scholarly journals Stagnation and mass loss on a Himalayan debris-covered glacier: processes, patterns and rates

2016 ◽  
Vol 62 (233) ◽  
pp. 467-485 ◽  
Author(s):  
SARAH THOMPSON ◽  
DOUGLAS I. BENN ◽  
JORDAN MERTES ◽  
ADRIAN LUCKMAN
Keyword(s):  
Mass Loss ◽  
Predictive Models ◽  
Rapid Expansion ◽  
Local Ablation ◽  
Sediment Redistribution ◽  
Reduction Of Area ◽  
Topographic Inversion ◽  
Near Future ◽  
Level Lowering ◽  
Area And Volume

ABSTRACTThe ablation areas of debris-covered glaciers typically consist of a complex mosaic of surface features with contrasting processes and rates of mass loss. This greatly complicates glacier response to climate change, and increases the uncertainty of predictive models. In this paper we present a series of high-resolution DEMs and repeat lake bathymetric surveys on Ngozumpa Glacier, Nepal, to study processes and patterns of mass loss on a Himalayan debris-covered glacier in unprecedented detail. Most mass loss occurs by melt below supraglacial debris, and melt and calving of ice cliffs (backwasting). Although ice cliffs cover only ~5% of the area of the lower tongue, they account for 40% of the ablation. The surface debris layer is subject to frequent re-distribution by slope processes, resulting in large spatial and temporal differences in debris-layer thickness, enhancing or inhibiting local ablation rates and encouraging continuous topographic inversion. A moraine-dammed lake on the lower glacier tongue (Spillway Lake) underwent a period of rapid expansion from 2001 to 2009, but later experienced a reduction of area and volume as a result of lake level lowering and sediment redistribution. Rapid lake growth will likely resume in the near future, and may eventually become up to 7 km long.

scholarly journals Recent and Future Studies of Circumstellar Matter – A Snapshot

1999 ◽  
Vol 191 ◽  
pp. 603-610
Author(s):  
M. Jura
Keyword(s):  
Mass Loss ◽  
Theoretical Models ◽  
Circumstellar Matter ◽  
Agb Stars ◽  
Future Studies ◽  
Instruments And Techniques ◽  
Near Future ◽  
New Instruments ◽  
Loss Mechanisms

At this meeting, powerful new images and spectroscopy of AGB stars were presented. Theoretical models have advanced, and we are learning more from studies of the pre-solar grains isolated from meteorites.We suggest that several mass loss mechanisms may be operating in AGB stars: current images imply both spherical winds and highly flattened outflows. There are good arguments that in some cases, a companion may be critical in driving the final outflow. In the near future, a number of extremely powerful new instruments and techniques will be available that will lead to a much deeper understanding of these systems.

scholarly journals Spectral Diagnoses of Chromospheres and Winds in A-Type Stars

1993 ◽  
Vol 138 ◽  
pp. 517-527 ◽  
Author(s):  
Thierry Lanz ◽  
Ivan Hubeny
Keyword(s):  
Mass Loss ◽  
Main Sequence ◽  
Stellar Winds ◽  
X Ray ◽  
Upper Limits ◽  
Radiative Diffusion ◽  
Increased Sensitivity ◽  
Chemical Anomalies ◽  
Set Up ◽  
Near Future

AbstractSo far, neither chromospheres nor stellar winds have been directly detected in main-sequence A stars. While radiative diffusion requires extremely weak stellar winds to reproduce chemical anomalies (10−15 to 10−12M⊙yr−1), two independent direct searches for mass loss set up upper limits to 10−10 M⊙yr−1, which is still several orders of magnitude higher. We discuss some new recent possibilities to detect chromospheres which arise thanks to new NLTE model atmospheres. In the near future, some progress is also expected from new observations of Lyman α with HST and from the increased sensitivity of ROSAT in the X-ray domain.

scholarly journals Digital Preservation for the Individuals

2019 ◽  
Vol 3 (2) ◽  
pp. 7-9
Author(s):  
Spiros Zervos ◽  
Eftichia Vraimaki
Keyword(s):  
Mass Loss ◽  
Web Service ◽  
General Public ◽  
Digital Preservation ◽  
The Public ◽  
Long Period ◽  
Near Future ◽  
Digital Assets

Purpose - This is a concept paper highlighting the most important points pertaining to the development of a web service for the preservation of the digital assets of individuals.Design/methodology/approach - A commercial web service aimed at the general public for the preservation of their digital assets is outlined. It encompasses the ability to legitimately bequeath one’s digital assets to another individual in case of death or inability, and ensures the preservation and accessibility of the digital files and their metadata for a given (long) period of time, by applying the principles of digital preservation, as described by OAIS. The development and scientific challenges of this endeavor are also briefly discussed.Originality/value - The project responds to a real contemporary public need, and offers a service which will become highly relevant in the near future. The lacking of such a service will very soon be painfully felt by the public, with the mass loss and depreciation of their personal digital assets.

scholarly journals Applications of Machine Learning Predictive Models in the Chronic Disease Diagnosis

2020 ◽  
Vol 10 (2) ◽  
pp. 21 ◽  
Author(s):  
Gopi Battineni ◽  
Getu Gamo Sagaro ◽  
Nalini Chinatalapudi ◽  
Francesco Amenta
Keyword(s):  
Machine Learning ◽  
Chronic Diseases ◽  
Predictive Models ◽  
Disease Diagnosis ◽  
Primary Diagnosis ◽  
Support Vector ◽  
Advantages And Disadvantages ◽  
Vector Machines ◽  
Applications Of Machine Learning ◽  
Near Future

This paper reviews applications of machine learning (ML) predictive models in the diagnosis of chronic diseases. Chronic diseases (CDs) are responsible for a major portion of global health costs. Patients who suffer from these diseases need lifelong treatment. Nowadays, predictive models are frequently applied in the diagnosis and forecasting of these diseases. In this study, we reviewed the state-of-the-art approaches that encompass ML models in the primary diagnosis of CD. This analysis covers 453 papers published between 2015 and 2019, and our document search was conducted from PubMed (Medline), and Cumulative Index to Nursing and Allied Health Literature (CINAHL) libraries. Ultimately, 22 studies were selected to present all modeling methods in a precise way that explains CD diagnosis and usage models of individual pathologies with associated strengths and limitations. Our outcomes suggest that there are no standard methods to determine the best approach in real-time clinical practice since each method has its advantages and disadvantages. Among the methods considered, support vector machines (SVM), logistic regression (LR), clustering were the most commonly used. These models are highly applicable in classification, and diagnosis of CD and are expected to become more important in medical practice in the near future.

scholarly journals Longbasaba Glacier recession and contribution to its proglacial lake volume between 1988 and 2018

2021 ◽  
pp. 1-12
Author(s):  
Junfeng Wei ◽  
Shiyin Liu ◽  
Xin Wang ◽  
Yong Zhang ◽  
Zongli Jiang ◽  
...  
Keyword(s):  
Mass Loss ◽  
Total Mass ◽  
Water Volume ◽  
Total Mass Loss ◽  
Lake Volume ◽  
Glacier Recession ◽  
Proglacial Lakes ◽  
Proglacial Lake ◽  
Near Future ◽  
The Himalaya

Abstract During the last few decades, the lake-terminating glaciers in the Himalaya have receded faster than the land-terminating glaciers as proglacial lakes have exacerbated the mass loss of their host glaciers. Monitoring the impacts of glacier recession and dynamics on lake extent and water volume provides an approach to assess the mass interplay between glaciers and proglacial lakes. We describe the recession of Longbasaba Glacier and estimate the mass wastage and its contribution to the water volume of its proglacial lake. The results show that the glacier area has decreased by 3% during 1988–2018, with a more variable recession prior to 2008 than in the last decade. Longbasaba Lake has expanded by 164% in area and 237% in water volume, primarily as a result of meltwater inflow produced from surface lowering of the glacier. Over the periods 1988–2000 and 2000–18, the mass loss contributed by glacier thinning has decreased from 81 to 61% of the total mass loss, accompanied by a nearly doubled contribution from terminus retreat. With the current rate of retreat, Longbasaba glacier is expected to terminate in its proglacial lake for another four decades. The hazard risk of this lake is expected to continue to increase in the near future because of the projected continued glacier mass loss and related lake expansion.

Lymphopenia in the COVID-19 Patient: More than a Predictor of Poor Prognosis?

2021 ◽  
Vol 53 (01) ◽  
pp. 96-103
Author(s):  
Julián Rondón-Carvajal ◽  
Keyword(s):  
Predictive Models ◽  
Poor Prognosis ◽  
Infectious Agent ◽  
Absolute Lymphocyte Count ◽  
Rapid Expansion ◽  
Current Evidence ◽  
Laboratory Findings ◽  
Disease Biomarker ◽  
The World ◽  
Review Current

The COVID-19 pandemic, caused by the infectious agent SARS-CoV-2, has claimed the life of thousands of people around the world following its rapid expansion from Wuhan, China, in early January 2020. Since then, multiple groups worldwide have attempted to describe predictive models for adverse clinical outcomes in patients affected by this disease. Within laboratory findings, the first Chinese cohorts described an inverse relationship between the absolute lymphocyte count and disease severity, and about 80% of severe patients exhibited lymphopenia. However, there are discrepancies regarding the predictive value of this clinical manifestation, as well as in the pathophysiological mechanisms involved. Here, we review current evidence regarding lymphopenia in patients with COVID-19, and the potential utility of this hematological finding as a disease biomarker.

scholarly journals A Data Mining-based Cross-Industry Process for Predicting Major Bleeding in Mechanical Circulatory Support

2021 ◽  
Author(s):  
S E A Felix ◽  
A Bagheri ◽  
F R Ramjankhan ◽  
M R Spruit ◽  
D Oberski ◽  
...  
Keyword(s):  
Data Mining ◽  
Major Bleeding ◽  
Predictive Models ◽  
Mechanical Circulatory Support ◽  
Predictive Analytics ◽  
Area Under The Curve ◽  
Circulatory Support ◽  
Contributing Factors ◽  
Using Data ◽  
Near Future

Abstract Background Over a third of patients, treated with mechanical circulatory support (MCS) for end-stage heart failure, experience major bleeding. Currently, the prediction of a major bleeding in the near future is difficult because of many contributing factors. Objectives Predictive analytics using data mining could help calculating the risk of bleeding, however its application is generally reserved for experienced researchers on this subject. We propose an easy applicable data mining tool to predict major bleeding in MCS patients. Methods All data of electronic health records of MCS patients in the University Medical Centre Utrecht were included. Based on the cross-industry standard process for data mining (CRISP-DM) methodology, an application named Auto-Crisp was developed. Auto-Crisp was used to evaluate the predictive models for a major bleeding in the next 3, 7 and 30 days after the first 30 days postoperatively following MCS implantation. The performance of the predictive models are investigated by the area under the curve (AUC) evaluation measure. Results In 25.6% of 273 patients, a total of 142 major bleedings occurred during a median follow-up period of 542 (IQR 205–1044) days. The best predictive models assessed by Auto-Crisp had AUC values of 0.792, 0.788, and 0.776 for bleedings in the next 3, 7, and 30 days, respectively. Conclusion The Auto-Crisp-based predictive model created in this study had an acceptable performance to predict major bleeding in MCS patients in the near future. However, further validation of the application is needed to evaluate Auto-Crisp in other research projects.

scholarly journals Identification of glacier motion and potentially dangerous glacial lakes in the Mt. Everest region/Nepal using spaceborne imagery

2008 ◽  
Vol 8 (6) ◽  
pp. 1329-1340 ◽  
Author(s):  
T. Bolch ◽  
M. F. Buchroithner ◽  
J. Peters ◽  
M. Baessler ◽  
S. Bajracharya
Keyword(s):  
Surface Velocity ◽  
Glacial Lakes ◽  
Movement Rates ◽  
Lake Development ◽  
Outburst Floods ◽  
Glacier Velocity ◽  
Near Future ◽  
Glacier Motion ◽  
Area And Volume ◽  
Additional Interpretation

Abstract. Failures of glacial lake dams can cause outburst floods and represents a serious hazard. The potential danger of outburst floods depends on various factors like the lake's area and volume, glacier change, morphometry of the glacier and its surrounding moraines and valley, and glacier velocity. Remote sensing offers an efficient tool for displacement calculations and risk assessment of the identification of potentially dangerous glacial lakes (PDGLs) and is especially helpful for remote mountainous areas. Not all important parameters can, however, be obtained using spaceborne imagery. Additional interpretation by an expert is required. ASTER data has a suitable accuracy to calculate surface velocity. Ikonos data offers more detail but requires more effort for rectification. All investigated debris-covered glacier tongues show areas with no or very slow movement rates. From 1962 to 2003 the number and area of glacial lakes increased, dominated by the occurrence and almost linear areal expansion of the moraine-dammed lakes, like the Imja Lake. Although the Imja Lake will probably still grow in the near future, the risk of an outburst flood (GLOF) is considered not higher than for other glacial lakes in the area. Potentially dangerous lakes and areas of lake development are identified. There is a high probability of further lake development at Khumbu Glacier, but a low one at Lhotse Glacier.

Identifying the the key factors of uncertainty in Helheim Glacier’s response to climate change

2020 ◽  
Author(s):  
Mathieu Morlighem ◽  
Doug Brinkerhoff
Keyword(s):  
Mass Loss ◽  
Model Parameters ◽  
Key Factors ◽  
Large Ensemble ◽  
The Third ◽  
Main Effect ◽  
Error Bars ◽  
Constrained Model ◽  
Near Future ◽  
Ensemble Of Simulations

<p>Helheim Glacier is one of the largest glaciers in Greenland and, despite its importance, remains poorly understood. While this glacier has been relatively stable in the 1980s and 1990s, its terminus retreated dramatically by 6 km between 2001 and 2005. By 2006, the glacier stopped thinning, slowed down, and re-advanced 4 km and has been stable since 2007. Helheim is today the third fastest glacier of Greenland, reaching speeds >7 km/a, and drains a surface area of 50,000 km<sup>2</sup>. It is not clear how this glacier will change over the coming century and if another episode of exceptional retreat will occur in the very near future. We construct here a large ensemble of simulations of Helheim glacier over the next century, using a numerical model that includes a dynamic ice front forced by oceanic and atmospheric scenarios. This large ensemble allows to quantify the uncertainty in future retreat and mass loss, and also to attribute the fraction of mass loss uncertainty due to poorly constrained model parameters using main-effect Sobol indices for each input variable. This work helps determine the processes that affect projections the most and provide error bars on model projections.</p>

scholarly journals Decay of a long-term monitored glacier: the Careser glacier (Ortles-Cevedale, European Alps)

2013 ◽  
Vol 7 (4) ◽  
pp. 3293-3335 ◽  
Author(s):  
L. Carturan ◽  
C. Baroni ◽  
M. Becker ◽  
A. Bellin ◽  
O. Cainelli ◽  
...  
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
European Alps ◽  
Systematic Observation ◽  
Average Mass ◽  
Observation Series ◽  
Area And Volume

Abstract. The continuation of valuable, long-term glacier observation series is threatened by the accelerated mass loss which currently affects a large portion of so-called "benchmark" glaciers. In this work we present the evolution of the Careser glacier, from the beginning of systematic observation at the end of the nineteenth century to its current condition in 2012. In addition to having one of the longest and richest observation record among the Italian glaciers, Careser is unique in the Italian Alps for its 45 yr mass balance series started in 1967. In the present study, variations in the length, area and volume of the glacier since 1897 are examined, updating the series of direct mass balance observations and extending it into the past using the geodetic method. The glacier is currently strongly out of balance and in rapid decay; its average mass loss rate over the last three decades was −1.5 m water equivalent per year, increasing to −2.0 m water equivalent per year in the last decade. If mass loss continues at this pace, the glacier will disappear within a few decades, putting an end to this unique observation series.

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