Monitoring of stable isotope composition of precipitation reveals thunderstorm dynamics.

The summer of 2019 is particularly well known for the famous heatwaves that swept across the European continent, with its associated drought and record-breaking air temperatures. This was followed by powerful thunderstorms, characterised by hail and heavy rain that damaged the crops on a regional scale. Here, we investigated one of the largest storm cells, lasting more than 6 h, which struck southwestern Romania.

Regional heterothermies recorded in the oxygen isotope composition of harbour seal skeletal elements.

Regional heterothermy is a strategy used by marine mammals to maintain a high and stable core body temperature, but its identification needs in situ measurements difficult to set up in extant wild organisms and inapplicable to extinct ones. We have analysed the oxygen isotope composition of bioapatite phosphate (δO) from one permanent tooth and from thirty-six skeletal elements of one adult male harbour seal (Phoca vitulina) from the Baie de Somme (Hauts-de-France, France). We propose that the observed intra-skeletal δO variability reflects tissue temperature heterogeneities typical of the pinniped regional heterothermy strategy.

Determination of water balance maintenance in Orcinus orca and Tursiops truncatus using oxygen isotopes.

The secondary adaptation of Cetacea to a fully marine lifestyle raises the question of their ability to maintain their water balance in a hyperosmotic environment. Cetacea have access to four potential sources of water: surrounding salt oceanic water, dietary free water, metabolic water and inhaled water vapour to a lesser degree. Here, we measured the 18O/16O oxygen isotope ratio of blood plasma from 13 specimens belonging to two species of Cetacea raised under human care (four killer whales Orcinus orca, nine common bottlenose dolphins Tursiops truncatus) to investigate and quantify the contribution of preformed water (dietary free water, surrounding salt oceanic water) and metabolic water to Cetacea body water using a box-modelling approach.

Determination of groundwater origins and vulnerability based on multi-tracer investigations: New contributions from passive sampling and suspect screening approach.

Knowledge about groundwater origins and their interactions with surface water is fundamental to assess their vulnerability. In this context, hydrochemical and isotopic tracers are useful tools to investigate water origins and mixing. More recent studies examined the relevance of contaminants of emerging concern (CECs) as co-tracers to distinguish sources contributing to groundwater bodies.

Multi-element stable isotope geochemistry and arsenic speciation of hydrothermal vent fauna (Alviniconcha sp., Ifremeria nautilei and Eochionelasmus ohtai manusensis), Manus Basin, Papua New Guinea.

Deep-sea hydrothermal vent communities, revealing patterns of niche partitioning, live in a limited area characterised by sharp physico-chemical gradients. In this study, we investigated carbon, sulfur, nitrogen stable isotopes as well as arsenic (As) speciations and concentrations for two snails (Alviniconcha sp. and Ifremeria nautilei) and a crustacean, (Eochionelasmus ohtai manusensis), occupying distinct niches in the hydrothermal vent field of the Vienna Woods, Manus Basin, Western Pacific.

Simultaneous δ H and δ O analyses of water inclusions in halite with off-axis integrated cavity output spectroscopy.

Stable isotope compositions of ancient halite fluid inclusions have been recognized to be valuable tools for reconstructing past environments. Nevertheless, in order to better understand the genesis of halite deposits, it could be of great interest to combine both δ H and δ O measurements of the water trapped as inclusions in the defects of the mineral lattice. We developed a method combining off-axis integrated cavity output spectroscopy (OA-ICOS) connected on line with a modified elemental analyzer (EA-OA-ICOS) to perform those measurements.

δ N values in plants are determined by both nitrate assimilation and circulation.

Nitrogen (N) assimilation is associated with N/ N fractionation such that plant tissues are generally N-depleted compared to source nitrate. In addition to nitrate concentration, the δ N value in plants is also influenced by isotopic heterogeneity amongst organs and metabolites. However, our current understanding of δ N values in nitrate is limited by the relatively small number of compound-specific data.

Combined oxygen and sulphur isotope analysis-a new tool to unravel vertebrate (paleo)-ecology.

Reconstructing the living environment of extinct vertebrates is often challenging due to the lack of proxies. We propose a new proxy to the living environment based on the combined oxygen and sulphur stable isotope analysis of vertebrate hydroxyapatite. We tested this isotopic proxy to 64 biogenic apatite (bones) samples that represent a wide spectrum of the extant vertebrate phylogenetic diversity including crocodiles, snakes, turtles, mammals, birds, lizards, fish and amphibians.

Thermophysiologies of Jurassic marine crocodylomorphs inferred from the oxygen isotope composition of their tooth apatite.

Teleosauridae and Metriorhynchidae were thalattosuchian crocodylomorph clades that secondarily adapted to marine life and coexisted during the Middle to Late Jurassic. While teleosaurid diversity collapsed at the end of the Jurassic, most likely as a result of a global cooling of the oceans and associated marine regressions, metriorhynchid diversity was largely unaffected, although the fossil record of Thalattosuchia is poor in the Cretaceous. In order to investigate the possible differences in thermophysiologies between these two thalattosuchian lineages, we analysed stable oxygen isotope compositions (expressed as δO values) of tooth apatite from metriorhynchid and teleosaurid specimens.

Improved online hydrogen isotope analysis of halite aqueous inclusions.

We demonstrate an improved method based on continuous-flow elemental analyser pyrolysis isotopic ratio mass spectrometry (CF-EA-PY-IRMS) to measure the H/ H ratios of water trapped in halite crystals. Two challenges to overcome are the low hydrogen concentration of samples (10-50 μmol H ·g ) and the high chloride concentration released when reacting halite in an elemental analyser. We describe an optimization procedure for determining the H/ H ratio of this trapped water with an acceptable accuracy.

Euryhaline ecology of early tetrapods revealed by stable isotopes.

The fish-to-tetrapod transition-followed later by terrestrialization-represented a major step in vertebrate evolution that gave rise to a successful clade that today contains more than 30,000 tetrapod species. The early tetrapod Ichthyostega was discovered in 1929 in the Devonian Old Red Sandstone sediments of East Greenland (dated to approximately 365 million years ago). Since then, our understanding of the fish-to-tetrapod transition has increased considerably, owing to the discovery of additional Devonian taxa that represent early tetrapods or groups evolutionarily close to them.

H/ H measurements of amphiboles and nominally anhydrous minerals (clinopyroxene, garnet and diamond) using high-temperature continuous flow elemental analyser/pyrolysis/isotope ratio mass spectrometry.

Rationale: We have used a high-precision, high-efficiency method for the measurement of the H/ H ratios of hydrous silicates (amphiboles) and nominally anhydrous minerals (NAM) such as clinopyroxene, garnet and diamond, which are usually extremely resistant to pyrolysis. This opens up new fields of investigation to better understand the conditions of formation for deep-Earth minerals.

Methods: The technique described here involves Isotope Ratio Mass Spectrometry (IRMS) on-line in continuous flow mode with an Elemental Analyser (EA) using "purge and trap" technology rather than separation by conventional packed column gas chromatography (GC).

CO and temperature decoupling at the million-year scale during the Cretaceous Greenhouse.

CO is considered the main greenhouse gas involved in the current global warming and the primary driver of temperature throughout Earth's history. However, the soundness of this relationship across time scales and during different climate states of the Earth remains uncertain. Here we explore how CO and temperature are related in the framework of a Greenhouse climate state of the Earth.

Oxygen isotopes suggest elevated thermometabolism within multiple Permo-Triassic therapsid clades.

The only true living endothermic vertebrates are birds and mammals, which produce and regulate their internal temperature quite independently from their surroundings. For mammal ancestors, anatomical clues suggest that endothermy originated during the Permian or Triassic. Here we investigate the origin of mammalian thermoregulation by analysing apatite stable oxygen isotope compositions (δO) of some of their Permo-Triassic therapsid relatives.

Carbon, nitrogen and oxygen isotope fractionation during food cooking: Implications for the interpretation of the fossil human record.

Objectives: Stable isotope data provide insight into the reconstruction of ancient human diet. However, cooking may alter the original stable isotope compositions of food due to losses and modifications of biochemical and water components.

Methods: To address this issue, carbon, nitrogen and oxygen isotope ratios were measured on meat aliquots sampled from various animals such as pork, beef, duck and chicken, and also from the flesh of fishes such as salmon, European seabass, European pilchard, sole, gilt-head bream, and tuna.

Oxygen isotope fractionation between bird bone phosphate and drinking water.

Oxygen isotope compositions of bone phosphate (δO) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate δO values (from 9.

Record of Nile seasonality in Nubian neonates.

The oxygen isotope compositions of bones (n = 11) and teeth (n = 20) from 12 Sudanese individuals buried on Sai Island (Nubia) were analysed to investigate the registration of the evolution of the Nile environment from 3700 to 500 years BP and the potential effects of ontogeny on the oxygen isotope ratios. The isotopic compositions were converted into the composition of drinking water, ultimately originating from the Nile. δO values decrease during ontogeny; this is mainly related to breastfeeding and physiology.

Oxygen isotope fractionation between bird eggshell calcite and body water: application to fossil eggs from Lanzarote (Canary Islands).

Oxygen and carbon isotope compositions of fossil bird eggshell calcite (δ(18)Ocalc and δ(13)Ccalc) are regularly used to reconstruct paleoenvironmental conditions. However, the interpretation of δ(18)Ocalc values of fossil eggshells has been limited to qualitative variations in local climatic conditions as oxygen isotope fractionations between calcite, body fluids, and drinking water have not been determined yet. For this purpose, eggshell, albumen water, and drinking water of extant birds have been analyzed for their oxygen and carbon isotope compositions.

High-precision (34) S/(32) S measurements in vertebrate bioapatites using purge-and-trap elemental analyser/isotope ratio mass spectrometry technology.

Rationale: In ecological studies, the sulfur isotope compositions (δ(34) S values) of soft tissues (e.g. hair, skin, nail, muscle, collagen) allow the determination of both past and present-day living environments of organisms.

Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients.

The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper ((65)Cu/(63)Cu) and sulfur ((34)S/(32)S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is (63)Cu-enriched by ∼0.

Simultaneous N, C, S stable isotope analyses using a new purge and trap elemental analyzer and an isotope ratio mass spectrometer.

Rationale: The evolution of stable isotope applications has demonstrated the increasing need for the determination of more than one isotopic signature from the same sample. Simultaneous determinations of (13)C/(12)C and (15)N/(14)N have become a widespread technique but up to now very few fully automated systems have offered the possibility of also measuring (34)S/(32)S from the same sample aliquot. This could be critical when sample amounts are limited, but it could also represent a significant gain of analytical time or cost.

Isotopic and anatomical evidence of an herbivorous diet in the Early Tertiary giant bird Gastornis. implications for the structure of Paleocene terrestrial ecosystems.

The mode of life of the early Tertiary giant bird Gastornis has long been a matter of controversy. Although it has often been reconstructed as an apex predator feeding on small mammals, according to other interpretations, it was in fact a large herbivore. To determine the diet of this bird, we analyze here the carbon isotope composition of the bone apatite from Gastornis and contemporaneous herbivorous mammals.

Stable isotope ecology of Miocene bovids from Northern Greece and the ape/monkey turnover in the Balkans.

Eurasia was home to a great radiation of hominoid primates during the Miocene. All were extinct by the end of the Miocene in Western Eurasia. Here, we investigate the hypothesis of climate and vegetation changes at a local scale when the cercopithecoid Mesopithecus replaced the hominoid Ouranopithecus along the Axios River, Greece.

Is aging recorded in blood Cu and Zn isotope compositions?

Recent isotopic observations of animal samples indicate body accumulation of heavy zinc and light copper throughout life. This hypothesis has never been tested for humans, but the existence of a relationship between blood isotopic composition and age could be promising for age assessment methodologies. Dietary habits can also influence the blood zinc isotope composition, being an additional source of isotopic variation.