Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
104,476
result(s) for
"isotopes"
Sort by:
Isotopes : a very short introduction
In this Very Short Introduction, Rob Ellam explains how isotopes have proved enormously important across all the sciences and in archaeology. Combining previous and new research, Ellam provides an overview of the nature of stable and radioactive isotopes, and considers their wide range of modern applications.
Book
Triple sulfur-oxygen-strontium isotopes probabilistic geographic assignment of archaeological remains using a novel sulfur isoscape of western Europe
Sulfur isotope composition of organic tissues is a commonly used tool for gathering information about provenance and diet in archaeology and paleoecology. However, the lack of maps predicting sulfur isotope variations on the landscape limits the possibility to use this isotopic system in quantitative geographic assignments. We compiled a database of 2,680 sulfur isotope analyses in the collagen of archaeological human and animal teeth from 221 individual locations across Western Europe. We used this isotopic compilation and remote sensing data to apply a multivariate machine-learning regression, and to predict sulfur isotope variations across Western Europe. The resulting model shows that sulfur isotope patterns are highly predictable, with 65% of sulfur isotope variations explained using only 4 variables representing marine sulfate deposition and local geological conditions. We used this novel sulfur isoscape and existing strontium and oxygen isoscapes of Western Europe to apply triple isotopes continuous-surface probabilistic geographic assignments to assess the origin of a series of teeth from local animals and humans from Brittany. We accurately and precisely constrained the origin of these individuals to limited regions of Brittany. This approach is broadly transferable to studies in archaeology and paleoecology as illustrated in a companion paper (Colleter et al. 2021).
Journal Article
Stable Isotope Turnover and Half-Life in Animal Tissues: A Literature Synthesis
Stable isotopes of carbon, nitrogen, and sulfur are used as ecological tracers for a variety of applications, such as studies of animal migrations, energy sources, and food web pathways. Yet uncertainty relating to the time period integrated by isotopic measurement of animal tissues can confound the interpretation of isotopic data. There have been a large number of experimental isotopic diet shift studies aimed at quantifying animal tissue isotopic turnover rate λ (%·day(-1), often expressed as isotopic half-life, ln(2)/λ, days). Yet no studies have evaluated or summarized the many individual half-life estimates in an effort to both seek broad-scale patterns and characterize the degree of variability. Here, we collect previously published half-life estimates, examine how half-life is related to body size, and test for tissue- and taxa-varying allometric relationships. Half-life generally increases with animal body mass, and is longer in muscle and blood compared to plasma and internal organs. Half-life was longest in ecotherms, followed by mammals, and finally birds. For ectotherms, different taxa-tissue combinations had similar allometric slopes that generally matched predictions of metabolic theory. Half-life for ectotherms can be approximated as: ln (half-life) = 0.22*ln (body mass) + group-specific intercept; n = 261, p<0.0001, r2 = 0.63. For endothermic groups, relationships with body mass were weak and model slopes and intercepts were heterogeneous. While isotopic half-life can be approximated using simple allometric relationships for some taxa and tissue types, there is also a high degree of unexplained variation in our models. Our study highlights several strong and general patterns, though accurate prediction of isotopic half-life from readily available variables such as animal body mass remains elusive.
Journal Article
the space between the riot and i
the space between the riot and i is a solo performed by Majesty Royale that uses movement and sound to investigate alternative modes of existence, memory, and ghostly inhabitance. The work exposes the physical body and sensorial landscape to rigorous transformation located in the liminal space between “here-now” and “then-there.” Majesty becomes a channel to emergent mythologies of the underworld with ritual practices derived from Black southern culture: sampling, chanting, sermon-ing, and marching. Majesty Royale is a dancer, shaper, sound explorer, and ghost. Majesty grew up in the land of the Eno and Occaneechi peoples (Durham, NC) and is based in Lenni-Lenape land (Philadelphia, PA). Majesty is a graduate of the University of the Arts (BFA Dance), 2020 Pina Bausch Choreography Fellow, and 2021 New York Live Arts Fresh Tracks Artist. https://www.glitterboiwonder.com/
Journal Article
Geographical traceability of bacteria based on a systematic stable isotope analysis method
The outbreak of certain bacteria can trigger severe diseases, even posing a threat to public safety, leading to significant social panic and economic losses. Thus, tracing the origin of bacteria is of great significance. Stable isotope analysis technology offers a new way to determine the geographical information of bacteria, yet related research still fails to meet the application requirements of this technology in practical cases of bacterial traceability. In this study, a systematic stable isotope analysis method for bacteria and their culture conditions, based on practical geographical environments, was established for the first time.
Escherichia coli
and
Staphylococcus aureus
were cultured with water from five regions and different culture media, and the stable isotope ratios of H/O/C/N in the two bacteria and the culture media were measured to explore the relationship between bacteria and their cultivation site. The results showed that there were linear relationships between the hydrogen and oxygen stable isotopes of the two bacteria and the culture water. The combined discriminant model constructed using multi-isotope (H/O/C/N) characteristics achieved a 100% accuracy rate in identifying the types of culture media. These results indicate that research on the isotope association between bacteria and their culture water can be used to infer the cultivation region, and the specific source of bacteria can be further inferred through the multi-isotope combination discriminant model. This study can provide a relatively complete research idea for bacterial geographical traceability research, and improve the efficiency and accuracy of bacterial traceability work in practical investigations.
Key points
Established a systematic stable isotope analysis method for bacteria.
E. coli and S. aureus have linear H/O isotope correlations with culture water.
Multi-isotope discriminant model achieves 100% accuracy in identifying culture media.
Journal Article
Large Sulfur Isotope Fractionation Does Not Require Disproportionation
The composition of sulfur isotopes in sedimentary sulfides and sulfates traces the sulfur cycle throughout Earth's history. In particular, depletions of sulfur-34 ( 34 S) in sulfide relative to sulfate exceeding 47 per mil (‰) often serve as a proxy for the disproportionation of intermediate sulfur species in addition to sulfate reduction. Here, we demonstrate that a pure, actively growing culture of a marine sulfate-reducing bacterium can deplete 34 S by up to 66‰ during sulfate reduction alone and in the absence of an extracellular oxidative sulfur cycle. Therefore, similar magnitudes of sulfur isotope fractionation in sedimentary rocks do not unambiguously record the presence of other sulfur-based metabolisms or the stepwise oxygenation of Earth's surface environment during the Proterozoic.
Journal Article