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A.s.t.e.r. Team - One of the best experts on this subject based on the ideXlab platform.
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Late Quaternary sackungen in the highest mountains of the Carpathians
Quaternary Science Reviews, 2017Co-Authors: Tomas Panek, Pavel Mentlik, Zbynek Engel, Régis Braucher, Albert Zondervan, A.s.t.e.r. TeamAbstract:Sackungen represents a common mode of deep-seated rock-slope failures in alpine landscapes, but proof of their temporal and causal relationship to extrinsic factors such as climatic changes, glacier retreat or seismic activity remains elusive. Based on the terrestrial cosmogenic nuclide (TCN) dating of 18 sackung scarps supported by one radiocarbon-dated scarp, we reconstructed the post-glacial chronology of sackungen in the Tatra Mts. (central Europe, Slovakia and Poland), the highest part of the Carpathians. The obtained ages (-15.7-4.3 ka) indicate that sackungen post-date the regional LGM and some of them originated soon after the glacier withdrawal from adjacent valleys. Furthermore, systematic decrease of scarp ages with their increasing altitude suggests a direct link between sackung origin and post-LGM glacier thinning. However, substantial lag (>5 ka) of some sackungen in respect to glacier retreat implies complex relationships between sackung onset and deglaciation where retreat of glaciers acted predominantly as a preparatory, not a triggering factor during the genesis of these slope deformations. They originated either as a Consequence of Stress relaxation within the rock mass lasting several ka or alternatively could be triggered by climatic processes or seismicity. Indeed, a significant part of sackung activity took place during predominantly warmer and more humid periods, with some dates coinciding with the Belling-Allerod chronozone, but especially with the onset of the Holocene and the Holocene Climatic Optimum. Earthquake triggering is less probable, as the Tatra Mts. lack significant modern and historic seismic activity and there is no geomorphic evidence of fault offsets on the Late Quaternary landforms. In concert with other recent studies, we propose that large rock slope failures in high mountains seldom react immediately to glacier withdrawal, but could display temporal delay lasting up to several millennia. (C) 2017 Elsevier Ltd. All rights reserved.
Tomas Panek - One of the best experts on this subject based on the ideXlab platform.
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Late Quaternary sackungen in the highest mountains of the Carpathians
Quaternary Science Reviews, 2017Co-Authors: Tomas Panek, Pavel Mentlik, Zbynek Engel, Régis Braucher, Albert Zondervan, A.s.t.e.r. TeamAbstract:Sackungen represents a common mode of deep-seated rock-slope failures in alpine landscapes, but proof of their temporal and causal relationship to extrinsic factors such as climatic changes, glacier retreat or seismic activity remains elusive. Based on the terrestrial cosmogenic nuclide (TCN) dating of 18 sackung scarps supported by one radiocarbon-dated scarp, we reconstructed the post-glacial chronology of sackungen in the Tatra Mts. (central Europe, Slovakia and Poland), the highest part of the Carpathians. The obtained ages (-15.7-4.3 ka) indicate that sackungen post-date the regional LGM and some of them originated soon after the glacier withdrawal from adjacent valleys. Furthermore, systematic decrease of scarp ages with their increasing altitude suggests a direct link between sackung origin and post-LGM glacier thinning. However, substantial lag (>5 ka) of some sackungen in respect to glacier retreat implies complex relationships between sackung onset and deglaciation where retreat of glaciers acted predominantly as a preparatory, not a triggering factor during the genesis of these slope deformations. They originated either as a Consequence of Stress relaxation within the rock mass lasting several ka or alternatively could be triggered by climatic processes or seismicity. Indeed, a significant part of sackung activity took place during predominantly warmer and more humid periods, with some dates coinciding with the Belling-Allerod chronozone, but especially with the onset of the Holocene and the Holocene Climatic Optimum. Earthquake triggering is less probable, as the Tatra Mts. lack significant modern and historic seismic activity and there is no geomorphic evidence of fault offsets on the Late Quaternary landforms. In concert with other recent studies, we propose that large rock slope failures in high mountains seldom react immediately to glacier withdrawal, but could display temporal delay lasting up to several millennia. (C) 2017 Elsevier Ltd. All rights reserved.
Stanley A. Nasraway - One of the best experts on this subject based on the ideXlab platform.
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gastric colonization as a Consequence of Stress ulcer prophylaxis a prospective randomized trial
Pharmacotherapy, 1998Co-Authors: Jorge Ortiz, Frank D. Sottile, Pamela Sigel, Stanley A. NasrawayAbstract:Study Objective. To evaluate gastric alkalization and bacterial colonization in critically ill patients receiving Stress ulcer prophylaxis with gastric tube feeds, sucralfate, intermittent intravenous cimetidine, or continuous intravenous cimetidine. Design. Prospective, randomized, unblinded trial. Setting. Medical and surgical intensive care units of a large university-affiliated, tertiary care community hospital. Patients. Fifty-three evaluable critically ill patients with respiratory failure requiring mechanical ventilation. Interventions. Patients not receiving nasogastric tube feeds were randomized to sucralfate 1 g every 6 hours, cimetidine 300 mg by intravenous bolus every 8 hours, or cimetidine 900 mg by continuous intravenous infusion/24 hours. Gastric samples were obtained daily for pH and culture. Measurements and Main Results. Patients with respiratory failure and a high mortality rate had a mean gastric pH of 1.96 ± 1.5 at study entry. There were no significant differences in gastric pH or gastric colonization among the three arms. Fourteen patients (26%) developed gastric colonization, which was statistically significant but poorly correlated with gastric alkalinity (r2=0.08, p<0.043). Conclusion. Gastric luminal pH was unchanged regardless of which method was used for Stress ulcer prophylaxis. Bacterial colonization was increasingly likely in patients with a persistent alkaline gastric environment.
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Gastric Colonization as a Consequence of Stress Ulcer Prophylaxis: A Prospective, Randomized Trial
Pharmacotherapy, 1998Co-Authors: Jorge Ortiz, Frank D. Sottile, Pamela Sigel, Stanley A. NasrawayAbstract:Study Objective. To evaluate gastric alkalization and bacterial colonization in critically ill patients receiving Stress ulcer prophylaxis with gastric tube feeds, sucralfate, intermittent intravenous cimetidine, or continuous intravenous cimetidine. Design. Prospective, randomized, unblinded trial. Setting. Medical and surgical intensive care units of a large university-affiliated, tertiary care community hospital. Patients. Fifty-three evaluable critically ill patients with respiratory failure requiring mechanical ventilation. Interventions. Patients not receiving nasogastric tube feeds were randomized to sucralfate 1 g every 6 hours, cimetidine 300 mg by intravenous bolus every 8 hours, or cimetidine 900 mg by continuous intravenous infusion/24 hours. Gastric samples were obtained daily for pH and culture. Measurements and Main Results. Patients with respiratory failure and a high mortality rate had a mean gastric pH of 1.96 ± 1.5 at study entry. There were no significant differences in gastric pH or gastric colonization among the three arms. Fourteen patients (26%) developed gastric colonization, which was statistically significant but poorly correlated with gastric alkalinity (r2=0.08, p
Zbynek Engel - One of the best experts on this subject based on the ideXlab platform.
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Late Quaternary sackungen in the highest mountains of the Carpathians
Quaternary Science Reviews, 2017Co-Authors: Tomas Panek, Pavel Mentlik, Zbynek Engel, Régis Braucher, Albert Zondervan, A.s.t.e.r. TeamAbstract:Sackungen represents a common mode of deep-seated rock-slope failures in alpine landscapes, but proof of their temporal and causal relationship to extrinsic factors such as climatic changes, glacier retreat or seismic activity remains elusive. Based on the terrestrial cosmogenic nuclide (TCN) dating of 18 sackung scarps supported by one radiocarbon-dated scarp, we reconstructed the post-glacial chronology of sackungen in the Tatra Mts. (central Europe, Slovakia and Poland), the highest part of the Carpathians. The obtained ages (-15.7-4.3 ka) indicate that sackungen post-date the regional LGM and some of them originated soon after the glacier withdrawal from adjacent valleys. Furthermore, systematic decrease of scarp ages with their increasing altitude suggests a direct link between sackung origin and post-LGM glacier thinning. However, substantial lag (>5 ka) of some sackungen in respect to glacier retreat implies complex relationships between sackung onset and deglaciation where retreat of glaciers acted predominantly as a preparatory, not a triggering factor during the genesis of these slope deformations. They originated either as a Consequence of Stress relaxation within the rock mass lasting several ka or alternatively could be triggered by climatic processes or seismicity. Indeed, a significant part of sackung activity took place during predominantly warmer and more humid periods, with some dates coinciding with the Belling-Allerod chronozone, but especially with the onset of the Holocene and the Holocene Climatic Optimum. Earthquake triggering is less probable, as the Tatra Mts. lack significant modern and historic seismic activity and there is no geomorphic evidence of fault offsets on the Late Quaternary landforms. In concert with other recent studies, we propose that large rock slope failures in high mountains seldom react immediately to glacier withdrawal, but could display temporal delay lasting up to several millennia. (C) 2017 Elsevier Ltd. All rights reserved.
Pavel Mentlik - One of the best experts on this subject based on the ideXlab platform.
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Late Quaternary sackungen in the highest mountains of the Carpathians
Quaternary Science Reviews, 2017Co-Authors: Tomas Panek, Pavel Mentlik, Zbynek Engel, Régis Braucher, Albert Zondervan, A.s.t.e.r. TeamAbstract:Sackungen represents a common mode of deep-seated rock-slope failures in alpine landscapes, but proof of their temporal and causal relationship to extrinsic factors such as climatic changes, glacier retreat or seismic activity remains elusive. Based on the terrestrial cosmogenic nuclide (TCN) dating of 18 sackung scarps supported by one radiocarbon-dated scarp, we reconstructed the post-glacial chronology of sackungen in the Tatra Mts. (central Europe, Slovakia and Poland), the highest part of the Carpathians. The obtained ages (-15.7-4.3 ka) indicate that sackungen post-date the regional LGM and some of them originated soon after the glacier withdrawal from adjacent valleys. Furthermore, systematic decrease of scarp ages with their increasing altitude suggests a direct link between sackung origin and post-LGM glacier thinning. However, substantial lag (>5 ka) of some sackungen in respect to glacier retreat implies complex relationships between sackung onset and deglaciation where retreat of glaciers acted predominantly as a preparatory, not a triggering factor during the genesis of these slope deformations. They originated either as a Consequence of Stress relaxation within the rock mass lasting several ka or alternatively could be triggered by climatic processes or seismicity. Indeed, a significant part of sackung activity took place during predominantly warmer and more humid periods, with some dates coinciding with the Belling-Allerod chronozone, but especially with the onset of the Holocene and the Holocene Climatic Optimum. Earthquake triggering is less probable, as the Tatra Mts. lack significant modern and historic seismic activity and there is no geomorphic evidence of fault offsets on the Late Quaternary landforms. In concert with other recent studies, we propose that large rock slope failures in high mountains seldom react immediately to glacier withdrawal, but could display temporal delay lasting up to several millennia. (C) 2017 Elsevier Ltd. All rights reserved.