Contemporaneously growing speleothems and their value to decipher in-cave processes

2021 ◽  
Author(s):  
Vanessa Skiba ◽  
Jens Fohlmeister
Keyword(s):  
Growth Rate ◽  
Isotopic Composition ◽  
Working Group ◽  
Calcite Precipitation ◽  
Climate Signal ◽  
Climate Conditions ◽  
Exchange Processes ◽  
Group Members ◽  
Version 2.0 ◽  
Rayleigh Process

<p>Speleothems have been developed to be valuable climate archives. Albeit much progress has been made to understand speleothem proxies, it remains difficult to differentiate between a direct climate signal and variations, which occurred due to in-cave processes like prior calcite precipitation, CO<sub>2</sub> degassing or C exchange between dissolved inorganic C-species and cave air CO<sub>2</sub>. Here, we analyse palaeoclimate proxies of contemporaneously growing speleothems, which were extracted from the SISALv2 database (Comas-Bru et al., 2020). We argue that differences in their stable O and C isotopic composition as well as in their growth rate can only arise by differences of drip site specific conditions as climate conditions for pairs of contemporaneously growing speleothems are similar. To better understand differences in the isotopic composition and growth rate of contemporaneously growing speleothems, we investigate the in-cave processes by applying a speleothem isotope and growth model. The model is based on a Rayleigh process, which includes CO<sub>2</sub> degassing and CaCO<sub>3</sub> precipitation, HCO<sub>3</sub><sup>-</sup> <—> H<sub>2</sub>O buffering as well as CO<sub>2</sub> exchange and is able to calculate growth rates. The model accounts for CaCO<sub>3</sub> deposition as prior calcite precipitation as well as CaCO<sub>3</sub> deposition at the speleothem. We find that C-exchange processes are necessary to explain the linked isotopic and growth rate differences in speleothems.</p><p> </p><p><strong>References</strong></p><p>Comas-Bru, L., Atsawawaranunt, K., Harrison, S., SISAL working group members (2020): SISAL (Speleothem Isotopes Synthesis and AnaLysis Working Group) database version 2.0. University Of Reading.</p>

scholarly journals StalGrowth—A Program to Estimate Speleothem Growth Rates and Seasonal Growth Variations

Geosciences ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 187
Author(s):  
Rolf Vieten ◽  
Francisco Hernandez
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Environmental Parameters ◽  
Ion Concentration ◽  
Radiometric Dating ◽  
Seasonal Growth ◽  
Climate Signal ◽  
Show Evidence ◽  
Cave Monitoring ◽  
Calcium Ion Concentration

Speleothems are one of the few archives which allow us to reconstruct the terrestrial paleoclimate and help us to understand the important climate dynamics in inhabited regions of our planet. Their time of growth can be precisely dated by radiometric techniques, but unfortunately seasonal radiometric dating resolution is so far not feasible. Numerous cave environmental monitoring studies show evidence for significant seasonal variations in parameters influencing carbonate deposition (calcium-ion concentration, cave air pCO2, drip rate and temperature). Variations in speleothem deposition rates need to be known in order to correctly decipher the climate signal stored in the speleothem archive. StalGrowth is the first software to quantify growth rates based on cave monitoring results, detect growth seasonality and estimate the seasonal growth bias. It quickly plots the predicted speleothem growth rate together with the influencing cave environmental parameters to identify which parameter(s) cause changes in speleothem growth rate, and it can also identify periods of no growth. This new program has been applied to multiannual cave monitoring studies in Austria, Gibraltar, Puerto Rico and Texas, and it has identified two cases of seasonal varying speleothem growth.

scholarly journals The Quest to solve the HL-LHC data access puzzle

2020 ◽  
Vol 245 ◽  
pp. 04027
Author(s):  
X. Espinal ◽  
S. Jezequel ◽  
M. Schulz ◽  
A. Sciabà ◽  
I. Vukotic ◽  
...  
Keyword(s):  
Data Storage ◽  
Working Group ◽  
Data Access ◽  
Current Data ◽  
Resource Needs ◽  
Lake Model ◽  
New Concepts ◽  
Depth Analysis ◽  
Group Members ◽  
The Impact

HL-LHC will confront the WLCG community with enormous data storage, management and access challenges. These are as much technical as economical. In the WLCG-DOMA Access working group, members of the experiments and site managers have explored different models for data access and storage strategies to reduce cost and complexity, taking into account the boundary conditions given by our community.Several of these scenarios have been evaluated quantitatively, such as the Data Lake model and incremental improvements of the current computing model with respect to resource needs, costs and operational complexity.To better understand these models in depth, analysis of traces of current data accesses and simulations of the impact of new concepts have been carried out. In parallel, evaluations of the required technologies took place. These were done in testbed and production environments at small and large scale.We will give an overview of the activities and results of the working group, describe the models and summarise the results of the technology evaluation focusing on the impact of storage consolidation in the form of Data Lakes, where the use of streaming caches has emerged as a successful approach to reduce the impact of latency and bandwidth limitation.We will describe the experience and evaluation of these approaches in different environments and usage scenarios. In addition we will present the results of the analysis and modelling efforts based on data access traces of the experiments.

scholarly journals Guidelines for Biobanking of Bone Marrow Adipose Tissue and Related Cell Types: Report of the Biobanking Working Group of the International Bone Marrow Adiposity Society

2021 ◽  
Vol 12 ◽  
Author(s):  
Stephanie Lucas ◽  
Michaela Tencerova ◽  
Benoit von der Weid ◽  
Thomas Levin Andersen ◽  
Camille Attané ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Adipose Tissue ◽  
Working Group ◽  
Cell Types ◽  
Bone Marrow Adipose Tissue ◽  
Marrow Adipose Tissue ◽  
Marrow Adiposity ◽  
Group Members ◽  
Number Of Publications ◽  
Different Sources

Over the last two decades, increased interest of scientists to study bone marrow adiposity (BMA) in relation to bone and adipose tissue physiology has expanded the number of publications using different sources of bone marrow adipose tissue (BMAT). However, each source of BMAT has its limitations in the number of downstream analyses for which it can be used. Based on this increased scientific demand, the International Bone Marrow Adiposity Society (BMAS) established a Biobanking Working Group to identify the challenges of biobanking for human BMA-related samples and to develop guidelines to advance establishment of biobanks for BMA research. BMA is a young, growing field with increased interest among many diverse scientific communities. These bring new perspectives and important biological questions on how to improve and build an international community with biobank databases that can be used and shared all over the world. However, to create internationally accessible biobanks, several practical and legislative issues must be addressed to create a general ethical protocol used in all institutes, to allow for exchange of biological material internationally. In this position paper, the BMAS Biobanking Working Group describes similarities and differences of patient information (PIF) and consent forms from different institutes and addresses a possibility to create uniform documents for BMA biobanking purposes. Further, based on discussion among Working Group members, we report an overview of the current isolation protocols for human bone marrow adipocytes (BMAds) and bone marrow stromal cells (BMSCs, formerly mesenchymal), highlighting the specific points crucial for effective isolation. Although we remain far from a unified BMAd isolation protocol and PIF, we have summarized all of these important aspects, which are needed to build a BMA biobank. In conclusion, we believe that harmonizing isolation protocols and PIF globally will help to build international collaborations and improve the quality and interpretation of BMA research outcomes.

The Effect of Surface Sublimation on the Snow Isotope Signal

2021 ◽  
Author(s):  
Sonja Wahl ◽  
Alexandra Zuhr ◽  
Maria Hörhold ◽  
Anne-Katrine Faber ◽  
Hans Christian Steen-Larsen
Keyword(s):  
Isotopic Composition ◽  
Climate Modeling ◽  
Ice Core ◽  
Greenland Ice Sheet ◽  
Layer By Layer ◽  
Climate Signal ◽  
North East ◽  
Depositional Processes ◽  
Surface Snow ◽  
Water Isotope

<p>Post-depositional processes affect the stable water isotope signal of surface snow between precipitation events. Combined vapor-snow exchange processes and isotope diffusion influence the top layer of snow as well as buried layers below. This implies, that ice core isotope climate proxy records can not be interpreted as a precipitation weighted temperature signal alone.</p><p>Here we present to what extend surface sublimation can explain in-situ observed changes of the stable water isotope signal in the snow.<br>We use direct observations of the isotopic composition of the sublimation flux together with surface snow samples taken in the North-East of the Greenland Ice Sheet accumulation zone throughout the summer months of 2019 to demonstrate sublimation impacts.<br>We show that, contrary to the understanding of effectless layer-by-layer removal of snow, sublimation involves fractionation and therefore influences the isotopic composition of the snow. Complementary measurements of humidity as well as isotope fluxes constrain the local vapor snow exchange and allow for the quantification of post-depositional influences while the snow is exposed to the atmosphere.<br>This improved process understanding of the formation of the climate signal found in snow is important for merging climate modeling and ice core proxies. </p>

A hotter-drought fingerprint on Earth’s forest mortality sites–warming accelerates risks

2021 ◽  
Author(s):  
William M. Hammond ◽  
A. Park Williams ◽  
John T. Abatzoglou ◽  
Henry D. Adams ◽  
Tamir Klein ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Global Climate ◽  
Climate Signal ◽  
Climate Conditions ◽  
Global Database ◽  
Complex Process ◽  
Climatic Drivers ◽  
Warming World ◽  
Globally Distributed

<p>Earth’s forests face grave challenges in the Anthropocene, including hotter droughts increasingly associated with widespread forest die-off. But despite the vital importance of forests—especially historical forests—to global ecosystem services, their fates in a warming world remain highly uncertain. Critically missing is quantitative determination of hotter-drought climatic drivers at globally-distributed, ground-based, tree-mortality sites. We established a precisely geo-referenced global database documenting climate-induced mortality events spanning all tree-supporting biomes from 154 studies since 1970. Here we quantify a lethal global hotter-drought fingerprint from these tree-mortality sites across 675 locations encompassing 1,303 database plots. Frequency of these lethal climate conditions accelerates under projected warming, up 140% by +4℃. Our database, soon available at tree-mortality.net, provides initial footing for further community development of quantitative, ground-based monitoring of global tree mortality (e.g., still including peer-reviewed observations, but importantly also those from forestry professionals, land managers, and citizen scientists). Furthermore, our database immediately enables critical predictive model validation and improved remote sensing of mortality. While our initial database enabled empirical quantification of a global climate signal for hotter-drought triggered tree mortality, ongoing and online contributions to the database (with efforts to be more spatially representative) will enable myriad future analyses and progress toward understanding the role of hotter-drought in the mechanistically complex process of tree mortality. Our global fingerprint of lethal hotter-drought confirms many of Earth’s forests are increasingly imperiled by further warming.</p>

13C discrimination patterns in oceanic phytoplankton: likely influence of CO2 concentrating mechanisms, and implications for palaeoreconstructions

2002 ◽  
Vol 29 (3) ◽  
pp. 323 ◽  
Author(s):  
Edward A. Laws ◽  
Brian N. Popp ◽  
Nicolas Cassar ◽  
Jamie Tanimoto
Keyword(s):  
Growth Rate ◽  
Organic Carbon ◽  
Isotopic Composition ◽  
Active Transport ◽  
Limiting Factor ◽  
Similar Species ◽  
Confounding Factors ◽  
Co2 Concentrations ◽  
Co2 Concentrating Mechanisms ◽  
The Impact

The isotopic composition of organic carbon buried in marine sediments is an appealing proxy for palaeo CO2 concentrations due to the well-documented effect of CO2 concentrations on carbon fractionation by phytoplankton. However, a number of factors, in addition to CO2 concentrations, influence this fractionation. Included among these factors are cell geometry, in particular surface/volume ratios, growth rate, and the presence of CO2 concentrating mechanisms. Other potentially confounding factors are calcification, diagenesis, and the nature of the growth-rate-limiting factor, e.g. light vs nutrients. Because of these confounding factors, palaeoreconstructions based on the isotopic composition of organic carbon (δ13C) will almost certainly have to be based on the isotopic signatures of organic compounds that can be associated with a single species, or group of physiologically similar species. Long-chain alkenones produced by certain species of coccolithophores may provide a suitable diagnostic marker. By combining the δ13C of the alkenone carbon with the δ13C of coccolith carbon and the Sr/Ca ratio of the coccoliths, it is possible to calculate the extent of carbon fractionation (εp) and estimate growth rates. However, active transport of inorganic carbon tends to make εp insensitive to CO2 concentrations when the ratio of growth rate to CO2 concentration exceeds 0.285/rkg mol–1d–1, where r is the effective spherical radius of the cell in microns. Palaeo CO2 concentrations calculated from alkenone and coccolith δ13C data capture the gross features of CO2 concentrations in the Vostok ice core, but explain only 30–35% of the variance in the latter. The absence of a higher correlation may in part reflect the impact of active transport, particularly during glacial times. The impact of active transport may have been less severe prior to the Pleistocene, since CO2 concentrations are believed to have been higher than present-day values during most of Phanerozoic time.

scholarly journals Impurity influence on normal grain growth in the GISP2 ice core, Greenland

1996 ◽  
Vol 42 (141) ◽  
pp. 255-260 ◽  
Author(s):  
R. B Alley ◽  
G. A. Woods
Keyword(s):  
Growth Rate ◽  
Grain Size ◽  
Isotopic Composition ◽  
Grain Growth ◽  
Forest Fire ◽  
Growth Rates ◽  
Slow Growth ◽  
Ice Core ◽  
Isotopic Data ◽  
Thin Sections

AbstractIntercept analysis of approximately bi-yearly vertical thin sections from the upper part of the GISP2 ice Core, central Greenland, shows that grain-size ranges increase with increasing age. This demonstrates that something in the ice affects grain-growth rates, and that grain-size cannot be used directly in paleothermometry as has been proposed. Correlation of grain-growth rates to chemical and isotopic data indicates slower growth in ice with higher impurity concentrations, and especially slow growth in “forest-fire” layers containing abundant ammonium; however, the impurity/grain-growth relations are quite noisy. Little correlation is found between growth rate and isotopic composition of ice.

scholarly journals Prediction of genetic merit for growth rate in pigs using animal models with indirect genetic effects and genomic information

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
Bjarke G. Poulsen ◽  
Birgitte Ask ◽  
Hanne M. Nielsen ◽  
Tage Ostersen ◽  
Ole F. Christensen
Keyword(s):  
Growth Rate ◽  
Animal Model ◽  
Genetic Effect ◽  
Predictive Performance ◽  
Genetic Effects ◽  
Relationship Matrix ◽  
Genomic Information ◽  
Indirect Genetic Effects ◽  
Group Members ◽  
Direct Genetic Effect

Abstract Background Several studies have found that the growth rate of a pig is influenced by the genetics of the group members (indirect genetic effects). Accounting for these indirect genetic effects in a selection program may increase genetic progress for growth rate. However, indirect genetic effects are small and difficult to predict accurately. Genomic information may increase the ability to predict indirect genetic effects. Thus, the objective of this study was to test whether including indirect genetic effects in the animal model increases the predictive performance when genetic effects are predicted with genomic relationships. In total, 11,255 pigs were phenotyped for average daily gain between 30 and 94 kg, and 10,995 of these pigs were genotyped. Two relationship matrices were used: a numerator relationship matrix ($${\mathbf{A}}$$ A ) and a combined pedigree and genomic relationship matrix ($${\mathbf{H}}$$ H ); and two different animal models were used: an animal model with only direct genetic effects and an animal model with both direct and indirect genetic effects. The predictive performance of the models was defined as the Pearson correlation between corrected phenotypes and predicted genetic levels. The predicted genetic level of a pig was either its direct genetic effect or the sum of its direct genetic effect and the indirect genetic effects of its group members (total genetic effect). Results The highest predictive performance was achieved when total genetic effects were predicted with genomic information (21.2 vs. 14.7%). In general, the predictive performance was greater for total genetic effects than for direct genetic effects (0.1 to 0.5% greater; not statistically significant). Both types of genetic effects had greater predictive performance when they were predicted with $${\mathbf{H}}$$ H rather than $${\mathbf{A}}$$ A (5.9 to 6.3%). The difference between predictive performances of total genetic effects and direct genetic effects was smaller when $${\mathbf{H}}$$ H was used rather than $${\mathbf{A}}$$ A . Conclusions This study provides evidence that: (1) corrected phenotypes are better predicted with total genetic effects than with direct genetic effects only; (2) both direct genetic effects and indirect genetic effects are better predicted with $${\mathbf{H}}$$ H than $${\mathbf{A}}$$ A ; (3) using $${\mathbf{H}}$$ H rather than $${\mathbf{A}}$$ A primarily improves the predictive performance of direct genetic effects.

A multispecialty approach to immuno-oncology education for community providers.

2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 80-80
Author(s):  
Tara Perloff ◽  
Monique Dawkins ◽  
Jennie Robertson Crews ◽  
Jeffrey P. Gregg ◽  
Ivo Abraham ◽  
...  
Keyword(s):  
Working Group ◽  
Community Setting ◽  
Educational Interventions ◽  
Educational Opportunities ◽  
Systemic Review ◽  
Training And Education ◽  
Oncology Education ◽  
Working Groups ◽  
Group Members ◽  
Cancer Immunotherapies

80 Background: The Association of Community Cancer Centers (ACCC) Immuno-Oncology Institute was developed in 2015 to prepare all members of the multidisciplinary cancer care team for the complex implementation of immuno-oncology in the community setting. Today, with more than 50 cancer immunotherapy indications and over 2,500 clinical trials with cancer immunotherapies, the challenges and issues related to recognizing and managing immune-related adverse events (irAEs) have grown even more complex for community practitioners. Methods: The ACCC Immuno-Oncology Institute assembled 4 working groups focused on addressing the diverse issues around the delivery and management of patients on cancer immunotherapies. The working groups were divided by 4 topics: staff training and education; multispecialty care coordination and communication; telemedicine; and big data. A detailed systemic review of the literature was conducted for each topic in the context of immuno-oncology, to determine the current landscape of information and available resources. The findings were then shared with the working group members and collaborative discussions ensued over 12 virtual committee meetings. The 19 working group members are diverse by discipline, including specialties such as emergency medicine, dermatology, primary care, survivorship, pathology, and academic researchers. Results: The ACCC Working Group Summit convened in September 2018 to develop innovative educational opportunities for community practitioners related to managing irAEs across the 4 topic areas. Eight unique action plans were developed by working group members. Conclusions: For each of the 4 key areas, working group members identified a list of opportunities that would improve how clinicians are managing irAEs for patients being treated with immunotherapy. It is critical for future educational interventions to encompass the multispecialty team perspective related to the management of irAEs.

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