143 research outputs found
Sustaining permafrost observations: priorities and needs of the Global Terrestrial Network for Permafrost (GTN-P)
The Global Terrestrial Network for Permafrost (GTN-P) is the primary international
programme concerned with sustained long-term monitoring of permafrost. GTN-P was
developed in the 1990s by the International Permafrost Association (IPA) under the Global
Terrestrial Observing System (GTOS) as part of the Global Climate Observing System (GCOS).
The two major components of GTN-P (Essential Climate Variables) are: (a) long-term
monitoring of the thermal state of permafrost in an extensive borehole network, the Thermal
State of Permafrost - TSP; and (b) monitoring of the Active-layer thickness - ALT. Long-term
monitoring of permafrost generates essential baseline information for the assessment of climate
change impacts in polar and high mountain regions
GTN-P - Strategy and Implementation Plan 2016-2020
Permafrost is recognized as Essential Climate Variable (ECV) within the Global Climate Observing System of UN and ICSU organisations. The Global Terrestrial Network for Permafrost (GTN-P) is the primary international programme concerned with long-term monitoring of permafrost. The core mission of the GTN-P is sustained comprehensive long-term monitoring network, in order to provide consistent, representative and high quality standardized long-term data series of selected permafrost parameters at key sites and to assess their state and changes over time. The Strategy and Implementation Plan 2016-2020 outlines recent progress and future challenges facing the network. It describes the governance and management structure of GTN-P, linkages to regional and global observing systems, management process and reporting strategies. It presents measurement methods and protocols used in field data collection and state of the art data management system, which was recently designed and implemented to process, analyse, and visualize permafrost data. It concludes with the outlook of the future developments of the network in order to sustain and succeed its core mission of providing long-term observations and maintain the availability of data collected
The state of the Martian climate
60°N was +2.0°C, relative to the 1981â2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
Potential climatic transitions with profound impact on Europe
We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the âtippingâ potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding. <br/
The relationship between cardiac and liver iron evaluated by MR imaging in haematological malignancies and chronic liver disease
Although iron overload is clinically significant, only limited data have been published on iron overload in haematological diseases. We investigated cardiac and liver iron accumulation by magnetic resonance imaging (MRI) in a cohort of 87 subjects who did not receive chelation, including 59 haematological patients. M-HIC (MRI-based hepatic iron concentration, normal values <36âÎŒmol/g) is a non-invasive, liver biopsy-calibrated method to analyse iron concentration. This method, calibrated to R2 (transverse relaxation rate), was used as a reference standard (M-HIC(R2)). Transfusions and ferritin were evaluated. Mean M-HIC(R2) and cardiac R* of all patients were 142âÎŒmol/g (95% CI, 114â170) and 36.4â1/s (95% CI, 34.2â38.5), respectively. M-HIC(R2) was higher in haematological patients than in patients with chronic liver disease or normal controls (P<0.001). Clearly elevated cardiac R2* was found in two myelodysplastic syndrome (MDS) patients with severe liver iron overload. A poor correlation was found between liver and cardiac iron (n=82, r=0.322, P=0.003), in contrast to a stronger correlation in MDS (n=7, r=0.905, P=0.005). In addition to transfusions, MDS seemed to be an independent factor in iron accumulation. In conclusion, the risk for cardiac iron overload in haematological diseases other than MDS is very low, despite the frequently found liver iron overload
Permafrost is warming at a global scale
Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007-2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39â±â0.15â°C. Over the same period, discontinuous permafrost warmed by 0.20â±â0.10â°C. Permafrost in mountains warmed by 0.19â±â0.05â°C and in Antarctica by 0.37â±â0.10â°C. Globally, permafrost temperature increased by 0.29â±â0.12â°C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged
The efficacy of iron chelator regimes in reducing cardiac and hepatic iron in patients with thalassaemia major: a clinical observational study
<p>Abstract</p> <p>Background</p> <p>Available iron chelation regimes in thalassaemia may achieve different changes in cardiac and hepatic iron as assessed by MR. The aim of this study was to assess the efficacy of four available iron chelator regimes in 232 thalassaemia major patients by assessing the rate of change in repeated measurements of cardiac and hepatic MR.</p> <p>Results</p> <p>For the heart, deferiprone and the combination of deferiprone and deferoxamine significantly reduced cardiac iron at all levels of iron loading. As patients were on deferasirox for a shorter time, a second analysis ("Initial interval analysis") assessing the change between the first two recorded MR results for both cardiac and hepatic iron (minimum interval 12 months) was made. Combination therapy achieved the most rapid fall in cardiac iron load at all levels and deferiprone alone was significantly effective with moderate and mild iron load. In the liver, deferasirox effected significant falls in iron load and combination therapy resulted in the most rapid decline.</p> <p>Conclusion</p> <p>With the knowledge of the efficacy of the different available regimes and the specific iron load in the heart and the liver, appropriate tailoring of chelation therapy should allow clearance of iron. Combination therapy is best in reducing both cardiac and hepatic iron, while monotherapy with deferiprone or deferasirox are effective in the heart and liver respectively. The outcomes of this study may be useful to physicians as to the chelation they should prescribe according to the levels of iron load found in the heart and liver by MR.</p
A massive rock and ice avalanche caused the 2021 disaster at Chamoli, Indian Himalaya
On 7 Feb 2021, a catastrophic mass flow descended the Ronti Gad, Rishiganga, and Dhauliganga valleys in Chamoli, Uttarakhand, India, causing widespread devastation and severely damaging two hydropower projects. Over 200 people were killed or are missing. Our analysis of satellite imagery, seismic records, numerical model results, and eyewitness videos reveals that ~27x106 m3 of rock and glacier ice collapsed from the steep north face of Ronti Peak. The rock and ice avalanche rapidly transformed into an extraordinarily large and mobile debris flow that transported boulders >20 m in diameter, and scoured the valley walls up to 220 m above the valley floor. The intersection of the hazard cascade with downvalley infrastructure resulted in a disaster, which highlights key questions about adequate monitoring and sustainable development in the Himalaya as well as other remote, high-mountain environments
The complex genetic landscape of familial MDS and AML reveals pathogenic germline variants.
The inclusion of familial myeloid malignancies as a separate disease entity in the revised WHO classification has renewed efforts to improve the recognition and management of this group of at risk individuals. Here we report a cohort of 86 acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) families with 49 harboring germline variants in 16 previously defined loci (57%). Whole exome sequencing in a further 37 uncharacterized families (43%) allowed us to rationalize 65 new candidate loci, including genes mutated in rare hematological syndromes (ADA, GP6, IL17RA, PRF1 and SEC23B), reported in prior MDS/AML or inherited bone marrow failure series (DNAH9, NAPRT1 and SH2B3) or variants at novel loci (DHX34) that appear specific to inherited forms of myeloid malignancies. Altogether, our series of MDS/AML families offer novel insights into the etiology of myeloid malignancies and provide a framework to prioritize variants for inclusion into routine diagnostics and patient management
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