Characterization and Dynamic Analysis of the Devils Castle Rock Avalanche, Alta, Utah

2020 ◽  
Vol 26 (2) ◽  
pp. 201-215 ◽  
Author(s):  
Patricia Pedersen ◽  
Jeffrey R. Moore ◽  
Brendon J. Quirk ◽  
Richard E. Giraud ◽  
Greg N. Mcdonald
Keyword(s):  
Case History ◽  
Large Scale ◽  
Rock Avalanche ◽  
High Mobility ◽  
Individual Case ◽  
Source Model ◽  
Mass Movements ◽  
Potential Hazard ◽  
Exposure Dating ◽  
Wasatch Mountains

ABSTRACT Rock avalanches are large-magnitude mass movements with high mobility and fluid-like runout; however, because of their scarcity, little information is typically available to describe the hazard posed by these events. Geologic records thus provide key data regarding rock avalanche size, timing, and dynamics. Here we present a detailed case history analysis of the Devils Castle rock avalanche located near the town of Alta in the Wasatch Mountains of Utah. The deposit is ∼1.5 km in length with a Fahrboeschung angle of 14 degrees (height-to-length ratio = 0.25). Through topographic reconstruction, we calculated a deposit volume of 1.7 million m3 with a maximum thickness of 25 m and an average thickness of 7 m. Cosmogenic surface exposure dating of six deposit boulders indicates a failure age of 14.4 ± 1.0 ka. The Devils Castle headwall displays no obvious evidence indicating precise source location and geometry; therefore, we reconstructed two plausible source volumes and performed numerical runout simulations for each. Results agree well with mapped deposit boundaries for both source scenarios; however, the east source model better represents material and dynamic characteristics of the deposit observed in the field. While the region is seismically active, the Late Pleistocene age for the rock avalanche precludes ascribing direct correlation with any currently known surface-rupturing paleoearthquakes. We identified and describe five similar events in the region highlighting the extent of the potential hazard. Individual case history analyses such as this allow us to better understand the processes and controls of large-scale mass movements in the region.

scholarly journals Metastable Intermediates as Stepping Stones on the Maturation Pathways of Viral Capsids

mBio ◽  
2014 ◽  
Vol 5 (6) ◽  
Author(s):  
Giovanni Cardone ◽  
Robert L. Duda ◽  
Naiqian Cheng ◽  
Lili You ◽  
James F. Conway ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Large Scale ◽  
Structural Changes ◽  
Energy Landscape ◽  
Potential Hazard ◽  
Stepping Stones ◽  
Scanning Calorimetry ◽  
Conformational Effects ◽  
Capsid Maturation ◽  
Capsid Integrity

ABSTRACT As they mature, many capsids undergo massive conformational changes that transform their stability, reactivity, and capacity for DNA. In some cases, maturation proceeds via one or more intermediate states. These structures represent local minima in a rich energy landscape that combines contributions from subunit folding, association of subunits into capsomers, and intercapsomer interactions. We have used scanning calorimetry and cryo-electron microscopy to explore the range of capsid conformations accessible to bacteriophage HK97. To separate conformational effects from those associated with covalent cross-linking (a stabilization mechanism of HK97), a cross-link-incompetent mutant was used. The mature capsid Head I undergoes an endothermic phase transition at 60°C in which it shrinks by 7%, primarily through changes in its hexamer conformation. The transition is reversible, with a half-life of ~3 min; however, >50% of reverted capsids are severely distorted or ruptured. This observation implies that such damage is a potential hazard of large-scale structural changes such as those involved in maturation. Assuming that the risk is lower for smaller changes, this suggests a rationalization for the existence of metastable intermediates: that they serve as stepping stones that preserve capsid integrity as it switches between the radically different conformations of its precursor and mature states. IMPORTANCE Large-scale conformational changes are widespread in virus maturation and infection processes. These changes are accompanied by the release of conformational free energy as the virion (or fusogenic glycoprotein) switches from a precursor state to its mature state. Each state corresponds to a local minimum in an energy landscape. The conformational changes in capsid maturation are so radical that the question arises of how maturing capsids avoid being torn apart. Offering proof of principle, severe damage is inflicted when a bacteriophage HK97 capsid reverts from the (nonphysiological) state that it enters when heated past 60°C. We suggest that capsid proteins have been selected in part by the criterion of being able to avoid sustaining collateral damage as they mature. One way of achieving this—as with the HK97 capsid—involves breaking the overall transition down into several smaller steps in which the risk of damage is reduced.

scholarly journals Comparison Between Pressure Swing Adsorption and Liquid Oxygen Enrichment Techniques in the Atacama Large Millimeter/Submillimeter Array Facility at the Chajnantor Plateau (5,050 m)

2021 ◽  
Vol 12 ◽  
Author(s):  
Ivan Lopez ◽  
Reinaldo Aravena ◽  
Daniel Soza ◽  
Alicia Morales ◽  
Silvia Riquelme ◽  
...  
Keyword(s):  
High Altitude ◽  
Pressure Swing Adsorption ◽  
Large Scale ◽  
High Mobility ◽  
Oxygen Enrichment ◽  
Oxygen Availability ◽  
Liquid Oxygen ◽  
High Altitudes ◽  
Pressure Swing ◽  
Very High

The Chilean workforce has over 200,000 people that are intermittently exposed to altitudes over 4,000 m. In 2012, the Ministry of Health provided a technical guide for high-altitude workers that included a series of actions to mitigate the effects of hypoxia. Previous studies have shown the positive effect of oxygen enrichment at high altitudes. The Atacama Large Millimeter/submillimeter Array (ALMA) radiotelescope operates at 5,050 m [Array Operations Site (AOS)] and is the only place in the world where pressure swing adsorption (PSA) and liquid oxygen technologies have been installed at a large scale. These technologies reduce the equivalent altitude by increasing oxygen availability. This study aims to perform a retrospective comparison between the use of both technologies during operation in ALMA at 5,050 m. In each condition, variables such as oxygen (O2), temperature, and humidity were continuously recorded in each AOS rooms, and cardiorespiratory variables were registered. In addition, we compared portable O2 by using continuous or demand flow during outdoor activities at very high altitudes. The outcomes showed no differences between production procedures (PSA or liquid oxygen) in regulating oxygen availability at AOS facilities. As a result, big-scale installations have difficulties reaching the appropriate O2 concentration due to leaks in high mobility areas. In addition, the PSA plant requires adequacy and maintenance to operate at a very high altitude. A continuous flow of 2–3 l/min of portable O2 is recommended at 5,050 m.

scholarly journals Usage and Scaling of an Open-Source Spiking Multi-Area Model of Monkey Cortex

2021 ◽  
pp. 47-59
Author(s):  
Sacha J. van Albada ◽  
Jari Pronold ◽  
Alexander van Meegen ◽  
Markus Diesmann
Keyword(s):  
Open Source ◽  
Large Scale ◽  
Network Models ◽  
Macaque Monkey ◽  
Source Model ◽  
Model Specification ◽  
Data Sets ◽  
Neural Network Models ◽  
Wide Range ◽  
Ict Infrastructure

AbstractWe are entering an age of ‘big’ computational neuroscience, in which neural network models are increasing in size and in numbers of underlying data sets. Consolidating the zoo of models into large-scale models simultaneously consistent with a wide range of data is only possible through the effort of large teams, which can be spread across multiple research institutions. To ensure that computational neuroscientists can build on each other’s work, it is important to make models publicly available as well-documented code. This chapter describes such an open-source model, which relates the connectivity structure of all vision-related cortical areas of the macaque monkey with their resting-state dynamics. We give a brief overview of how to use the executable model specification, which employs NEST as simulation engine, and show its runtime scaling. The solutions found serve as an example for organizing the workflow of future models from the raw experimental data to the visualization of the results, expose the challenges, and give guidance for the construction of an ICT infrastructure for neuroscience.

scholarly journals Unsupervised Domain Adaptation by Statistics Alignment for Deep Sleep Staging Networks

2021 ◽  
Author(s):  
Jiahao Fan ◽  
Hangyu Zhu ◽  
Xinyu Jiang ◽  
Long Meng ◽  
Cong Fu ◽  
...  
Keyword(s):  
Large Scale ◽  
Domain Adaptation ◽  
Source Model ◽  
Deep Sleep ◽  
Sleep Staging ◽  
Target Domain ◽  
Source Domain ◽  
Unsupervised Domain Adaptation ◽  
Generalization Problem ◽  
Source Models

Deep sleep staging networks have reached top performance on large-scale datasets. However, these models perform poorer when training and testing on small sleep cohorts due to data inefficiency. Transferring well-trained models from large-scale datasets (source domain) to small sleep cohorts (target domain) is a promising solution but still remains challenging due to the domain-shift issue. In this work, an unsupervised domain adaptation approach, domain statistics alignment (DSA), is developed to bridge the gap between the data distribution of source and target domains. DSA adapts the source models on the target domain by modulating the domain-specific statistics of deep features stored in the Batch Normalization (BN) layers. Furthermore, we have extended DSA by introducing cross-domain statistics in each BN layer to perform DSA adaptively (AdaDSA). The proposed methods merely need the well-trained source model without access to the source data, which may be proprietary and inaccessible. DSA and AdaDSA are universally applicable to various deep sleep staging networks that have BN layers. We have validated the proposed methods by extensive experiments on two state-of-the-art deep sleep staging networks, DeepSleepNet+ and U-time. The performance was evaluated by conducting various transfer tasks on six sleep databases, including two large-scale databases, MASS and SHHS, as the source domain, four small sleep databases as the target domain. Thereinto, clinical sleep records acquired in Huashan Hospital, Shanghai, were used. The results show that both DSA and AdaDSA could significantly improve the performance of source models on target domains, providing novel insights into the domain generalization problem in sleep staging tasks.<br>

Large-scale lateral spreading and related mass movements in the Northern Calcareous Alps

2004 ◽  
Vol 63 (1) ◽  
pp. 71-75 ◽  
Author(s):  
J. Rohn ◽  
M. Resch ◽  
H. Schneider ◽  
T. M. Fernandez-Steeger ◽  
K. Czurda
Keyword(s):  
Large Scale ◽  
Lateral Spreading ◽  
Northern Calcareous Alps ◽  
Mass Movements ◽  
Northern Calcareous

scholarly journals Why Earthquakes Threaten Two Major European Cities: Istanbul and Bucharest

2017 ◽  
Vol 26 (1) ◽  
pp. 30-49 ◽  
Author(s):  
Gregory A. Houseman
Keyword(s):  
Upper Mantle ◽  
Large Scale ◽  
Mass Movements ◽  
European Continent ◽  
European Cities ◽  
The North ◽  
Two Cities ◽  
The City ◽  
Large Earthquakes ◽  
Better Than

Istanbul and Bucharest are major European cities that face a continuing threat of large earthquakes. The geological contexts for these two case studies enable us to understand the nature of the threat and to predict more precisely the consequences of future earthquakes, although we remain unable to predict the time of those events with any precision better than multi-decadal. These two cities face contrasting threats: Istanbul is located on a major geological boundary, the North Anatolian Fault, which separates a westward moving Anatolia from the stable European landmass. Bucharest is located within the stable European continent, but large-scale mass movements in the upper mantle beneath the lithosphere cause relatively frequent large earthquakes that represent a serious threat to the city and surrounding regions.

scholarly journals Surface Exposure Dating and Geophysical Tomography of the Royal Arches Meadow Rock Avalanche, Yosemite Valley, California

2020 ◽  
Vol 8 ◽  
Author(s):  
Marcus Pacheco ◽  
Alain M. Plattner ◽  
Greg M. Stock ◽  
Dylan H. Rood ◽  
Christopher J. Pluhar
Keyword(s):  
Rock Avalanche ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Yosemite Valley ◽  
Geophysical Tomography

scholarly journals Anisotropic source modelling for turbulent jet noise prediction

2019 ◽  
Vol 377 (2159) ◽  
pp. 20190075 ◽  
Author(s):  
Xihai Xu ◽  
Xiaodong Li
Keyword(s):  
Large Scale ◽  
Noise Source ◽  
Jet Noise ◽  
Source Model ◽  
Noise Prediction ◽  
Reynolds Stresses ◽  
Acoustic Analogy ◽  
Mean Flow ◽  
Navier Stokes Equation ◽  
Anisotropic Source

An anisotropic component of the jet noise source model for the Reynolds-averaged Navier–Stokes equation-based jet noise prediction method is proposed. The modelling is based on Goldstein's generalized acoustic analogy, and both the fine-scale and large-scale turbulent noise sources are considered. To model the anisotropic characteristics of jet noise source, the Reynolds stress tensor is used in place of the turbulent kinetic energy. The Launder–Reece–Rodi model (LRR), combined with Menter's ω -equation for the length scale, with modified coefficients developed by the present authors, is used to calculate the mean flow velocities and Reynolds stresses accurately. Comparison between predicted results and acoustic data has been carried out to verify the accuracy of the new anisotropic source model. This article is part of the theme issue ‘Frontiers of aeroacoustics research: theory, computation and experiment’.

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