50 results on '"Ehlers, T."'
Search Results
2. Producibility
- Author
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Ehlers, T., Lachmayer, R., Vajna, S., Halle, T., and Vajna, Sándor, editor
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- 2020
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3. Exercise training alters skeletal muscle microvascular endothelial cell properties in recent postmenopausal females.
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Nørregaard, L. B., Hansen, C. C., Wickham, K. A., Møller, S., Olsen, K., Ehlers, T., Bangsbo, J., and Hellsten, Y.
- Subjects
SKELETAL muscle ,PHYSICAL training & conditioning ,POSTMENOPAUSE ,REACTIVE oxygen species ,GLYCOLYSIS - Abstract
The present study examined and compared the impact of exercise training on redox and molecular properties of human microvascular endothelial cells derived from skeletal muscle biopsies from sedentary recent (RPF, ≤ 5 years as postmenopausal) and late (LPF, ≥ 10 years as postmenopausal) postmenopausal females. Resting skeletal muscle biopsies were obtained before and after 8 weeks of intense aerobic exercise training for isolation of microvascular endothelial cells and determination of skeletal muscle angiogenic proteins and capillarisation. The microvascular endothelial cells were analysed for mitochondrial respiration and production of reactive oxygen species (ROS), glycolysis and proteins related to vascular function, redox balance and oestrogen receptors. Exercise training led to a reduced endothelial cell ROS formation (∼50%; P = 0.009 and P = 0.020 for intact and permeabilized cells (state 3), respectively) in RPF only, with no effect on endothelial mitochondrial capacity in either group. Basal endothelial cell lactate formation was higher (7%; P = 0.028), indicating increased glycolysis, after compared to before the exercise training period in RPF only. Baseline endothelial G protein‐coupled oestrogen receptor (P = 0.028) and muscle capillarisation (P = 0.028) was lower in LPF than in RPF. Muscle vascular endothelial growth factor protein was higher (32%; P = 0.002) following exercise training in LPF only. Exercise training did not influence endothelial cell proliferation or skeletal muscle capillarisation in either group, but the CD31 level in the muscle tissue, indicating endothelial cell content, was higher (>50%; P < 0.05) in both groups. In conclusion, 8 weeks of intense aerobic exercise training reduces ROS formation and enhances glycolysis in microvascular endothelial cells from RPF but does not induce skeletal muscle angiogenesis. Key points: Late postmenopausal females have been reported to achieve limited vascular adaptations to exercise training.There is a paucity of data on the effect of exercise training on isolated skeletal muscle microvascular endothelial cells (MMECs).In this study the formation of reactive oxygen species in MMECs was reduced and glycolysis increased after 8 weeks of aerobic exercise training in recent but not late postmenopausal females.Late postmenopausal females had lower levels of G protein‐coupled oestrogen receptor in MMECs and lower skeletal muscle capillary density at baseline.Eight weeks of intense exercise training altered MMEC properties but did not induce skeletal muscle angiogenesis in postmenopausal females. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Coupled surface to deep Earth processes: Perspectives from TOPO-EUROPE with an emphasis on climate- and energy-related societal challenges
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Cloetingh, S, Sternai, P, Koptev, A, Ehlers, T, Gerya, T, Kovacs, I, Oerlemans, J, Beekman, F, Lavallee, Y, Dingwell, D, Bekesi, E, Porkolab, K, Tesauro, M, Lavecchia, A, Botsyun, S, Muller, V, Roure, F, Serpelloni, E, Matenco, L, Castelltort, S, Giovannelli, D, Brovarone, A, Malaspina, N, Coletti, G, Valla, P, Limberger, J, Cloetingh S., Sternai P., Koptev A., Ehlers T. A., Gerya T., Kovacs I., Oerlemans J., Beekman F., Lavallee Y., Dingwell D., Bekesi E., Porkolab K., Tesauro M., Lavecchia A., Botsyun S., Muller V., Roure F., Serpelloni E., Matenco L., Castelltort S., Giovannelli D., Brovarone A. V., Malaspina N., Coletti G., Valla P., Limberger J., Cloetingh, S, Sternai, P, Koptev, A, Ehlers, T, Gerya, T, Kovacs, I, Oerlemans, J, Beekman, F, Lavallee, Y, Dingwell, D, Bekesi, E, Porkolab, K, Tesauro, M, Lavecchia, A, Botsyun, S, Muller, V, Roure, F, Serpelloni, E, Matenco, L, Castelltort, S, Giovannelli, D, Brovarone, A, Malaspina, N, Coletti, G, Valla, P, Limberger, J, Cloetingh S., Sternai P., Koptev A., Ehlers T. A., Gerya T., Kovacs I., Oerlemans J., Beekman F., Lavallee Y., Dingwell D., Bekesi E., Porkolab K., Tesauro M., Lavecchia A., Botsyun S., Muller V., Roure F., Serpelloni E., Matenco L., Castelltort S., Giovannelli D., Brovarone A. V., Malaspina N., Coletti G., Valla P., and Limberger J.
- Abstract
Understanding the interactions between surface and deep Earth processes is important for research in many diverse scientific areas including climate, environment, energy, georesources and biosphere. The TOPO-EUROPE initiative of the International Lithosphere Program serves as a pan-European platform for integrated surface and deep Earth sciences, synergizing observational studies of the Earth structure and fluxes on all spatial and temporal scales with modelling of Earth processes. This review provides a survey of scientific developments in our quantitative understanding of coupled surface-deep Earth processes achieved through TOPO-EUROPE. The most notable innovations include (1) a process-based understanding of the connection of upper mantle dynamics and absolute plate motion frames; (2) integrated models for sediment source-to-sink dynamics, demonstrating the importance of mass transfer from mountains to basins and from basin to basin; (3) demonstration of the key role of polyphase evolution of sedimentary basins, the impact of pre-rift and pre-orogenic structures, and the evolution of subsequent lithosphere and landscape dynamics; (4) improved conceptual understanding of the temporal evolution from back-arc extension to tectonic inversion and onset of subduction; (5) models to explain the integrated strength of Europe's lithosphere; (6) concepts governing the interplay between thermal upper mantle processes and stress-induced intraplate deformation; (7) constraints on the record of vertical motions from high-resolution data sets obtained from geo-thermochronology for Europe's topographic evolution; (8) recognition and quantifications of the forcing by erosional and/or glacial-interglacial surface mass transfer on the regional magmatism, with major implications for our understanding of the carbon cycle on geological timescales and the emerging field of biogeodynamics; and (9) the transfer of insights obtained on the coupling of deep Earth and surface processes to
- Published
- 2023
5. Design Rules for Laser Beam Melted Particle Dampers
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Ehlers, T. and Lachmayer, R.
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design guidelines ,functional integration ,Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau ,particle damping ,lightweight design ,ddc:620 ,additive manufacturing ,Konferenzschrift - Abstract
By means of additive manufacturing, especially laser powder bed fusion, particle dampers can be integrated locally into structural components and thus significantly reduce component vibrations. However, detailed design recommendations for additively manufactured particle dampers do not yet exist. The research question in this paper is: How can the effect of particle damping be described as a function of excitation force, cavity width and cavity length? For beams made of AlSi10Mg, it is shown that a powder-filled cavity of 2.5% to 5% is sufficient to increase the damping by more than x10.
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- 2022
6. Cenozoic Proxy Constraints on Earth System Sensitivity to Greenhouse Gases
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Ring, S. J., primary, Mutz, S. G., additional, and Ehlers, T. A., additional
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- 2022
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7. Deciphering topographic signals of glaciation and rock uplift in an active orogen: a case study from the Olympic Mountains, USA
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Adams, B. A. and Ehlers, T. A.
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- 2017
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8. Plate corner subduction and rapid localized exhumation: Insights from 3D coupled geodynamic and geomorphological modelling
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Koptev, A., Nettesheim, M., Ehlers, T., Nettesheim, Matthias, 1 Department of Geosciences University of Tübingen Tübingen Germany, and Ehlers, Todd A.
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Geology ,ddc:551.1 - Abstract
Rapid, localized exhumation has been reported at many plate corners between adjacent subduction/collision segments. Here we use a fully‐coupled geodynamic and geomorphological modelling approach to investigate overriding plate deformation and resulting rock uplift patterns in these narrow, cuspate regions. In this study, we focus on the effects of internal deformation within a subducting convex‐upward‐shaped indenter and the strength of the interface between the upper and downgoing plate. The strongest localization of high rock uplift rates in the region above the indenter apex is predicted in experiments with a deformable lower plate, a weak interface layer and lateral shortening accommodated only by subduction (i.e., without an upper plate advance component). Our results suggest that bull’s eye shaped structures characterized by young thermochronological ages can, in principle, be reproduced numerically when taking into account a non‐rigid subducting plate together with complex brittle‐ductile rheology and stratification of the overriding lithosphere and realistically implemented fluvial erosion at its surface., Alexander von Humboldt‐Stiftung http://dx.doi.org/10.13039/100005156, Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659, European Research Council http://dx.doi.org/10.13039/100010663
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- 2022
9. (LiDAR) 3D Point Clouds and Topographic Data from the Chilean Coastal Cordillera
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Kügler, M., Hoffmann, T., Beer, A., Übernickel, K., Ehlers, T., Scherler, D., and Eichel, J.
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The DFG Priority Program 1803 “EarthShape” (www.earthshape.net) investigates Earth surface shaping by biota. As part of this project, we present Light Detection and Ranging (LiDAR) data of land surface areas for the four core research sites of the project. The research sites are located along a latitudinal gradient between ~26 °S and ~38 °S in the Chilean Coastal Cordillera. From north to south, the names of these sites are: National Park Pan de Azúcar; Private Reserve Santa Gracia; National Park La Campana; and National Park Nahuelbuta. The three datasets contain raw 3D point cloud data captured from an airborne LiDAR system, and the following derivative products: a) digital terrain models (DTM, sometimes also referred to as DEM [digital elevation model]) which are (2.5D) raster datasets created by rendering only the LiDAR returns which are assumed to be ground/bare-earth returns and b) digital surface models (DSM) which are also 2.5D raster datasets produced by rendering all the returns from the top of the Earth’s surface, including all objects and structures (e.g. buildings and vegetation). The LiDAR data were acquired in 2008 (southernmost Nahuelbuta [NAB] catchment), 2016 (central La Campana [LC] catchment) and 2020 (central Santa Gracia [SGA] catchment). Except for Nahuelbuta (data already was available from the data provider from a previous project), the flights were carried out as part of the "EarthShape" project. The LiDAR raw data (point cloud/ *.las files) were compressed, merged (as *.laz files) and projected using UTM 19 S (UTM 18 S for the southernmost Nahuelbuta catchment, respectively) and WGS84 as coordinate reference system. A complementary fourth dataset for the northernmost site in the National Park Pan de Azúcar, derived from Uncrewed Aerial Vehicle (UAV) flights and Structure from Motion (SfM) photogrammetry, is expected to be obtained during the first half of 2022 and will be added to the above data set.
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- 2022
10. Compilation of Cenozoic temperature proxies for terrestrial and marine surface environments
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Ring, S., Mutz, S., and Ehlers, T.
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We provide a globally distributed compilation of published surface temperature proxies for eight Cenozoic time periods that cover the range of paleoclimate states. The proxies have both a marine and terrestrial provenance and are compared to the annual temperature of the same location today. This data is then used to quantify long-term temperature changes on zonal and global levels. When coupled with recent estimates of atmospheric CO2 concentration, temperature data constrains the sensitivity of Earth's climate system to perturbation of the radiative balance, with possible implications for the future response to anthropogenic forcing. The dataset consists of an excel file with eight sheets for the eight selected timeslices, namely, • mid-Pliocene (3,0 - 3,3 Ma) • late Miocene (7,2 - 11,6 Ma) • mid-Miocene (14,7 - 17,0 Ma) • early Miocene (20,3 - 23,0 Ma) • early Oligocene (27,8 - 33,9 Ma) • late Eocene (33,9 - 37,8 Ma) • middle Eocene (42 - 46 Ma) • early Eocene (48 - 55 Ma)
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- 2022
11. Grounding‐Zone Flow Variability of Priestley Glacier, Antarctica, in a Diurnal Tidal Regime
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Drews, R., primary, Wild, C. T., additional, Marsh, O. J., additional, Rack, W., additional, Ehlers, T. A., additional, Neckel, N., additional, and Helm, V., additional
- Published
- 2021
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12. Glacial catchment erosion from detrital zircon (U‐Th)/He thermochronology: Patagonian Andes
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Falkowski, S., primary, Ehlers, T. A., additional, Madella, A., additional, Glotzbach, C., additional, Georgieva, V., additional, and Strecker, M. R., additional
- Published
- 2021
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13. Quantifying Tectonic and Glacial Controls on Topography in the Patagonian Andes (46.5°S) From Integrated Thermochronometry and Thermo-Kinematic Modeling
- Author
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Andrić-Tomašević, Nevena, Falkowski, S., Georgieva, V., Glotzbach, C., Strecker, M. R., and Ehlers, T. A.
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Geography & travel ,ddc:910 - Abstract
The Patagonian Andes have been used to illustrate the dependency of major topographic changes in response to glacial erosion processes dominating over tectonic deformation and uplift. Here, we investigate tectonic and glacial contributors to the erosion history and evolution of topography in the Patagonian Andes at 46.5��S. We present 33 new apatite and zircon (U���Th)/He (AHe and ZHe, respectively) and fission track (AFT and ZFT, respectively) ages integrated with 46 previously published bedrock thermochronometric ages in a 3D thermo���kinematic model. Observed thermochronometer ages increase from the eastern flank of the topographic crest of the orogen toward the eastern retro���foreland basin (from AFT 4���10 Ma, ZHe 4���12 Ma, ZFT 6���14 Ma to AFT 28���32 Ma, ZHe 68���117 Ma). Thermo���kinematic modeling indicates that spatial gradients in thermochronometric ages can be explained by an up to 100���km���wide, parabolic���shaped pattern in exhumation rates with a maximum rate of 0.5 mm/yr from 15 Ma until the onset of glaciation at ���7 Ma. Furthermore, model results suggest that the youngest AHe ages require a localized acceleration in erosion from ���0.5 mm/yr to ���2.2 mm/yr starting between ���5 and ���3 Ma, coeval with intensified glaciation and subduction of the Chile Rise. Our results suggest that the long���wavelength (���100 km) topography and erosion patterns are likely controlled by rock uplift above mid���crustal ramp(s) and subsequent transpression along the Liqui��e���Ofqui Fault. Superposed on these tectonic processes, Late Cenozoic glaciation resulted in localized and accelerated erosion over wavelengths of, Key Points: Low���temperature thermochronology records non���uniform erosion in the retro���wedge of the Southern Patagonian Andes. Erosion pattern and long���wavelength topography are largely a function of regional tectonic activity over the last 15 Myr. Glaciation has modified erosion rates and topography on sub���valley scales over the last 5���3 Myr., Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659, MINEDUC | CONICYT | Fondo Nacional de Desarrollo Cient��fico y Tecnol��gico (FONDECYT) http://dx.doi.org/10.13039/501100002850
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- 2021
14. Grounding-Zone Flow Variability of Priestley Glacier, Antarctica, in a Diurnal Tidal Regime
- Author
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Drews, R., Wild, C. T., Marsh, O. J., Rack, W., Ehlers, T. A., Neckel, N., Helm, V., Drews, R., Wild, C. T., Marsh, O. J., Rack, W., Ehlers, T. A., Neckel, N., and Helm, V.
- Abstract
Tidal modulation of ice streams and their adjacent ice shelves is a real-world experiment to understand ice-dynamic processes. We observe the dynamics of Priestley Glacier, Antarctica, using Terrestrial Radar Interferometry (TRI) and GNSS. Ocean tides are predominantly diurnal but horizontal GNSS displacements also oscillate semi-diurnally. The oscillations are strongest in the ice shelf and tidal signatures decay near-linearly in the TRI data over >10 km upstream of the grounding line. Tidal flexing is observed >6 km upstream of the grounding line including cm-scale uplift. Tidal grounding line migration is small and <40% of the ice thickness. The frequency doubling of horizontal displacements relative to the ocean tides is consistent with variable ice-shelf buttressing demonstrated with a visco-elastic Maxwell model. Taken together, this supports previously hypothesized flexural ice softening in the grounding-zone through tides and offers new observational constraints for the role of ice rheology in ice-shelf buttressing.
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- 2021
15. Time series of meteorological station data in the EarthShape study areas in the Coastal Cordillera, Chile
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Übernickel, K., Ehlers, T., Ershadi, M., Paulino, L., Fuentes Espoz, J., Maldonado, A., Oses-Pedraza, R., and von Blanckenburg, F.
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The DFG Priority Program 1803 "EarthShape - Earth Surface Shaping by Biota” (www.earthshape.net, short description of the project below) installed a meteorological station network consisting of four stations between ~}26 °S to {~38 °S in the Coastal Cordillera of Chile, South America. The stations are intended to provide baseline meteorological data along the climate and ecological gradient investigated in the EarthShape program. The stations are located in the EarthShape study areas, encompassing desert, semi-desert, mediterranean, and temperate climate zones. Each station is configured to include sensors that record precipitation at ground level, radiation at 2.8 m height, wind at 3 m height, 25 cm depth soil temperature, soil water content and bulk electrical conductivity, 2 m air temperature and relative humidity, and barometric pressure at 30-minute intervals. The data recording started in March/April 2016. The EarthShape project runs until December 2021. Data collection will continue until that date, and potentially longer depending on available funds. This publication provides two sets of data: raw data and processed data. The raw data contains 2 file types per meteorological station: (1) all measured parameters of the whole dataset measured in 30 minutes intervals as downloaded from the station. Furthermore, we provide (2) one table per station of high-resolution precipitation events, measured in 5 min. intervals that were triggered during rain events at each station. The processed data consists of a continuous timeseries of observations since the activation of each station. The processing consists of the exclusion of erroneous data, caused by maintenance of the weather-stations and sporadic malfunction of sensors detected during data screening. The excluded data is communicated in a logfile (excel table), comments from data screening, solar eclipse and others are summarized in history files (ASCII ). the full description of the data and methods is provided in the data description file (Data description file).
- Published
- 2020
16. Ischemic Preconditioning Improves Microvascular Endothelial Function in Remote Vasculature by Enhanced Prostacyclin Production.
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Rytter, N., Carter, H., Piil, P., Sørensen, H., Ehlers, T., Holmegaard, F., Tuxen, C., Jones, H., Thijssen, D.H.J., Gliemann, L., Hellsten, Y., Rytter, N., Carter, H., Piil, P., Sørensen, H., Ehlers, T., Holmegaard, F., Tuxen, C., Jones, H., Thijssen, D.H.J., Gliemann, L., and Hellsten, Y.
- Abstract
Contains fulltext : 225973.pdf (publisher's version ) (Open Access), BACKGROUND The mechanisms underlying the effect of preconditioning on remote microvasculature remains undisclosed. The primary objective was to document the remote effect of ischemic preconditioning on microvascular function in humans. The secondary objective was to test if exercise also induces remote microvascular effects. METHODS AND RESULTS A total of 12 healthy young men and women participated in 2 experimental days in a random counterbalanced order. On one day the participants underwent 4×5 minutes of forearm ischemic preconditioning, and on the other day they completed 4×5 minutes of hand-grip exercise. On both days, catheters were placed in the brachial and femoral artery and vein for infusion of acetylcholine, sodium nitroprusside, and epoprostenol. Vascular conductance was calculated from blood flow measurements with ultrasound Doppler and arterial and venous blood pressures. Ischemic preconditioning enhanced (P<0.05) the remote vasodilator response to intra-arterial acetylcholine in the leg at 5 and 90 minutes after application. The enhanced response was associated with a 6-fold increase (P<0.05) in femoral venous plasma prostacyclin levels and with a transient increase (P<0.05) in arterial plasma levels of brain-derived neurotrophic factor and vascular endothelial growth factor. In contrast, hand-grip exercise did not influence remote microvascular function. CONCLUSIONS These findings demonstrate that ischemic preconditioning of the forearm improves remote microvascular endothelial function and suggest that one of the underlying mechanisms is a humoral-mediated potentiation of prostacyclin formation.
- Published
- 2020
17. Atmospheric and oceanographic signatures in the ice‐shelf channel morphology of Roi Baudouin Ice Shelf, East Antarctica, inferred from radar data
- Author
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Drews, R., Schannwell, C., Ehlers, T. A., Gladstone, R., Pattyn, Frank, Matsuoka, K., Drews, R., Schannwell, C., Ehlers, T. A., Gladstone, R., Pattyn, Frank, and Matsuoka, K.
- Abstract
Ice shelves around Antarctica can provide back stress for outlet glaciers and control ice sheet mass loss. They often contain narrow bands of thin ice termed ice shelf channels. Ice shelf channel morphology can be interpreted through surface depressions and exhibits junctions and deflections from flowlines. Using ice flow modeling and radar, we investigate ice shelf channels in the Roi Baudouin Ice Shelf. These are aligned obliquely to the prevailing easterly winds. In the shallow radar stratigraphy, syncline and anticline stacks occur beneath the upwind and downwind side, respectively. The structures are horizontally and vertically coherent, except near an ice shelf channel junction where patterns change structurally with depth. Deeper layers truncate near basal incisions. Using ice flow modeling, we show that the stratigraphy is ∼9 times more sensitive to atmospheric variability than to oceanic variability. This is due to the continual adjustment toward flotation. We propose that syncline-anticline pairs in the shallow stratigraphy are caused by preferential snow deposition on the windward side and wind erosion at the downwind side. This drives downwind deflection of ice shelf channels of several meters per year. The depth variable structures indicate formation of an ice shelf channel junction by basal melting. We conclude that many ice shelf channels are seeded at the grounding line. Their morphology farther seaward is shaped on different length scales by ice dynamics, the ocean, and the atmosphere. These processes act on finer (subkilometer) scales than are captured by most ice, atmosphere, and ocean models, yet the dynamics of ice shelf channels may have broader implications for ice shelf stability., SCOPUS: ar.j, info:eu-repo/semantics/published
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- 2020
18. Atmospheric and Oceanographic Signatures in the Ice Shelf Channel Morphology of Roi Baudouin Ice Shelf, East Antarctica, Inferred From Radar Data
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Drews, R., primary, Schannwell, C., additional, Ehlers, T. A., additional, Gladstone, R., additional, Pattyn, F., additional, and Matsuoka, K., additional
- Published
- 2020
- Full Text
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19. Latitudinal effect of vegetation on erosion rates identified along western South America
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Starke, J., primary, Ehlers, T. A., additional, and Schaller, M., additional
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- 2020
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20. Opportunities and Challenges for Paleoaltimetry in “Small” Orogens: Insights From the European Alps
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Botsyun, S., primary, Ehlers, T. A., additional, Mutz, S. G., additional, Methner, K., additional, Krsnik, E., additional, and Mulch, A., additional
- Published
- 2020
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21. Seismic monitoring of small alpine rockfalls – validity, precision and limitations
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Dietze, M., Mohadjer, S., Turowski, J., Ehlers, T., and Hovius, N.
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lcsh:Dynamic and structural geology ,lcsh:QE500-639.5 - Abstract
Rockfall in deglaciated mountain valleys is perhaps the most important post-glacial geomorphic process for determining the rates and patterns of valley wall erosion. Furthermore, rockfall poses a significant hazard to inhabitants and motivates monitoring efforts in populated areas. Traditional rockfall detection methods, such as aerial photography and terrestrial laser scanning (TLS) data evaluation, provide constraints on the location and released volume of rock but have limitations due to significant time lags or integration times between surveys, and deliver limited information on rockfall triggering mechanisms and the dynamics of individual events. Environmental seismology, the study of seismic signals emitted by processes at the Earth's surface, provides a complementary solution to these shortcomings. However, this approach is predominantly limited by the strength of the signals emitted by a source and their transformation and attenuation towards receivers. To test the ability of seismic methods to identify and locate small rockfalls, and to characterise their dynamics, we surveyed a 2.16 km2 large, near-vertical cliff section of the Lauterbrunnen Valley in the Swiss Alps with a TLS device and six broadband seismometers. During 37 days in autumn 2014, 10 TLS-detected rockfalls with volumes ranging from 0.053 ± 0.004 to 2.338 ± 0.085 m3 were independently detected and located by the seismic approach, with a deviation of 81−29+59 m (about 7 % of the average inter-station distance of the seismometer network). Further potential rockfalls were detected outside the TLS-surveyed cliff area. The onset of individual events can be determined within a few milliseconds, and their dynamics can be resolved into distinct phases, such as detachment, free fall, intermittent impact, fragmentation, arrival at the talus slope and subsequent slope activity. The small rockfall volumes in this area require significant supervision during data processing: 2175 initially picked potential events reduced to 511 potential events after applying automatic rejection criteria. The 511 events needed to be inspected manually to reveal 19 short earthquakes and 37 potential rockfalls, including the 10 TLS-detected events. Rockfall volume does not show a relationship with released seismic energy or peak amplitude at this spatial scale due to the dominance of other, process-inherent factors, such as fall height, degree of fragmentation, and subsequent talus slope activity. The combination of TLS and environmental seismology provides, despite the significant amount of manual data processing, a detailed validation of seismic detection of small volume rockfalls, and revealed unprecedented temporal, spatial and geometric details about rockfalls in steep mountainous terrain.
- Published
- 2017
22. Data supplement to 'Pedogenic and microbial interrelations to regional climate and local topography: New insights from a climate gradient (arid to humid) along the Coastal Cordillera of Chile'
- Author
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Bernhard, N., Moskwa, L., Schmidt, K., Oeser, R., Aburto, F., Bader, M., Baumann, K., von Blanckenburg, F., Boy, J., van den Brink, L., Brucker, E., Büdel, B., Canessa, R., Dippold, M., Ehlers, T., Fuentes, J., Godoy, R., Jung, P., Karsten, U., Köster, M., Kuzyakov, Y., Leinweber, P., Neidhardt, H., Matus, F., Mueller, C., Oelmann, Y., Oses, R., Osses, P., Paulino, L., Samolov, E., Schaller, M., Schmid, M., Spielvogel, S., Spohn, M., Stock, S., Stroncik, N., Tielbörger, K., Übernickel, K., Scholten, T., Seguel, O., Wagner, D., and Kühn, P.
- Subjects
ComputingMethodologies_PATTERNRECOGNITION ,Data_MISCELLANEOUS - Abstract
Dataset
- Published
- 2018
23. Data supplement to: Chemistry and microbiology of the Critical Zone along a steep climate and vegetation gradient in the Chilean Coastal Cordillera
- Author
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Oeser, R., Stroncik, N., Moskwa, L., Bernhard, N., Schaller, M., Canessa, R., van den Brink, L., Köster, M., Brucker, E., Stock, S., Fuentes, J., Godoy, R., Matus, F., Oses Pedraza, R., Osses McIntyre, P., Paulino, L., Seguel, O., Bader, M., Boy, J., Dippold, M., Ehlers, T., Kühn, P., Kuzyakov, Y., Leinweber, P., Scholten, T., Spielvogel, S., Spohn, M., Übernickel, K., Tielbörger, K., Wagner, D., and von Blanckenburg, F.
- Subjects
ComputingMethodologies_PATTERNRECOGNITION ,Data_MISCELLANEOUS - Abstract
Dataset
- Published
- 2018
24. Quantifying landslide frequency and sediment residence time in the Nepal Himalaya
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Whipp, D. M., primary and Ehlers, T. A., additional
- Published
- 2019
- Full Text
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25. Sediment storage in the Southern Alps of New Zealand : New observations from tracer thermochronology
- Author
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Lang, K. A., Ehlers, T. A., Kamp, P. J. J., Ring, Uwe, Lang, K. A., Ehlers, T. A., Kamp, P. J. J., and Ring, Uwe
- Abstract
Careful study of the processes transporting sediment across Earth's surface is critical for robust interpretation of the sedimentary record. Here we consider the specific influence of cyclic glaciation on the export of sediment from mountain landscapes to ocean basins. Using detrital apatite fission-track tracer thermochronology, we present new observations of sediment provenance from six large river systems draining the eastern flank of the Southern Alps, New Zealand. Detrital cooling ages in all six rivers reflect erosion of partially-reset and fully-unreset bedrock exposed in lower catchment areas and indicate that sediment is not currently contributed in proportion to long-term (>10(6) yr) erosion patterns. Instead, detrital cooling ages are better explained by either localized erosion along the eastern mountain front or intermontane sediment storage. Of these two alternatives, only intermontane sediment storage is further consistent with suspended sediment flux measurements in eastern rivers. Our observations are consistent with prior interpretations of Holocene sediment retention, and contrast with tracer thermochronology from continental margin deposits indicating sediment was rapidly exported to the continental shelf during the late Pleistocene. Collectively, this evidence argues for a reactive sediment routing system east of the main drainage divide that responds to cyclic glaciation by retaining sediment onshore following deglaciation and evacuating sediment reservoirs offshore during the subsequent glacial advance. Our research demonstrates the importance of intermontane sediment storage on the transmission of high-frequency (similar to 10(4-5) yr) climate signals to offshore sedimentary archives while highlighting a novel approach to detailing sediment provenance in tectonically active mountain ranges.
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- 2018
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26. Addressing the contribution of climate and vegetation cover on hillslope denudation, Chilean Coastal Cordillera (26 degrees-38 degrees S)
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Schaller, M., Ehlers, T. A., Lang, Karl A. H., Schmid, M., Fuentes-Espoz, J. P., Schaller, M., Ehlers, T. A., Lang, Karl A. H., Schmid, M., and Fuentes-Espoz, J. P.
- Abstract
The Earth surface is modulated by interactions among tectonics, climate, and biota. The influence of each of these factors on hillslope denudation rates is difficult to disentangle. The Chilean Coastal Cordillera offers a strong climate and vegetation gradient from arid and unvegetated in the North to humid and vegetated in the South. A similar (convergent) plate tectonic boundary lies to the West of the Coastal Cordillera. We present eight depth profiles analyzed for in situ-produced cosmogenic Be-10 in four study areas. These profiles reveal denudation rates of soil-mantled hillslopes and the depth of mobile layers. Depth profiles were investigated from both S- and N-facing mid-slope positions. Results indicate the depth of the mobile layers in the four study areas increase from N to S in latitude. When mixing is present in the mobile layers they are completely mixed. In the S- and N-facing hillslopes of each study area, mid-slope positions do not show a systematic change in depth of the mobile layers nor in denudation rates based on cosmogenic depth profiles. From N to S in latitude, modelled denudation rates of hillslopes increase from similar to 0.46 to similar to 5.65 cm/kyr and then decrease to similar to 3.22 cm/kyr in the southernmost, highest vegetation cover, study area. Calculated turnover times of soils decrease from 30 to similar to 11 kyr and then increase to similar to 22 kyr. In this work, the increasing denudation rates are attributed to increasing mean annual precipitation from N to S. However, despite the ongoing increase in precipitation from N to S, the denudation rate in the southernmost location does not continue to increase due to the protective nature of increasing vegetation cover. This indicates a vegetation induced non-linear relationship with denudation rates.
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- 2018
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27. Spatial Scales in Topography and Strain Rate Magnitude in the Western United States
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Bomberger, C., primary, Bendick, R., additional, Flesch, L., additional, and Ehlers, T. A., additional
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- 2018
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28. Tectonic control on rock uplift, exhumation, and topography above an oceanic ridge collision: Southern Patagonian Andes (47°S), Chile
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Georgieva, V., Melnick, D., Schildgen, T., Ehlers, T., Lagabrielle, Y., Enkelmann, E., Strecker, M., Institute of Earth and Environmental Science [Potsdam], University of Potsdam, Department of Geosciences [Tübingen], Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Department of Geology, University of Cincinnati (UC), University of Potsdam = Universität Potsdam, Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics - Abstract
International audience; The subduction of bathymetric anomalies at convergent margins can profoundly affect subduction dynamics, magmatism, and the structural and geomorphic evolution of the overriding plate. The Northern Patagonian Icefield (NPI) is located east of the Chile Triple Junction at ~47°S, where the Chile Rise spreading center collides with South America. This region is characterized by an abrupt increase in summit elevations and relief that has been controversially debated in the context of geodynamic versus glacial erosion effects on topography. Here we present geomorphic, thermochronological, and structural data that document neotectonic activity along hitherto unrecognized faults along the flanks of the NPI. New apatite (U-Th)/He bedrock cooling ages suggest faulting since 2–3 Ma. We infer the northward translation of an ~140 km long fore-arc sliver—the NPI block—results from enhanced partitioning of oblique plate convergence due to the closely spaced collision of three successive segments of the Chile Rise. In this model, greater uplift occurs in the hanging wall of the Exploradores thrust at the northern leading edge of the NPI block, whereas the Cachet and Liquiñe-Ofqui dextral faults decouple the NPI block along its eastern and western flanks, respectively. Localized extension possibly occurs at its southern trailing edge along normal faults associated with margin-parallel extension, tectonic subsidence, and lower elevations along the Andean crest line. Our neotectonic model provides a novel explanation for the abrupt topographic variations inland of the Chile Triple Junction and emphasizes the fundamental effects of local tectonics on exhumation and topographic patterns in this glaciated landscape.
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- 2016
29. Tectonic and Climatic Controls on the Spatial Distribution of Denudation Rates in Northern Chile (18°S to 23°S) Determined From Cosmogenic Nuclides
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Starke, J., primary, Ehlers, T. A., additional, and Schaller, M., additional
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- 2017
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30. Constraints on the tectonic and landscape evolution of the Bhutan Himalaya from thermochronometry
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Adams, B. A., Hodges, K. V., Whipple, K. X., Ehlers, T. A., van Soest, M. C., and Wartho, J.-A.
- Abstract
The observed geomorphology and calculated thermal histories of the Bhutan Himalaya provide an excellent platform to test ideas regarding the influence of tectonics and climate on the evolution of a convergentmountain range. However, little consensus has been reached regarding the late Cenozoic history of the Bhutan Himalaya. Some researchers have argued that observed geologic relationships show slowing deformation rates, such that the range is decaying from a geomorphic perspective, while others see the range as growing and steepening. We suggest that a better understanding is possible through the integrated interpretation of geomorphic and thermochronometric data from the comparison of predictions from models of landscape evolution and thermal-kinematic models of orogenic systems. New thermochronometric data throughout Bhutan aremost consistent with a significant decrease in erosion rates, from2 to 3 km/Ma down to 0.1–0.3 km/Ma, around 6–4Ma. We interpret this pattern as a decrease in rock uplift rates due to the activation of contractional structures of the Shillong Plateau, an uplifted region approximately 100 km south of Bhutan. However, low-relief, fluvial landscapes throughout the Bhutanese hinterland record a late pulse of surface uplift likely due to a recent increase in rock uplift rates. Constraints from our youngest thermochronometers suggest that this increase in rock uplift and surface uplift occurred within the last 1.75Ma. These results imply that the dynamics of the Bhutan Himalaya and Shillong Plateau have been linked during the late Cenozoic, with structural elements of both regions active in variable ways and times over that interval.
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- 2015
31. Elliptic flow of identified hadrons in Pb-Pb collisions at √s_NN = 2.76 TeV
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Abelev, A., Adam, B., Adamová, J., Aggarwal, D., Agnello, M. M., Agostinelli, M., Agrawal, A., Ahammed, N., Ahmad, Z., Ahmed, N., Ahn, I., Ahn, S. U., Aimo, S. A., Aiola, I., Ajaz, S., Akindinov, M., Alam, A., Aleksandrov, S. N., Alessandro, D., Alexandre, B., Alici, D., Alkin, A., Alme, A., Alt, J., Altinpinar, T., Altsybeev, S., Alves Garcia Prado, I., Andrei, C., Andronic, C., Anguelov, A., Anielski, V., Antičić, J., Antinori, T., Antonioli, F., Aphecetche, P., Appelshäuser, L., Arcelli, H., Armesto, S., Arnaldi, N., Aronsson, R., Arsene, T., Arslandok, I. C., Augustinus, M., Averbeck, A., Awes, R., Azmi, T. C., Bach, M. D., Badalà, M., Baek, A., Bagnasco, Y. W., Bailhache, S., Bala, R., Baldisseri, R., Baltasar Dos Santos Pedrosa, A., Baral, F., Barbera, R. C., Barile, R., Barnaföldi, F., Barnby, G. G., Barret, L. S., Bartke, V., Basile, J., Bastid, M., Basu, N., Bathen, S., Batigne, B., Batista Camejo, G., Batyunya, A., Batzing, B., Baumann, P. C., Bearden, C., Beck, I. G., Bedda, H., Behera, C., Belikov, N. K., Bellini, I., Bellwied, F., Belmont-Moreno, R., Belmont, E., Belyaev, R., Bencedi, V., Beole, G., Berceanu, S., Bercuci, I., Berdnikov, A., Berenyi, Y., Berger, D., Bertens, M. E., Berzano, R. A., Betev, D., Bhasin, L., Bhat, A., Bhati, I. R., Bhattacharjee, A. K., Bhom, B., Bianchi, J., Bianchi, L., Bianchin, N., Bielčík, C., Bielčíková, J., Bilandzic, J., Bjelogrlic, A., Blanco, S., Blau, F., Blume, D., Bock, C., Bogdanov, F., Bøggild, A., Bogolyubsky, H., Böhmer, M., Boldizsár, F. V., Bombara, L., Book, M., Borel, J., Borissov, H., Bossú, A., Botje, F., Botta, M., Böttger, E., Braun-Munzinger, S., Bregant, P., Breitner, M., Broker, T., Browning, T. A., Broz, T. A., Bruna, M., Bruno, E., Budnikov, G. E., Buesching, D., Bufalino, H., Buncic, S., Busch, P., Buthelezi, O., Caffarri, Z., Cai, D., Caines, X., Calero Diaz, H., Caliva, L., Calvo Villar, A., Camerini, E., Carena, P., Carena, F., Castillo Castellanos, W., Casula, J., Catanescu, E. A. R., Cavicchioli, V., Ceballos Sanchez, C., Cepila, C., Cerello, J., Chang, P., Chapeland, B., Charvet, S., Chattopadhyay, J. L., Chattopadhyay, S., Chelnokov, S., Cherney, V., Cheshkov, M., Cheynis, C., Chibante Barroso, B., Chinellato, V., Chochula, D. D., Chojnacki, P., Choudhury, M., Christakoglou, S., Christensen, P., Christiansen, C. H., Chujo, P., Chung, T., Cicalo, S. U., Cifarelli, C., Cindolo, L., Cleymans, F., Colamaria, J., Colella, F., Collu, D., Colocci, A., Conesa Balbastre, M., Conesa del Valle, G., Connors, Z., Contreras, M. E., Cormier, J. G., Corrales Morales, T. M., Cortese, Y., Cortés Maldonado, P., Cosentino, I., Costa, M. R., Crochet, F., Cruz Albino, P., Cuautle, R., Cunqueiro, E., Dainese, L., Dang, A., Danu, R., Das, A., Das, D., Das, I., Das, K., Dash, S., Dash, A., De, S., Delagrange, S., Deloff, H., Dénes, A., D’Erasmo, E., De Caro, G., de Cataldo, A., de Cuveland, G., De Falco, J., De Gruttola, A., De Marco, D., De Pasquale, N., de Rooij, S., Diaz Corchero, R., Dietel, M. A., Dillenseger, T., Divià, P., Di Bari, R., Di Liberto, D., Di Mauro, S., Di Nezza, A., Djuvsland, P., Dobrin, Ø., Dobrowolski, A., Domenicis Gimenez, T., Dönigus, D., Dordic, B., Dørheim, O., Dubey, S., Dubla, A. K., Ducroux, A., Dupieux, L., Dutta Majumdar, P., Hilden, A. K., Ehlers, T. E., Elia, R. J., Engel, D., Erazmus, H., Erdal, B., Eschweiler, H. A., Espagnon, D., Esposito, B., Estienne, M., Esumi, M., Evans, S., Evdokimov, D., Fabris, S., Faivre, D., Falchieri, J., Fantoni, D., Fasel, A., Fehlker, M., Feldkamp, D., Felea, L., Feliciello, D., Feofilov, A., Ferencei, G., Fernández Téllez, J., Ferreiro, A., Ferretti, E. G., Festanti, A., Figiel, A., Figueredo, J., Filchagin, M. A. S., Finogeev, S., Fionda, D., Fiore, F. M., Floratos, E. M., Floris, E., Foertsch, M., Foka, S., Fokin, P., Fragiacomo, S., Francescon, E., Frankenfeld, A., Fuchs, U., Furget, U., Fusco Girard, C., Gaardhøje, M., Gagliardi, J. J., Gago, M., Gallio, A. M., Gangadharan, M., Ganoti, D. R., Garabatos, P., Garcia-Solis, C., Gargiulo, E., Garishvili, C., Gerhard, I., Germain, J., Gheata, M., Gheata, A., Ghidini, M., Ghosh, B., Ghosh, P., Gianotti, S. K., Giubellino, P., Gladysz-Dziadus, P., Glässel, E., Gomez Ramirez, P., González-Zamora, A., Gorbunov, P., Görlich, S., Gotovac, L., Graczykowski, S., Grelli, L. K., Grigoras, A., Grigoriev, C., Grigoryan, V., Grigoryan, A., Grinyov, S., Grion, B., Grosse-Oetringhaus, N., Grossiord, J. F., Grosso, J. -Y., Guber, R., Guernane, F., Guerzoni, R., Guilbaud, B., Gulbrandsen, M., Gulkanyan, K., Gumbo, H., Gunji, M., Gupta, T., Gupta, A., Khan, R., Haake, K. H., Haaland, R., Hadjidakis, Ø., Haiduc, C., Hamagaki, M., Hamar, H., Hanratty, G., Hansen, L. D., Harris, A., Hartmann, J. W., Harton, H., Hatzifotiadou, A., Hayashi, D., Heckel, S., Heide, S. T., Helstrup, M., Herghelegiu, H., Herrera Corral, A., Hess, G., Hetland, B. A., Hippolyte, K. F., Hladky, B., Hristov, J., Huang, P., Humanic, M., Hussain, T. J., Hutter, N., Hwang, D., Ilkaev, D. S., Ilkiv, R., Inaba, I., Innocenti, M., Ionita, G. M., Ippolitov, C., Irfan, M., Ivanov, M., Jacholkowski, V., Jacobs, A., Jahnke, P. M., Jang, C., Janik, H. J., Jayarathna, M. A., Jena, P. H. S. Y., Jena, C., Jimenez Bustamante, S., Jones, R. T., Jung, P. G., Jusko, H., Kadyshevskiy, A., Kalcher, V., Kalinak, S., Kalweit, P., Kamin, A., Kang, J., Kaplin, J. H., Kar, V., Karasu Uysal, S., Karavichev, A., Karavicheva, O., Karpechev, T., Kebschull, E., Keidel, U., Keijdener, R., Keil SVN, D. L. D., Khan, M., Khan, M. M., Khan, P., Khanzadeev, S. A., Kharlov, A., Kileng, Y., Kim, B., Kim, D. W., Kim, D. J., Kim, J. S., Kim, M., Kim, S., Kirsch, T., Kisel, S., Kiselev, I., Kisiel, S., Kiss, A., Klay, G., Klein, J. L., Klein-Bösing, J., Kluge, C., Knichel, A., Knospe, M. L., Kobdaj, A. G., Kofarago, C., Köhler, M., Kollegger, M. K., Kolojvari, T., Kondratiev, A., Kondratyeva, V., Konevskikh, N., Kovalenko, A., Kowalski, V., Kox, M., Koyithatta Meethaleveedu, S., Kral, G., Králik, J., Kramer, I., Kravčáková, F., Krelina, A., Kretz, M., Krivda, M., Krizek, M., Kryshen, F., Krzewicki, E., Kučera, M., Kucheriaev, V., Kugathasan, Y., Kuhn, T., Kuijer, C., Kulakov, P. G., Kumar, I., Kurashvili, J., Kurepin, P., Kurepin, A., Kuryakin, A. B., Kushpil, A., Kweon, S., Kwon, M. J., Ladron de Guevara, Y., Lagana Fernandes, P., Lakomov, C., Langoy, I., Lara, R., Lardeux, C., Lattuca, A., La Pointe, A., La Rocca, S. L., Lea, P., Leardini, R., Lee, L., Legrand, G. R., Lehnert, I., Lemmon, J., Lenti, R. C., Leogrande, V., Leoncino, E., León Monzón, M., Lévai, I., Li, P., Lien, S., Lietava, J., Lindal, R., Lindenstruth, S., Lippmann, V., Lisa, C., Ljunggren, M. A., Lodato, H. M., Loenne, D. F., Loggins, P. I., Loginov, V. R., Lohner, V., Loizides, D., Lopez, C., López Torres, X., Lu, E., Luettig, X. -G., Lunardon, P., Luparello, M., Ma, G., Maevskaya, R., Mager, A., Mahapatra, M., Mahmood, D. P., Maire, S. M., Majka, A., Malaev, R. D., Maldonado Cervantes, M., Malinina, I., Mal’Kevich, L., Malzacher, D., Mamonov, P., Manceau, A., Manko, L., Manso, V., Manzari, F., Marchisone, V., Mareš, M., Margagliotti, J., Margotti, G. V., Marín, A., Markert, A., Marquard, C., Martashvili, M., Martin, I., Martinengo, N. A., Martínez, P., Martínez García, M. I., Martin Blanco, G., Martynov, J., Mas, Y., Masciocchi, A., Masera, S., Masoni, M., Massacrier, A., Mastroserio, L., Matyja, A., Mayer, A., Mazer, C., Mazzoni, J., Meddi, M. A., Menchaca-Rocha, F., Mercado Pérez, A., Meres, J., Miake, M., Mikhaylov, Y., Milano, K., Milosevic, L., Mischke, J., Mishra, A., Miskowiec, A. N., Mitra, D., Mitu, J., Mlynarz, C. M., Mohammadi, J., Mohanty, N., Molnar, B., Montaño Zetina, L., Montes, L., Morando, E., Moreira De Godoy, M., Moretto, D. A., Morsch, S., Muccifora, A., Mudnic, V., Mühlheim, E., Muhuri, D., Mukherjee, S., Müller, M., Munhoz, H., Murray, M. G., Musa, S., Musinsky, L., Nandi, J., Nania, B. K., Nappi, R., Nattrass, E., Nayak, C., Nayak, K., Nazarenko, T. K., Nedosekin, S., Nicassio, A., Niculescu, M., Nielsen, M., Nikolaev, B. S., Nikulin, S., Nilsen, V., Noferini, B. S., Nomokonov, F., Nooren, P., Norman, G., Nyanin, J., Nystrand, A., Oeschler, J., Oh, H., Oh, S., Okatan, S. K., Olah, A., Oleniacz, L., Oliveira Da Silva, J., Onderwaater, A. C., Oppedisano, J., Ortiz Velasquez, C., Oskarsson, A., Otwinowski, A., Oyama, J., Sahoo, K., Pachmayer, P., Pachr, Y., Pagano, M., Paić, P., Painke, G., Pajares, F., Pal, C., Palmeri, S. K., Pant, A., Papikyan, D., Pappalardo, V., Pareek, G. S., Park, P., Parmar, W. J., Passfeld, S., Patalakha, A., Paticchio, D. I., Paul, V., Pawlak, B., Peitzmann, T., Pereira Da Costa, T., Pereira De Oliveira Filho, H., Peresunko, E., Pérez Lara, D., Pesci, C. E., Peskov, A., Pestov, V., Petráček, Y., Petran, V., Petris, M., Petrovici, M., Petta, M., Piano, C., Pikna, S., Pillot, M., Pinazza, P., Pinsky, O., Piyarathna, L., Ploskon, D. B., Planinic, M., Pluta, M., Pochybova, J., Podesta-Lerma, S., Poghosyan, P. L. M., Pohjoisaho, M. G., Polichtchouk, E. H. O., Poljak, B., Pop, N., Porteboeuf-Houssais, A., Porter, S., Potukuchi, J., Prasad, B., Preghenella, S. K., Prino, R., Pruneau, F., Pshenichnov, C. A., Puddu, I., Pujahari, G., Punin, P., Putschke, V., Qvigstad, J., Rachevski, H., Raha, A., Rak, S., Rakotozafindrabe, J., Ramello, A., Raniwala, L., Raniwala, R., Räsänen, S., Rascanu, S. S., Rathee, B. T., Rauf, D., Razazi, A. W., Read, V., Real, K. F., Redlich, J. S., Reed, K., Rehman, R. J., Reichelt, A., Reicher, P., Reidt, M., Renfordt, F., Reolon, R., Reshetin, A. R., Rettig, A., Revol, F., Reygers, J. -P., Riabov, K., Ricci, V., Richert, R. A., Richter, T., Riedler, M., Riegler, P., Riggi, W., Rivetti, F., Rocco, A., Rodríguez Cahuantzi, E., Rodriguez Manso, M., Røed, A., Rogochaya, K., Rohni, E., Rohr, S., Röhrich, D., Romita, D., Ronchetti, R., Ronflette, F., Rosnet, L., Rossi, P., Roukoutakis, A., Roy, F., Roy, A., Roy, C., Rubio Montero, P., Rui, A. J., Russo, R., Ryabinkin, R., Ryabov, E., Rybicki, Y., Sadovsky, A., Šafařík, S., Sahlmuller, K., Sahoo, B., Sahu, R., Saini, P. K., Sakai, J., Salgado, S., Salzwedel, C. A., Sambyal, J., Samsonov, S., Sanchez Castro, V., Sánchez Rodríguez, X., Šándor, F. J., Sandoval, L., Sano, A., Santagati, M., Sarkar, G., Scapparone, D., Scarlassara, E., Scharenberg, F., Schiaua, R. P., Schicker, C., Schmidt, R., Schmidt, C., Schuchmann, H. R., Schukraft, S., Schulc, J., Schuster, M., Schutz, T., Schwarz, Y., Schweda, K., Scioli, K., Scomparin, G., Scott, E., Segato, R., Seger, G., Sekiguchi, J. E., Selyuzhenkov, Y., Seo, I., Serradilla, J., Sevcenco, E., Shabetai, A., Shabratova, A., Shahoyan, G., Shangaraev, R., Sharma, A., Sharma, N., Shigaki, S., Shtejer, K., Sibiriak, K., Siddhanta, Y., Siemiarczuk, S., Silvermyr, T., Silvestre, D., Simatovic, C., Singaraju, G., Singh, R., Singha, R., Singhal, S., Sinha, V., Sinha, B. C., Sitar, T., Sitta, B., Skaali, M., Skjerdal, T. B., Slupecki, K., Smirnov, M., Snellings, N., Søgaard, R. J. M., Soltz, C., Song, R., Song, J., Soramel, M., Sorensen, F., Spacek, S., Spiriti, M., Sputowska, E., Spyropoulou-Stassinaki, I., Srivastava, M., Stachel, B. K., Stan, J., Stefanek, I., Steinpreis, G., Stenlund, M., Steyn, E., Stiller, G., Stocco, J. H., Stolpovskiy, D., Strmen, M., Suaide, P., Sugitate, A. A. P., Suire, T., Suleymanov, C., Sultanov, M., Šumbera, R., Susa, M., Symons, T., Szabo, T. J. M., Szanto de Toledo, A., Szarka, A., Szczepankiewicz, I., Szymanski, A., Takahashi, M., Tangaro, J., Tapia Takaki, M. A., Tarantola Peloni, J. D., Tarazona Martinez, A., Tarzila, A., Tauro, M. G., Tejeda Muñoz, A., Telesca, G., Terrevoli, A., Thäder, C., Thomas, J., Tieulent, D., Timmins, R., Toia, A. R., Trubnikov, A., Trzaska, V., Tsuji, W. H., Tumkin, T., Turrisi, A., Tveter, R., Ullaland, T. S., Uras, K., Usai, A., Vajzer, G. L., Vala, M., Valencia Palomo, M., Vallero, L., Vande Vyvre, S., Van Der Maarel, P., Van Hoorne, J., van Leeuwen, J. W., Vargas, M., Vargyas, A., Varma, M., Vasileiou, R., Vasiliev, M., Vechernin, A., Veldhoen, V., Velure, M., Venaruzzo, A., Vercellin, M., Vergara Limón, E., Vernet, S., Verweij, R., Vickovic, M., Viesti, L., Viinikainen, G., Vilakazi, J., Villalobos Baillie, Z., Vinogradov, O., Vinogradov, A., Vinogradov, L., Virgili, Y., Viyogi, T., Vodopyanov, Y. P., Völkl, A., Voloshin, M. A., Voloshin, K., Volpe, S. A., von Haller, G., Vorobyev, B., Vranic, I., Vrláková, D., Vulpescu, J., Vyushin, B., Wagner, A., Wagner, B., Wagner, J., Wang, V., Wang, M., Watanabe, Y., Weber, D., Wessels, M., Westerhoff, J. P., Wiechula, U., Wikne, J., Wilde, J., Wilk, M., Wilkinson, G., Williams, J., Windelband, M. C. S., Winn, B., Yaldo, M., Yamaguchi, C. G., Yang, Y., Yang, H., Yang, P., Yano, S., Yasnopolskiy, S., Yi, S., Yin, J., Yoo, Z., Yushmanov, I. -K., Zaccolo, I., Zach, V., Zaman, C., Zampolli, A., Zaporozhets, C., Zarochentsev, S., Závada, A., Zaviyalov, P., Zbroszczyk, N., Zgura, H., Zhalov, I. S., Zhang, M., Zhang, H., Zhang, X., Zhao, Y., Zhigareva, C., Zhou, N., Zhou, D., Zhou, F., Zhou, Y., Zhu, Z., Zhu, H., Zhu, J., Zichichi, X., Zimmermann, A., Zinovjev, M. B., Zoccarato, G., and Zyzak, Y.
- Subjects
Collective flow ,Heavy Ions ,Particle correlations and fluctuations ,High Energy Physics::Experiment ,Nuclear Experiment - Published
- 2015
32. 10Be Surface-Exposure Age Dating of the Last Glacial Maximum in the Northern Pamir (Tajikistan)
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Grin, E., Ehlers, T. A., Schaller, M., Sulaymonova, V., Ratschbacher, L., Gloaguen, R., Grin, E., Ehlers, T. A., Schaller, M., Sulaymonova, V., Ratschbacher, L., and Gloaguen, R.
- Abstract
Knowledge of the spatial and temporal variations in Alpine glaciations is essential for reconstructing the regional and global timing of ice ages. This study investigates glacial deposits at the mouth of the Muksu catchment in the northern Pamir using 10Be surface-exposure age dating. We sampled boulders from the furthest downstream recessional moraine (20 samples) and five lateral moraines (41 samples) near the former terminus of the Fedchenko Glacier, the longest (∼72 km) present-day Alpine glacier of the Pamir. After the identification of outliers, the boulder population of the recessional moraine yielded a mean exposure age of 17.5 ± 1.9 ka. The maximum exposure age of the lateral moraines, collected ∼5 km up-valley of the recessional moraine, is 18.2 ± 1.7 ka. The boulder ages reflect glacial deposition during the Last Glacial Maximum (Marine Isotope Stage 2) in the region; they are in accordance with published glacial deposition ages in the western Tian Shan.
- Published
- 2016
33. A systematic thermochronologic transect across the Himalayan rain shadow is consistent with coupling of precipitation patterns and Pliocene-recent exhumation
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Schultz, M., Hodges, K. V., Ehlers, T. A., Van Soest, Matthijs C., Wartho, Jo-Anne, McDonald, Christopher, Schultz, M., Hodges, K. V., Ehlers, T. A., Van Soest, Matthijs C., Wartho, Jo-Anne, and McDonald, Christopher
- Abstract
Models of the exhumation histories of mountain ranges are often quantified through thermal-kinematic modeling of thermochronologic datasets. The Himalaya correspond with one of the world’s starkest rain shadows, with data from NASA’s Tropical Rainfall Measurement Mission (TRMM) suggesting that regions on the southern flank of the Himalaya may receive up to four meters of rainfall per year, while areas of southern Tibet north of the range crest obtain only about half a meter of rainfall annually. While the precise position of this transition is only generally defined by the spatial resolution of the TRMM data to within a few kilometers, the data clearly indicate that the transition occurs south of the range crest. New multichronometer datasets (40Ar/39Ar muscovite and (U-Th)/He zircon and apatite) for bedrock samples collected along a transect from north of Mount Everest, on the Tibetan Plateau, to the southern flank of the Himalaya in the Khumbu region of Nepal, show a dramatic break in cooling histories at a position well south of the range crest and within spatial uncertainty of the TRMM-derived position of the rainfall transition. 1D inverse thermal-kinematic and erosion modeling of the thermochronometer data for the range of possible transient denudation histories indicates that the thermochronometric transition marks a shift between two regions with dramatically different exhumation histories within the late Miocene-Pliocene, with high, presumably erosional exhumation of post-Miocene age constrained to the region of high modern precipitation related to the South Asian summer monsoon. These results support a model in which the current precipitation patterns across the rain shadow, which clearly correlate with exhumation rate patterns today, had developed by at least the late Miocene. Our results do not support the model of Carrapa et al. (2016, Geology), who used their thermochronologic data for samples collected north of Mount Everest, together with pre-existin
- Published
- 2016
34. A Quaternary Fault Database for Central Asia
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Mohadjer, S., primary, Ehlers, T. A., additional, Bendick, R., additional, Stübner, K., additional, and Strube, T., additional
- Published
- 2015
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35. Constraints on the tectonic and landscape evolution of the Bhutan Himalaya from thermochronometry
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Adams, B. A., primary, Hodges, K. V., additional, Whipple, K. X., additional, Ehlers, T. A., additional, van Soest, M. C., additional, and Wartho, J., additional
- Published
- 2015
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36. Ice flow models and glacial erosion over multiple glacial–interglacial cycles
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Headley, R. M., primary and Ehlers, T. A., additional
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- 2015
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37. Guidelines for the coordinated enhancement of the maritime position, navigation and time data system.
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Engler, E., Hoppe, M., Ritterbusch, J., Ehlers, T., Becker, C., Ehrke, K. -C., and Callsen-Bracker, H.
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SHIPS ,LOCOMOTION ,NAVIGATION ,COLLISIONS at sea ,FISHERIES navigation - Abstract
Reliable knowledge of a ship's position and movement in relation to other traffic participants and obstacles is a fundamental requirement for navigation and avoiding collisions and groundings. Consequently, the onboard provision of resilient position, navigation and time data (PNT) is emphasized by the International Maritime Organization's (IMO) e-navigation strategy, solution S3 "Improved reliability, resilience and integrity of bridge equipment and navigation information" and by the assigned risk control option RCO5 "Improved reliability and resilience of onboard PNT systems". An initial step towards resilient PNT has been realized by the maritime community with the development of the performance standards for shipborne multi-system radionavigation receiver equipment (MRR). This MRR performance standard (PS) supports the full use of data coming from current and future radionavigation systems and services. Consequently, the combined use of several global navigation satellite systems (GNSS) and the additional use of space based augmentation systems (SBAS) as well as optional terrestrial radionavigation systems (e.g. eLoran or R-Mode) will be supported to increase the performance of positioning and timing. As a second step, the development of guidelines for an onboard PNT (data processing) unit has been identified as supplementary and necessary. The starting point is the onboard use of a combination of GNSS receivers and autarkic systems (e.g. radar, gyro, echosounders with bathymetric data) for a comprehensive provision of required PNT data. Redundancy in the available data enables the application of integrity monitoring functions to evaluate the current usability of safety-critical data and components. The aim of the guidelines is the specification of data processing rules towards the resilient provision of standardized PNT data and integrity information. For this purpose, a modular architecture for an onboard PNT system is introduced and scaled to the need for data input as well as the performance of data output. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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38. A Quaternary Fault Database for Central Asia.
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Mohadjer, S., Ehlers, T. A., Stübner, K., Strube, T., and Bendick, R.
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GEOLOGIC faults ,DATABASES - Abstract
Earthquakes represent the highest risk in terms of potential loss of lives and economic damage for Central Asian countries. Knowledge of fault location and behavior is essential in calculating and mapping seismic hazard. Previous efforts in compiling fault information for Central Asia have generated a large amount of data that are published in limited-access journals with no digital maps publicly available, or are limited in their description of important fault parameters such as slip rates. This study builds on previous work by improving access to fault information through a webbased interactive map and an online database with search capabilities that allow users to organize data by different fields. The data presented in this compilation include fault location, its geographic, seismic and structural characteristics, short descriptions, narrative comments and references to peer-reviewed publications. The interactive map displays 1196 fault segments and 34 000 earthquake locations on a shaded-relief map. The online database contains attributes for 122 faults mentioned in the literature, with Quaternary and geodetic slip rates reported for 38 and 26 faults respectively, and earthquake history reported for 39 faults. This work has implications for seismic hazard studies in Central Asia as it summarizes important fault parameters, and can reduce earthquake risk by enhancing public access to information. It also allows scientists and hazard assessment teams to identify structures and regions where data gaps exist and future investigations are needed. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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39. Assessing the geometry of the Main Himalayan thrust in central Nepal: A thermokinematic approach.
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Ghoshal, S., McQuarrie, N., Robinson, D. M., and Ehlers, T. A.
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- *
THRUST , *NEPAL Earthquake, 2015 , *GEOLOGICAL mapping , *GEOLOGICAL maps - Abstract
Since the 2015 Gorkha earthquake in Nepal, the relationship between the geometry of megathrusts and the control it exerts over the nucleation and propagation of major earthquakes has become an important topic of debate. In this study, we integrate new geologic mapping, a newly interpreted cross section from the Daraundi valley of central Nepal, two published cross sections from the neighboring Marsyangdi and Budhi Gandaki valleys, and a suite of 270 thermochronometric ages to create an integrated and validated three-dimensional kinematic model for the central Nepal Himalaya. We use this model to investigate the assertion that the westward propagation of the Gorkha rupture was restricted by deep-seated structures in the Main Himalayan thrust. The integrated kinematic model based on these cross sections indicates that the ~30 km southward step in the Main Central thrust system mapped in the Daraundi valley, along with the corresponding step in the distribution of reset muscovite (Ar-Ar) ages, is not the result of a lateral structure in the modern Main Himalayan thrust. Instead, the step in the surface geology is the result of a considerably shorter Trishuli thrust sheet in the Daraundi transect (~30 km compared to between 105 and 120 km in the other transects). The corresponding southward step in the distribution of reset muscovite Ar-Ar ages is the result of the Lesser Himalayan duplex being completely translated over the Main Himalayan thrust ramp, elevating and exposing rocks heated to >400 °C farther south in the Daraundi transect. Our integrated model also highlights the 10–15 km of out-of-sequence thrusting that occurs on the Main Central thrust system across central Nepal. Importantly, these out-of-sequence thrusts sole directly into the modern Main Himalayan thrust ramp, and, together with the distribution of reset zircon (U-Th)/He and apatite fission track ages, show that the modern ramp is distinctly linear from east to west, with no support for a lateral structure at the ramp or to the south. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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40. Coupled surface to deep Earth processes: Perspectives from TOPO-EUROPE with an emphasis on climate- and energy-related societal challenges
- Author
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Cloetingh, Sierd, Sternai, Pietro, Koptev, Alexander, Ehlers, Todd A., Gerya, Taras, Kovács, István, Oerlemans, Johannes, Beekman, Fred, Lavallée, Yan, Dingwell, Donald, Békési, Eszter, Porkolàb, Kristóf, Tesauro, Magdala, Lavecchia, Alessio, Botsyun, Svetlana, Muller, Veleda, Roure, François, Serpelloni, Enrico, Matenco, Liviu, Castelltort, Sébastien, Giovannelli, Donato, Brovarone, Alberto Vitale, Malaspina, Nadia, Coletti, Giovanni, Valla, Pierre, Limberger, Jon, Cloetingh, S, Sternai, P, Koptev, A, Ehlers, T, Gerya, T, Kovacs, I, Oerlemans, J, Beekman, F, Lavallee, Y, Dingwell, D, Bekesi, E, Porkolab, K, Tesauro, M, Lavecchia, A, Botsyun, S, Muller, V, Roure, F, Serpelloni, E, Matenco, L, Castelltort, S, Giovannelli, D, Brovarone, A, Malaspina, N, Coletti, G, Valla, P, Limberger, J, and Tectonics
- Subjects
Global and Planetary Change ,Coupled surface-deep Earth interaction ,Climate changes across timescale ,Earth environment ,Geo-energy ,Geo-biosphere ,Climate changes across timescales ,Oceanography ,Earth system science ,Coupled surface-deep Earth interactions - Abstract
Understanding the interactions between surface and deep Earth processes is important for research in many diverse scientific areas including climate, environment, energy, georesources and biosphere. The TOPO-EUROPE initiative of the International Lithosphere Program serves as a pan-European platform for integrated surface and deep Earth sciences, synergizing observational studies of the Earth structure and fluxes on all spatial and temporal scales with modelling of Earth processes. This review provides a survey of scientific developments in our quantitative understanding of coupled surface-deep Earth processes achieved through TOPO-EUROPE. The most notable innovations include (1) a process-based understanding of the connection of upper mantle dynamics and absolute plate motion frames; (2) integrated models for sediment source-to-sink dynamics, demonstrating the importance of mass transfer from mountains to basins and from basin to basin; (3) demonstration of the key role of polyphase evolution of sedimentary basins, the impact of pre-rift and pre-orogenic structures, and the evolution of subsequent lithosphere and landscape dynamics; (4) improved conceptual understanding of the temporal evolution from back-arc extension to tectonic inversion and onset of subduction; (5) models to explain the integrated strength of Europe's lithosphere; (6) concepts governing the interplay between thermal upper mantle processes and stress-induced intraplate deformation; (7) constraints on the record of vertical motions from high-resolution data sets obtained from geo-thermochronology for Europe's topographic evolution; (8) recognition and quantifications of the forcing by erosional and/or glacial-interglacial surface mass transfer on the regional magmatism, with major implications for our understanding of the carbon cycle on geological timescales and the emerging field of biogeodynamics; and (9) the transfer of insights obtained on the coupling of deep Earth and surface processes to the domain of geothermal energy exploration. Concerning the future research agenda of TOPO-EUROPE, we also discuss the rich potential for further advances, multidisciplinary research and community building across many scientific frontiers, including research on the biosphere, climate and energy. These will focus on obtaining a better insight into the initiation and evolution of subduction systems, the role of mantle plumes in continental rifting and (super)continent break-up, and the deformation and tectonic reactivation of cratons; the interaction between geodynamic, surface and climate processes, such as interactions between glaciation, sea level change and deep Earth processes; the sensitivity, tipping points, and spatio-temporal evolution of the interactions between climate and tectonics as well as the role of rock melting and outgassing in affecting such interactions; the emerging field of biogeodynamics, that is the impact of coupled deep Earth – surface processes on the evolution of life on Earth; and tightening the connection between societal challenges regarding renewable georesources, climate change, natural geohazards, and novel process-understanding of the Earth system.
- Published
- 2023
41. Atmospheric and Oceanographic Signatures in the Ice Shelf Channel Morphology of Roi Baudouin Ice Shelf, East Antarctica, Inferred From Radar Data
- Author
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Reinhard Drews, Kenichi Matsuoka, Rupert Gladstone, Clemens Schannwell, Todd A. Ehlers, Frank Pattyn, Schannwell, C., 1 Department of Geoscience University of Tübingen Tübingen Germany, Ehlers, T. A., Gladstone, R., 2 Arctic Centre University of Lapland Rovaniemi Finland, Pattyn, F., 3 Laboratoire de Glaciologie Université Libre de Bruxelles Brussels Belgium, Matsuoka, K., and 4 Norwegian Polar Institute Tromsø Norway
- Subjects
010504 meteorology & atmospheric sciences ,010502 geochemistry & geophysics ,01 natural sciences ,Ice shelf ,law.invention ,law ,glaciology ,14. Life underwater ,ice shelf channels ,Radar ,ice shelves ,0105 earth and related environmental sciences ,Earth-Surface Processes ,geography ,geography.geographical_feature_category ,geophysics ,East antarctica ,ice‐ocean interaction ,Glaciology ,Oceanography ,13. Climate action ,Antarctica ,Geology ,Communication channel ,Sciences exactes et naturelles - Abstract
Ice shelves around Antarctica can provide back stress for outlet glaciers and control ice sheet mass loss. They often contain narrow bands of thin ice termed ice shelf channels. Ice shelf channel morphology can be interpreted through surface depressions and exhibits junctions and deflections from flowlines. Using ice flow modeling and radar, we investigate ice shelf channels in the Roi Baudouin Ice Shelf. These are aligned obliquely to the prevailing easterly winds. In the shallow radar stratigraphy, syncline and anticline stacks occur beneath the upwind and downwind side, respectively. The structures are horizontally and vertically coherent, except near an ice shelf channel junction where patterns change structurally with depth. Deeper layers truncate near basal incisions. Using ice flow modeling, we show that the stratigraphy is ∼9 times more sensitive to atmospheric variability than to oceanic variability. This is due to the continual adjustment toward flotation. We propose that syncline‐anticline pairs in the shallow stratigraphy are caused by preferential snow deposition on the windward side and wind erosion at the downwind side. This drives downwind deflection of ice shelf channels of several meters per year. The depth variable structures indicate formation of an ice shelf channel junction by basal melting. We conclude that many ice shelf channels are seeded at the grounding line. Their morphology farther seaward is shaped on different length scales by ice dynamics, the ocean, and the atmosphere. These processes act on finer (subkilometer) scales than are captured by most ice, atmosphere, and ocean models, yet the dynamics of ice shelf channels may have broader implications for ice shelf stability., Plain Language Summary Ice flows from Antarctica's interior toward the coast. At the contact point between ice and ocean, the ice becomes afloat and forms fast‐flowing ice shelves. Snowfall continuously accumulates at the ice shelf surface, and at the ice shelf bottom the relatively warm ocean water can melt ice from below. Ice shelves sometimes exhibit a network of surface depressions resembling a river network. At the base, the depressions are accompanied by large incisions termed ice shelf channels. Using radar as a tool for echolocation, we investigate how the shape of this network is formed. We find that snow preferentially collects in the upwind side of the surface depressions. This makes ice shelf channels move to the downwind side. We also find that ice shelf channels can form junctions through localized ocean melting. This is important because it helps us to better understand how the Antarctic ice sheet interacts with the surrounding ocean., Key Points The radar stratigraphy in ice shelves is 9 times more sensitive to variability in snow deposition than to variability in basal melting Some ice shelf channels at Roi Baudouin Ice Shelf deflect from flowlines; the radar stratigraphy reflects related processes Variable snow deposition causes slow deflection, and basal melting can form ice shelf channel junctions far from the grounding line, InBev Baillet Latour Antarctica Fellowship, Belgian Science Policy Office http://dx.doi.org/10.13039/501100002749, DFG Emmy Noether, Academy of Finland http://dx.doi.org/10.13039/501100002341, Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659, “Antarctic Research with comparative investigations in Arctic ice areas”, Academy of Finnland, Belgium Science Policy Office
- Published
- 2020
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42. Opportunities and Challenges for Paleoaltimetry in 'Small' Orogens: Insights From the European Alps
- Author
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Todd A. Ehlers, Emilija Krsnik, Katharina Methner, Andreas Mulch, Svetlana Botsyun, Sebastian G. Mutz, Ehlers, T. A., 1 Department of Geosciences University of Tübingen Tübingen Germany, Mutz, S. G., Methner, K., 2 Senckenberg Biodiversity and Climate Research Centre Frankfurt Frankfurt am Main Germany, Krsnik, E., and Mulch, A.
- Subjects
Thesaurus (information retrieval) ,paleoaltimetry ,GCM transcription factors ,GCM ,World Wide Web ,Geophysics ,isotope tracking model ,paleoclimate ,ddc:550 ,General Earth and Planetary Sciences ,stable water isotopes ,European Alps ,Geology - Abstract
Many stable isotope paleoaltimetry studies have focused on paleoelevation reconstructions of orogenic plateaus such as the Tibetan or Andean Plateaus. We address the opportunities and challenges of applying stable isotope paleoaltimetry to “smaller” orogens. We do this using a high‐resolution isotope tracking general circulation model (ECHAM5‐wiso) and explore the precipitation δ18O (δ18Op) signal of Cenozoic paleoclimate and topographic change in the European Alps. Results predict a maximum δ18Op change of 4–5‰ (relative to present day) during topographic development of the Alps. This signal of topographic change has the same magnitude as changes in δ18Op values resulting from Pliocene and Last Glacial Maximum global climatic change. Despite the similar magnitude of the isotopic signals resulting from topographic and paleoclimate changes, their spatial patterns across central Europe differ. Our results suggest that an integration of paleoclimate modeling, multiproxy approaches, and low‐elevation reference proxy records distal from an orogen improve topographic reconstructions., Plain Language Summary: Here we use a climate model with water isotopes implemented to explore the maximum precipitation isotopic signal of Cenozoic topographic and paleoclimate change in the European Alps. Our results show that the impact of topography change has the same magnitude as changes in the isotopic composition of local precipitation resulting from Pliocene and Last Glacial Maximum global climatic change., Key Points: High‐resolution isotope tracking general circulation model (ECHAM5‐wiso) is used to explore changes in past oxygen isotope ratios in precipitation in the Alps. Model‐simulated isotopic signals of topographic change and difference between glacials and interglacials show the same magnitude. Low‐elevation proxy records improve reconstructions of paleotopography by reducing long‐term climate change bias., German Research Foundation (DFG) http://dx.doi.org/10.13039/501100001659
- Published
- 2020
43. Tumoral Calcinosis with an Atypical Presentation in the Foot: A Case Report.
- Author
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Ehlers T, Luong K, Karlic K, and Giakoumis M
- Subjects
- Humans, Female, Foot Diseases diagnosis, Foot Diseases diagnostic imaging, Foot Diseases surgery, Diagnosis, Differential, Tomography, X-Ray Computed, Male, Calcinosis diagnostic imaging, Calcinosis complications, Calcinosis diagnosis
- Abstract
Tumoral calcinosis is a rare disorder defined as the development of periarticular calcified masses, typically surrounding large joints, although they may occur in the foot. We present a case of a patient with systemic tumoral calcinosis with lesions in both shoulders and wrists and a relatively large lesion in the right foot presenting with foot pain.
- Published
- 2024
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44. Development of a density-based topology optimization of homogenized lattice structures for individualized hip endoprostheses and validation using micro-FE.
- Author
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Müller P, Synek A, Stauß T, Steinnagel C, Ehlers T, Gembarski PC, Pahr D, and Lachmayer R
- Subjects
- Humans, Prosthesis Design, Femur, Finite Element Analysis, Stress, Mechanical, Hip Prosthesis, Arthroplasty, Replacement, Hip methods
- Abstract
Prosthetic implants, particularly hip endoprostheses, often lead to stress shielding because of a mismatch in compliance between the bone and the implant material, adversely affecting the implant's longevity and effectiveness. Therefore, this work aimed to demonstrate a computationally efficient method for density-based topology optimization of homogenized lattice structures in a patient-specific hip endoprosthesis. Thus, the root mean square error (RMSE) of the stress deviations between the physiological femur model and the optimized total hip arthroplasty (THA) model compared to an unoptimized-THA model could be reduced by 81 % and 66 % in Gruen zone (GZ) 6 and 7. However, the method relies on homogenized finite element (FE) models that only use a simplified representation of the microstructural geometry of the bone and implant. The topology-optimized hip endoprosthesis with graded lattice structures was synthesized using algorithmic design and analyzed in a virtual implanted state using micro-finite element (micro-FE) analysis to validate the optimization method. Homogenized FE and micro-FE models were compared based on averaged von Mises stresses in multiple regions of interest. A strong correlation (CCC > 0.97) was observed, indicating that optimizing homogenized lattice structures yields reliable outcomes. The graded implant was additively manufactured to ensure the topology-optimized result's feasibility., (© 2024. The Author(s).)
- Published
- 2024
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45. Exercise training induces thrombogenic benefits in recent but not late postmenopausal females.
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Nørregaard LB, Wickham KA, Ehlers T, Rocha MP, Fischer M, Lundberg Slingsby MH, Cheung SS, Evans PA, Bangsbo J, and Hellsten Y
- Subjects
- Male, Humans, Female, Infant, Menopause, Blood Platelets, Exercise physiology, Postmenopause, Thrombosis prevention & control
- Abstract
Although regular physical activity is known to improve cardiovascular health in men, evidence for its beneficial effects in postmenopausal females is less convincing and it remains unclear whether initiation of exercise training soon after, rather than many years after menopause impacts the magnitude of training-induced adaptations. We evaluated exercise-induced changes in markers of thrombotic risk and conduit artery function in recent
≤5yr compared with late≥10yr postmenopausal females. Fourteen recent≤5yr and 13 late≥10yr healthy postmenopausal females completed 8 wk of regular intensive exercise training, consisting of floorball and cycling. Markers of thrombotic risk and vascular health were assessed before and after the intervention, and data were analyzed using a linear mixed model. Exercise training reduced markers of thrombotic risk, including an 11% reduction ( P = 0.007) in agonist-induced platelet reactivity and a reduction ( P = 0.027) in incipient clot microstructure (∼40% reduction in clot mass) in the recent≤5yr but not the late≥10yr ( P = 0.380; P = 0.739, respectively) postmenopausal females. There was no change in conduit artery function, as measured by brachial (recent≤5yr , P = 0.804; late≥10yr , P = 0.311) and popliteal artery (recent≤5yr , P = 0.130; late≥10yr , P = 0.434) flow-mediated dilation. Only the late≥10yr postmenopausal females exhibited an increase (by 9.6%, P = 0.022) in intracellular adhesion molecule-1 levels after training, which may have impacted the thrombogenic adaptation in this group. These findings suggest that 8 wk of high-intensity exercise training reduces thrombotic risk in recent≤5yr , but not late≥10yr postmenopausal females. Thus, regular physical activity initiated soon after, rather than many years after menopause and at a higher age, may be more efficient for reducing thrombogenic risk. NEW & NOTEWORTHY Eight weeks of high-intensity exercise training reduces platelet reactivity as well as blood clot density and strength in females ≤5 yr past menopause but not in females ≥10 yr past menopause. The divergent response in the late postmenopausal females may be explained by training-induced low-grade systemic inflammation. These findings suggest that regular physical activity initiated soon after menopause, compared with many years after menopause, may be more efficient for reducing the risk of blood clots.- Published
- 2023
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46. Additive manufacturing of multi-material parts - Design guidelines for manufacturing of 316L/CuCrZr in laser powder bed fusion.
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Meyer I, Oel M, Ehlers T, and Lachmayer R
- Abstract
Additive manufacturing (AM) can be used to produce multi-material parts in which the material can be varied voxel-wise in all three spatial directions. This means that the paradigm of the homogeneous material can be abandoned and local effects such as heat conduction or damping can be selectively adjusted in the part. Recently, continuous development of machine technology has allowed the production of multi-metal materials in laser powder bed fusion (PBF-LB/MM). Compared to other additive manufacturing processes for multi-material production, this allows greater design freedom and detail accuracy to be realized. However, due to the novel character of multi-material manufacturing in PBF-LB, the process knowledge for successful and reproducible fabrication is currently lacking. This paper focuses on establishing design guidelines for manufacturing the material pairing of stainless steel 316L (1.4404) and copper alloy CuCrZr (CW106C). The article is accompanied by the development of a specific process chain. As a result of this work, design guidelines for multi-material parts are available for the first time, in regard to arrangement, size, overhangs, economy, powder quality and laser scanning., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)
- Published
- 2023
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47. Is the Pannexin-1 Channel a Mechanism Underlying Hypertension in Humans? a Translational Study of Human Hypertension.
- Author
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Gliemann L, Tamariz-Ellemann A, Collin Hansen C, Svare Ehlers T, Møller S, and Hellsten Y
- Subjects
- Connexins, Essential Hypertension, Humans, Male, Middle Aged, Nerve Tissue Proteins, Nitroprusside pharmacology, Receptors, Adrenergic, alpha physiology, Tyramine pharmacology, Acetylcholine pharmacology, Hypertension
- Abstract
Background: In preclinical models, the pannexin-1 channel has been shown to be involved in blood pressure regulation through an effect on peripheral vascular resistance. Pannexin-1 releases ATP, which can activate constrictive purinergic receptors on the smooth muscle cells. Pannexin-1 opening is proposed to be mediated by α-adrenergic receptors to potentiate sympathetic constriction. This positions pannexin-1 as a putative pharmacological target in blood pressure regulation in humans. The aim was to provide the first translational evidence for a role of pannexin-1 in essential hypertension in humans by use of an advanced invasive mechanistic approach., Methods: Middle-aged stage-1 hypertensive (n=13; 135.7±6.4 over 83.7±3.7 mm Hg) and normotensive men (n=12; 117.3±5.7 over 72.2±3.5 mm Hg) were included. Blood pressure and leg vascular resistance were determined during femoral arterial infusion of tyramine (α-adrenergic receptor stimulation), sodium nitroprusside, and acetylcholine. Measurements were made during control conditions and with pannexin-1 blockade (3000 mg probenecid). Expression of Pannexin-1, purinergic- and α-adrenergic receptors in skeletal muscle biopsies was determined by Western blot., Results: The changes in leg vascular resistance in response to tyramine (+289% versus +222%), sodium nitroprusside (-82% versus -78%) and acetylcholine (-40% versus -44%) infusion were not different between the 2 groups ( P >0.05) and pannexin-1 blockade did not alter these variables ( P >0.05). Expression of pannexin-1 and of purinergic- and α-adrenergic receptors was not different between the 2 groups ( P >0.05)., Conclusions: Contrary to our hypothesis, the data demonstrate that pannexin-1 does not contribute to the elevated blood pressure in essential hypertension, a finding, which also opposes that reported in preclinical models.
- Published
- 2022
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48. Redox balance in human skeletal muscle-derived endothelial cells - Effect of exercise training.
- Author
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Hansen C, Møller S, Ehlers T, Wickham KA, Bangsbo J, Gliemann L, and Hellsten Y
- Subjects
- Exercise, Humans, Male, Muscle, Skeletal metabolism, Oxidation-Reduction, Endothelial Cells, Hydrogen Peroxide metabolism
- Abstract
Aerobic training can improve vascular endothelial function in-vivo. The aim of this study was to elucidate the mechanisms underlying this improvement in isolated human microvascular endothelial cells. Sedentary males, aged 57 ± 6 years completed 8 weeks of intense aerobic training. Resting muscle biopsies were obtained from the thigh muscle and used for isolation of endothelial cells (pre n = 23, post n = 16). The cells were analyzed for mitochondrial respiration, H
2 O2 emission, glycolysis, protein levels of antioxidants, NADPH oxidase, endothelial nitric oxide (NO) synthase and prostacyclin synthase (PGI2 S). In-vivo microvascular function, assessed by acetylcholine infusion and arterial blood pressure were also determined. Endothelial mitochondrial respiration and H2 O2 formation were similar before and after training whereas the expression of superoxide dismutase and the expression of glutathione peroxidase were 2.4-fold (p = 0.012) and 2.3-fold (p = 0.006) higher, respectively, after training. In-vivo microvascular function was increased by 1.4-fold (p = 0.036) in parallel with a 2.1-fold increase in endothelial PGI2 S expression (p = 0.041). Endothelial cell glycolysis was reduced after training, as indicated by a 65% lower basal production of lactate (p = 0.003) and a 30% lower expression of phosphofructokinase (p = 0.011). Subdivision of the participants according to blood pressure at base-line (n = 23), revealed a 2-fold higher (p = 0.049) rate of H2 O2 production in endothelial cells from hypertensive participants. Our data show that exercise training increases skeletal muscle microvascular endothelial cell metabolism, antioxidant capacity and the capacity to form prostacyclin. Moreover, elevated blood pressure is associated with increased endothelial mitochondrial ROS formation., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2022
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49. Ischemic Preconditioning Improves Microvascular Endothelial Function in Remote Vasculature by Enhanced Prostacyclin Production.
- Author
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Rytter N, Carter H, Piil P, Sørensen H, Ehlers T, Holmegaard F, Tuxen C, Jones H, Thijssen D, Gliemann L, and Hellsten Y
- Subjects
- Blood Circulation physiology, Blood Pressure physiology, Brachial Artery metabolism, Brachial Artery physiology, Endothelium, Vascular metabolism, Exercise physiology, Female, Femoral Artery metabolism, Femoral Artery physiology, Femoral Vein metabolism, Femoral Vein physiology, Humans, Male, Microvessels metabolism, Young Adult, Endothelium, Vascular physiology, Epoprostenol metabolism, Ischemic Preconditioning, Microvessels physiology
- Abstract
BACKGROUND The mechanisms underlying the effect of preconditioning on remote microvasculature remains undisclosed. The primary objective was to document the remote effect of ischemic preconditioning on microvascular function in humans. The secondary objective was to test if exercise also induces remote microvascular effects. METHODS AND RESULTS A total of 12 healthy young men and women participated in 2 experimental days in a random counterbalanced order. On one day the participants underwent 4×5 minutes of forearm ischemic preconditioning, and on the other day they completed 4×5 minutes of hand-grip exercise. On both days, catheters were placed in the brachial and femoral artery and vein for infusion of acetylcholine, sodium nitroprusside, and epoprostenol. Vascular conductance was calculated from blood flow measurements with ultrasound Doppler and arterial and venous blood pressures. Ischemic preconditioning enhanced ( P <0.05) the remote vasodilator response to intra-arterial acetylcholine in the leg at 5 and 90 minutes after application. The enhanced response was associated with a 6-fold increase ( P <0.05) in femoral venous plasma prostacyclin levels and with a transient increase ( P <0.05) in arterial plasma levels of brain-derived neurotrophic factor and vascular endothelial growth factor. In contrast, hand-grip exercise did not influence remote microvascular function. CONCLUSIONS These findings demonstrate that ischemic preconditioning of the forearm improves remote microvascular endothelial function and suggest that one of the underlying mechanisms is a humoral-mediated potentiation of prostacyclin formation.
- Published
- 2020
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50. Methionine AminoPeptidase Type-2 Inhibitors Targeting Angiogenesis.
- Author
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Ehlers T, Furness S, Robinson TP, Zhong HA, Goldsmith D, Aribser J, and Bowen JP
- Subjects
- Aminopeptidases metabolism, Animals, Cell Proliferation drug effects, Cyclohexanes chemistry, Cyclohexanes pharmacology, Cyclohexanes therapeutic use, Enzyme Inhibitors chemistry, Glycoproteins metabolism, Humans, Methionyl Aminopeptidases, Models, Molecular, Molecular Conformation, Neovascularization, Pathologic metabolism, O-(Chloroacetylcarbamoyl)fumagillol, Sesquiterpenes chemistry, Sesquiterpenes pharmacology, Sesquiterpenes therapeutic use, Aminopeptidases antagonists & inhibitors, Enzyme Inhibitors pharmacology, Glycoproteins antagonists & inhibitors, Neovascularization, Pathologic drug therapy
- Abstract
Angiogenesis has been identified as a crucial process in the development and spread of cancers. There are many regulators of angiogenesis which are not yet fully understood. Methionine aminiopeptidase is a metalloenzyme with two structurally distinct forms in humans, Type-1 (MetAP-1) and Type-2 (MetAP-2). It has been shown that small molecule inhibitors of MetAP-2 suppress endothelial cell proliferation. The initial discovery by Donald Ingber of MetAP-2 inhibition as a potential target in angiogenesis began with a fortuitous observation similar to the discovery of penicillin activity by Sir Alexander Fleming. From a drug design perspective, MetAP-2 is an attractive target. Fumagillin and ovalicin, known natural products, bind with IC50 values in low nanomolar concentrations. Crystal structures of the bound complexes provide 3-dimensional coordinates for advanced computational studies. More recent discoveries have shown other biological activities for MetAP-2 inhibition, which has generated new interests in the design of novel inhibitors. Semisynthetic fumagillin derivatives such as AGM-1470 (TNP-470) have been shown to have better drug properties, but have not been very successful in clinical trials. The rationale and development of novel multicyclic analogs of fumagillin are reviewed.
- Published
- 2016
- Full Text
- View/download PDF
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