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Rationale: Steam equilibration overcomes the problem of the traditional measurements of H isotope compositions, which leave an arbitrary amount of adsorbed water in the sample, by controlling for the entire exchangeable H pool, including adsorbed water and hydroxyl‐H. However, the use of steam equilibration to determine nonexchangeable stable H isotope compositions in environmental media (expressed as δ2Hn values) by mathematically eliminating the influence of exchangeable H after sample equilibration with waters of known H‐isotopic composition requires the knowledge of the equilibrium isotope fractionation factor between steam‐H and exchangeable H of the sample (αex‐w), which is frequently unknown. Methods: We developed a new method to determine the αex‐w values for clay minerals, topsoil clay fractions, and mica by manipulating the contributions of exchangeable H to the total H pool via different degrees of post‐equilibration sample drying. We measured the δ2H values of steam‐equilibrated mineral and soil samples using elemental analyzer‐pyrolysis‐isotope ratio mass spectrometry. Results: The αex‐w values of seven clay minerals ranged from 1.071 to 1.140, and those of 19 topsoil clay fractions ranged from 0.885 to 1.216. The αex‐w value of USGS57 biotite, USGS58 muscovite, and of cellulose was 0.965, 0.871, and 1.175, respectively. The method did not work for kaolinite, because its small exchangeable H pool did not respond to the selected drying conditions. Structurally different mineral groups such as two‐ and three‐layer clay minerals or mica showed systematically different αex‐w values. The αex‐w value of the topsoil clay fractions correlated with the soil clay content (r = 0.63, P = 0.004), the local mean annual temperature (r = 0.68, P = 0.001), and the δ2H values of local precipitation (r = 0.72, P < 0.001), likely to reflect the different clay mineralogy under different weathering regimes. Conclusions: Our new αex‐w determination method yielded realistic results in line with the few previously published values for cellulose. The determined αex‐w values were similar to the widely assumed values of 1.00–1.08 in the literature, suggesting that the adoption of one of these values in steam equilibration approaches is appropriate. [ABSTRACT FROM AUTHOR]

Triple oxygen isotope ratios (∆′17O) offer new opportunities to improve reconstructions of past climate by quantifying evaporation, relative humidity, and diagenesis in geologic archives. However, the utility of ∆′17O in paleoclimate applications is hampered by a limited understanding of how precipitation ∆′17O values vary across time and space. To improve applications of ∆′17O, we present δ18O, d‐excess, and ∆′17O data from 26 precipitation sites in the western and central United States and three streams from the Willamette River Basin in western Oregon. In this data set, we find that precipitation ∆′17O tracks evaporation but appears insensitive to many controls that govern variation in δ18O, including Rayleigh distillation, elevation, latitude, longitude, and local precipitation amount. Seasonality has a large effect on ∆′17O variation in the data set and we observe higher seasonally amount‐weighted average precipitation ∆′17O values in the winter (40 ± 15 per meg [± standard deviation]) than in the summer (18 ± 18 per meg). This seasonal precipitation ∆′17O variability likely arises from a combination of sub‐cloud evaporation, atmospheric mixing, moisture recycling, sublimation, and/or relative humidity, but the data set is not well suited to quantitatively assess isotopic variability associated with each of these processes. The seasonal ∆′17O pattern, which is absent in d‐excess and opposite in sign from δ18O, appears in other data sets globally; it showcases the influence of seasonality on ∆′17O values of precipitation and highlights the need for further systematic studies to understand variation in ∆′17O values of precipitation. Key Points: Precipitation δ′18O‐δ′17O slopes often differ from the 0.528 reference valuePrecipitation ∆′17O values are typically higher in the winter and lower in the summerDifferent controls on ∆′17O and δ18O mean that ∆′17O provides new information for paleoclimate reconstructions [ABSTRACT FROM AUTHOR]

The demanding precision of triple oxygen isotope (Δ17 O) analyses in water has restricted their measurement to dual-inlet mass spectrometry until the recent development of commercially available infrared laser analyzers. Laser-based measurements of triple oxygen isotope ratios are now increasingly performed by laboratories seeking to better constrain the source and history of meteoric waters. However, in practice, these measurements are subject to large analytical errors that remain poorly documented in scientific literature and by instrument manufacturers, which can effectively restrict the confident application of Δ17 O to settings where variations are relatively large (∼ 25–60 per meg). We present our operating method of a Picarro L2140-i cavity ring-down spectrometer (CRDS) during the analysis of low-latitude rainwater where confidently resolving daily variations in Δ17 O (differences of ∼ 10–20 per meg) was desired. Our approach was optimized over ∼ 3 years and uses a combination of published best practices plus additional steps to combat spectral contamination of trace amounts of dissolved organics, which, for Δ17 O, emerges as a much more substantial problem than previously documented, even in pure rainwater. We resolve the extreme sensitivity of the Δ17 O measurement to organics through their removal via Picarro's micro-combustion module, whose performance is evaluated in each sequence using alcohol-spiked standards. While correction for sample-to-sample memory and instrumental drift significantly improves traditional isotope metrics, these corrections have only a marginal impact (0–1 per meg error reduction) on Δ17 O. Our post-processing scheme uses the analyzer's high-resolution data, which improves δ2 H measurement (0.25 ‰ error reduction) and allows for much more rich troubleshooting and data processing compared to the default user-facing data output. In addition to competitive performance for traditional isotope metrics, we report a long-term, control standard root mean square error for Δ17 O of 12 per meg. Overall performance (Δ17 O error of 6 per meg, calculated by averaging three replicates spread across distinct, independently calibrated sequences) is comparable to mass spectrometry and requires only ∼ 6.3 h per sample. We demonstrate the impact of our approach using a rainfall dataset from Uganda and offer recommendations for other efforts that aim to measure meteoric Δ17 O via CRDS. [ABSTRACT FROM AUTHOR]

The deuterium excess (d‐excess) and more recently developed 17O excess (Δ′17O) of precipitation are isotopic tracers that are sensitive to oceanic moisture source (OMS) conditions. However, other regional and local processes also affect precipitation d‐excess and Δ′17O and may modify or overprint their OMS signals. Here, I leverage the new atmospheric moisture flow data set to diagnose the OMS regions and conditions globally and show that OMS temperature and relative humidity together explain 41% of the variability in monthly mean precipitation d‐excess in low‐ and mid‐latitudes. Based on a few sites currently having paired d‐excess and Δ′17O data, I also show that the contrasting sensitivity between d‐excess and Δ′17O to OMS temperature, which is initially predicted by theory, is distinguishable from precipitation observations under annual mean conditions. This study contributes to disentangling the complex controls on precipitation d‐excess and Δ′17O by quantifying the crucial role of OMS dynamics. Plain Language Summary: Stable isotopes of water molecules are process tracers of the water cycle. The "excess" quantities of deuterium and 17O in precipitation are second‐order isotopic parameters that are sensitive to moisture source conditions over oceans. However, these isotopic "excess" values measured in precipitation are also affected by other factors, such as continental moisture recycling and local condensation or evaporation of raindrops. Here, a new atmospheric moisture flow data set is used to diagnose oceanic moisture source (OMS) regions and conditions across the globe. In this way, the OMS fingerprint in terrestrial precipitation sites is directly quantified. The analysis indicates that OMS temperature and relative humidity together explain 41% of the variability in precipitation deuterium excess in low‐ and mid‐latitude sites, meaning that most of the variability might be attributed to other processes. While 17O excess data are currently limited to a few sites, the analysis also clearly distinguishes that precipitation 17O excess is insensitive but deuterium excess is sensitive to OMS temperature under annual mean conditions. This finding validates an earlier theory‐based prediction. The quantitative appraisal of the OMS effect presented in this study assists in disentangling the complex controls of water isotope tracers. Key Points: Precipitation d‐excess and Δ′17O are affected by a combination of oceanic moisture source (OMS) conditions and other regional/local factorsOMS temperature and humidity together explain 41% of the variability in precipitation d‐excess in low‐ and mid‐latitudesThe theoretically contrasting sensitivity between d‐excess and Δ′17O to OMS temperature is validated [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Sandalwood and other high value tree species are under significant threat from illegal harvest. Illegal logging is an increasing problem contributing to deforestation, biodiversity loss, human rights abuses and funding transnational crime. Successful prosecution of illegal logging is hindered by a lack of methods to provide evidence of the origin of timber. New analytical techniques have been developed to trace timber back to its source. These methods, together with the establishment of sustainable sources of forest resources, can help protect vulnerable species by providing evidence to prosecute illegal harvest and ensure that commercially available forest products come from sustainable sources. Summary: Sandalwood is highly valued for its fragrant oil and has a long history of cultural and economic importance in many regions of the world. Historical overharvest and poor management have depleted natural populations of sandalwood, which are slow to regenerate. The increasing establishment of plantation sandalwood creates an alternative resource for the sandalwood industry while potentially relieving harvesting pressure on natural stands. Due to the high demand for sandalwood, remaining wild populations are still under threat from illegal logging and methods to identify the source of harvested sandalwood are needed. Laws and regulations aimed at preventing illegal harvest and possession of sandalwood have been put in place but cannot be enforced without the forensic tools to independently verify claimed origin or product quality. The high value of sandalwood combined with the difficulties in enforcing illegal logging laws makes these species particularly vulnerable to poaching. There is an immediate need to develop tools that can identify illegally sourced and adulterated sandalwood products. This paper reviews the current and developing scientific tools that can help identify and control illegal activity in sandalwood supply chains and provides recommendations for future research. Topics include isotope and DNA analysis for tracing illegally harvested sandalwood, chemical profiling for quality control of sandalwood oils, network and policy development to establish a framework for future regulation of the sandalwood trade. [ABSTRACT FROM AUTHOR]

Background: The mummified body of a small child was found in a sealed Barstow cast iron casket during construction activity in San Francisco in 2016. Using historical records and ancient DNA the child was determined to be Edith H. Cook. She was born 28 November, 1873 in the city of San Francisco, and died of "marasmus" on 13 October, 1876 also in San Francisco., Aims: Currently, there are few techniques for estimating human season of death in archaeological cases. Hydrogen isotope ratios (δ2H) in hair keratin is known to strongly correlate with drinking water. We explore δ2H in serial hair samples as a potential technique to estimate season of death by comparing the δ2H record from hair to the known date of death., Materials & Methods: Approximately 50 hairs were removed from the scalp, aligned from the root, and cut into 5cm serial sections, each representing approximately 2 weeks of growth, and the total sequence a total of 1 year of growth. δ2H was measured on each 5cm segment and compared to previously-reported δ13C, δ15N, and δ34S values., Results: δ2H in the serial hair samples ranged between -56‰ and -48‰, consistent with her water values recorded in surface waters from San Francisco, and follow a sinusoidal pattern. Decreasing δ2H in terminal samples before death suggest Fall as the season of death, consistent with the known date of death., Discussion: This test case shows that archaeological hair preserves a seasonal signature in the form of changing keratin δ2H values that correlate to changing δ2H in surface drinking water. Terminal values in root record water ingested during the final week(s) before death., Conclusions: We argue that this technique can be used to estimate season of death in future archaeological or forensic cases where hair has been preserved but date of death is unknown., (© 2020 Wiley Periodicals LLC.)

In this study a methodology for identifying the geographic origin of unidentified persons, their residence and moving patterns while providing information on lifestyle, diet and socio-economic status by combining stable isotopic data, with the biological information (isotopic composition of the skeleton), is presented. This is accomplished by comparing the oxygen isotopic composition of the spring water that individuals were drinking, during their living period, with the oxygen isotopic composition of their tooth enamel bioapatite. Spring water and teeth samples were collected from individuals from three different areas of Greece: North Greece, Central Greece and South Greece and isotopic analysis of δ 13 C and δ 18 O of tooth enamel bioapatite and δ 18 O of spring water were conducted. For these three areas the isotopic methodology is a promising tool for discriminating the provenance. Furthermore, as a case study, this methodology is applied to two archeological sites of Greece (Medieval-Thebes and Roman-Edessa) in order to determine paleomobility patterns.

Objective: The main objective of this study is to investigate diet patterns among rural and urban populations of the Center-West, Northeast, and Amazon regions of Brazil through the carbon and nitrogen isotopic composition of fingernails, recognizing that the extent of market integration is a key driver of food consumption., Materials and Methods: In the Center-West, Northeast, and Amazon regions of Brazil, fingernails were sampled in clusters encompassing a major city, town, and rural village. A total of 2,133 fingernails were analyzed. Fingernails were clipped by donors using fingernail clippers. In the laboratory, samples were cleaned then weighed in small tin capsules before being isotopically analyzed for carbon and nitrogen., Results: The overall mean δ 13 C and δ 15 N were -19.7 ± 2.8‰ and 10.6 ± 1.1‰, respectively. In the more remote villages, where access to food markets is more challenging, lower δ 13 C prevails, suggesting that Brazilian staple foods (rice, beans, and farinha) still dominate. In areas with easier access to food markets, δ 13 C values were higher, suggesting a change to a diet based on C 4 plants, typical of a Brazilian supermarket diet. The variability among inhabitants in the same location expressed by a significant inverse correlation between δ 13 C and δ 15 N fingernail values suggested that "market integration" does not affect everyone equally in each community., Discussion and Conclusion: The nutrition transition has not yet reached some remote villages in these regions of Brazil or that the nutrition transition has not yet reached all residents of these remote villages. On the other hand, in several villages there is a considerable adherence to the supermarket diet or that some residents of these villages are already favoring processed food., (© 2020 Wiley Periodicals, Inc.)

Rationale: The use of multi-isotopic analysis (δ 2 H, δ 13 C, δ 15 N, δ 18 O, and δ 34 S values) of modern human body tissues for provenancing of unknown individuals in forensics is increasing. Tooth dentine develops during childhood and adolescence, therefore providing geographical information from that period of life. Tooth apatite δ 18 O values are commonly used for the reconstruction of drinking water values, and H-C-N-S isotope ratios in collagen supply additional information about the composition of diet. We tested if dentine collagen δ 2 H values provide similar information to apatite δ 18 O values with a proof-of-concept study., Methods: Tooth samples were taken from modern-day individuals born in different regions of the world. Apatite and collagen were prepared from dentine. Stable isotope analyses were performed on apatite phosphate oxygen (δ 18 O phos ); oxygen and carbon of the structural carbonate (δ 18 O carb , δ 13 C carb ); and hydrogen, carbon, nitrogen, and sulfur of the collagen (δ 2 H coll, δ 13 C coll , δ 15 N, δ 34 S)., Results: δ 18 O phos , δ 18 O carb , and δ 2 H coll values are highly correlated in modern human dentine. There are significant relationships of δ 18 O values in the apatite fraction and δ 2 H values in the collagen fraction with local δ 18 O and δ 2 H precipitation values, respectively. Pearson correlation coefficients indicate no direct relationship between δ 15 N values and the isotope ratios of any other element. Weak relationships exist between collagen δ 34 S values and δ 18 O carb or δ 18 O phos values., Conclusions: The highly significant correlation of δ 18 O phos , δ 18 O carb , and δ 2 H coll values in the modern human dentine implies that measurement of δ 2 H values in collagen or δ 18 O values in bioapatite will provide reliable information about the climate at the person's whereabouts., (© 2019 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd.)

Trade in pangolins is illegal, and yet tons of their scales and products are seized at various ports. These large seizures are challenging to process and comprehensively genotype for upstream provenance tracing and species identification for prosecution. We implemented a scalable DNA barcoding pipeline in which rapid DNA extraction and MinION sequencing were used to genotype a substantial proportion of pangolin scales subsampled from 2 record shipments seized in Singapore in 2019 (37.5 t). We used reference sequences to match the scales to phylogeographical regions of origin. In total, we identified 2346 cytochrome b (cytb) barcodes of white-bellied (Phataginus tricuspis) (from 1091 scales), black-bellied (Phataginus tetradactyla) (227 scales), and giant (Smutsia gigantea) (1028 scales) pangolins. Haplotype diversity was higher for P. tricuspis scales (121 haplotypes, 66 novel) than that for P. tetradactyla (22 haplotypes, 15 novel) and S. gigantea (25 haplotypes, 21 novel) scales. Of the novel haplotypes, 74.2% were likely from western and west-central Africa, suggesting potential resurgence of poaching and newly exploited populations in these regions. Our results illustrate the utility of extensively subsampling large seizures and outline an efficient molecular approach for rapid genetic screening that should be accessible to most forensic laboratories and enforcement agencies., (© 2023 Nparks and The Authors. Conservation Biology published by Wiley Periodicals LLC on behalf of Society for Conservation Biology.)

Rationale: Hydrogen isotope (δ2H) analysis of keratinaceous bulk tissues has been used in forensic science to reconstruct an individual's travel history or determine their region‐of‐origin. Here, we use a compound‐specific approach to examine patterns of individual amino acid δ2H values in relation to those of local tap water, bulk scalp hair tissues, and region‐of‐origin. Methods: We measured δ2H values of amino acids in anonymously collected scalp hair (n = 67) and tap water from 28 locations in the United States. Samples were hydrolyzed into their constituent amino acids, derivatized alongside in‐house reference materials, and analyzed in triplicate using a GC‐C‐IRMS system. Results: Non‐essential amino acid (AANESS) δ2H values and their corresponding tap water samples varied systematically across continental regions. Hydrogen isotope values of alanine, glutamic acid, and glycine were significantly correlated with tap water and an estimated 42%–51% of the hydrogen atoms in these AANESS were derived from tap water. We used linear discriminate analysis (LDA) to explore regional patterns in scalp hair bulk tissue and amino acid δ2H values. For the model that included AANESS data, 87% of the variance was explained by the first linear discriminant axis (LD1), and was driven by bulk hair tissue, alanine, and proline. This model had an overall 72% successful reclassification with samples from the south and northwest regions reclassifying correctly 92% and 78% of the time, respectively. For the model that included AAESS data, LD1 explained 81% of the variation and was driven bulk hair, threonine, valine, phenylalanine, and isoleucine. The overall reclassification rate for the model that included AAESS was 70%. Conclusions: Our findings suggest that δ2H analyses of AANESS and AAESS could help improve geolocation models for human and wildlife forensics by simultaneously providing information about both dietary and tap water inputs of hydrogen to tissue synthesis. [ABSTRACT FROM AUTHOR]

Obtaining the maximum amount of wax from honey bees is the basis of beekeeping technological processes. However, the intensification of its production leads to partial exhaustion of the honey bee's body. Therefore, today the question of researching factors that will contribute to their body's recovery is relevant. The article provides data on the influence of the strength of colonies, the type, and the amount of feed on the body's functional state of honey bees when obtaining wax. The obtained research results indicate that wax secretion is proportionally dependent on the presence in nature and the intensity of carbohydrate (nectar, sugar syrup) and protein (pollen) food entering the nest. As daily nectar intake increases for every 250 g, the wax productivity of a 700 g family increases by an average of 43.18 g (from 35.62 to 54.14 g). When receiving pollen in the amount of 500-550 g, wax secretion is 190-210 g. In the complete absence of honey collection, wax secretion in bees stops. It was established that a large amount of honeycombed honey practically does not affect the bees' wax secretion. At the same level of food supply, with an increase in the strength of the family, its total wax secretion increases due to an increase in the number of wax-producing workers. From colonies weighing 1.5 and 4.5 kg, 667.05 and 1484.55 g of wax were obtained, respectively. At the same time, the individual wax-secreting activity, which is calculated per unit mass of workers, decreases from 444.7 g to 329.9 g of wax/1 kg of bees. This is due to a decrease in the nutrition of waxproducing individuals, as the number of bees increases with the same intensity of carbohydrate food entering the nest. It was also established that the amount of wax released simultaneously is proportional to the number of young bees in the colonies. [ABSTRACT FROM AUTHOR]

Stable isotope ratios (isotope values) of surface water reflect hydrological pathways, mixing processes, and atmospheric exchange within catchments. Development of maps of surface water isotope values (isoscapes) is limited by methods to interpolate point measures across river networks. Catchment attributes that alter surface water isotope values affect downstream river reaches via flow, but some attributes such as artificial dams are no more likely to affect nearby unconnected catchments than distant ones. Hence, simple distance-based geospatial and statistical interpolation methods used to develop isoscapes for precipitation and terrestrial systems are less appropriate for river networks. We used a water-balance-based method to map long-term average δ2H and δ18O for New Zealand rivers, incorporating corrections using catchment environmental predictors. Inputs to the model are national rainfall precipitation isoscapes, a digital elevation layer, a national river water isotope monitoring dataset (3 years of monthly sampling at 58 sites), and river environmental databases covering around 600 000 reaches and over 400 000 km of rivers. Much of the spatial variability in δ2H and δ18O of New Zealand river water was explained using the initial combination of precipitation isoscapes and a simple water balance model. δ2H and δ18O isoscapes produced by subsequently applying residuals from the water balance model as a correction factor across the river network using regression kriging showed improved fits to the validation data compared to the correction using ordinary kriging. Predictors of high importance in the regression included upstream lake and wetland area, which was not strongly spatially autocorrelated nationally. Hence, additional hydrological process information such as evaporation effects can be incorporated into river isoscapes using regression kriging of residuals. The resulting isoscapes have potential applications in ecological, hydrological, and provenance studies that consider differences between surface water isotope values and those of other components of the hydrological cycle (e.g. subsurface runoff or local precipitation). [ABSTRACT FROM AUTHOR]

Water sources carry chemicals that can have a significant impact on the water environment of a river network, and understanding the contribution of different water sources to the river network can help to manage the pollution of the river network at its source. The hydrological connectivity of a river network affects the self‐purification capacity and flood prevention capacity of the river. Therefore, an isotope tracer approach was applied to determine the contribution rate of different water bodies to a river network and hydrological connectivity was quantified by introducing the retention rate. Changzhou city was selected as the study area because it is an urbanized city with the characteristics of a plain river network and it is faced with poor hydrological connectivity due to artificial constructions (dams and pumps) and human activity (urbanization). River water, well water (shallow groundwater), lake water and rainfall were collected during the flood season and nonflood season, and hydrogen and oxygen isotopes were determined. The temporal and spatial variations in hydrogen and oxygen isotopes in different water bodies and the state of the water cycle in different water bodies were analysed. IsoSource and MixSIAR models were established to analyse the contribution rate of river network water sources in the study area, and their effectiveness was compared. The results of the MixSIAR model were selected to evaluate the hydrological connectivity of the river network in the study area, providing a method to quantify the hydrological connectivity of specific rivers of the river network in Changzhou city. This method could also be applied to other urban plain river network areas to study river connectivity. [ABSTRACT FROM AUTHOR]

Objectives: Intentional cranial modification and diet serve as markers of identity. Here, we explore the intersection between the body and social persona in the San Pedro oases through the complex relationship(s) between these markers and other aspects of society and the individual. Methods: Skeletal remains of 1190 individuals were analyzed for evidence of intentional head shaping and classed as unmodified, tabular, or annular. Stable carbon and nitrogen isotope analyses of bone (n = 203) focused on the contribution of C3 plants, C4/CAM plants, beans, and terrestrial animal meat per the Bayesian model, FRUITS. Strontium isotope data from dental enamel was considered for more detailed analyses. Results: Cranial modification was present in 520 individuals (43.7%; N = 1190). Modification was significantly more common among females (χ2 = 7.403, p = 0.007). There was no significant difference in presence or type between periods. Average values for the four modeled food groupings differ significantly. There is a significant difference in consumption of C4/CAM plants by those individuals with modified heads consuming more (26.5 ± 9.9% vs. 23.6 ± 9.4%, Wilcoxon signed‐rank test, p < 0.05). In the Middle Period sample, males consume significantly more C4/CAM plants (p < 0.05) and females more C3 plants (p < 0.01). Four of those with outlier C4 values were analyzed for strontium, yielding values outside the "local" range. Conclusions: As head shaping is permanently imposed in infancy while dietary patterns are the consequence of ongoing choices and constraints in the social and ecological environment, these markers of identity are not parallel. The numerous points of intersection between these markers and other aspects of identity are highlighted. [ABSTRACT FROM AUTHOR]

Across populations, human morbidity and mortality risks generally follow clear gradients, with socially‐disadvantaged individuals and groups tending to have higher morbidity and mortality at all life stages relative to those more socially advantaged. Anthropologists specialize in understanding the proximate and ultimate factors that shape variation in human biological functioning and health and are therefore well‐situated to explore the relationships between social position and health in diverse ecological and cultural contexts. While human biologists have developed sophisticated methods for assessing health using minimally‐invasive methods, at a disciplinary level, we have room for conceptual and methodological improvement in how we frame, measure, and analyze the social inequities that might shape health inequities. This toolkit paper elaborates on some steps human biologists should take to enhance the quality of our research on health inequities. Specifically, we address: (1) how to frame unequal health outcomes (i.e., inequalities vs. disparities vs. inequities) and the importance of identifying our conceptual models of how these inequities emerge; (2) how to measure various axes of social inequities across diverse cultural contexts, and (3) approaches to community collaboration and dissemination. We end by discussing (4) future directions in human biology research of health inequities, including understanding the ultimate causes of sensitivity to social inequities and transitioning from research to action. [ABSTRACT FROM AUTHOR]

This study sought to explore the relationship between teacher leadership and teacher self-efficacy with the mediating role of teacher professional learning. The study employed a cross-sectional quantitative design with data compiled among public elementary, middle, and high schools across different regions of Turkey. We employed structural equation model (SEM) to estimate the structural relationships between teacher leadership capacity at school, teacher professional learning, and teacher self-efficacy. The results revealed a positive and statistically significant relationship between all three variables. While the effect sizes for the relationship between teacher professional learning and teacher self-efficacy, and between teacher leadership and teacher self-efficacy were small, there was a large effect size for the relationship between teacher leadership and teacher professional learning. [ABSTRACT FROM AUTHOR]

In western and north-western Europe there has been a growing focus on exploring how major economic, political, and social changes during the Medieval period impacted the lived experience of different populations and sectors of society. Stable isotope analysis has proven particularly powerful in this regard, providing direct insights into the long-term diets of individuals and communities. Despite experiencing similarly dramatic social reconfigurations and changes, eastern Europe has, however, received far less attention in this regard. The territory of Belarus has, especially, so far remained a relative blank spot on the bioarchaeological map of Europe, though cities such as Polack emerged rapidly as key nodes within a growing economic and religious network. To gain direct insight into the diets of inhabitants of the Polack region of Belarus in the 11-18th centuries, we applied stable carbon and nitrogen isotope analysis to bone and dentine collagen from human (n = 143) and animal (n = 105) individuals from the city of Polack and surrounding rural sites. Results indicate a diet based on C3 terrestrial resources, which did not differ between sexes and showed limited variation over time. Contrary to expectations, it appears that animal products were commonly consumed by rural dwellers, but no significant reliance on fish resources or millet consumption is found. In contrast to examples from western Europe, we argue that the diets in the city and the surrounding villages remained broadly similar for the majority of the population, and similar to commoners analysed in Poland and Lithuania, perhaps suggestive of slightly different economic changes operating in this part of the Medieval world. [ABSTRACT FROM AUTHOR]

Triple oxygen isotope ratios have been increasingly acknowledged as useful hydrological tracers but measuring both 17O/16O and 18O/16O ratios with meaningful precision has been challenging due to the much lower natural abundance of 17O than 16O and even 18O. In this study, in line with the advancement of laser-based techniques and their growing applications, we demonstrate how to optimize the determination of 17O-excess (Δ17O = ln(δ17O + 1) − 0.528 × ln(δ18O + 1)) in natural water using a commercial wavelength-scanned cavity ring-down spectrometer (WS-CRDS). We particularly focus on how to decide the injection numbers of samples and standard solutions utilized for normalization of sample results to the VSMOW-SLAP reference scale. With a measurement strategy aimed at an uncertainty better than 10 per meg (1σ), the Δ17O of Greenland Ice Sheet Precipitation (GISP) is determined to be 24 ± 9 per meg (n = 104), in agreement with previous literature values. By applying this method to Antarctic glacial ice, it is shown to be useful in detecting the seasonality of Δ17O values in Antarctic precipitation. Our approach represents an underlying analytical method that provides guidelines for determining Δ17O from various types of natural waters. [ABSTRACT FROM AUTHOR]

Beeswax is the secretion of a bee's abdominal glands. According to its chemical composition, beeswax belongs to the group of lipids and it is formed a very complex composition of about 300 organic substances. It mostly contains different classes of esters, of which the majority are monoesters. Alkaline hydrolysis of esters (saponification) is a significant chemical reaction in the chemical industry. The saponification value together with the melting point, the acid value and the ester value represent the basic physico-chemical parameters for determining the quality, authenticity and potential faking of beeswax. Saponification has not been fully researched, nor is it an efficient process. Many researchers examine the reaction of ester hydrolysis in order to obtain a process with as little energy consumption as possible, a higher yield and a shorter duration of the hydrolysis process. The main factors that affect the wax saponification process are the size and structure of the alcohol and acid that make up the ester, the wax/alkali mass (molar) ratio, the duration of the process and the temperature of the reaction. With an increase in the mass of the wax sample, i.e. an increase in the wax/alkali mass ratio, the saponification value, i.e. the degree of hydrolysis, decreases. With an increase in the duration of hydrolysis and temperature, the degree of hydrolysis of wax esters, increases. The highest saponification value (SV=79.3; degree of hydrolysis 76.5%) was achieved by the hydrolysis of 0.5 g of wax at a temperature of 105°C for 150 minutes. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Wildlife / Yesheng Dongwu Xuebao is the property of Chinese Journal of Wildlife Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Living labs (LLs) have emerged as an interface for higher education institutions to collaborate with companies, citizens, non-profit and government organizations to address a variety of problems around social challenges and sustainable development. In this systematic literature review, we summarize the existing knowledge on how universities shape and manage the LLs they are associated with and how they align with their core missions of education and research and—in particular—their social missions. Following PRISMA guidelines for a systematic literature review (SLR), we analyzed journal articles, conference papers, and book chapters published between 2008 and 2020, capturing 93 university-governed LL experiences from across the world. Our findings show that LLs are developing from bottom-up initiatives, often at the fringe of higher education institutions, towards more self-standing entities implementing strategies to undertake social outreach activities. LLs require their host universities to intensify the relationships with their stakeholders and work on capacity building and focus on inter- and transdisciplinary research methodologies. Finally, our literature review points to the need for further research on the hybrid governance approaches displayed by LLs, particularly looking at the roles and responsibilities of academics involved in managing LL initiatives. [ABSTRACT FROM AUTHOR]

The deuterium excess (d‐excess) of precipitation varies seasonally at sites across the globe, an observation that has often been linked to seasonal changes in oceanic evaporation conditions, continental moisture recycling, and subcloud raindrop re‐evaporation. However, there have been very few studies to quantify and evaluate the relative importance of these processes. Here, we revisit the mechanisms of precipitation d‐excess seasonality in low‐latitudes and mid‐latitudes through a new analysis of precipitation isotope databases along with climate reanalysis products and moisture tracking models. In low‐latitudes, the raindrop re‐evaporation effect, indicated by local relative humidity, exerts a strong and prevalent control on observed d‐excess seasonality and overprints the effect of oceanic evaporation conditions. In mid‐latitudes, the effect of oceanic evaporation conditions becomes stronger and seems dominant in the observed d‐excess seasonality. However, the ultimate d‐excess signals are produced after complex modulations by several reinforcing or competing processes, including prior distillations, moisture recycling, supersaturation in snow formation, and raindrop re‐evaporation. Among these processes, substantial increases in the proportion of recycled moisture during the warm and dry season do not produce higher precipitation d‐excess in mid‐latitude continental interiors. We develop a simple seasonal water storage model to show that contributions of previously evaporated residual water storage and higher transpiration fractions may lead to relatively low d‐excess in evapotranspiration fluxes during periods of enhanced continental moisture recycling. This study underscores the ubiquitous nonconservative behavior in d‐excess throughout the water cycle, as opposed to using d‐excess as a simple tracer for remote conditions at oceanic moisture sources. Key Points: Deuterium excess in precipitation is affected by multiple processes in the water cycle and an interpretative framework is neededOceanic evaporation and raindrop re‐evaporation effects dominate deuterium excess seasonality in mid‐latitudes and low‐latitudes, respectivelySeasonal shifts in moisture recycling weakly affect deuterium excess due to terrestrial water storage and evapotranspiration partitioning [ABSTRACT FROM AUTHOR]

Elephants are on the verge of extinction due to extensive poaching to obtain ivory and illegal income. According to international law, the trade in ivory of African elephants is outlawed, with a few exceptions, as for example in European Union for antique ivory obtained before 1947. There is basically only one physical method for determining the age of ivory and that is radiocarbon dating. The method uses artificially temporarily enhanced 14C content in the atmosphere to date relevant samples with high resolution. Since this advantage is slowly fading, the question arises of how to fill in the loss of the resolution. One possibility is exploiting the chronology of ivory. This work studies a whole elephant tusk and uses radiocarbon dating of samples obtained longitudinally and transversely from along the tusk to analyse the growth rate. [ABSTRACT FROM AUTHOR]

Stable hydrogen isotope ratios (δ2H values) in structural hydroxyl groups of pedogenic clay minerals are inherited from the surrounding water at the time of their formation. Only non‐exchangeable H preserves the environmental forensic and paleoclimate information (δ2Hn value). To measure δ2Hn values in structural H of clay minerals and soil clay fractions, we adapted a steam equilibration method by accounting for high hygroscopicity. Our δ2Hn values for USGS57 biotite (−95.3 ± SD 0.9‰) and USGS58 muscovite (30.7 ± 1.4‰) differed slightly but significantly from the reported δ2H values (−91.5 ± 2.4‰ and −28.4 ± 1.6‰), because the minerals contained 1.1%–4.4% of exchangeable H. The low SD of replicate measurements (n = 3) confirmed a high precision. The clay separation method including destruction of Fe oxides, carbonates and soil organic matter, and dispersion did not significantly change the δ2Hn values of five different clay minerals. However, we were unable to remove all organic matter from the soil clay fractions resulting in an estimated bias of 1‰ in two samples and 15‰ in the carbon‐richest sample. Our results demonstrate that δ2Hn values of structural H of clay minerals and soil clay fractions can be reliably measured without interference from atmospheric water and the method used to separate the soil clay fraction. Highlights: We tested steam equilibration to determine stable isotope ratios of structural H in clay.Gas‐tight capsule sealing in Ar atmosphere was necessary to avoid remoistening.Our steam equilibration method showed a high accuracy and precision.The clay separation method did not change stable isotope ratios of structural H in clay. [ABSTRACT FROM AUTHOR]

Copyright of Revista Argentina de Antropología Biológica is the property of Revista Argentina de Antropologia Biologica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Urban water supply systems (WSS) are complex and challenging to manage since the properties of water in the WSS change from source to the end user over time. However, understanding these changes requires a more profound knowledge of the WSS. This study describes the urban water cycle within the WSS of Ljubljana, Slovenia, where different water parameters such as temperature, electrical conductivity, total alkalinity, δ2H, δ18O, and δ13CDIC were monitored from September to November 2018. Altogether 108 samples were collected, including from the source (3) and at different levels of the WSS: wells (41), joint exits from water pumping stations (7), reservoirs (22), water treatment locations (2), drinking fountains (13), taps (19) and wastewater system (1). The data show that although the ranges of δ2H and δ18O values were small, each well is represented by a unique fingerprint when considering additional parameters. A statistically significant difference was observed between sampling months, and temperature and most parameters showed higher variability within the wells than across the WSS, suggesting a more unified WSS. Finally, based on δ13CDIC values, a distinction could be made between river/groundwater interactions within the WSS and between shallower and deeper wells and their distance from the river bank. [ABSTRACT FROM AUTHOR]

The hydroclimatology of Northern South America responds to the coupling between the Pacific and Atlantic oceans, the Amazon–Andes interactions, and the orographic barrier of the regional Andes. The relative contributions of oceanic and terrestrial moisture sources have been mostly evaluated in modelling studies, with limited observational data for validation. We combine observations from stable isotopes in precipitation and output from the Lagrangian moisture trajectory tracking model FLEXPART to characterize and contrast the relative contribution of oceanic (from the Atlantic and the Pacific) and terrestrial (from different regions in the continent) moisture sources to mean monthly precipitation in the Andes and Caribbean regions of Colombia. Our results indicate that most moisture becoming rain in the region has an atmospheric residence time that deviates from commonly assumed 10 days. These residence times vary between source and sink regions from 1 day in the case of recycling to more than 10 days in Andean precipitation originating in the Atlantic Ocean. Common integration times for both regions from all sources are commonly in the order of three to 7 days. Most precipitation in the region comes from terrestrial sources including moisture recycling from the same region (>30% for all months), the Orinoco River basin (up to 28% in April), and the northern Amazon basin (up to 17% in June, July, and August); followed by individually considered oceanic sources including the Tropical South Pacific (up to 30% monthly in October, November and December) and Tropical North Atlantic (up to 30% monthly for January). The fact that a significant proportion of rainfall is recycled highlights that water availability in the Andean and Caribbean regions of Colombia could potentially be altered by current widespread and pervasive changes in vegetation cover. More generally, our results highlight the need to assess the hydrological consequences of land cover change in South America, particularly in a country like Colombia where water, food, and energy security all depend directly on precipitation. [ABSTRACT FROM AUTHOR]

This study investigated the relationship between 18 O and 2 H isotopes in samples of Mexican hair and drinking water. The purpose of this study was twofold: to quantify the relationship between isotopes in Mexican hair and tap water, in order to understand the impact of water stress and differing socioeconomic status on accurate predictions of drinking water; and to determine whether currently existing semimechanistic models can accurately represent the relationship between hair and tap water. This study used a subset of paired samples of human hair ( n = 62) and tap water ( n = 76). Isotope values in tap water ranged from -11.4‰ to -4.3‰ and -79.1‰ to -22.5‰, and in hair from +9.5‰ to +16.1‰ and -90.8‰ to -53.7‰, for δ 18 O and δ 2 H, respectively. The most depleted δ 18 O and δ 2 H hair values came from individuals in the state of Morelos. For modern Mexican populations, positive correlations between isotopes in hair and water were not significant, with correlation coefficients r = 0.61 ( p = 0.05) and r = 0.60 ( p = 0.06) for 18 O and 2 H, respectively. Error-in-variables regression yielded linear fits that were somewhat better for 2 H relative to 18 O: δ 18 O h = 0.183 [±0.132] δ 18 O tw + 15.7 [±0.9]‰ ( r 2 = 0.23); δ 2 H h = 0.181 [±0.076] δ 2 H tw - 64.0 [±3.0]‰ ( r 2 = 0.34). In short, data from this Mexican population did not exhibit the strong relationships between isotope values of 18 O and 2 H in tap water and hair that have been characteristic of other populations studied to date. Given the economic stratification of this region and the poor correlation between hair and water samples, the authors considered the possibility that l , the fraction of the diet derived from local sources, and f s , the fraction of nonexchangeable H in keratin that was fixed in vivo, are local rather than global parameters for this population. The authors estimated different values of l and f s for each location. Given the anticipated importance of the nonlocal dietary contribution, they treated the isotopic content of nonlocal food and the offset parameters for predicting isotopes in locally derived food as tuning parameters and compared the results with parameters based on the American supermarket diet. They found that, although O and H isotopes in water and hair maintained similar geographic distributions, O and H isotopes in tap water explained only a small part of the variation observed in hair samples. Compared to the standard American supermarket diet, the Mexican estimates for nonlocal diet and local diet offsets predicted regional distributions of l and f s that cleanly segregated urban areas from rural towns.

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: This study examines the biological sex and geographical origins of adolescents buried at the St Mary Magdalen leprosarium (Winchester, UK). The data are combined with archaeological and palaeopathological evidence to broaden the understanding of mobility and its relationship to leprosy and leprosaria in Medieval England. Materials and Methods: Nineteen individuals (~10–25 at death) with skeletal lesions diagnostic of leprosy were analyzed using standard osteological methods. Amelogenin peptides were extracted from five individuals whose biological sex could not be assessed from macroscopic methods. Enamel samples were analyzed to produce 87Sr/86Sr and δ18O values to explore mobility histories. Results: Amelogenin peptides revealed three males and two females. Tooth enamel samples provided an 87Sr/86Sr ratio range from 0.7084 to 0.7103 (mean 0.7090, ±0.0012, 2σ). δ18OP values show a wide range of 15.6‰–19.3‰ (mean 17.8 ± 1.6‰ 2σ), with corresponding δ18ODW values ranging from −9.7‰ to −4.1‰ (mean −6.3 ± 2.4‰ 2σ). Discussion: Amelogenin peptide data reveal the presence of adolescent females with bone changes of leprosy, making them the youngest confirmed females with leprosy in the archaeological record. Results also show at least 12 adolescents were local, and seven were from further afield, including outside Britain. Since St. Mary Magdalen was a leprosarium, it is possible that these people traveled there specifically for care. Archaeological and palaeopathological data support the notion that care was provided at this facility and that leprosy stigma, as we understand it today, may not have existed in this time and place. [ABSTRACT FROM AUTHOR]

The Scientific Analysis Directorate of the U.S. Department of Defense's (DoD) Defense POW/MIA Accounting Agency (DPAA) is a unique entity within the U.S. Government. This agency currently houses the world's largest, accredited skeletal identification laboratory in the world, in terms of the size of the scientific staff, global mission, and number of annual identifications. Traditional forensic anthropology is used for the formation of a biological profile (biological sex, stature, population affinity/ancestry, and age) as well as trauma and pathologies that may be compared with historical records and personnel files. Since World War II, various scientists associated with DoD have conducted base‐line research in support of the identification of U.S. war dead, including, but not limited to, histology, the use of chest radiography and clavicle comparison, and statistical models to deal with commingling issues. The primary goal of the identification process of the Scientific Analysis Directorate is to use all available historical, field, and forensic methods to establish the most robust and defendable identification as scientifically and legally possible. This article is categorized under:Forensic Anthropology > Age AssessmentForensic Anthropology > Sex AssessmentForensic Anthropology > Ancestry Determination [ABSTRACT FROM AUTHOR]

In 2014, 157 years after the Sepoy Mutiny of 1857, several unidentified human skeletons were discovered in an abandoned well at Ajnala, Punjab. The most prevailing hypothesis suggested them as Indian soldiers who mutinied during the Indian uprising of 1857. However, there is an intense debate on their geographic affinity. Therefore, to pinpoint their area of origin, we have successfully isolated DNA from cementum-rich material of 50 good-quality random teeth samples and analyzed mtDNA haplogroups. In addition to that, we analyzed 85 individuals for oxygen isotopes (δ18O values). The mtDNA haplogroup distribution and clustering pattern rejected the local ancestry and indicated their genetic link with the populations living east of Punjab. In addition, the oxygen isotope analysis (δ18O values) from archaeological skeletal remains corroborated the molecular data and suggested the closest possible geographical affinity of these skeletal remains toward the eastern part of India, largely covering the Gangetic plain region. The data generated from this study are expected to expand our understanding of the ancestry and population affinity of martyr soldiers. [ABSTRACT FROM AUTHOR]

Despite the growing appeal of teacher leadership and teacher collaboration, we know little about the relationship between teacher leadership roles and collaboration. In this study, we use surveys (n = 523) and interviews (n = 47) of teachers to examine whether teacher leadership roles were associated with collaboration. We find that collaboration was an incentive to pursue a teacher leadership role and teacher leaders perceived their role improved and increased collaboration with peers. Teacher leaders' perceptions varied significantly by role type, school level, and school effectiveness. These findings offer promising evidence for school leaders interested in using teacher leadership to spur collaboration among teachers. [ABSTRACT FROM AUTHOR]

The analytical techniques applied to verify honey authenticity are multifaceted and often result in complex data rich certificates of analysis that are open to interpretation and may be opaque to stakeholders without specialist knowledge. In these cases, the drawing of an independent overarching opinion is challenging. Two questions arise: (Q1) Is it acceptable to report interpretation, particularly if it is adverse, without exhibiting the supporting data? (Q2) How may a valid overarching opinion on authenticity be derived from a large, partially conflicting, dataset? To Q1, it is demonstrated that full disclosure of the data used in interpretation is mandatory. To Q2 it is proposed, with worked examples, to adopt 'evaluative reporting'; a formalised likelihood ratio thought process used in forensic science for evaluation of findings and their strength assessment. In the absence of consensus on techniques for honey authenticity adoption of reporting conventions will allow objective assessments of reports, with equity to all and provide a better basis to identify and address fraud. [ABSTRACT FROM AUTHOR]

In the field of food traceability analysis, stable isotope ratio analysis is a relatively new technology. The measurement and calibration of isotope data depends on stable isotope reference materials. The isotope reference materials commonly used are chemical matrix. These reference materials are inappropriate-especially for food matrix origin analysis. This review focuses on the research progress on stable isotope reference materials by (1) classification of stable isotope reference materials, (2) application of stable isotope reference materials, and (3) research progress of preparation of stable isotope reference materials. Selecting appropriate isotope reference materials will help improve the effectiveness of stable isotope ratio analysis in food traceability. By cooperation with different laboratories, high-quality isotope reference materials can be prepared to add new food matrix types to provide more choices for users. [ABSTRACT FROM AUTHOR]

Vast stores of millennial‐aged soil carbon (MSC) in permafrost peatlands risk leaching into the contemporary carbon cycle after thaw caused by climate warming or increased wildfire activity. Here we tracked the export and downstream fate of MSC from two peatland‐dominated catchments in subarctic Canada, one of which was recently affected by wildfire. We tested whether thermokarst bog expansion and deepening of seasonally thawed soils due to wildfire increased the contributions of MSC to downstream waters. Despite being available for lateral transport, MSC accounted for ≤6% of dissolved organic carbon (DOC) pools at catchment outlets. Assimilation of MSC into the aquatic food web could not explain its absence at the outlets. Using δ13C‐Δ14C‐δ15N‐δ2H measurements, we estimated only 7% of consumer biomass came from MSC by direct assimilation and algal recycling of heterotrophic respiration. Recent wildfire that caused seasonally thawed soils to reach twice as deep in one catchment did not change these results. In contrast to many other Arctic ecosystems undergoing climate warming, we suggest waterlogged peatlands will protect against downstream delivery and transformation of MSC after climate‐ and wildfire‐induced permafrost thaw. [ABSTRACT FROM AUTHOR]

The hydrologic cycle couples the Earth's energy and carbon budgets through evaporation, moisture transport, and precipitation. Despite a wealth of observations and models, fundamental limitations remain in our capacity to deduce even the most basic properties of the hydrological cycle, including the spatial pattern of the residence time (RT) of water in the atmosphere and the mean distance traveled from evaporation sources to precipitation sinks. Meanwhile, geochemical tracers such as stable water isotope ratios provide a tool to probe hydrological processes, yet their interpretation remains equivocal despite several decades of use. As a result, there is a need for new mechanistic tools that link variations in water isotope ratios to underlying hydrological processes. Here we present a new suite of "process‐oriented tags," which we use to explicitly trace hydrological processes within the isotopically enabled Community Atmosphere Model, version 6 (iCAM6). Using these tags, we test the hypotheses that precipitation isotope ratios respond to parcel rainout, variations in atmospheric RT, and preserve information regarding meteorological conditions during evaporation. We present results for a historical simulation from 1980 to 2004, forced with winds from the ERA5 reanalysis. We find strong evidence that precipitation isotope ratios record information about atmospheric rainout and meteorological conditions during evaporation, but little evidence that precipitation isotope ratios vary with water vapor RT. These new tracer methods will enable more robust linkages between observations of isotope ratios in the modern hydrologic cycle or proxies of past terrestrial environments and the environmental processes underlying these observations. Plain Language Summary: The heavy‐to‐light isotope ratio of atmospheric water, which records a wide array of water cycle processes, is readily observable and has therefore long been thought to hold much promise to help examine changes in water cycle processes. However, as multiple processes influence water isotope ratios, it is often difficult to tie observations to hydrological processes without using an atmospheric model. In this work, we develop a comprehensive set of numerical tracers to elucidate water cycle processes in the atmosphere from source to sink. In the context of water isotope ratios, these numerical tracers provide a method to explicitly test hypotheses of how variations in water isotope ratios map to underlying hydrological processes. The new tracers we outline here permit a fuller understanding of the hydrologic cycle and allow new ways to test model parameterizations and understand the processes governing hydrologic change. Key Points: Process‐based tracers in iCAM6 allow for expanded hypothesis testing of water cycle change and more informed use of water isotope ratiosThe degree of parcel rainout is a primary control on both δ18O and d‐excess, consistent with Rayleigh theoryWater vapor residence time does not strongly influence precipitation δ18O, but evaporative conditions influence precipitation d‐excess [ABSTRACT FROM AUTHOR]

Complex networks of both natural and engineered flow paths control the hydrology of streams in major cities through spatio‐temporal variations in connection and disconnection of diverse water sources. We used spatially extensive and temporally intensive sampling of water stable isotopes to disentangle the hydrological sources of the heavily urbanized Panke catchment (~220 km2) in the north of Berlin, Germany. The isotopic data enabled us to partition stream water sources across the catchment using a Bayesian mixing analysis. The upper part of the catchment streamflow is dominated by groundwater (~75%) from gravel aquifers. In dry summer periods, streamflow becomes intermittent in the upper catchment, possibly as a result of local groundwater abstractions. Storm drainage dominates the responses to precipitation events. Although such events can dramatically change the isotopic composition of the upper stream network, storm drainage only accounts for 10%–15% of annual streamflow. Moving downstream, subtle changes in sources and isotope signatures occur as catchment characteristics vary and the stream is affected by different tributaries. However, effluents from a wastewater treatment plant (WWTP), serving 700,000 people, dominate stream flow in the lower catchment (~90% of annual runoff) where urbanization effects are more dramatic. The associated increase in sealed surfaces downstream also reduces the relative contribution of groundwater to streamflow. The volume and isotopic composition of storm runoff is again dominated by urban drainage, though in the lower catchment, still only about 10% of annual runoff comes from storm drains. The study shows the potential of stable water isotopes as inexpensive tracers in urban catchments that can provide a more integrated understanding of the complex hydrology of major cities. This offers an important evidence base for guiding the plans to develop and re‐develop urban catchments to protect, restore, and enhance their ecological and amenity value. [ABSTRACT FROM AUTHOR]

Understanding physiological traits and ecological conditions that influence a species reliance on metabolic water is critical to creating accurate physiological models that can assess their ability to adapt to environmental perturbations (e.g., drought) that impact water availability. However, relatively few studies have examined variation in the sources of water animals use to maintain water balance, and even fewer have focused on the role of metabolic water. A key reason is methodological limitations. Here, we applied a new method that measures the triple oxygen isotopic composition of a single blood sample to estimate the contribution of metabolic water to the body water pool of three passerine species. This approach relies on Δ'17O, defined as the residual from the tight linear correlation that naturally exists between δ17O and δ18O values. Importantly, Δ'17O is relatively insensitive to key fractionation processes, such as Rayleigh distillation in the water cycle that have hindered previous isotope-based assessments of animal water balance. We evaluated the effects of changes in metabolic rate and water intake on Δ'17O values of captive rufous-collared sparrows (Zonotrichia capensis) and two invertivorous passerine species in the genus Cinclodes from the field. As predicted, colder acclimation temperatures induced increases in metabolic rate, decreases in water intake, and increases in the contribution of metabolic water to the body water pool of Z. capensis , causing a consistent change in Δ'17O. Measurement of Δ'17O also provides an estimate of the δ18O composition of ingested pre-formed (drinking/food) water. Estimated δ18O values of drinking/food water for captive Z. capensis were ~ −11‰, which is consistent with that of tap water in Santiago, Chile. In contrast, δ18O values of drinking/food water ingested by wild-caught Cinclodes were similar to that of seawater, which is consistent with their reliance on marine resources. Our results confirm the utility of this method for quantifying the relative contribution of metabolic versus pre-formed drinking/food water to the body water pool in birds. [ABSTRACT FROM AUTHOR]

Objectives: Gigantopithecus blacki, the largest hominoid known, is one of the representative Pleistocene mammals in southern China and northern Southeast Asia. Here we investigate the feeding ecology of G. blacki in its core habitat (Guangxi, Southern China) during the early Early Pleistocene, which was the early period in its evolution. Materials and methods: The stable isotopic (C, O) analysis of tooth enamel of the fauna associated with G. blacki (n = 58), including the largest number of G. blacki teeth (n = 12) to date from the Liucheng Gigantopithecus Cave (~2 Ma), Guangxi, China, is undertaken. Results: The δ13C values of Liucheng fauna range from −12.9 to −19.0‰ with an average of −16.1 ± 1.3‰ (n = 58) and the δ18O values range from −4.3 to −9.6‰ with an average of −6.9 ± 1.2‰ (n = 58). The δ13C values of G. blacki range from −15.9‰ to −17.0‰ with an average of −16.5 ± 0.4‰ (n = 12), and the δ18O values vary from −5.9‰ to −7.5‰ with an average of −6.6 ± 0.5‰ (n = 12). Conclusions: The isotopic data show Guangxi was characterized by closed C3 forest and humid climate in the early Early Pleistocene. Niche partitioning is found among G. blacki, Sinomastodon, Ailuropoda and Stegodon, the typical megafauna in South China in the early Early Pleistocene. This could be one of the important factors for them to co‐exist until the Middle Pleistocene. Smallest isotopic variations of G. blacki are found compared with those of contemporary animals, indicating a conservative foraging ecology i.e., limited foraging area and/or narrow dietary flexibility. Furthermore, the more confined foraging ecology of G. blacki is also seen in comparison with fossil and extant large‐bodied primates. However, the unique dietary pattern of G. blacki does not seem to have hindered its survival. The environment in Guangxi during the early Early Pleistocene offered the suitable conditions for G. blacki to become one of the typical species in the faunal assemblages. Highlights: Isotopic results of Gigantopithecus fauna from Liucheng Gigantopithecus Cave, southern China, indicate a paleoecological setting of a C3 dense forest under humid conditions during the early Early Pleistocene.Significant foraging differences are found among G. blacki, giant panda, Stegodon and Sinomastodon.Small isotopic variations of G. blacki provide the first direct evidence of conservative foraging ecology (limited foraging area and/or confined dietary flexibility) in its core habitat during its early evolution.Narrower dietary breadth of G. blacki during the early Early Pleistocene might relate to its large body size in comparison with other modern and fossil large‐bodied primates. [ABSTRACT FROM AUTHOR]

Continental atmospheric relative humidity is a major climate parameter whose variability is poorly understood by global climate models. Models' improvement relies on model–data comparisons for past periods. However, there are no truly quantitative indicators of relative humidity for the pre-instrumental period. Previous studies highlighted a quantitative relationship between the triple oxygen isotope composition of phytoliths, particularly the 17O excess of phytoliths, and atmospheric relative humidity. Here, as part of a series of calibrations, we examine the respective controls of soil water isotope composition, temperature, CO2 concentration and relative humidity on phytolith 17O excess. For that purpose, the grass species Festuca arundinacea was grown in growth chambers where these parameters were varying. The setup was designed to control the evolution of the triple oxygen isotope composition of phytoliths and all the water compartments of the soil–plant–atmosphere continuum. Different analytical techniques (cavity ring-down spectroscopy and isotope ratio mass spectrometry) were used to analyze water and silica. An inter-laboratory comparison allowed to strengthen the isotope data matching. Water and phytolith isotope compositions were compared to previous datasets obtained from growth chamber and natural tropical sites. The results show that the δ′18O value of the source water governs the starting point from which the triple oxygen isotope composition of leaf water, phytolith-forming water and phytoliths evolves. However, since the 17O excess varies little in the growth chamber and natural source waters, this has no impact on the strong relative humidity dependency of the 17O excess of phytoliths, demonstrated for the 40 %–80% relative humidity range. This relative humidity dependency is not impacted by changes in air temperature or CO2 concentration either. A relative humidity proxy equation is proposed. Each per meg of change in phytolith 17O excess reflects a change in atmospheric relative humidity of ca. 0.2 %. The ±15 per meg reproducibility on the measurement of phytolith 17O excess corresponds to a ±3.6 % precision on the reconstructed relative humidity. The low sensitivity of phytolith 17O excess to climate parameters other than relative humidity makes it particularly suitable for quantitative reconstructions of continental relative humidity changes in the past. [ABSTRACT FROM AUTHOR]

This study examined possible predictors of upper respiratory tract symptom (URTS) episodes in elite rugby union and league players (n = 51) during intensive pre-season training. Baseline saliva and blood samples were collected in the first week of pre-season training for analysis of salivary secretory immunoglobulin A (SIgA) and cytomegalovirus. Thereafter, SIgA, URTS, internal training load and self-reported wellness data were repeatedly measured throughout a 10-week pre-season training period. Univariate frailty model analysis, which included 502 observations, was performed for each rugby code for the following independent predictor variables: SIgA concentration, internal training load, total wellness, sleep quantity, sleep quality and stress. Rugby union and league players experienced a similar number of URTS episodes; however, predictors of URTS episodes differed between the codes. No biomarkers or self-reported measures significantly predicted URTS risk in rugby union players, while reductions in self-reported total wellness (HR: 0.731, p = 0.004) and sleep quality (HR: 0.345, p = 0.001) predicted increased URTS risk in rugby league players. The findings from this study highlight that factors influencing URTS risk are perhaps sport specific and this may be attributed to different sporting demands and/or different management of players by team-practitioners. [ABSTRACT FROM AUTHOR]