Results 61 to 70 of about 10,002 (189)

Microbially generated ferruginous crusts: A potential biosignature of continental input in coastal settings

open access: yesSedimentology, EarlyView.
ABSTRACT Thin ferruginous sandy crusts are common on top of sandstone beds in the Early Permian post‐glacial deposits of the Paraná Basin in southern Brazil. These crusts usually preserve wrinkle structures, suggesting that they might be a product of microbial mediation.
Patrícia Weschenfelder   +2 more
wiley   +1 more source

Development of Holocene lacustrine microbialites on the Iberian Peninsula: Insights into environmental and depositional controls using X‐ray CT and petrography

open access: yesSedimentology, EarlyView.
ABSTRACT Microbial mats and microbialites are common in modern and ancient saline lacustrine environments and are highly responsive to biological and environmental factors. As such, they represent important sources of high‐resolution environmental data across a wide range of geological time. Nonetheless, interpretation of fossil mats is non‐trivial due
Connor Doyle   +6 more
wiley   +1 more source

Unveiling microbial preservation under hyperacidic and oxidizing conditions in the Oligocene Rio Tinto deposit

open access: yesScientific Reports, 2021
The preservation of biosignatures on Mars is largely associated with extensive deposits of clays formed under mild early Noachian conditions (> 3.9 Ga). They were followed by widespread precipitation of acidic sulfates considered adverse for biomolecule ...
David C. Fernández-Remolar   +8 more
doaj   +1 more source

Mars simulated exposure and the characteristic Raman biosignatures of amino acids and halophilic microbes [PDF]

open access: yes, 2017
Though Raman bands of α-amino acids (AA) are well documented, often only the strongest intensity bands are quoted as identifiers (e.g. Jenkins et al., 2005; De Gelder et al., 2007; Zhu et al., 2011).
Gilmour, I.   +5 more
core  

Fluorination of Silver Phosphate in Nickel Reaction Vessels for Triple Oxygen Isotope Analysis

open access: yesRapid Communications in Mass Spectrometry, Volume 40, Issue 7, 15 April 2026.
ABSTRACT Rationale Increasingly, more laboratories are measuring the triple oxygen isotope values of phosphate. Standardization is key to having good interlaboratory results. Here, we present the triple oxygen isotope values of a suite of standards using fluorination and compare them with previously reported triple oxygen isotope values. Methods Silver
Jordan A. G. Wostbrock   +4 more
wiley   +1 more source

Increased Stability in Carbon Isotope Records Reflects Emerging Complexity of the Biosphere

open access: yesFrontiers in Earth Science, 2019
Preference for certain stable isotopes (isotope fractionation) during enzyme-mediated reactions is a universal aspect of life. For instance, carbon isotopes are fractionated during anabolic (e.g., photosynthate production) and catabolic (e.g ...
Martin Schobben, Bas van de Schootbrugge
doaj   +1 more source

Spectral signatures of photosynthesis II: coevolution with other stars and the atmosphere on extrasolar worlds

open access: yes, 2007
As photosynthesis on Earth produces the primary signatures of life that can be detected astronomically at the global scale, a strong focus of the search for extrasolar life will be photosynthesis, particularly photosynthesis that has evolved with a ...
Antígona Segura   +12 more
core   +2 more sources

Multi‐Parametric MRI Approach at 3 T and 7 T for Assessing Skeletal Muscle Pathology in Myofibrillar Myopathies: A Pilot Study

open access: yesJournal of Cachexia, Sarcopenia and Muscle, Volume 17, Issue 2, April 2026.
ABSTRACT Background Myofibrillar myopathies (MFM) form a large group of clinically and genetically heterogeneous protein aggregate diseases. We investigated whether a novel quantitative MRI protocol can reveal new aspects of structural and biochemical muscle pathology in three classic MFM subtypes.
Claudius S. Mathy   +15 more
wiley   +1 more source

Assessing the utility of trace and rare earth elements as biosignatures in microbial iron oxyhydroxides

open access: yesFrontiers in Earth Science, 2015
Microbial iron oxyhydroxides are common deposits in natural waters, recent sediments and mine drainage systems and often contain significant accumulations of trace and rare earth elements (TREE). TREE patterns are widely used to characterize minerals and
Christine eHeim   +7 more
doaj   +1 more source

The Spectroscopic Impact of Sublimation Under Martian Surface Conditions: Implications for Sample Analysis by the Rosalind Franklin Rover and Biosignature Preservation

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 4, April 2026.
Abstract The 2028 ESA/NASA Rosalind Franklin Mission (RFM) will search for signs of past and present life in the shallow subsurface of Mars. It is crucial to understand how minerals and any biosignatures uncovered during these sampling activities might change and be identified under today's Martian conditions.
Louisa J. Preston   +5 more
wiley   +1 more source

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