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171 results for “carbon isotopes”
Stable carbon and nitrogen isotope analysis data for sequentially sampled whiskers of caracals (Caracal caracal) on the Cape Peninsula, South Africa
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Small shelly fossils and carbon isotopes from the early Cambrian (Stage 3-4) Mural Formation of western Laurentia
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Dataset S1 - Noelaerhabdaceae organic carbon isotope culture data compilation
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Contents and isotope carbon compositions (δ13C) of main biochemical fractions in organs at different growth stages in Phyllostachys edulis
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Quality control for modern bone collagen stable carbon and nitrogen isotope measurements
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Isotopic evidence for increased carbon and nitrogen exchanges between peatland plants and their symbiotic microbes with rising atmospheric CO2 concentrations since 15000 cal. yr BP
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Data from: Metabolic proxy for cephalopods: Stable carbon isotope values recorded in different biogenic carbonates
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Five Points Plant Isotopic Values for Carbon and Nitrogen
To quantify foraging strategies in the small mammal community of the Sevilleta National Wildlife Refuge, plant samples were collected at green-up (generally March for forbs and July for grasses), and when going to seed (generally May for forbs and October for grasses). Plants were analyzed for C:N ratio, delta15N and delta13C isotopic values and for carbon and nitrogen percent content by mass in both leaf and seed. These isotopic values can be compared to mouse plasma values to determine forage width (Carbon) and forage breadth (Nitrogen). Please see Sevilleta Dataset 313 on small mammal plasma to quantify resource preferences within and between small mammal communities.
Five Points Small Mammal Blood Plasma Isotopic Values for Carbon, Nitrogen and Hydrogen
There has been little comprehensive research undertaken to quantify resource use by small mammal communities in a nutrient limited, highly stochastic ecosystem. The most abundant small mammals in this ecosystem are Heteromyids, food-caching granivores, and Cricetids, omnivores that must utilize on board fat stores as energy reserves. Heteromyid populations co-vary with primary production whereas the cricetids can forage at multiple trophic levels reducing their dependence on primary productivity. Using isotopic values for Carbon, delta13C (a ratio of 13C to 12C), of primary producers consistent within a photosynthetic pathway, C3 = -26.6 +/- 1.8Permille and C4, = -14.4 +/- 0.8Permille we can track mouse dietary assimilation of forage by plant functional type. Nitrogen isotopic values 15N (a ratio of 15N to 14N) fluctuate constantly, reflecting the landscape of primary production. Therefore, tracking nitrogen values in small mammal plasma provides a landscape level tool for studying diet by trophic level and nutritional value.
Permafrost soil database with information on site, topography, geomorphology, hydrology, soil stratigraphy, soil carbon, ground ice isotopes, and vegetation at thermokarst features near Toolik and Noatak River, 2009-2013
This database contains soil and permafrost stratigraphy associated with thermokarst features near Toolik Lake and the Noatak River collected by Torre Jorgenson and Andrew Balser during summers 2009-2011. The Access Database has main data tables (tbl_) for site (environmental), soil stratigraphy, soil physical data, soil chemical data, soil isotopes (ground ice), soil radiocarbon dates, topography and bathymetry, and vegetation cover. The site data includes information of location, observers, geomorphology, topography, hydrology, soil summary characteristics, pH and EC, soil classification, and vegetation cover by species. Soil stratigrapy has information on soil texture and ground ice. Soil physical and chemical data includes lab data on bulk density, moisture, carbon, and nitrogen. The database has 37 reference tables (REF_) that have codes and descriptions for variables used in site, soil stratigraphy, and vegetation cover tables.
Calcium stable isotopes of Tonga and Mariana arc lavas and implications for slab fluid-mediated carbonate transfer in subduction zones
<p>The Table 1 shows Ca isotopes and selected major and trace element compositions of the Tonga rear arc and Mariana arc lavas.</p> <p>Supporting imformation includ Figure S1 and Table S1</p> <p>Figure S1 shows the δ<sup>44/42</sup>Ca‰ versus δ<sup>43/42</sup>Ca‰ in all samples and reference materials measured by Nu Plasma 1700 MC-ICP-MS in GPMR.</p> <p>Table S1 lists the major and trace element contents of NW Rota-1 and Esmeralda Bank samples from Mariana arc. Major elements are tested on board and trace elements are measured by ICP-MS in GPMR.</p>
Carbon and hydrogen isotope fractionation during uncultured aerobic oxidation of short-chain alkanes that discharged from a natural hydrothermal system
<p>Aerobic oxidation of short-chain alkanes was observed in gas samples from the Lutao intertidal hydrothermal vents in Taiwan, during storage without adding strains and replenishing substrates at 20 <sup>o</sup>C up to 29 months. The carbon isotope fractionation factors (<em>ε<sub>C</sub></em>) of methane (C<sub>1</sub>), ethane (C<sub>2</sub>), and propane (C<sub>3</sub>), were calculated using the Rayleigh fractionation equation to be -37.1 ± 7.5‰, -14.8 ± 4.8‰, and -4.7 ± 5.2‰, respectively. The hydrogen isotope fractionation factor (<em>ε<sub>H</sub></em>) of methane was determined to be -281 ± 187‰. DNA sequencing of the 16sRNA gene in the vent fluids suggests that aerobic oxidation is dominated by methanotrophs of the genera <em>Methylomicrobium</em> and <em>Methylophaga,</em> which use the ribulose monophosphate pathway (RuMP). The degrees of isotope fractionation (<em>ε<sub>C</sub></em> and <em>ε<sub>H</sub></em> values) herein are larger than previously reported values, possibly due to the limited O<sub>2</sub> supply and low abundance of aerobic methane-oxidizing bacteria in the experiments. Since the fractionation factor of methane is higher than those of ethane and propane, the aerobic oxidation of thermogenic or microbial alkanes could produce carbon isotope reversal, which is frequently noted as a trait of abiotic hydrocarbons. This work demonstrates that in addition to anaerobic microbial oxidation, aerobic oxidation with a low cell density can also produce significant isotope fractionation of alkanes in geological closed/semi-closed environments that are characterized by moderate temperatures and a limited supply of substrates and O<sub>2</sub>; these environments include cold seeps, mud volcanoes, and low-temperature hydrothermal aquifers/reservoirs.</p>
Food sources of benthic communities at the Caiwei Guyot and Yap Trench, northwestern Pacific Ocean: inferences from carbon and nitrogen isotopes
<p>To investigate nutritional resources for benthic communities at two sites in the northwestern Pacific Ocean (the Caiwei Guyot and the Yap Trench), stable isotopes of carbon and nitrogen (δ<sup>13</sup>C and δ<sup>15</sup>N) were measured in the tissues of megabenthic consumers (Porifera, Asteroidea, Crinoidea, Holothuroidea, Ophiuroidea, Gammaridea, and Actiniaria) as well as four potential food sources (suspended particles, sinking particles, zooplankton, and sedimentary organic matter, SOM). Fast-sinking particles are generally thought to be the primary food source for benthic consumers, but that paradigm does not seem to apply at these abyssal sites. Here, the δ<sup>13</sup>C and δ<sup>15</sup>N signatures of fast-sinking particles (as collected by sediment traps; δ<sup>13</sup>C = −24.1 to −22.6‰, δ<sup>15</sup>N = 1.4 to 5.4‰) were significantly lower than those of the megabenthos (δ<sup>13</sup>C = −20.1 to −16.1‰, δ<sup>15</sup>N = 10.2 to 17.9‰), indicating that these particles are not likely a direct food source for the animals. Buoyant particles (and slow-sinking particles), on the other hand, seem to be a significant direct food source for the megabenthos. Sedimentary organic matter and zooplankton are also important direct food sources. Trophic level analysis similarly indicates a diversity of food sources and suggests that for at least some animals, microbes (e.g., bacteria) may be a food source as well.</p>
Data from: Carbon isotopes of C3 herbs correlate with temperature on removing the influence of precipitation across a temperature transect in the agro-pastoral ecotone of Northern China
Plant δ13C–temperature (δ-T) relation has been established in many systems and is often used as paleotemperature transfer function. However, it is still unclear about the exact contributions of temperature variation to plant 13C discrimination because of covariation between temperature and precipitation (aridity), which reduces confidence in reconstruction of paleoclimate. In this study, we measured carbon isotope composition (δ13C) of 173 samples of C3 perennial herbs from 22 sites across a temperature gradient along the 400 mm isohyet in the farming-pastoral zone of North China. The results showed that precipitation obviously affected the correlations of temperatures and foliar δ13C. After removing the influence of precipitation by analysis of covariance (ANCOVA), a more strongly positive relationship was obtained between site-mean foliar δ13C and annual mean temperature (AMT), with a regression coefficient of 0.1636‰/°C (p = .0024). For widespread species, Artemisia lavandulaefolia and Artemisia capillaries, the slopes (or coefficients) of foliar δ13C and AMT were significantly steeper (larger) than those of foliar δ13C and AMT where the precipitation influence was not excluded, whereas the δ-T coefficients of Polygonum persicaria and Leymus chinensis showed little change across the transect after deducting the precipitation effect. Moreover, the positive relationship between temperature and δ13C over the transect could be explained by soil moisture availability related to temperature. Our results may afford new opportunities for investigating the nature of past climate variability.
Data from: Photosynthetic pathways in Bromeliaceae: phylogenetic and ecological significance of CAM and C3 based on carbon isotope ratios for 1893 species
A comprehensive analysis of photosynthetic pathways in relation to phylogeny and elevational distribution was conducted in Bromeliaceae, an ecologically diverse Neotropical family containing large numbers of both terrestrial and epiphytic species. Tissue carbon isotope ratio (δ13C) was used to determine the occurrence of crassulacean acid metabolism (CAM) and C3 photosynthesis in 1893 species, representing 57% of species and all 56 genera in the family. The frequency of δ13C values showed a strongly bimodal distribution: 1074 species (57%) had values more negative than −20‰ (mode = −26.7‰), typical of predominantly daytime carbon fixation via the C3 pathway, whereas 819 species (43%) possessed values less negative than −20‰ (mode = −13.3‰), indicative of predominantly nocturnal fixation of carbon via the CAM pathway. Amongst the six almost exclusively terrestrial subfamilies in Bromeliaceae, Brocchinioideae, Lindmanioideae and Navioideae consisted entirely of C3 species, with CAM species being restricted to Hechtioideae (all species of Hechtia tested), Pitcairnioideae (all species belonging to a xeric clade comprising Deuterocohnia, Dyckia and Encholirium) and Puyoideae (21% of Puya spp.). Of the other two subfamilies, in the overwhelmingly epiphytic (plus lithophytic) Tillandsioideae, 28% of species possessed CAM photosynthesis, all restricted to the derived genus Tillandsia and tending towards the more extreme epiphytic 'atmospheric' life-form. In Bromelioideae, with comparable numbers of terrestrial and epiphytic species, 90% of taxa showed CAM; included in these are the first records of CAM photosynthesis in Androlepis, Canistropsis, Deinacanthon, Disteganthus, Edmundoa, Eduandrea, Hohenbergiopsis, Lymania, Pseudananas, Ronnbergia and Ursulaea. With respect to elevational gradients, the greatest number of C3 bromeliad species were found at mid-elevations between 500 and 1500 m, whereas the frequency of CAM species declined monotonically with increasing elevation. However, in Puya, at least ten CAM species have been recorded at elevations > 3000 m, showing that CAM photosynthesis is not necessarily incompatible with low temperatures. This survey identifies five major origins of CAM photosynthesis at a higher taxonomic level in Bromeliaceae, but future phylogenetic work is likely to reveal a more fine-scale pattern of gains and losses of this trait, especially in ecologically diverse and widely distributed genera such as Tillandsia and Puya
Data from: Leaf carbon and oxygen isotopes are coordinated with the leaf economics spectrum in Mediterranean rangeland species
The leaf economics spectrum (LES) describes covariation of traits relevant to carbon and nutrient economics across plant species, but much less is known about the relationship between the LES and leaf water economy. We propose an approach combining the measurement of two leaf traits related to water use economy, leaf carbon (δ13C) and oxygen (δ18O) isotopic composition, and the measurement of leaf morphological and nutrient traits to investigate the link between leaf carbon and nutrient economics and water use. We tested the relationships between leaf traits linked to carbon and nutrient use within the LES and water use traits using leaf δ18O as a proxy of stomatal conductance (gs) and δ13C as a proxy of intrinsic water use efficiency (WUEi) across 15 Mediterranean rangeland species grown in an irrigated common garden and in a natural grassland in Southern France. The target species spanned a wide range of variation in leaf morphological and nutrient trait values and a wide range of leaf δ18O and δ13C values. PCA analysis revealed multiple associations among leaf morphology, nutrients and isotopic composition, with the first axis alone explaining 56.0% of the total variation across species. Leaf δ18O and δ13C covaried with leaf morphology and leaf nutrient concentrations along a single resource use axis. Species with high leaf δ18O and δ13C (low gs and high WUEi) exhibited a resource-conservative strategy (high LDMC, low leaf N, P and K) whereas species with low leaf δ18O and δ13C (high gs and low WUEi) showed a more resource-acquisitive strategy (high SLA and leaf N, P and K). These leaf trait syndromes and resource use strategies were strongly conserved across sites with contrasting environmental conditions, indicating that foliar δ18O and δ13C can be included as an integral part of the LES for this set of rangeland species. Overall, the data suggest a tight coupling and coordination between water, carbon and nutrient use strategies across herbaceous plant species. A dual δ18O and δ13C isotope approach combined with LES trait measurements is a promising tool to more comprehensively assess the diversity of resource use strategies among coexisting plant species.
Alkenone carbon isotopic fractionation and sea surface temperature trends from 30 to 16 Ma. Sites IODP 1406, ODP 1168 and ODP 925
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Constraining carbonate diagenesis using clumped isotope temperatures and U-Pb dating: a case study from the Gerze area in western central Tibet and implications for paleoelevation interpretations
<p>Data S1: clumped isotope data of new samples; Data S2: clumped isotope data of standards; and Data S32: carbonate LA-ICPMS U-Pb data</p>
DATASET: Isotope Ratios, Carbon and Nitrogen Concentrations, and Phytoplankton Composition Data from the ACE Expedition
<p>This dataset represents the averaged observations derived from the Antarctic Circumnavigation Expedition (ACE - 2016/2017) and has been utilized for the analyses presented in the publication: "A circum-Antarctic plankton isoscape: Carbon export potential across the summertime Southern Ocean". It encompasses a comprehensive suite of biogeochemical measurements, specifically the isotopic ratios (δ13C, δ15N) and concentrations of carbon and nitrogen in Suspended Particulate Matter (SPM). Additionally, it includes data from High-Performance Liquid Chromatography (HPLC) analyses (i.e., Total Chl-a and fractions of pico-, nano-, and micro-phytoplankton).</p><p>This dataset also contains the outputs of our calculations based on the two-endmember isotope mixing model (Fawcett et al., 2011), complemented by the Rayleigh model (Mariotti et al., 1981) to deduce the fraction of phytoplankton biomass originating from new nitrogen source (New Production).</p>
Isotopic Constraints from Carbonates on the Thermochronologic Evolution of Fluid Flow and Faulting in the Monitor Range, Central Nevada, USA
<p>The dataset contains the following information:</p> <p>"Full data summary"- Isotopic data and GPS coordinates for all samples analyzed in this study.</p> <p>"L013 report", "L052 report"- Raw clumped isotope data for all samples.</p> <p>"U-Pb raw data"- Calcite U/Pb ratios of psuedo-spots for all unknown samples and standards analyzed in this study.</p> <p>"Yanay CC20"- Zircon U/Pb data for standards and unkown sample grains.</p>
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.