Nina DavtianDec 5

RE: https://mastodon.social/@EuroGeosciences/115666291558411415

Featuring my co-authored #review #article « #Reviews and #syntheses: Best practices for the application of #marine #GDGTs as proxy for #paleotemperatures: #sampling, #processing, #analyses, #interpretation, and #archiving protocols » published in the @EuroGeosciences journal #Biogeosciences one month ago!
https://doi.org/10.5194/bg-22-6465-2025
#Science
#ScienceMastodon
#AcademicMastodon
#Consensus #Synthesis
#isoGDGTs #brGDGTs #TeamArchaea #TeamBacteria
#archaeal #bacterial #tetraether #lipids

Nina DavtianDec 2
I am so happy to co-author this #preprint #review on #archaeal #tetraether #lipids, aka #GDGTs, as #marine paleoenvironmental indicators led by Felix Elling and Gordon Inglis!
The #consensus presented in this preprint review was written by 40 experts on GDGTs, including both lead authors and myself.
The Earth and Space Science Open Archive preprint is available there:
https://doi.org/10.22541/essoar.176409484.44403346/v1
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#Science
#ScienceMastodon
#AcademicMastodon
#isoGDGTs #TeamArchaea
Nina DavtianNov 6

RE: https://mastodon.world/@nina_davtian/114502798389880294

Let's give a try to the new #QuotePost functionality, so that I can remind the names of the lead authors of my new co-authored #review paper published in the @EuroGeosciences #journal #Biogeosciences, as well as which team and research center I represent in this #synthesis!
https://doi.org/10.5194/bg-22-6465-2025
#Science
#ScienceMastodon
#AcademicMastodon
#Consensus #Scientific #Publication
#isoGDGTs #brGDGTs #TeamArchaea #TeamBacteria
#archaeal #bacterial #tetraether #lipids
#Paleotemperature #Biogeoscience

Nina DavtianNov 6
My first co-authored #review #article « #Reviews and #syntheses: Best practices for the application of #marine #GDGTs as proxy for #paleotemperatures: #sampling, #processing, #analyses, #interpretation, and #archiving protocols » is now published in the @EuroGeosciences journal #Biogeosciences!
https://doi.org/10.5194/bg-22-6465-2025
#Science
#ScienceMastodon
#AcademicMastodon
#Consensus #Synthesis #Analysis
#isoGDGTs #brGDGTs #TeamArchaea #TeamBacteria
#archaeal #bacterial #tetraether #lipids
#Paleotemperature
Nina DavtianSep 26
As we* hoped, my co-authored #marine GDGT « cookbook » #review #paper (https://doi.org/10.5194/egusphere-2025-1467) was accepted for publication in the @EuroGeosciences #journal #Biogeosciences after peer-review and (minor) revision! 🥳 🍾
*Peter Bijl, Kasia Sliwinska, and all co-authors, including myself.
#Science
#ScienceMastodon
#AcademicMastodon
#PaperAccepted
#GDGTs #isoGDGTs #brGDGTs #TeamArchaea #TeamBacteria
#archaeal #bacterial #tetraether #lipids
Nina DavtianMay 13, 2025
Four weeks ago, my first co-authored @EuroGeosciences #preprint « #Reviews and syntheses: Best practices for the application of #marine #GDGTs as proxy for paleotemperatures: sampling, processing, analyses, interpretation, and archiving protocols » went online!
https://doi.org/10.5194/egusphere-2025-1467
#Science #ScienceMastodon #AcademicMastodon
#Review #Consensus
#EGUsphere
#isoGDGTs #brGDGTs #TeamArchaea #TeamBacteria
#archaeal #bacterial #tetraether #lipids
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Reviews and syntheses: Best practices for the application of marine GDGTs as proxy for paleotemperatures: sampling, processing, analyses, interpretation, and archiving protocols

Abstract. Marine glycerol dialkyl glycerol tetraethers (GDGTs) are used in various proxies (such as TEX86) to reconstruct past ocean temperatures. Over 20 years of improvements in GDGT sample processing, analytical techniques, data interpretation and our understanding of proxy functioning have led to the collective development of a set of best practices in all these areas. Further, the importance of Open Science in research has increased the emphasis on the systematic documentation of data generation, reporting and archiving processes for optimal reusability of data. In this paper, we provide protocols and best practices for obtaining, interpreting and presenting GDGT data (with a focus on marine GDGTs), from sampling to data archiving. The purpose of this paper is to optimize inter-laboratory comparability of GDGT data, and to ensure published data follows modern open access principles.

Nina DavtianMay 12, 2025
The last #scientific #publication from Devika Varma’s #PhD #thesis at @NIOZnieuws (https://www.nioz.nl/en/news/investigating-paleotemperature-proxies-based-on-archaeal-hydroxylated-tetraether-lipids) is now published in #OrganicGeochemistry:
https://doi.org/10.1016/j.orggeochem.2025.105010
Many thanks to Isla Castañeda for the invitation to review this paper—yes, I signed the review report.
#Science #ScienceMastodon #AcademicMastodon
#GDGTs #isoGDGTs #TeamArchaea
#Archaeal #tetraether #lipids
Investigating paleotemperature proxies based on archaeal hydroxylated tetraether lipids

Understanding past sea surface temperatures (SSTs) is crucial for reconstructing Earth's climate history. Devika Varma has focused her PhD research pr…

Nina DavtianMar 8, 2025
On this #InternationalWomensDay, let me highlight two #WomenInSTEM.
First, Amy Cromartie, who leads the following @EuroGeosciences #preprint:
https://egusphere.copernicus.org/preprints/2025/egusphere-2025-526/
Second, Devika Varma, who recently defended her #PhD #thesis. Her PhD work at @NIOZnieuws aimed to investigate #paleotemperature indicators based on #archaeal hydroxylated #tetraether #lipids (OH-isoGDGTs):
https://www.nioz.nl/en/news/investigating-paleotemperature-proxies-based-on-archaeal-hydroxylated-tetraether-lipids
#IWD #IWD25 #IWD2025
#Science #ScienceMastodon #AcademicMastodon
#GDGTs #brGDGTs #isoGDGTs
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Utilizing Probability Estimates from Machine Learning and Pollen to Understand the Depositional Influences on Branched GDGT in Wetlands, Peatlands, and Lakes

Abstract. Branched glycerol dialkyl glycerol tetraethers (brGDGTs) serve as critical molecular biomarkers for the quantitative reconstruction of past environments, ambient temperature and pH across various archives. Despite their success, numerous issues persist that limit their application. The distribution of brGDGTs varies significantly based on provenance, resulting in biases in environmental reconstructions that rely on fractional abundances and derived indices, such as the MBT’5ME. This issue is especially significant in shallow lakes, wetlands, and peatlands within semi-arid and arid regions, where ecosystems are sensitive to diverse environmental and climatic factors. Recent advancements, such as machine learning techniques, have been developed to identify changes in sources; however, these techniques are insufficient for detecting mixed source environments. The probability estimates derived from five machine learning algorithms are employed here to detect provenance changes in brGDGT downcore records and to identify periods of mixed provenance. A new global modern database (n=2301) was compiled to train, validate, test, and apply these algorithms to two sedimentary records. Our findings are corroborated by pollen and non-pollen palynomorphs obtained from the identical records. These microfossil proxies are utilized to discuss changes in provenance, hydrology, and ecology that influence the distribution of brGDGTs. Probability estimates derived from Random Forest with a sigmoid calibration are most effective in detecting changes in brGDGT distribution. Minor changes in the relative contributions of brGDGTs provenance can significantly influence the distribution of brGDGTs, especially regarding the MBT'5ME index. This study introduces a novel brGDGT wetland index aimed at monitoring potential biases arising from wetland development.

Jocelyn EtienneMar 5, 2025

Announcement of #BactoGre 27 May - #bacteriology in #Grenoble meeting of #microbiologists focusing on #bacterial and #archaeal organisms and communities.

Registration is free but mandatory
https://forms.gle/nDi25ogQbdBP3yvQ7

submissions close 25 April,
registration 16 May

Invited speakers:
#CatherineLarose, "Institut des Géosciences de l’Environnement", Grenoble
#SamMeyer, "Microbiologie, Adaptation et Pathogénie", Lyon

Organisers: Sylvie Elsen, Pierre Marcoux and Sophie Abby

BactoGre 2025 registration

Event Timing: May 27th, 2025 Event Address: IMAG building, auditorium, St Martin d'Hères

Google Docs
PLOS BiologyApr 5, 2023
Contrary to current orthodoxy, #archaeal #membrane mimics are more permeable to core metabolites than #bacterial #lipid membrane mimics, informing some of the earliest transitions in cell evolution @Ula_Lapinska @AncestralState @PagliaraExeter #PLOSBiology https://plos.io/3Kxa15c
Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes

An assessment of the permeability function of different prokaryotic lipid membrane mimics reveals that, contrary to current orthodoxy, archaeal membrane mimics are more permeable to a range of core metabolites than bacterial lipid membrane mimics, with implications for understanding some of the earliest transitions in cell evolution.