl, S. A1 - Ohm, S. A1 - Opitz, B. A1 - Ostrowski, M. A1 - Oya, I. A1 - Panter, M. A1 - Parsons, R. D. A1 - Arribas, M. Paz A1 - Pekeur, N. W. A1 - Pelletier, G. A1 - Petrucci, P-O. A1 - Peyaud, B. A1 - Pita, S. A1 - Poon, H. A1 - Prokoph, H. A1 - Puehlhofer, G. A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raab, S. A1 - Reichardt, I. A1 - Reimer, A. A1 - Reimer, O. A1 - Renaud, M. A1 - de los Reyes, R. A1 - Rieger, F. A1 - Romoli, C. A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, V. A1 - Salek, D. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Sasaki, M. A1 - Schlickeiser, R. A1 - Schuessler, F. A1 - Schulz, A. A1 - Schwanke, U. A1 - Schwemmer, S. A1 - Seyffert, A. S. A1 - Simoni, R. A1 - Sol, H. A1 - Spanier, F. A1 - Spengler, G. A1 - Spies, F. A1 - Stawarz, L. A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Tavernet, J-P. A1 - Tavernier, T. A1 - Taylor, A. M. A1 - Terrier, R. A1 - Tluczykont, M. A1 - Trichard, C. A1 - Tuffs, R. A1 - Valerius, K. A1 - van der Walt, J. A1 - van Eldik, C. A1 - van Soelen, B. A1 - Vasileiadis, G. A1 - Veh, J. A1 - Venter, C. A1 - Viana, A. A1 - Vincent, P. A1 - Vink, J. A1 - Voisin, F. A1 - Voelk, H. J. A1 - Vuillaume, T. A1 - Wagner, S. J. A1 - Wagner, P. A1 - Wagner, R. M. A1 - Weidinger, M. A1 - Weitzel, Q. A1 - White, R. A1 - Wierzcholska, A. A1 - Willmann, P. A1 - Woernlein, A. A1 - Wouters, D. A1 - Yang, R. A1 - Zabalza, V. A1 - Zaborov, D. A1 - Zacharias, M. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Zefi, F. A1 - Zywucka, N. T1 - Acceleration of petaelectronvolt protons in the Galactic Centre JF - Nature : the international weekly journal of science N2 - Galactic cosmic rays reach energies of at least a few petaelectronvolts (of the order of 1015 electronvolts). This implies that our Galaxy contains petaelectronvolt accelerators (‘PeVatrons’), but all proposed models of Galactic cosmic-ray accelerators encounter difficulties at exactly these energies. Dozens of Galactic accelerators capable of accelerating particles to energies of tens of teraelectronvolts (of the order of 1013 electronvolts) were inferred from recent γ-ray observations3. However, none of the currently known accelerators—not even the handful of shell-type supernova remnants commonly believed to supply most Galactic cosmic rays—has shown the characteristic tracers of petaelectronvolt particles, namely, power-law spectra of γ-rays extending without a cut-off or a spectral break to tens of teraelectronvolts4. Here we report deep γ-ray observations with arcminute angular resolution of the region surrounding the Galactic Centre, which show the expected tracer of the presence of petaelectronvolt protons within the central 10 parsecs of the Galaxy. We propose that the supermassive black hole Sagittarius A* is linked to this PeVatron. Sagittarius A* went through active phases in the past, as demonstrated by X-ray outbursts5and an outflow from the Galactic Centre6. Although its current rate of particle acceleration is not sufficient to provide a substantial contribution to Galactic cosmic rays, Sagittarius A* could have plausibly been more active over the last 106–107 years, and therefore should be considered as a viable alternative to supernova remnants as a source of petaelectronvolt Galactic cosmic rays. Y1 - 2016 U6 - https://doi.org/10.1038/nature17147 SN - 0028-0836 SN - 1476-4687 VL - 531 SP - 476 EP - + PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Abdalla, Hassan E. A1 - Abramowski, Attila A1 - Aharonian, Felix A. A1 - Benkhali, Faiçal Ait A1 - Akhperjanian, A. G. A1 - Angüner, Ekrem Oǧuzhan A1 - Arrieta, M. A1 - Aubert, Pierre A1 - Backes, Michael A1 - Balzer, Arnim A1 - Barnard, Michelle A1 - Becherini, Yvonne A1 - Tjus, Julia Becker A1 - Berge, David A1 - Bernhard, Sabrina A1 - Bernlöhr, K. A1 - Birsin, E. A1 - Blackwell, R. A1 - Bottcher, Markus A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Bregeon, Johan A1 - Brun, Francois A1 - Brun, Pierre A1 - Bryan, Mark A1 - Bulik, Tomasz A1 - Capasso, M. A1 - Carr, John A1 - Casanova, Sabrina A1 - Chakraborty, N. A1 - Chalme-Calvet, R. A1 - Chaves, Ryan C. G. A1 - Chen, Andrew A1 - Chevalier, J. A1 - Chretien, M. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Condon, B. A1 - Conrad, Jan A1 - Couturier, C. A1 - Cui, Y. A1 - Davids, I. D. A1 - Degrange, B. A1 - Deil, Christoph A1 - deWilt, P. A1 - Djannati-Atai, Arache A1 - Domainko, Wilfried A1 - Donath, Axel A1 - Dubus, Guillaume A1 - Dutson, Kate A1 - Dyks, J. A1 - Dyrda, M. A1 - Edwards, T. A1 - Egberts, Kathrin A1 - Eger, P. A1 - Ernenwein, J. -P. A1 - Eschbach, S. A1 - Farnier, C. A1 - Fegan, Stuart A1 - Fernandes, M. V. A1 - Fiasson, A. A1 - Fontaine, G. A1 - Foerster, A. A1 - Funk, S. A1 - Füßling, Matthias A1 - Gabici, Stefano A1 - Gajdus, M. A1 - Gallant, Y. A. A1 - Garrigoux, T. A1 - Giavitto, Gianluca A1 - Giebels, B. A1 - Glicenstein, J. F. A1 - Gottschall, Daniel A1 - Goyal, A. A1 - Grondin, M. -H. A1 - Grudzinska, M. A1 - Hadasch, Daniela A1 - Hahn, J. A1 - Hawkes, J. A1 - Heinzelmann, G. A1 - Henri, Gilles A1 - Hermann, G. A1 - Hervet, Olivier A1 - Hillert, A. A1 - Hinton, James Anthony A1 - Hofmann, Werner A1 - Hoischen, Clemens A1 - Holler, M. A1 - Horns, D. A1 - Ivascenko, Alex A1 - Jacholkowska, A. A1 - Jamrozy, Marek A1 - Janiak, M. A1 - Jankowsky, D. A1 - Jankowsky, Felix A1 - Jingo, M. A1 - Jogler, Tobias A1 - Jouvin, Lea A1 - Jung-Richardt, Ira A1 - Kastendieck, M. A. A1 - Katarzynski, Krzysztof A1 - Katz, Uli A1 - Kerszberg, D. A1 - Khelifi, B. A1 - Kieffer, M. A1 - King, J. A1 - Klepser, S. A1 - Klochkov, Dmitry A1 - Kluzniak, W. A1 - Kolitzus, D. A1 - Komin, Nu. A1 - Kosack, K. A1 - Krakau, S. A1 - Kraus, Michael A1 - Krayzel, F. A1 - Kruger, P. P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lau, Jeanie A1 - Lees, J. -P. A1 - Lefaucheur, J. A1 - Lefranc, V. A1 - Lemiere, A. A1 - Lemoine-Goumard, M. A1 - Lenain, J. -P. A1 - Leser, Eva A1 - Lohse, Thomas A1 - Lorentz, M. A1 - Lui, R. A1 - Lypova, Iryna A1 - Marandon, Vincent A1 - Marcowith, Alexandre A1 - Mariaud, C. A1 - Marx, R. A1 - Maurin, G. A1 - Maxted, N. A1 - Mayer, Michael A1 - Meintjes, Petrus Johannes A1 - Menzler, U. A1 - Meyer, Manuel A1 - Mitchell, A. M. W. A1 - Moderski, R. A1 - Mohamed, M. A1 - Mora, K. A1 - Moulin, Emmanuel A1 - Murach, T. A1 - de Naurois, Mathieu A1 - Niederwanger, F. A1 - Niemiec, J. A1 - Oakes, L. A1 - Odaka, Hirokazu A1 - Ohm, Stefan A1 - Oettl, S. A1 - Ostrowski, M. A1 - Oya, I. A1 - Padovani, Marco A1 - Panter, M. A1 - Parsons, R. D. A1 - Arribas, M. Paz A1 - Pekeur, N. W. A1 - Pelletier, G. A1 - Petrucci, P. -O. A1 - Peyaud, B. A1 - Pita, S. A1 - Poon, Helen A1 - Prokhorov, Dmitry A1 - Prokoph, Heike A1 - Puehlhofer, Gerd A1 - Punch, Michael A1 - Quirrenbach, Andreas A1 - Raab, S. A1 - Reimer, Anita A1 - Reimer, Olaf A1 - Renaud, M. A1 - de los Reyes, R. A1 - Rieger, Frank A1 - Romoli, Carlo A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, V. A1 - Salek, David A1 - Sanchez, David A. A1 - Santangelo, Andrea A1 - Sasaki, Manami A1 - Schlickeiser, Reinhard A1 - Schussler, F. A1 - Schulz, Andreas A1 - Schwanke, U. A1 - Schwemmer, S. A1 - Seyffert, A. S. A1 - Shafi, N. A1 - Simoni, R. A1 - Sol, H. A1 - Spanier, Felix A1 - Spengler, G. A1 - Spiess, F. A1 - Stawarz, Lukasz A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Tavernet, J. -P. A1 - Tavernier, T. A1 - Taylor, A. M. A1 - Terrier, R. A1 - Tluczykont, Martin A1 - Trichard, C. A1 - Tuffs, R. A1 - van der Walt, Johan A1 - van Eldik, Christopher A1 - van Soelen, Brian A1 - Vasileiadis, Georges A1 - Veh, J. A1 - Venter, C. A1 - Viana, A. A1 - Vincent, P. A1 - Vink, Jacco A1 - Voisin, F. A1 - Voelk, Heinrich J. A1 - Vuillaume, Thomas A1 - Wadiasingh, Z. A1 - Wagner, Stefan J. A1 - Wagner, P. A1 - Wagner, R. M. A1 - White, R. A1 - Wierzcholska, Alicja A1 - Willmann, P. A1 - Woernlein, A. A1 - Wouters, Denis A1 - Yang, R. A1 - Zabalza, Victor A1 - Zaborov, D. A1 - Zacharias, M. A1 - Zdziarski, A. A. A1 - Zech, Andreas A1 - Zefi, F. A1 - Ziegler, A. A1 - Zywucka, Natalia T1 - Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with HESS JF - Physical review letters N2 - The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using gamma-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant gamma-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section . These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach values of 6 x 10(-26) cm(3) s(-1) in the W+W- channel for a DM particle mass of 1.5 TeV, and 2 x 10(-26) cm(3) s(-1) in the tau(+)tau(-) channel for a 1 TeV mass. For the first time, ground-based gamma-ray observations have reached sufficient sensitivity to probe values expected from the thermal relic density for TeV DM particles. Y1 - 2016 U6 - https://doi.org/10.1103/PhysRevLett.117.111301 SN - 0031-9007 SN - 1079-7114 VL - 117 PB - American Physical Society CY - College Park ER - TY - GEN A1 - Abramowski, Attila A1 - Aharonian, Felix A. A1 - Benkhali, Faical Ait A1 - Akhperjanian, A. G. A1 - Angüner, Ekrem Oǧuzhan A1 - Backes, Michael A1 - Balenderan, Shangkari A1 - Balzer, Arnim A1 - Barnacka, Anna A1 - Becherini, Yvonne A1 - Tjus, Julia Becker A1 - Berge, David A1 - Bernhard, Sabrina A1 - Bernlöhr, Konrad A1 - Birsin, E. A1 - Biteau, Jonathan A1 - Böttcher, Markus A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Bregeon, Johan A1 - Brun, Francois A1 - Brun, Pierre A1 - Bryan, Mark A1 - Bulik, Tomasz A1 - Carrigan, Svenja A1 - Casanova, Sabrina A1 - Chadwick, Paula M. A1 - Chakraborty, Nachiketa A1 - Chalme-Calvet, R. A1 - Chaves, Ryan C. G. A1 - Chretien, M. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Conrad, Jan A1 - Couturier, Claire A1 - Cui, Yudong A1 - Davids, Isak Delberth A1 - Degrange, Bernhard A1 - Deil, Christoph A1 - deWilt, P. A1 - Djannati-Ataï, A. A1 - Domainko, Wilfried A1 - Donath, Axel A1 - Dubus, G. A1 - Dutson, K. A1 - Dyks, J. A1 - Dyrda, M. A1 - Edwards, Tanya A1 - Egberts, Kathrin A1 - Eger, Peter A1 - Espigat, P. A1 - Farnier, C. A1 - Fegan, Stephen A1 - Feinstein, Fabrice A1 - Fernandes, Milton Virgilio A1 - Fernandez, Diane A1 - Fiasson, A. A1 - Fontaine, Gerard A1 - Förster, Andreas A1 - Fuessling, M. A1 - Gabici, S. A1 - Gajdus, M. A1 - Gallant, Yves A. A1 - Garrigoux, Tania A1 - Giavitto, G. A1 - Giebels, Berrie A1 - Glicenstein, Jean-Francois A1 - Gottschall, Daniel A1 - Grondin, M. -H. A1 - Grudzinska, M. A1 - Hadasch, Daniela A1 - Haeffner, S. A1 - Hahn, Joachim A1 - Harris, Jonathan A1 - Heinzelmann, Götz A1 - Henri, G. A1 - Hermann, German A1 - Hervet, O. A1 - Hillert, Andreas A1 - Hinton, James Anthony A1 - Hofmann, Werner A1 - Hofverberg, Petter A1 - Holler, Markus A1 - Horns, Dieter A1 - Ivascenko, Alex A1 - Jacholkowska, A. A1 - Jahn, C. A1 - Jamrozy, Marek A1 - Janiak, M. A1 - Jankowsky, F. A1 - Jung-Richardt, I. A1 - Kastendieck, Max Anton A1 - Katarzynski, K. A1 - Katz, U. A1 - Kaufmann, S. A1 - Khelifi, B. A1 - Kieffer, Michel A1 - Klepser, S. A1 - Klochkov, Dmitry A1 - Kluzniak, W. A1 - Kolitzus, David A1 - Komin, Nu A1 - Kosack, Karl A1 - Krakau, Steffen A1 - Krayzel, F. A1 - Krueger, Pat P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lefaucheur, J. A1 - Lefranc, Valentin A1 - Lemiere, A. A1 - Lemoine-Goumard, M. A1 - Lenain, J. -P. A1 - Lohse, Thomas A1 - Lopatin, A. A1 - Lu, Chia-Chun A1 - Marandon, Vincent A1 - Marcowith, Alexandre A1 - Marx, Ramin A1 - Maurin, G. A1 - Maxted, Nigel A1 - Mayer, Michael A1 - McComb, T. J. Lowry A1 - Mehault, J. A1 - Meintjes, P. J. A1 - Menzler, Ulf A1 - Meyer, M. A1 - Mitchell, Alison M. W. A1 - Moderski, R. A1 - Mohamed, M. A1 - Mora, K. A1 - Moulin, Emmanuel A1 - Murach, Thomas A1 - de Naurois, Mathieu A1 - Niemiec, J. A1 - Nolan, Sam J. A1 - Oakes, Louise A1 - Odaka, Hirokazu A1 - Ohm, S. A1 - Optiz, Björn A1 - Ostrowski, Michal A1 - Oya, I. A1 - Panter, Michael A1 - Parsons, R. Daniel A1 - Arribas, M. Paz A1 - Pekeur, Nikki W. A1 - Pelletier, G. A1 - Petrucci, P. -O. A1 - Peyaud, B. A1 - Pita, S. A1 - Poon, Helen A1 - Pühlhofer, Gerd A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raab, S. A1 - Reichardt, I. A1 - Reimer, Anita A1 - Reimer, Olaf A1 - Renaud, Metz A1 - de los Reyes, Raquel A1 - Rieger, Frank A1 - Romoli, C. A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, Vardan A1 - Salek, D. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Schlickeiser, Reinhard A1 - Schuessler, F. A1 - Schulz, A. A1 - Schwanke, Ullrich A1 - Schwarzburg, S. A1 - Schwemmer, S. A1 - Sol, H. A1 - Spanier, Felix A1 - Spengler, G. A1 - Spies, Franziska A1 - Stawarz, Lukasz A1 - Steenkamp, Riaan A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Tavernet, J. -P. A1 - Tavernier, T. A1 - Taylor, A. M. A1 - Terrier, R. A1 - Tluczykont, Martin A1 - Trichard, C. A1 - Valerius, K. A1 - van Eldik, C. A1 - van Soelen, B. A1 - Vasileiadis, Georges A1 - Veh, J. A1 - Venter, Christo A1 - Viana, Aion A1 - Vincent, P. A1 - Vink, Jacco A1 - Völk, Heinrich J. A1 - Volpe, Francesca A1 - Vorster, Martine A1 - Vuillaume, T. A1 - Wagner, S. J. A1 - Wagner, P. A1 - Wagner, R. M. A1 - Ward, Martin A1 - Weidinger, Matthias A1 - Weitzel, Quirin A1 - White, R. A1 - Wierzcholska, A. A1 - Willmann, P. A1 - Woernlein, A. A1 - Wouters, D. A1 - Yang, Ruizhi A1 - Zabalza, Victor A1 - Zaborov, Dmitry A1 - Zacharias, M. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Zechlin, Hannes -S. T1 - H.E.S.S. detection of TeV emission from the interaction region between the supernova remnant G349.7+0.2 and a molecular cloud (vol 574, A100, 2015) T2 - Astronomy and astrophysics : an international weekly journal KW - gamma rays: general KW - ISM: supernova remnants KW - ISM: clouds KW - errata, addenda Y1 - 2015 U6 - https://doi.org/10.1051/0004-6361/201425070e SN - 1432-0746 VL - 580 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Diekmann, Martin A1 - Andres, Christian A1 - Becker, Thomas A1 - Bennie, Jonathan A1 - Blueml, Volker A1 - Bullock, James M. A1 - Culmsee, Heike A1 - Fanigliulo, Miriam A1 - Hahn, Annett A1 - Heinken, Thilo A1 - Leuschner, Christoph A1 - Luka, Stefanie A1 - Meissner, Justus A1 - Müller, Josef A1 - Newton, Adrian A1 - Peppler-Lisbach, Cord A1 - Rosenthal, Gert A1 - van den Berg, Leon J. L. A1 - Vergeer, Philippine A1 - Wesche, Karsten T1 - Patterns of long-term vegetation change vary between different types of semi-natural grasslands in Western and Central Europe JF - Journal of vegetation science N2 - Questions Has plant species richness in semi-natural grasslands changed over recent decades? Do the temporal trends of habitat specialists differ from those of habitat generalists? Has there been a homogenization of the grassland vegetation? Location Different regions in Germany and the UK. Methods We conducted a formal meta-analysis of re-survey vegetation studies of semi-natural grasslands. In total, 23 data sets were compiled, spanning up to 75 years between the surveys, including 13 data sets from wet grasslands, six from dry grasslands and four from other grassland types. Edaphic conditions were assessed using mean Ellenberg indicator values for soil moisture, nitrogen and pH. Changes in species richness and environmental variables were evaluated using response ratios. Results In most wet grasslands, total species richness declined over time, while habitat specialists almost completely vanished. The number of species losses increased with increasing time between the surveys and were associated with a strong decrease in soil moisture and higher soil nutrient contents. Wet grasslands in nature reserves showed no such changes or even opposite trends. In dry grasslands and other grassland types, total species richness did not consistently change, but the number or proportions of habitat specialists declined. There were also considerable changes in species composition, especially in wet grasslands that often have been converted into intensively managed, highly productive meadows or pastures. We did not find a general homogenization of the vegetation in any of the grassland types. Conclusions The results document the widespread deterioration of semi-natural grasslands, especially of those types that can easily be transformed to high production grasslands. The main causes for the loss of grassland specialists are changed management in combination with increased fertilization and nitrogen deposition. Dry grasslands are most resistant to change, but also show a long-term trend towards an increase in more mesotrophic species. KW - dry grasslands KW - fragmentation KW - homogenization KW - management KW - meta-analysis KW - nitrogen deposition KW - quasi-permanent plot KW - re-survey KW - species richness KW - wet grasslands Y1 - 2019 U6 - https://doi.org/10.1111/jvs.12727 SN - 1100-9233 SN - 1654-1103 VL - 30 IS - 2 SP - 187 EP - 202 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Meyer, Susann A1 - Schroeter, M. -A. A1 - Hahn, Marc B. A1 - Solomun, T. A1 - Sturm, Heinz A1 - Kunte, H. J. T1 - Ectoine can enhance structural changes in DNA in vitro JF - Scientific reports N2 - Strand breaks and conformational changes of DNA have consequences for the physiological role of DNA. The natural protecting molecule ectoine is beneficial to entire bacterial cells and biomolecules such as proteins by mitigating detrimental effects of environmental stresses. It was postulated that ectoine-like molecules bind to negatively charged spheres that mimic DNA surfaces. We investigated the effect of ectoine on DNA and whether ectoine is able to protect DNA from damages caused by ultraviolet radiation (UV-A). In order to determine different isoforms of DNA, agarose gel electrophoresis and atomic force microscopy experiments were carried out with plasmid pUC19 DNA. Our quantitative results revealed that a prolonged incubation of DNA with ectoine leads to an increase in transitions from supercoiled (undamaged) to open circular (single-strand break) conformation at pH 6.6. The effect is pH dependent and no significant changes were observed at physiological pH of 7.5. After UV-A irradiation in ectoine solution, changes in DNA conformation were even more pronounced and this effect was pH dependent. We hypothesize that ectoine is attracted to the negatively charge surface of DNA at lower pH and therefore fails to act as a stabilizing agent for DNA in our in vitro experiments. Y1 - 2017 U6 - https://doi.org/10.1038/s41598-017-07441-z SN - 2045-2322 VL - 7 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Schröter, M. -A. A1 - Meyer, S. A1 - Hahn, M. B. A1 - Solomun, T. A1 - Sturm, H. A1 - Kunte, H. J. T1 - Ectoine protects DNA from damage by ionizing radiation JF - Scientific reports N2 - Ectoine plays an important role in protecting biomolecules and entire cells against environmental stressors such as salinity, freezing, drying and high temperatures. Recent studies revealed that ectoine also provides effective protection for human skin cells from damage caused by UV-A radiation. These protective properties make ectoine a valuable compound and it is applied as an active ingredient in numerous pharmaceutical devices and cosmetics. Interestingly, the underlying mechanism resulting in protecting cells from radiation is not yet fully understood. Here we present a study on ectoine and its protective influence on DNA during electron irradiation. Applying gel electrophoresis and atomic force microscopy, we demonstrate for the first time that ectoine prevents DNA strand breaks caused by ionizing electron radiation. The results presented here point to future applications of ectoine for instance in cancer radiation therapy. Y1 - 2017 U6 - https://doi.org/10.1038/s41598-017-15512-4 SN - 2045-2322 VL - 7 PB - Nature Publ. Group CY - London ER -