--- _id: '9677' abstract: - lang: eng text: Progress in the atomic-scale modeling of matter over the past decade has been tremendous. This progress has been brought about by improvements in methods for evaluating interatomic forces that work by either solving the electronic structure problem explicitly, or by computing accurate approximations of the solution and by the development of techniques that use the Born–Oppenheimer (BO) forces to move the atoms on the BO potential energy surface. As a consequence of these developments it is now possible to identify stable or metastable states, to sample configurations consistent with the appropriate thermodynamic ensemble, and to estimate the kinetics of reactions and phase transitions. All too often, however, progress is slowed down by the bottleneck associated with implementing new optimization algorithms and/or sampling techniques into the many existing electronic-structure and empirical-potential codes. To address this problem, we are thus releasing a new version of the i-PI software. This piece of software is an easily extensible framework for implementing advanced atomistic simulation techniques using interatomic potentials and forces calculated by an external driver code. While the original version of the code (Ceriotti et al., 2014) was developed with a focus on path integral molecular dynamics techniques, this second release of i-PI not only includes several new advanced path integral methods, but also offers other classes of algorithms. In other words, i-PI is moving towards becoming a universal force engine that is both modular and tightly coupled to the driver codes that evaluate the potential energy surface and its derivatives. article_processing_charge: No article_type: original author: - first_name: Venkat full_name: Kapil, Venkat last_name: Kapil - first_name: Mariana full_name: Rossi, Mariana last_name: Rossi - first_name: Ondrej full_name: Marsalek, Ondrej last_name: Marsalek - first_name: Riccardo full_name: Petraglia, Riccardo last_name: Petraglia - first_name: Yair full_name: Litman, Yair last_name: Litman - first_name: Thomas full_name: Spura, Thomas last_name: Spura - first_name: Bingqing full_name: Cheng, Bingqing id: cbe3cda4-d82c-11eb-8dc7-8ff94289fcc9 last_name: Cheng orcid: 0000-0002-3584-9632 - first_name: Alice full_name: Cuzzocrea, Alice last_name: Cuzzocrea - first_name: Robert H. full_name: Meißner, Robert H. last_name: Meißner - first_name: David M. full_name: Wilkins, David M. last_name: Wilkins - first_name: Benjamin A. full_name: Helfrecht, Benjamin A. last_name: Helfrecht - first_name: Przemysław full_name: Juda, Przemysław last_name: Juda - first_name: Sébastien P. full_name: Bienvenue, Sébastien P. last_name: Bienvenue - first_name: Wei full_name: Fang, Wei last_name: Fang - first_name: Jan full_name: Kessler, Jan last_name: Kessler - first_name: Igor full_name: Poltavsky, Igor last_name: Poltavsky - first_name: Steven full_name: Vandenbrande, Steven last_name: Vandenbrande - first_name: Jelle full_name: Wieme, Jelle last_name: Wieme - first_name: Clemence full_name: Corminboeuf, Clemence last_name: Corminboeuf - first_name: Thomas D. full_name: Kühne, Thomas D. last_name: Kühne - first_name: David E. full_name: Manolopoulos, David E. last_name: Manolopoulos - first_name: Thomas E. full_name: Markland, Thomas E. last_name: Markland - first_name: Jeremy O. full_name: Richardson, Jeremy O. last_name: Richardson - first_name: Alexandre full_name: Tkatchenko, Alexandre last_name: Tkatchenko - first_name: Gareth A. full_name: Tribello, Gareth A. last_name: Tribello - first_name: Veronique full_name: Van Speybroeck, Veronique last_name: Van Speybroeck - first_name: Michele full_name: Ceriotti, Michele last_name: Ceriotti citation: ama: 'Kapil V, Rossi M, Marsalek O, et al. i-PI 2.0: A universal force engine for advanced molecular simulations. Computer Physics Communications. 2019;236:214-223. doi:10.1016/j.cpc.2018.09.020' apa: 'Kapil, V., Rossi, M., Marsalek, O., Petraglia, R., Litman, Y., Spura, T., … Ceriotti, M. (2019). i-PI 2.0: A universal force engine for advanced molecular simulations. Computer Physics Communications. Elsevier. https://doi.org/10.1016/j.cpc.2018.09.020' chicago: 'Kapil, Venkat, Mariana Rossi, Ondrej Marsalek, Riccardo Petraglia, Yair Litman, Thomas Spura, Bingqing Cheng, et al. “I-PI 2.0: A Universal Force Engine for Advanced Molecular Simulations.” Computer Physics Communications. Elsevier, 2019. https://doi.org/10.1016/j.cpc.2018.09.020.' ieee: 'V. Kapil et al., “i-PI 2.0: A universal force engine for advanced molecular simulations,” Computer Physics Communications, vol. 236. Elsevier, pp. 214–223, 2019.' ista: 'Kapil V, Rossi M, Marsalek O, Petraglia R, Litman Y, Spura T, Cheng B, Cuzzocrea A, Meißner RH, Wilkins DM, Helfrecht BA, Juda P, Bienvenue SP, Fang W, Kessler J, Poltavsky I, Vandenbrande S, Wieme J, Corminboeuf C, Kühne TD, Manolopoulos DE, Markland TE, Richardson JO, Tkatchenko A, Tribello GA, Van Speybroeck V, Ceriotti M. 2019. i-PI 2.0: A universal force engine for advanced molecular simulations. Computer Physics Communications. 236, 214–223.' mla: 'Kapil, Venkat, et al. “I-PI 2.0: A Universal Force Engine for Advanced Molecular Simulations.” Computer Physics Communications, vol. 236, Elsevier, 2019, pp. 214–23, doi:10.1016/j.cpc.2018.09.020.' short: V. Kapil, M. Rossi, O. Marsalek, R. Petraglia, Y. Litman, T. Spura, B. Cheng, A. Cuzzocrea, R.H. Meißner, D.M. Wilkins, B.A. Helfrecht, P. Juda, S.P. Bienvenue, W. Fang, J. Kessler, I. Poltavsky, S. Vandenbrande, J. Wieme, C. Corminboeuf, T.D. Kühne, D.E. Manolopoulos, T.E. Markland, J.O. Richardson, A. Tkatchenko, G.A. Tribello, V. Van Speybroeck, M. Ceriotti, Computer Physics Communications 236 (2019) 214–223. date_created: 2021-07-16T08:53:01Z date_published: 2019-03-01T00:00:00Z date_updated: 2021-08-09T12:37:16Z day: '01' doi: 10.1016/j.cpc.2018.09.020 extern: '1' external_id: arxiv: - '1808.03824' intvolume: ' 236' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1808.03824 month: '03' oa: 1 oa_version: Preprint page: 214-223 publication: Computer Physics Communications publication_identifier: issn: - 0010-4655 publication_status: published publisher: Elsevier quality_controlled: '1' scopus_import: '1' status: public title: 'i-PI 2.0: A universal force engine for advanced molecular simulations' type: journal_article user_id: 6785fbc1-c503-11eb-8a32-93094b40e1cf volume: 236 year: '2019' ... --- _id: '9680' abstract: - lang: eng text: Atomistic modeling of phase transitions, chemical reactions, or other rare events that involve overcoming high free energy barriers usually entails prohibitively long simulation times. Introducing a bias potential as a function of an appropriately chosen set of collective variables can significantly accelerate the exploration of phase space, albeit at the price of distorting the distribution of microstates. Efficient reweighting to recover the unbiased distribution can be nontrivial when employing adaptive sampling techniques such as metadynamics, variationally enhanced sampling, or parallel bias metadynamics, in which the system evolves in a quasi-equilibrium manner under a time-dependent bias. We introduce an iterative unbiasing scheme that makes efficient use of all the trajectory data and that does not require the distribution to be evaluated on a grid. The method can thus be used even when the bias has a high dimensionality. We benchmark this approach against some of the existing schemes on model systems with different complexity and dimensionality. article_processing_charge: No article_type: original author: - first_name: F. full_name: Giberti, F. last_name: Giberti - first_name: Bingqing full_name: Cheng, Bingqing id: cbe3cda4-d82c-11eb-8dc7-8ff94289fcc9 last_name: Cheng orcid: 0000-0002-3584-9632 - first_name: G. A. full_name: Tribello, G. A. last_name: Tribello - first_name: M. full_name: Ceriotti, M. last_name: Ceriotti citation: ama: Giberti F, Cheng B, Tribello GA, Ceriotti M. Iterative unbiasing of quasi-equilibrium sampling. Journal of Chemical Theory and Computation. 2019;16(1):100-107. doi:10.1021/acs.jctc.9b00907 apa: Giberti, F., Cheng, B., Tribello, G. A., & Ceriotti, M. (2019). Iterative unbiasing of quasi-equilibrium sampling. Journal of Chemical Theory and Computation. American Chemical Society. https://doi.org/10.1021/acs.jctc.9b00907 chicago: Giberti, F., Bingqing Cheng, G. A. Tribello, and M. Ceriotti. “Iterative Unbiasing of Quasi-Equilibrium Sampling.” Journal of Chemical Theory and Computation. American Chemical Society, 2019. https://doi.org/10.1021/acs.jctc.9b00907. ieee: F. Giberti, B. Cheng, G. A. Tribello, and M. Ceriotti, “Iterative unbiasing of quasi-equilibrium sampling,” Journal of Chemical Theory and Computation, vol. 16, no. 1. American Chemical Society, pp. 100–107, 2019. ista: Giberti F, Cheng B, Tribello GA, Ceriotti M. 2019. Iterative unbiasing of quasi-equilibrium sampling. Journal of Chemical Theory and Computation. 16(1), 100–107. mla: Giberti, F., et al. “Iterative Unbiasing of Quasi-Equilibrium Sampling.” Journal of Chemical Theory and Computation, vol. 16, no. 1, American Chemical Society, 2019, pp. 100–07, doi:10.1021/acs.jctc.9b00907. short: F. Giberti, B. Cheng, G.A. Tribello, M. Ceriotti, Journal of Chemical Theory and Computation 16 (2019) 100–107. date_created: 2021-07-19T06:56:45Z date_published: 2019-01-14T00:00:00Z date_updated: 2021-08-09T12:37:37Z day: '14' doi: 10.1021/acs.jctc.9b00907 extern: '1' external_id: arxiv: - '1911.01140' pmid: - '31743021' intvolume: ' 16' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1911.01140 month: '01' oa: 1 oa_version: Preprint page: 100-107 pmid: 1 publication: Journal of Chemical Theory and Computation publication_identifier: eissn: - 1549-9626 issn: - 1549-9618 publication_status: published publisher: American Chemical Society quality_controlled: '1' scopus_import: '1' status: public title: Iterative unbiasing of quasi-equilibrium sampling type: journal_article user_id: 6785fbc1-c503-11eb-8a32-93094b40e1cf volume: 16 year: '2019' ... --- _id: '12600' abstract: - lang: eng text: The snow cover dynamics of High Mountain Asia are usually assessed at spatial resolutions of 250 m or greater, but this scale is too coarse to clearly represent the rugged topography common to the region. Higher-resolution measurement of snow-covered area often results in biased sampling due to cloud cover and deep shadows. We therefore develop a Normalized Difference Snow Index-based workflow to delineate snow lines from Landsat Thematic Mapper/Enhanced Thematic Mapper+ imagery and apply it to the upper Langtang Valley in Nepal, processing 194 scenes spanning 1999 to 2013. For each scene, we determine the spatial distribution of snow line altitudes (SLAs) with respect to aspect and across six subcatchments. Our results show that the mean SLA exhibits distinct seasonal behavior based on aspect and subcatchment position. We find that SLA dynamics respond to spatial and seasonal trade-offs in precipitation, temperature, and solar radiation, which act as primary controls. We identify two SLA spatial gradients, which we attribute to the effect of spatially variable precipitation. Our results also reveal that aspect-related SLA differences vary seasonally and are influenced by solar radiation. In terms of seasonal dominant controls, we demonstrate that the snow line is controlled by snow precipitation in winter, melt in premonsoon, a combination of both in postmonsoon, and temperature in monsoon, explaining to a large extent the spatial and seasonal variability of the SLA in the upper Langtang Valley. We conclude that while SLA and snow-covered area are complementary metrics, the SLA has a strong potential for understanding local-scale snow cover dynamics and their controlling mechanisms. article_processing_charge: No article_type: original author: - first_name: Marc full_name: Girona‐Mata, Marc last_name: Girona‐Mata - first_name: Evan S. full_name: Miles, Evan S. last_name: Miles - first_name: Silvan full_name: Ragettli, Silvan last_name: Ragettli - first_name: Francesca full_name: Pellicciotti, Francesca id: b28f055a-81ea-11ed-b70c-a9fe7f7b0e70 last_name: Pellicciotti citation: ama: Girona‐Mata M, Miles ES, Ragettli S, Pellicciotti F. High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment. Water Resources Research. 2019;55(8):6754-6772. doi:10.1029/2019wr024935 apa: Girona‐Mata, M., Miles, E. S., Ragettli, S., & Pellicciotti, F. (2019). High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment. Water Resources Research. American Geophysical Union. https://doi.org/10.1029/2019wr024935 chicago: Girona‐Mata, Marc, Evan S. Miles, Silvan Ragettli, and Francesca Pellicciotti. “High‐resolution Snowline Delineation from Landsat Imagery to Infer Snow Cover Controls in a Himalayan Catchment.” Water Resources Research. American Geophysical Union, 2019. https://doi.org/10.1029/2019wr024935. ieee: M. Girona‐Mata, E. S. Miles, S. Ragettli, and F. Pellicciotti, “High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment,” Water Resources Research, vol. 55, no. 8. American Geophysical Union, pp. 6754–6772, 2019. ista: Girona‐Mata M, Miles ES, Ragettli S, Pellicciotti F. 2019. High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment. Water Resources Research. 55(8), 6754–6772. mla: Girona‐Mata, Marc, et al. “High‐resolution Snowline Delineation from Landsat Imagery to Infer Snow Cover Controls in a Himalayan Catchment.” Water Resources Research, vol. 55, no. 8, American Geophysical Union, 2019, pp. 6754–72, doi:10.1029/2019wr024935. short: M. Girona‐Mata, E.S. Miles, S. Ragettli, F. Pellicciotti, Water Resources Research 55 (2019) 6754–6772. date_created: 2023-02-20T08:12:59Z date_published: 2019-08-01T00:00:00Z date_updated: 2023-02-28T12:14:18Z day: '01' doi: 10.1029/2019wr024935 extern: '1' intvolume: ' 55' issue: '8' keyword: - Water Science and Technology language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1029/2019WR024935 month: '08' oa: 1 oa_version: Published Version page: 6754-6772 publication: Water Resources Research publication_identifier: eissn: - 1944-7973 issn: - 0043-1397 publication_status: published publisher: American Geophysical Union quality_controlled: '1' scopus_import: '1' status: public title: High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 55 year: '2019' ... --- _id: '12602' abstract: - lang: eng text: 'This study aims at developing and applying a spatially-distributed coupled glacier mass balance and ice-flow model to attribute the response of glaciers to natural and anthropogenic climate change. We focus on two glaciers with contrasting surface characteristics: a debris-covered glacier (Langtang Glacier in Nepal) and a clean-ice glacier (Hintereisferner in Austria). The model is applied from the end of the Little Ice Age (1850) to the present-day (2016) and is forced with four bias-corrected General Circulation Models (GCMs) from the historical experiment of the CMIP5 archive. The selected GCMs represent region-specific warm-dry, warm-wet, cold-dry, and cold-wet climate conditions. To isolate the effects of anthropogenic climate change on glacier mass balance and flow runs from these GCMs with and without further anthropogenic forcing after 1970 until 2016 are selected. The outcomes indicate that both glaciers experience the largest reduction in area and volume under warm climate conditions, whereas area and volume reductions are smaller under cold climate conditions. Simultaneously with changes in glacier area and volume, surface velocities generally decrease over time. Without further anthropogenic forcing the results reveal a 3% (9%) smaller decline in glacier area (volume) for the debris-covered glacier and a 18% (39%) smaller decline in glacier area (volume) for the clean-ice glacier. The difference in the magnitude between the two glaciers can mainly be attributed to differences in the response time of the glaciers, where the clean-ice glacier shows a much faster response to climate change. We conclude that the response of the two glaciers can mainly be attributed to anthropogenic climate change and that the impact is larger on the clean-ice glacier. The outcomes show that the model performs well under different climate conditions and that the developed approach can be used for regional-scale glacio-hydrological modeling.' article_number: '143' article_processing_charge: No article_type: original author: - first_name: René R. full_name: Wijngaard, René R. last_name: Wijngaard - first_name: Jakob F. full_name: Steiner, Jakob F. last_name: Steiner - first_name: Philip D. A. full_name: Kraaijenbrink, Philip D. A. last_name: Kraaijenbrink - first_name: Christoph full_name: Klug, Christoph last_name: Klug - first_name: Surendra full_name: Adhikari, Surendra last_name: Adhikari - first_name: Argha full_name: Banerjee, Argha last_name: Banerjee - first_name: Francesca full_name: Pellicciotti, Francesca id: b28f055a-81ea-11ed-b70c-a9fe7f7b0e70 last_name: Pellicciotti - first_name: Ludovicus P. H. full_name: van Beek, Ludovicus P. H. last_name: van Beek - first_name: Marc F. P. full_name: Bierkens, Marc F. P. last_name: Bierkens - first_name: Arthur F. full_name: Lutz, Arthur F. last_name: Lutz - first_name: Walter W. full_name: Immerzeel, Walter W. last_name: Immerzeel citation: ama: Wijngaard RR, Steiner JF, Kraaijenbrink PDA, et al. Modeling the response of the Langtang Glacier and the Hintereisferner to a changing climate since the Little Ice Age. Frontiers in Earth Science. 2019;7. doi:10.3389/feart.2019.00143 apa: Wijngaard, R. R., Steiner, J. F., Kraaijenbrink, P. D. A., Klug, C., Adhikari, S., Banerjee, A., … Immerzeel, W. W. (2019). Modeling the response of the Langtang Glacier and the Hintereisferner to a changing climate since the Little Ice Age. Frontiers in Earth Science. Frontiers Media. https://doi.org/10.3389/feart.2019.00143 chicago: Wijngaard, René R., Jakob F. Steiner, Philip D. A. Kraaijenbrink, Christoph Klug, Surendra Adhikari, Argha Banerjee, Francesca Pellicciotti, et al. “Modeling the Response of the Langtang Glacier and the Hintereisferner to a Changing Climate since the Little Ice Age.” Frontiers in Earth Science. Frontiers Media, 2019. https://doi.org/10.3389/feart.2019.00143. ieee: R. R. Wijngaard et al., “Modeling the response of the Langtang Glacier and the Hintereisferner to a changing climate since the Little Ice Age,” Frontiers in Earth Science, vol. 7. Frontiers Media, 2019. ista: Wijngaard RR, Steiner JF, Kraaijenbrink PDA, Klug C, Adhikari S, Banerjee A, Pellicciotti F, van Beek LPH, Bierkens MFP, Lutz AF, Immerzeel WW. 2019. Modeling the response of the Langtang Glacier and the Hintereisferner to a changing climate since the Little Ice Age. Frontiers in Earth Science. 7, 143. mla: Wijngaard, René R., et al. “Modeling the Response of the Langtang Glacier and the Hintereisferner to a Changing Climate since the Little Ice Age.” Frontiers in Earth Science, vol. 7, 143, Frontiers Media, 2019, doi:10.3389/feart.2019.00143. short: R.R. Wijngaard, J.F. Steiner, P.D.A. Kraaijenbrink, C. Klug, S. Adhikari, A. Banerjee, F. Pellicciotti, L.P.H. van Beek, M.F.P. Bierkens, A.F. Lutz, W.W. Immerzeel, Frontiers in Earth Science 7 (2019). date_created: 2023-02-20T08:13:08Z date_published: 2019-06-04T00:00:00Z date_updated: 2023-02-28T12:04:48Z day: '04' doi: 10.3389/feart.2019.00143 extern: '1' intvolume: ' 7' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.3389/feart.2019.00143 month: '06' oa: 1 oa_version: Published Version publication: Frontiers in Earth Science publication_identifier: issn: - 2296-6463 publication_status: published publisher: Frontiers Media quality_controlled: '1' scopus_import: '1' status: public title: Modeling the response of the Langtang Glacier and the Hintereisferner to a changing climate since the Little Ice Age type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 7 year: '2019' ... --- _id: '12601' abstract: - lang: eng text: Ice cliffs and ponds on debris-covered glaciers have received increased attention due to their role in amplifying local melt. However, very few studies have looked at these features on the catchment scale to determine their patterns and changes in space and time. We have compiled a detailed inventory of cliffs and ponds in the Langtang catchment, central Himalaya, from six high-resolution satellite orthoimages and DEMs between 2006 and 2015, and a historic orthophoto from 1974. Cliffs cover between 1.4% (± 0.4%) in the dry and 3.4% (± 0.9%) in the wet seasons and ponds between 0.6% (± 0.1%) and 1.6% (± 0.3%) of the total debris-covered tongues. We find large variations between seasons, as cliffs and ponds tend to grow in the wetter monsoon period, but there is no obvious trend in total area over the study period. The inventory further shows that cliffs are predominately north-facing irrespective of the glacier flow direction. Both cliffs and ponds appear in higher densities several hundred metres from the terminus in areas where tributaries reach the main glacier tongue. On the largest glacier in the catchment ~10% of all cliffs and ponds persisted over nearly a decade. article_processing_charge: No article_type: original author: - first_name: JAKOB F. full_name: STEINER, JAKOB F. last_name: STEINER - first_name: PASCAL full_name: BURI, PASCAL last_name: BURI - first_name: EVAN S. full_name: MILES, EVAN S. last_name: MILES - first_name: SILVAN full_name: RAGETTLI, SILVAN last_name: RAGETTLI - first_name: Francesca full_name: Pellicciotti, Francesca id: b28f055a-81ea-11ed-b70c-a9fe7f7b0e70 last_name: Pellicciotti citation: ama: 'STEINER JF, BURI P, MILES ES, RAGETTLI S, Pellicciotti F. Supraglacial ice cliffs and ponds on debris-covered glaciers: Spatio-temporal distribution and characteristics. Journal of Glaciology. 2019;65(252):617-632. doi:10.1017/jog.2019.40' apa: 'STEINER, J. F., BURI, P., MILES, E. S., RAGETTLI, S., & Pellicciotti, F. (2019). Supraglacial ice cliffs and ponds on debris-covered glaciers: Spatio-temporal distribution and characteristics. Journal of Glaciology. Cambridge University Press. https://doi.org/10.1017/jog.2019.40' chicago: 'STEINER, JAKOB F., PASCAL BURI, EVAN S. MILES, SILVAN RAGETTLI, and Francesca Pellicciotti. “Supraglacial Ice Cliffs and Ponds on Debris-Covered Glaciers: Spatio-Temporal Distribution and Characteristics.” Journal of Glaciology. Cambridge University Press, 2019. https://doi.org/10.1017/jog.2019.40.' ieee: 'J. F. STEINER, P. BURI, E. S. MILES, S. RAGETTLI, and F. Pellicciotti, “Supraglacial ice cliffs and ponds on debris-covered glaciers: Spatio-temporal distribution and characteristics,” Journal of Glaciology, vol. 65, no. 252. Cambridge University Press, pp. 617–632, 2019.' ista: 'STEINER JF, BURI P, MILES ES, RAGETTLI S, Pellicciotti F. 2019. Supraglacial ice cliffs and ponds on debris-covered glaciers: Spatio-temporal distribution and characteristics. Journal of Glaciology. 65(252), 617–632.' mla: 'STEINER, JAKOB F., et al. “Supraglacial Ice Cliffs and Ponds on Debris-Covered Glaciers: Spatio-Temporal Distribution and Characteristics.” Journal of Glaciology, vol. 65, no. 252, Cambridge University Press, 2019, pp. 617–32, doi:10.1017/jog.2019.40.' short: J.F. STEINER, P. BURI, E.S. MILES, S. RAGETTLI, F. Pellicciotti, Journal of Glaciology 65 (2019) 617–632. date_created: 2023-02-20T08:13:03Z date_published: 2019-08-01T00:00:00Z date_updated: 2023-02-28T12:11:07Z day: '01' doi: 10.1017/jog.2019.40 extern: '1' intvolume: ' 65' issue: '252' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1017/jog.2019.40 month: '08' oa: 1 oa_version: Published Version page: 617-632 publication: Journal of Glaciology publication_identifier: eissn: - 1727-5652 issn: - 0022-1430 publication_status: published publisher: Cambridge University Press quality_controlled: '1' scopus_import: '1' status: public title: 'Supraglacial ice cliffs and ponds on debris-covered glaciers: Spatio-temporal distribution and characteristics' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 65 year: '2019' ... --- _id: '12192' abstract: - lang: eng text: Transposable elements (TEs), the movement of which can damage the genome, are epigenetically silenced in eukaryotes. Intriguingly, TEs are activated in the sperm companion cell – vegetative cell (VC) – of the flowering plant Arabidopsis thaliana. However, the extent and mechanism of this activation are unknown. Here we show that about 100 heterochromatic TEs are activated in VCs, mostly by DEMETER-catalyzed DNA demethylation. We further demonstrate that DEMETER access to some of these TEs is permitted by the natural depletion of linker histone H1 in VCs. Ectopically expressed H1 suppresses TEs in VCs by reducing DNA demethylation and via a methylation-independent mechanism. We demonstrate that H1 is required for heterochromatin condensation in plant cells and show that H1 overexpression creates heterochromatic foci in the VC progenitor cell. Taken together, our results demonstrate that the natural depletion of H1 during male gametogenesis facilitates DEMETER-directed DNA demethylation, heterochromatin relaxation, and TE activation. acknowledgement: We thank David Twell for the pDONR-P4-P1R-pLAT52 and pDONR-P2R-P3-mRFP vectors, the John Innes Centre Bioimaging Facility (Elaine Barclay and Grant Calder) for their assistance with microscopy, and the Norwich BioScience Institute Partnership Computing infrastructure for Science Group for High Performance Computing resources. This work was funded by a Biotechnology and Biological Sciences Research Council (BBSRC) David Phillips Fellowship (BB/L025043/1; SH, JZ and XF), a European Research Council Starting Grant ('SexMeth' 804981; XF) and a Grant to Exceptional Researchers by the Gatsby Charitable Foundation (SH and XF). article_number: '42530' article_processing_charge: No article_type: original author: - first_name: Shengbo full_name: He, Shengbo last_name: He - first_name: Martin full_name: Vickers, Martin last_name: Vickers - first_name: Jingyi full_name: Zhang, Jingyi last_name: Zhang - first_name: Xiaoqi full_name: Feng, Xiaoqi id: e0164712-22ee-11ed-b12a-d80fcdf35958 last_name: Feng orcid: 0000-0002-4008-1234 citation: ama: He S, Vickers M, Zhang J, Feng X. Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation. eLife. 2019;8. doi:10.7554/elife.42530 apa: He, S., Vickers, M., Zhang, J., & Feng, X. (2019). Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation. ELife. eLife Sciences Publications, Ltd. https://doi.org/10.7554/elife.42530 chicago: He, Shengbo, Martin Vickers, Jingyi Zhang, and Xiaoqi Feng. “Natural Depletion of Histone H1 in Sex Cells Causes DNA Demethylation, Heterochromatin Decondensation and Transposon Activation.” ELife. eLife Sciences Publications, Ltd, 2019. https://doi.org/10.7554/elife.42530. ieee: S. He, M. Vickers, J. Zhang, and X. Feng, “Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation,” eLife, vol. 8. eLife Sciences Publications, Ltd, 2019. ista: He S, Vickers M, Zhang J, Feng X. 2019. Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation. eLife. 8, 42530. mla: He, Shengbo, et al. “Natural Depletion of Histone H1 in Sex Cells Causes DNA Demethylation, Heterochromatin Decondensation and Transposon Activation.” ELife, vol. 8, 42530, eLife Sciences Publications, Ltd, 2019, doi:10.7554/elife.42530. short: S. He, M. Vickers, J. Zhang, X. Feng, ELife 8 (2019). date_created: 2023-01-16T09:17:21Z date_published: 2019-05-28T00:00:00Z date_updated: 2023-05-08T10:54:12Z day: '28' ddc: - '580' department: - _id: XiFe doi: 10.7554/elife.42530 extern: '1' external_id: unknown: - '31135340' file: - access_level: open_access checksum: ea6b89c20d59e5eb3646916fe5d568ad content_type: application/pdf creator: alisjak date_created: 2023-02-07T09:42:46Z date_updated: 2023-02-07T09:42:46Z file_id: '12525' file_name: 2019_elife_He.pdf file_size: 2493837 relation: main_file success: 1 file_date_updated: 2023-02-07T09:42:46Z has_accepted_license: '1' intvolume: ' 8' keyword: - General Immunology and Microbiology - General Biochemistry - Genetics and Molecular Biology - General Medicine - General Neuroscience language: - iso: eng license: https://creativecommons.org/licenses/by/4.0/ main_file_link: - open_access: '1' url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6594752/ month: '05' oa: 1 oa_version: Published Version publication: eLife publication_identifier: issn: - 2050-084X publication_status: published publisher: eLife Sciences Publications, Ltd quality_controlled: '1' scopus_import: '1' status: public title: Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 8 year: '2019' ... --- _id: '12190' abstract: - lang: eng text: Meiotic crossover frequency varies within genomes, which influences genetic diversity and adaptation. In turn, genetic variation within populations can act to modify crossover frequency in cis and trans. To identify genetic variation that controls meiotic crossover frequency, we screened Arabidopsis accessions using fluorescent recombination reporters. We mapped a genetic modifier of crossover frequency in Col × Bur populations of Arabidopsis to a premature stop codon within TBP-ASSOCIATED FACTOR 4b (TAF4b), which encodes a subunit of the RNA polymerase II general transcription factor TFIID. The Arabidopsis taf4b mutation is a rare variant found in the British Isles, originating in South-West Ireland. Using genetics, genomics, and immunocytology, we demonstrate a genome-wide decrease in taf4b crossovers, with strongest reduction in the sub-telomeric regions. Using RNA sequencing (RNA-seq) from purified meiocytes, we show that TAF4b expression is meiocyte enriched, whereas its paralog TAF4 is broadly expressed. Consistent with the role of TFIID in promoting gene expression, RNA-seq of wild-type and taf4b meiocytes identified widespread transcriptional changes, including in genes that regulate the meiotic cell cycle and recombination. Therefore, TAF4b duplication is associated with acquisition of meiocyte-specific expression and promotion of germline transcription, which act directly or indirectly to elevate crossovers. This identifies a novel mode of meiotic recombination control via a general transcription factor. acknowledgement: "We thank Gregory Copenhaver (University of North Carolina), Avraham Levy (The Weizmann Institute), and Scott Poethig (University of Pennsylvania) for FTLs; Piotr Ziolkowski for Col-420/Bur seed; Sureshkumar Balasubramanian\r\n(Monash University) for providing British and Irish Arabidopsis accessions; Mathilde Grelon (INRA, Versailles) for providing the MLH1 antibody; and the Gurdon Institute for access to microscopes. This work was supported by a BBSRC DTP studentship (E.J.L.), European Research Area Network for Coordinating Action in Plant Sciences/BBSRC ‘‘DeCOP’’ (BB/M004937/1; C.L.), a BBSRC David Phillips Fellowship (BB/L025043/1; H.G. and X.F.), the European Research Council (CoG ‘‘SynthHotspot,’’ A.J.T., C.L., and I.R.H.; StG ‘‘SexMeth,’’ X.F.), and a Sainsbury Charitable Foundation Studentship (A.R.B.)." article_processing_charge: No article_type: original author: - first_name: Emma J. full_name: Lawrence, Emma J. last_name: Lawrence - first_name: Hongbo full_name: Gao, Hongbo last_name: Gao - first_name: Andrew J. full_name: Tock, Andrew J. last_name: Tock - first_name: Christophe full_name: Lambing, Christophe last_name: Lambing - first_name: Alexander R. full_name: Blackwell, Alexander R. last_name: Blackwell - first_name: Xiaoqi full_name: Feng, Xiaoqi id: e0164712-22ee-11ed-b12a-d80fcdf35958 last_name: Feng orcid: 0000-0002-4008-1234 - first_name: Ian R. full_name: Henderson, Ian R. last_name: Henderson citation: ama: Lawrence EJ, Gao H, Tock AJ, et al. Natural variation in TBP-ASSOCIATED FACTOR 4b controls meiotic crossover and germline transcription in Arabidopsis. Current Biology. 2019;29(16):2676-2686.e3. doi:10.1016/j.cub.2019.06.084 apa: Lawrence, E. J., Gao, H., Tock, A. J., Lambing, C., Blackwell, A. R., Feng, X., & Henderson, I. R. (2019). Natural variation in TBP-ASSOCIATED FACTOR 4b controls meiotic crossover and germline transcription in Arabidopsis. Current Biology. Elsevier BV. https://doi.org/10.1016/j.cub.2019.06.084 chicago: Lawrence, Emma J., Hongbo Gao, Andrew J. Tock, Christophe Lambing, Alexander R. Blackwell, Xiaoqi Feng, and Ian R. Henderson. “Natural Variation in TBP-ASSOCIATED FACTOR 4b Controls Meiotic Crossover and Germline Transcription in Arabidopsis.” Current Biology. Elsevier BV, 2019. https://doi.org/10.1016/j.cub.2019.06.084. ieee: E. J. Lawrence et al., “Natural variation in TBP-ASSOCIATED FACTOR 4b controls meiotic crossover and germline transcription in Arabidopsis,” Current Biology, vol. 29, no. 16. Elsevier BV, p. 2676–2686.e3, 2019. ista: Lawrence EJ, Gao H, Tock AJ, Lambing C, Blackwell AR, Feng X, Henderson IR. 2019. Natural variation in TBP-ASSOCIATED FACTOR 4b controls meiotic crossover and germline transcription in Arabidopsis. Current Biology. 29(16), 2676–2686.e3. mla: Lawrence, Emma J., et al. “Natural Variation in TBP-ASSOCIATED FACTOR 4b Controls Meiotic Crossover and Germline Transcription in Arabidopsis.” Current Biology, vol. 29, no. 16, Elsevier BV, 2019, p. 2676–2686.e3, doi:10.1016/j.cub.2019.06.084. short: E.J. Lawrence, H. Gao, A.J. Tock, C. Lambing, A.R. Blackwell, X. Feng, I.R. Henderson, Current Biology 29 (2019) 2676–2686.e3. date_created: 2023-01-16T09:16:33Z date_published: 2019-08-19T00:00:00Z date_updated: 2023-05-08T10:54:54Z day: '19' department: - _id: XiFe doi: 10.1016/j.cub.2019.06.084 extern: '1' external_id: pmid: - '31378616' intvolume: ' 29' issue: '16' keyword: - General Agricultural and Biological Sciences - General Biochemistry - Genetics and Molecular Biology language: - iso: eng month: '08' oa_version: None page: 2676-2686.e3 pmid: 1 publication: Current Biology publication_identifier: issn: - 0960-9822 publication_status: published publisher: Elsevier BV quality_controlled: '1' scopus_import: '1' status: public title: Natural variation in TBP-ASSOCIATED FACTOR 4b controls meiotic crossover and germline transcription in Arabidopsis type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 29 year: '2019' ... --- _id: '8305' abstract: - lang: eng text: In this paper, we present the first fully asynchronous distributed key generation (ADKG) algorithm as well as the first distributed key generation algorithm that can create keys with a dual (f,2f+1)−threshold that are necessary for scalable consensus (which so far needs a trusted dealer assumption). In order to create a DKG with a dual (f,2f+1)− threshold we first answer in the affirmative the open question posed by Cachin et al. how to create an AVSS protocol with recovery thresholds f+1