scholarly journals Ice Cliff Dynamics of Debris-Covered Trakarding Glacier in the Rolwaling Region, Nepal Himalaya

2021 ◽  
Vol 9 ◽  
Author(s):  
Yota Sato ◽  
Koji Fujita ◽  
Hiroshi Inoue ◽  
Sojiro Sunako ◽  
Akiko Sakai ◽  
...  
Keyword(s):  
High Resolution ◽  
Mass Loss ◽  
Spatial Relationship ◽  
Remote Sensing Data ◽  
Water Drainage ◽  
Nepal Himalaya ◽  
Aerial Photogrammetry ◽  
Covered Area ◽  
Hydrological System

Ice cliffs can act as “hot spots” for melt on debris-covered glaciers and promote local glacier mass loss. Repeat high-resolution remote-sensing data are therefore required to monitor the role of ice cliff dynamics in glacier mass loss. Here we analyze high-resolution aerial photogrammetry data acquired during the 2007, 2018, and 2019 post-monsoon seasons to delineate and monitor the morphology, distribution, and temporal changes of the ice cliffs across the debris-covered Trakarding Glacier in the eastern Nepal Himalaya. We generate an ice cliff inventory from the 2018 and 2019 precise terrain data, with ice cliffs accounting for 4.7 and 6.1% of the debris-covered area, respectively. We observe large surface lowering (>2.0 m a−1) where there is a denser distribution of ice cliffs. We also track the survival, formation, and disappearance of ice cliffs from 2018 to 2019, and find that ∼15% of the total ice cliff area is replaced by new ice cliffs. Furthermore, we observe the overall predominance of northwest-facing ice cliffs, although we do observe spatial heterogeneities in the aspect variance of the ice cliffs (ice cliffs face in similar/various directions). Many new ice cliffs formed across the stagnant middle sections of the glacier, coincident with surface water drainage and englacial conduit intake observations. This spatial relationship between ice cliffs and the glacier hydrological system suggests that these englacial and supraglacial hydrological systems play a significant role in ice cliff formation.

scholarly journals Analyzing glacier retreat and mass balances using aerial and UAV photogrammetry in the Ötztal Alps, Austria

2021 ◽  
Vol 15 (8) ◽  
pp. 3699-3717
Author(s):  
Joschka Geissler ◽  
Christoph Mayer ◽  
Juilson Jubanski ◽  
Ulrich Münzer ◽  
Florian Siegert
Keyword(s):  
High Resolution ◽  
Mass Loss ◽  
Large Scale ◽  
Glacier Retreat ◽  
Aerial Images ◽  
Mass Balances ◽  
Ice Dynamics ◽  
Aerial Photogrammetry ◽  
Multi Temporal ◽  
Elevation Changes

Abstract. We use high-resolution aerial photogrammetry to investigate glacier retreat in great spatial and temporal detail in the Ötztal Alps, a heavily glacierized area in Austria. Long-term in situ glaciological observations are available for this region as well as a multitemporal time series of digital aerial images with a spatial resolution of 0.2 m acquired over a period of 9 years. Digital surface models (DSMs) are generated for the years 2009, 2015, and 2018. Using these, glacier retreat, extent, and surface elevation changes of all 23 glaciers in the region, including the Vernagtferner, are analyzed. Due to different acquisition dates of the large-scale photogrammetric surveys and the glaciological data, a correction is successfully applied using a designated unmanned aerial vehicle (UAV) survey across a major part of the Vernagtferner. The correction allows a comparison of the mass balances from geodetic and glaciological techniques – both quantitatively and spatially. The results show a clear increase in glacier mass loss for all glaciers in the region, including the Vernagtferner, over the last decade. Local deviations and processes, such as the influence of debris cover, crevasses, and ice dynamics on the mass balance of the Vernagtferner, are quantified. Since those local processes are not captured with the glaciological method, they underline the benefits of complementary geodetic surveying. The availability of high-resolution multi-temporal digital aerial imagery for most of the glaciers in the Alps provides opportunities for a more comprehensive and detailed analysis of climate-change-induced glacier retreat and mass loss.

Quantitative accuracy of serotonergic neurotrans-mission imaging with high-resolution 123I SPECT

2004 ◽  
Vol 43 (06) ◽  
pp. 185-189 ◽  
Author(s):  
J. T. Kuikka
Keyword(s):  
High Resolution ◽  
Scatter Correction ◽  
Region Of Interest ◽  
Binding Potential ◽  
Partial Volume ◽  
Therapeutic Drugs ◽  
Quantitative Accuracy ◽  
Critical Error ◽  
Statistical Noise

Summary Aim: Serotonin transporter (SERT) imaging can be used to study the role of regional abnormalities of neurotransmitter release in various mental disorders and to study the mechanism of action of therapeutic drugs or drugs’ abuse. We examine the quantitative accuracy and reproducibility that can be achieved with high-resolution SPECT of serotonergic neurotransmission. Method: Binding potential (BP) of 123I labeled tracer specific for midbrain SERT was assessed in 20 healthy persons. The effects of scatter, attenuation, partial volume, mis-registration and statistical noise were estimated using phantom and human studies. Results: Without any correction, BP was underestimated by 73%. The partial volume error was the major component in this underestimation whereas the most critical error for the reproducibility was misplacement of region of interest (ROI). Conclusion: The proper ROI registration, the use of the multiple head gamma camera with transmission based scatter correction introduce more relevant results. However, due to the small dimensions of the midbrain SERT structures and poor spatial resolution of SPECT, the improvement without the partial volume correction is not great enough to restore the estimate of BP to that of the true one.

Which is the role of dynamic high-resolution ultrasound (D-HRUS) in the assessment of plantar plate tears?

2008 ◽  
Vol 29 (S 1) ◽  
Author(s):  
LM Sconfienza ◽  
F Lacelli ◽  
G Grillo ◽  
G Serafini ◽  
G Garlaschi ◽  
...  
Keyword(s):  
High Resolution ◽  
Plantar Plate

High-Resolution CT in Paraquat Poisoning of the Lung: Role of Prognosis Prediction

1998 ◽  
Vol 38 (6) ◽  
pp. 1027
Author(s):  
Kyoung Suk Kim ◽  
Young Tong Kim ◽  
Eun Joo Kwon ◽  
Choung Sik Choi ◽  
Han Heag Im ◽  
...  
Keyword(s):  
High Resolution ◽  
Prognosis Prediction ◽  
High Resolution Ct ◽  
Paraquat Poisoning

Assessment of the national market demand for high-resolution remote sensing data

2002 ◽  
Vol 8 (1) ◽  
pp. 15-22
Author(s):  
V.N. Astapenko ◽  
◽  
Ye.I. Bushuev ◽  
V.P. Zubko ◽  
V.I. Ivanov ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Remote Sensing Data ◽  
Market Demand ◽  
Sensing Data ◽  
National Market

scholarly journals The Role of High-Resolution Analytical Techniques in the Development of Functional Foods

2021 ◽  
Vol 22 (6) ◽  
pp. 3220
Author(s):  
Álvaro Fernández-Ochoa ◽  
Francisco Javier Leyva-Jiménez ◽  
María De la Luz Cádiz-Gurrea ◽  
Sandra Pimentel-Moral ◽  
Antonio Segura-Carretero
Keyword(s):  
High Resolution ◽  
Functional Foods ◽  
Intervention Studies ◽  
Analytical Techniques ◽  
Nutritional Intervention ◽  
Bioactive Properties ◽  
Metabolic Reactions ◽  
Bioactive Potential ◽  
Endogenous Metabolites

The approaches based on high-resolution analytical techniques, such as nuclear magnetic resonance or mass spectrometry coupled to chromatographic techniques, have a determining role in several of the stages necessary for the development of functional foods. The analyses of botanical extracts rich in bioactive compounds is one of the fundamental steps in order to identify and quantify their phytochemical composition. However, the compounds characterized in the extracts are not always responsible for the bioactive properties because they generally undergo metabolic reactions before reaching the therapeutic targets. For this reason, analytical techniques are also applied to analyze biological samples to know the bioavailability, pharmacokinetics and/or metabolism of the compounds ingested by animal or human models in nutritional intervention studies. In addition, these studies have also been applied to determine changes of endogenous metabolites caused by prolonged intake of compounds with bioactive potential. This review aims to describe the main types and modes of application of high-resolution analytical techniques in all these steps for functional food development.

Sign in / Sign up

Export Citation Format

Share Document