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Marine-derived proteins, such as blue whiting-derived protein hydrolysates (BWPH), represent high-quality sources of dietary protein, but their ability to support postexercise anabolism is not established. The impact of BWPH on whole-body anabolism was compared with an isonitrogenous whey protein isolate (WPI) and nonessential amino acid (NEAA) control in 10 trained young males (31 ± 4 years) who, on three separate visits, performed a session of whole-body resistance exercise and then consumed, in randomized crossover fashion, BWPH, WPI, or NEAA (0.33 g/kg; 19, 33, and 0 mg/kg leucine, respectively) with L-[1-13C]leucine. Breath, blood, and urine samples were collected for 6-hr postprandial to assess dietary leucine oxidation, amino acid (AA) concentrations, and 3-methylhistidine: creatinine ratio. Peak and area under the curve concentrations for leucine, branched-chain amino acids, and essential amino acids were greater in WPI compared with BWPH (all p <.05) but with no differences in time to peak concentration. Total oxidation reflected leucine intake (WPI > BWPH > NEAA; p <.01), whereas relative oxidation was greater (p <.01) in WPI (28.6 ± 3.6%) compared with NEAA (21.3 ± 4.2%), but not BWPH (28.6 ± 8.8%). Leucine retention, a proxy for whole-body protein synthesis, was greater in WPI (185.6 ± 9.5 μmol/kg) compared with BWPH (109.3 ± 14.1 μmol/kg) and NEAA (5.74 ± 0.30 μmol/kg; both p <.01), with BWPH being greater than NEAA (p <.01). Urinary 3-methylhistidine: creatinine ratio did not differ between conditions. Both WPI and BWPH produced essential aminoacidemia and supported whole-body anabolism after resistance exercise, but a higher intake of BWPH to better approximate the leucine and EAA content of WPI may be needed to produce an equivalent anabolic response. Consuming protein after exercise is generally considered to be important for recovery from a single session of exercise, and over time can support muscle growth in response to long-term strength training. This study aimed to understand how different types of protein might affect these so-called "anabolic" processes by studying a marker of the body's ability to recovery and grow muscle after exercise. Specifically, this study compared how well three different protein sources—a dairy-based protein in the form of whey protein isolate, a novel fish protein powder derived from blue whiting, and a blend of what are known as nonessential amino acids—help the body retain another amino acid named leucine, which is a key indicator of muscle-building potential, during the 6 hr of recovery after exercise. There are 20 amino acids that are used in the body, some come from our food and some can be made in the body, but regardless of source, these amino acids serve as building blocks for all of the proteins in the body. Ten healthy young men who had been regularly doing strength training participated in the study. On three different occasions, each participant completed a full-body workout and then drank one of the three protein drinks. The amount of protein they consumed was based on their body weight. The drink provided 20–30 g of protein depending, on body size. After each workout, how much leucine the body retained over a 6-hr period was assessed by collecting samples of blood, breath, and urine which effectively measures how well the proteins were absorbed and used by the body for processes supporting muscle recovery, repair, and growth. One of the key questions was whether this fish-derived protein could be a good alternative to whey protein for supporting muscle recovery after exercise. Whey protein is well-known for its ability to support these processes and help build muscle, but there is much interest in whether other protein sources, particularly those from fish, could offer similar benefits. Fish proteins may also have the added advantage of being more sustainable, which is increasingly important in today's world. The nonessential amino acid blend served as a control, as it was not expected to contribute to processes that support muscle recovery and growth due to its lack of essential amino acids. The results showed that whey protein was the most effective by leading to the highest concentrations of essential amino acids in the blood, and the greatest amount of leucine retained in the body, meaning that the body was potentially able to use more of it for muscle recovery and growth. The fish protein performed better than the nonessential amino acids, supporting the idea that it could help with muscle recovery, but it was not as effective as whey protein. This finding is likely because the fish protein contained less essential amino acids, which are critical for muscle recovery and growth processes. Consuming a larger amount of the fish protein could potentially provide benefits similar to whey protein, but more studies would be needed to confirm this. The nonessential amino acid blend was the least effective, as expected, because it lacked the necessary components to stimulate these anabolic processes in muscle. The interpretation of these results is that while whey protein would be the most effective of the three protein sources for promoting muscle recovery after exercise, fish-derived proteins, like the one tested in this study, could be a good alternative, especially for those who are looking for nondairy sources of protein. While the fish protein didn't perform as well as whey protein in this study, it did still support muscle recovery, suggesting it could be a viable option to match the effects of whey if provided at the right dosage. Overall, this research adds to our understanding of how different protein sources can help the body recover after exercise, and suggests that future research could focus on how adjusting the amount of fish protein consumed could improve its potential to support recovery and growth in response to exercise. Consuming protein after exercise is generally considered to be important for recovery from a single session of exercise, and over time can support muscle growth in response to long term strength training. This study aimed to understand how different types of protein might affect these so-called "anabolic" processes by studying a marker of the body's ability to recovery and grow muscle after exercise. Specifically, this study compared how well three different protein sources—a dairy-based protein in the form of whey protein isolate, a novel fish protein powder derived from blue whiting, and a blend of what are known as nonessential amino acids—help the body retain another amino acid named leucine, which is a key indicator of muscle-building potential, during the 6 hr of recovery after exercise. There are 20 amino acids that are used in the body, some come from our food and some can be made in the body, but regardless of source, these amino acids serve as building blocks for all of the proteins in the body. Ten healthy young men who had been regularly doing strength training participated in the study. On three different occasions, each participant completed a full-body workout and then drank one of the three protein drinks. The amount of protein they consumed was based on their body weight, and so the drink provided 20–30 g of protein depending on body size. After each workout, how much leucine the body retained over a 6-hr period was assessed by collecting samples of blood, breath, and urine, and this is effectively a measure of how well the proteins were absorbed and used by the body for processes supporting muscle recovery, repair, and growth. One of the key research questions was whether this fish-derived protein could be a good alternative to whey protein for supporting muscle recovery after exercise. Whey protein is well-known for its ability to support these processes and help build muscle, but there is much interest in whether other protein sources, particularly those from fish, could offer similar benefits. Fish proteins may also have the added advantage of being more sustainable, which is increasingly important in today's world. The nonessential amino acid blend served as a control, as it was not expected to contribute to processes that support muscle recovery and growth due to its lack of essential amino acids. The results showed that whey protein was the most effective by leading to the highest concentrations of essential amino acids in the blood, and the greatest amount of leucine retained in the body, meaning that the body was potentially able to use more of it for muscle recovery and growth. The fish protein performed better than the nonessential amino acids, supporting the idea that it could help with muscle recovery, but it was not as effective as whey protein. This finding is likely because the fish protein contained less essential amino acids, which are critical for muscle recovery and growth processes. Consuming a larger amount of the fish protein could potentially provide similar benefits to whey protein, but more studies would be needed to confirm this. The nonessential amino acid blend was the least effective, as expected, because it lacked the necessary components to stimulate these anabolic processes in muscle. The interpretation of these results is that while whey protein would be the most effective of the three protein sources for promoting muscle recovery after exercise, fish-derived proteins like the one tested in this study could still be a good alternative, especially for those who are looking for nondairy sources of protein. While the fish protein didn't perform as well as whey protein in this study, it did still support muscle recovery, suggesting it could be a viable option to match the effects of whey if provided at the right dosage. Overall, this research adds to our understanding of how different protein sources can help the body recover after exercise, and suggests that future research could focus on how adjusting the amount of fish protein consumed could improve its potential to support recovery and growth in response to exercise. [ABSTRACT FROM AUTHOR]

Water shows anomalous properties that are enhanced upon supercooling. The unusual behavior is observed in both H2O and D2O, however, with different temperature dependences for the two isotopes. It is often noted that comparing the properties of the isotopes at two different temperatures (i.e., a temperature shift) approximately accounts for many of the observations—with a temperature shift of 7.2 K in the temperature of maximum density being the most well-known example. However, the physical justification for such a shift is unclear. Motivated by recent work demonstrating a "corresponding-states-like" rescaling for water properties in three classical water models that all exhibit a liquid–liquid transition and critical point [Uralcan et al., J. Chem. Phys. 150, 064503 (2019)], the applicability of this approach for reconciling the differences in the temperature- and pressure-dependent thermodynamic properties of H2O and D2O is investigated here. Utilizing previously published data and equations-of-state for H2O and D2O, we show that the available data and models for these isotopes are consistent with such a low temperature correspondence. These observations provide support for the hypothesis that a liquid–liquid critical point, which is predicted to occur at low temperatures and high pressures, is the origin of many of water's anomalies. [ABSTRACT FROM AUTHOR]

Light and heavy water show similar anomalies in thermodynamic and dynamic properties, with a consistent trend of anomalies occurring at higher temperatures in heavy water. Viscosity also increases faster upon cooling in heavy water, causing a giant isotope effect, with a viscosity ratio near 2.4 at 244 K. While a simple temperature shift apparently helps in collapsing experimental data for both isotopes, it lacks a clear justification, changes value with the property considered, and requires additional ad hoc scaling factors. Here, we use a corresponding states analysis based on the possible existence of a liquid–liquid critical point in supercooled water. This provides a coherent framework that leads to the collapse of thermodynamic data. The ratio between the dynamic properties of the isotopes is strongly reduced. In particular, the decoupling between viscosity η and self-diffusion D, measured as a function of temperature T by the Stokes–Einstein ratio Dη/T, is found to collapse after applying the corresponding states analysis. Our results are consistent with simulations and suggest that the various isotope effects mirror the one on the liquid–liquid transition. [ABSTRACT FROM AUTHOR]

Present and future climatic trends are expected to markedly alter water fluxes and stores in the hydrologic cycle. In addition, water demand continues to grow due to increased human use and a growing population. Sustainably managing water resources requires a thorough understanding of water storage and flow in natural, agricultural, and urban ecosystems. Measurements of stable isotopes of water (hydrogen and oxygen) in the water cycle (atmosphere, soils, plants, surface water, and groundwater) can provide information on the transport pathways, sourcing, dynamics, ages, and storage pools of water that is difficult to obtain with other techniques. However, the potential of these techniques for practical questions has not been fully exploited yet. Here, we outline the benefits and limitations of potential applications of stable isotope methods useful to water managers, farmers, and other stakeholders. We also describe several case studies demonstrating how stable isotopes of water can support water management decision-making. Finally, we propose a workflow that guides users through a sequence of decisions required to apply stable isotope methods to examples of water management issues. We call for ongoing dialogue and a stronger connection between water management stakeholders and water stable isotope practitioners to identify the most pressing issues and develop best-practice guidelines to apply these techniques.

Nitrous oxide (N2O), a potent greenhouse gas, can be generated by multiple biological and abiotic processes in diverse contexts. Accurately tracking the dominant sources of N2O has the potential to improve our understanding of N2O fluxes from soils as well as inform the diagnosis of human infections. Isotopic Site Preference (SP) values have been used toward this end, as bacterial and fungal nitric oxide reductases (NORs) produce N2O with different isotopic fingerprints, spanning a large range. Here, we show that flavohemoglobin (Fhp), a hitherto biogeochemically neglected yet widely distributed detoxifying bacterial NO reductase, imparts a distinct SP value onto N2O under anoxic conditions (~+10‰) that correlates with typical environmental N2O SP measurements. Using Pseudomonas aeruginosa as a model organism, we generated strains that only contained Fhp or the dissimilatory NOR, finding that in vivo N2O SP values imparted by these enzymes differ by over 10‰. Depending on the cellular physiological state, the ratio of Fhp:NOR varies significantly in wild-type cells and controls the net N2O SP biosignature: When cells grow anaerobically under denitrifying conditions, NOR dominates; when cells experience rapid, increased nitric oxide concentrations under anoxic conditions but are not growing, Fhp dominates. Other bacteria that only make Fhp generate similar N2O SP biosignatures to those measured from our P. aeruginosa Fhp-only strain. Fhp homologs in sequenced bacterial genomes currently exceed NOR homologs by nearly a factor of four. Accordingly, we suggest a different framework to guide the attribution of N2O biological sources in nature and disease.

A fully automated dual-column purification procedure for Zn from biological samples, designed for subsequent Zn isotopic analysis, is presented that utilizes the prepFAST MC™ system (Elemental Scientific), DGA resin (TrisKem International), and TK201 resin (TrisKem International). The procedure developed enables the unattended processing of 20 samples per day and is characterized by low and reproduceable blanks (< 1.5 ng), no carry-over or memory effect, high reusability (> 50 times), high Zn yields 100.1% ± 5.3% (2 SD, N = 22), and strong robustness to matrix variations across biological samples (bone, liver, hair, blood). Additionally, Zn isotopic analysis using MC-ICP-MS showed no significant on-column fractionation. The measured δ66Zn/64ZnIRMM values for NIST SRM 1400 (0.67‰ ± 0.07‰, U, k = 2), NIST SRM 1486 (0.91‰ ± 0.06‰, U, k = 2), NIST SRM 1577c (− 0.45‰ ± 0.05‰, U, k = 2), ERM-DB001 (− 0.35‰ ± 0.05‰, U, k = 2), GBW09101 (− 0.32‰ ± 0.08‰, U, k = 2), and SeroNorm whole blood L-3 (-0.15 ‰ ± 0.05 ‰, U, k = 2) are consistent with published values. The procedure developed makes Zn, an analytically challenging isotope system, more accessible, feasible, and reliable for a broader range of users while enabling high sample throughput. [ABSTRACT FROM AUTHOR]

Beryllium isotopes (stable 9Be and cosmogenic meteoric 10Be) enter the oceans through distinct pathways – i.e., from the continents and the atmosphere respectively – and display non-conservative behaviour in seawater. This isotope system has served as a powerful tool for quantifying a variety of processes, including geomagnetism, sedimentation, continental input, and ocean circulation. However, processes at land–ocean boundaries and within the ocean interior may either amplify or buffer the seawater isotope response to environmental changes. In the last decade, substantial effort has been invested in understanding external sources and internal cycling of Be isotopes, offering an excellent opportunity to revisit their modern oceanic cycle. Here, we investigate the controls on the modern oceanic cycling of Be isotopes using a three-dimensional ocean model, constrained by observational data on input fluxes and water-column distributions of 9Be and 10Be. In addition to modelling the previously known controls, we highlight the key role of marine benthic fluxes and scavenging onto particulate organic matter and opal in determining the mass balance and spatial distribution of Be isotopes. Inter-basin Be transport by the circulation is less important than external inputs at continent/atmosphere–ocean boundaries, except in the South Pacific. Therefore, the distribution of seawater 10Be/9Be ratios largely reflects that of the external inputs in most basins in the modern ocean. Finally, we apply our data-constrained mechanistic model to test the sensitivity of basin-wide 10Be/9Be ratios to changes of external sources and internal cycling. This analysis shows that seawater 10Be/9Be ratios are to some extent buffered against changes in continental denudation. For example, a 50 % decrease in denudation rates results in a 13–48 % increase in ocean-wide 10Be/9Be ratios. Moreover, the interplay between particle scavenging and ocean circulation can cause divergent responses in 10Be/9Be ratios in different basins. Weaker scavenging (e.g., 50 % decrease in intensity) would increase the homogenising effect of ocean circulation, making North Atlantic and North Pacific 10Be/9Be ratios converge (∼20 % change in isotope ratios). The mechanistic understanding developed from this Be cycling model provides important insights into the various applications of marine Be isotopes, and offers additional tools to assess the causes of spatio-temporal Be isotope variations. We also identify the key oceanic processes that require further constraints to achieve a complete understanding of Be cycling in the modern ocean and back through time. [ABSTRACT FROM AUTHOR]

Much has been learned about Mars through data returned from space missions and analyses of martian meteorites. There are, however, many questions still outstanding which cannot currently be answered--including the issue of whether there is, or was, life on Mars. The return of a cache of samples--including of the atmosphere--from separate locations in Jezero Crater and with differing petrogeneses will provide the international community with the opportunity to explore part of the evolutionary history of Mars in great detail. Specifically, measurements of the isotopic compositions of the light elements H, C, N, O, Cl, and S can be used to follow how volatile species cycle through the different martian volatile reservoirs (atmosphere, lithosphere, cryosphere, and hydrosphere). Measurement of isotopic fractionation enables inference of the environmental conditions (e.g., temperature, water/rock ratio) under which fractionation occurred. Knowing the contextual relationship of the materials to their geological settings, coupled with precise compositional measurements will enable a more thorough understanding of martian volatile history and allow a picture to be constructed of water and climate on Mars as represented at Jezero Crater. [ABSTRACT FROM AUTHOR]

The radiogenic isotopic compositions of basaltic Martian meteorites (shergottites) and clinopyroxene/olivine cumulate meteorites (nakhlite/chassignites) are used to define the global evolution of Mars. However, the two main groups of meteorites demonstrate that their sources underwent divergent styles of magmatic evolution. The shergottites portray a planet that differentiated ~4.52 billion years ago via solidification of a magma ocean, producing incompatible element-depleted and -enriched reservoirs that remained isolated until melt production. In contrast, the reservoir from which the nakhlite/chassignites derive may have formed earlier, produced melts that fractionated Sm/Nd and Hf/W differently, was compositionally less variable, and experienced a significantly more complex history following primordial differentiation than the shergottite sources. The disparate histories recorded by these two groups of meteorites elucidate important questions that could be addressed by acquiring additional samples. Obtaining samples that shared the isotopic systematics of the shergottites would provide confidence that extrapolating the primordial differentiation history of Mars from shergottite radiogenic isotope systematics is reasonable. Returned samples from Mars will also constrain the physical locations of the meteorite source regions, providing insights into the general structure of the Martian mantle. In addition, they will help constrain the phases present in the martian mantle during melting and the conditions under which they are stable. Finally, identifying an evolved lithology that satisfies the geochemical and isotopic constraints placed on the incompatible element-enriched endmember observed in the shergottites would define the nature of magmatic evolution on Mars and whether it is more akin to processes on the Earth or the Moon. [ABSTRACT FROM AUTHOR]

Stable isotope techniques (δ18Ο, δ2Η of H2O) were applied in the transboundary Prespa Lakes (Great and Little Prespa) to assess the water dynamics and the evolution of evaporation losses over the past several decades. The lakes currently experience high evaporation losses to inflows (E/I > 60%), which are significantly higher than in the 1980s. The results showed that the Great Prespa Lake (GPL) water level decline could be due to a drastic decrease in lake inflows over evaporation over the years due to climate change and water abstractions. River runoff contributed more (~57%) to the recharge of the GPL in the wet period, whereas in the dry period direct precipitation was more significant. Our work highlights the advantage of using stable isotope techniques to address hydrological problems in comparison to conventional methods, and the need for collaborative efforts between countries to ensure sustainable usage of transboundary water resources. [ABSTRACT FROM AUTHOR]

Here, we present the North American Repository for Archaeological Isotopes (NARIA), the largest open-access compilation of previously reported isotopic measurements (n = 28,374) from bioarchaeological samples in North America (i.e., Canada, Greenland, Mexico, and the United States of America) covering a time-frame of more than 12,000 years. This database consists of stable (δ13C, δ15N, δ18O) and radiogenic (87Sr/86Sr) isotope measurements from archaeological human, animal, and plant sources and their corresponding contextual information (e.g., location, chronology, cultural affiliation, etc.). This synthesis of isotopic measurements and other forms of data presents significant research potential for investigating past human lifeways, particularly in the realms of paleomobility, paleoenvironment, and paleodiet. Additionally, it serves to pinpoint spatial and temporal data gaps, offering valuable insights for future research directions. [ABSTRACT FROM AUTHOR]

The Moche archaeological culture flourished along Peru's North Coast between the 4th and 10th centuries CE and was characterized by a complex social hierarchy dominated by political and religious elites. Previous archaeological evidence suggests kinship was a key factor in maintaining political authority within Moche society. To test this hypothesis, we applied archaeological, genetic, and isotopic methods to examine familial relationships between six individuals, including the prominent Señora de Cao (~500 CE), buried together in a pyramid-like, painted temple, Huaca Cao Viejo, in the Chicama Valley, Peru. Our findings reveal that all six individuals were biologically related, with varying degrees of kinship. The Señora de Cao was interred with a sacrificed juvenile, identified as a possible niece, and at least one, and potentially two siblings and a grandparent in separate tombs nearby. One of the male siblings was accompanied in death by his sacrificed son. Isotopic analysis indicates that while most individuals had diets rich in maize and animal protein and spent their childhoods in or near the Chicama Valley, the sacrificed juvenile accompanying the Señora had a distinct diet and geographic origin. These results demonstrate that Moche elites were interred with family members, including some raised far from their parental homes. This supports the hypothesis that kinship was central to transmitting status and authority. Moreover, sacrificing family members to accompany deceased elites underscores the significance of ritual sacrifice in reinforcing familial ties and linking the deceased to both ancestors and the divine. [ABSTRACT FROM AUTHOR]

Calcium‐aluminum‐rich inclusions (CAIs) are the first objects that formed in the solar accretion disk and therefore provide valuable insights into the evolution of the early solar system. A long‐standing question regarding this earliest formative period relates to the storage of CAIs in the 1–4 Myr time period between their formation and later accretion into chondrite parent bodies. Were the CAIs stored in a pre‐existing parent body, or in distant parts of the solar accretion disk? In the latter scenario, CAIs might have been exposed to cosmic rays, either from the galaxy or from the Sun and such pre‐accretion irradiation effects might be detectable. We searched for such pre‐accretional irradiation effects in 7 fine‐ and 11 coarse‐grained CAIs from the CV 3.6 carbonaceous chondrite Allende. The extracted samples were analyzed for their major chemical composition and all samples were analyzed using μCT techniques. Using physical model calculations, 21Necos and (22Ne/21Ne)cos production rate ratios were calculated for each CAI by fully considering their individual chemical composition. Measured He, Ne, Ar, and Kr isotope compositions of the CAIs show cosmogenic signals; clear signals for He and Ne isotopes; and detectable signals for some of the Ar and Kr isotopes. In addition, most samples show clear indications for radiogenic 4He and some samples show evidence for radiogenic 40Ar. Higher 36Ar/38Ar, 22Ne/21Ne, 80Kr/84Kr, and 82Kr/84Kr ratios together with lower cosmogenic 38Arcos concentrations in fine‐grained CAIs compared to coarse‐grained CAIs are consistent with more alteration of the former compared to the latter. The CRE ages for the CAIs range between 4.12 ± 0.41 Myr and 6.40 ± 0.63 Myr. Statistical tests indicate that the data are normally distributed with no outliers, indicating that all CAIs share a common irradiation history, likely the irradiation in the Allende meteoroid. The average CRE age of 4.87 ± 0.19 Myr agrees with the nominally accepted CRE age of Allende of ~5.2 Myr. There is no correlation between 21Necos concentrations and indicators of aqueous alteration like Na and/or U concentrations. The lack of correlation together with the finding of normally distributed modeled CRE ages indicates that either none of the studied CAIs experienced a pre‐accretion irradiation before parent body compaction and/or that any pre‐accretion irradiation effects have been completely erased during aqueous alteration events. Taking alteration aside, the findings are not in favor of X‐wind type models but are more consistent with the idea of CAI outward transport in an expanding disk. [ABSTRACT FROM AUTHOR]

Wetlands in the Qinghai–Tibet Plateau are a unique and fragile ecosystem undergoing rapid changes. We show two unique patterns of mercury (Hg) accumulation in wetland sediments. One is the 'surface peak' in monsoon-controlled regions and the other is the 'subsurface peak' in westerly-controlled regions. The former is attributed to the combined effects of increasing anthropogenic emissions and climate-induced changes in the cryosphere and wetland hydrology in the last 100−150 years. The climate changes in westerly-controlled regions in the last 50−70 years led to a fluctuation in hydrology and Hg peak in the sediment subsurface. The increase in legacy Hg input from soil erosion has largely enhanced the Hg accumulation rate in wetlands since the 1950s, especially in the proglacial wetlands. We highlight that accelerated glacier melting and permafrost thawing caused by global warming have altered geomorphology and hydrology, and affected Hg transport and accumulation in wetlands. [ABSTRACT FROM AUTHOR]

Atomic nuclei serve as prime laboratories for investigations of complex quantum phenomena, where minor nucleon rearrangements cause significant structural changes. 190Pb is the heaviest known neutron-deficient Pb isotope that can exhibit three distinct shapes: prolate, oblate, and spherical, with nearly degenerate excitation energies. Here we report on the combined results from three state-of-the-art measurements to directly observe these deformations in 190Pb. Contrary to earlier interpretations, we associate the collective yrast band as predominantly oblate, while the non-yrast band with higher collectivity follows characteristics of more deformed, predominantly prolate bands. Direct measurement of the E 0 ( 0 2 + → 0 1 + ) transition and γ-e− coincidence relations allowed us to locate and firmly assign the 0 2 + state in the level scheme and to discover a spherical 2 3 + state at 1281(1) keV with B (E 2 ; 2 3 + → 0 1 + ) = 1.2 (3) W.u. These assignments are based purely on observed transition probabilities and monopole strength values, and do not rely on model calculations for their interpretation. Direct measurements reveal that the neutron-deficient isotope 190Pb can adopt three different deformations near the ground state. The present work identifies the collective yrast band as predominantly oblate, the non-yrast band as predominantly prolate, and discovers a candidate spherical 2 3 + state at 1281 keV. [ABSTRACT FROM AUTHOR]

Stable isotope ratios of nitrate (NO3−) can be used as a tool to investigate NO3− dynamics in watersheds over the world. However, most of the NO3− source analyses from watersheds using isotopes have been conducted during baseflow conditions, and more information is required on conditions during rainfall, which is a crucial period for nitrogen export to downstream ecosystems. Additionally, there is limited information regarding the sources of stable isotopes of NO3− in watersheds of Japan. We measured the nitrogen and oxygen isotopes of NO3− (δ15N–NO3− and δ18O–NO3−) in the Yasu River during baseflow and rainfall events and those from major NO3− sources in the watershed. The δ15N–NO3− exported from forests and rice paddies showed small fluctuations, while there were large fluctuations in the δ15N–NO3− exported from sewage treatment plants, suggesting the need to obtain data on δ15N–NO3− exported from sewage treatment plants. The NO3− concentrations in the Yasu River during summer baseflow were too low to be explained by the mixing of NO3− sources within the watershed, suggesting that NO3− consumption processes within the river and groundwater influence the NO3− concentrations. Furthermore, the sources of NO3− exported from the watershed differed during baseflow and rainfall, with a larger contribution of forest-derived NO3− during rainfall. Monitoring during rainfall is therefore essential to determine the sources of NO3− exported from the watershed. [ABSTRACT FROM AUTHOR]

The paper considers the concentration of 95–97Mo in a square cascade with large stage separation coefficients corresponding to gas centrifuges. Cascades were calculated using a method for varying the sections of partial stage streams and minimizing the deviation of calculated stage feeding streams from the specified one. A computational experiment on the multi-step separation of a molybdenum hexafluoride mixture was carried out. Isotopes of 95–97Mo can be efficiently concentrated in a single square cascade. In streams depleted of these isotopes, isotopically modified molybdenum is accumulated for use as a structural material for fuel element claddings having improved thermophysical characteristics. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the level of bone mass in digital orthopantomograms in two populations (medieval and current) using two radiomorphometric indexes, and to correlate the mandibular bone mass value, in the medieval mandible population, with stable isotope data δ13C and δ15N. An observational, cross-sectional, and analytical study on mandibles from two diachronic groups, 15 mandibles from the medieval settlement of La Torrecilla (Granada, Spain) and 15 mandibles from current patients at the Faculty of Dentistry of the University of Granada (Spain), matched by age and sex was conducted. The bone mass density was determined using the Mandibular Cortical Width Index (MCW) and the Mandibular Panoramic Index (PMI) in digital panoramic radiographs. In the medieval group, the values of bone mass density were correlated with those of two stable isotopes (δ13C and δ15N). The mean value of MCW in mm in the medieval group was 3.96 ± 0.60 (mean ± standard deviation) and in the current group was 4.02 ± 1.01. The PMI was 0.33 ± 0.06 and 0.35 ± 0.08 in the medieval and current groups respectively, with similar results in both groups (p = 0.820 and p = 0.575). A negative correlation was found between both morphometric indices and the δ15N isotope (rs = 0.56, p = 0.030 and rs = 0.61, p = 0.016, respectively). The bone mass density in mandibles belonging to the two compared populations, determined by two quantitative radiomorphometric indices, is similar. Within the medieval population, there is an inverse correlation between the δ15N value and bone mass density. [ABSTRACT FROM AUTHOR]

The deformations and the corresponding configurations of the odd-mass Kr, Br, and Rb isotopes are investigated using the adiabatic and configuration-fixed constrained triaxial relativistic mean field theory. Several minima with prominent triaxial deformation and proper configuration are obtained in 75,77,79,81Kr, 75,77,79,81Br, and 75,79,81,83Rb nuclei, indicating the existence of chiral doublet bands. Based on the discussions about the involved orbitals in the chiral configurations, the possible coexistence of chiral and reflection based on the pseudospin orbitals in the 77,79,81Kr, 77,79Br, and 79,81Rb nuclei has been suggested. [ABSTRACT FROM AUTHOR]

Introduction: The Global Meteoric Water Line (GMWL) describes the linear relationship between stable hydrogen (δ 2H) and oxygen (δ 18O) isotopes in precipitation over large spatial scales and therefore represents a unique reference for water isotopic values. Although trees have the potential to capture the isotopic composition of precipitation, it remains unclear if the GMWL can be reconstructed from tree-ring stable isotopes, since δ 18O and δ 2H undergo in vivo physiological fractionation. Methods: We analyze the tree rings δ 18O and δ 2H values from six regions along a latitudinal gradient from Spain to Greenland. Results: The data show that the covariance between δ 18O and δ 2H closely follows the GMWL, which reflects the isotopic signature of large-scale precipitation patterns. We show that changes in regional tree-ring δ 18O and δ 2H values along wide latitudinal ranges are influenced by the isotopic composition of precipitation with temperature and latitude being the most significant drivers of spatial variation across the studied regions. In contrast, local tree-ring δ 18O and δ 2H values are mainly controlled by plant physiological fractionation processes that mask the isotopic signature of precipitation. Conclusion: We conclude that covariance in tree-ring δ 18O and δ 2H reflects the GMWL at larger spatial scales, but not when evaluating them at individual sites. [ABSTRACT FROM AUTHOR]

High-frequency precipitation (solid/liquid) isotope datasets are useful for identification of moisture sources and various dynamical and thermodynamical processes controlling precipitation formation. Here, we report three-year (2019–2021) daily rain isotope (both oxygen, δ18O hereafter, and hydrogen, δ2H, hereafter) datasets from three unique locations in India during the Indian Summer Monsoon (ISM). The locations are- (1) Port Blair- an island situated in the Bay of Bengal (BoB); (2) Mahabaleshwar, located at the crest of the Western Ghats Mountain; and (3) Tezpur, in northeast India, situated close to a dense forest. These stations receive moisture from different sources and experience different rain mechanisms during ISM. Therefore, the isotope datasets presented here would be useful for envisaging the impact of diverse rain formation processes on isotope values during the ISM. [ABSTRACT FROM AUTHOR]

An improved formula including shell closure effects is proposed to investigate α-decay half-lives. The coefficients of the improved formula are obtained by fitting the experimental α-decay half-lives of 677 nuclei with 62≤Z≤118. The root mean square deviation between α-decay half-lives calculated by the improved formula and experimental data is reduced from 0.435 to 0.385. The result indicates that the improved formula considering the shell closure effects is reliable in reproducing the experimental α-decay half-lives. In addition, the improved formula is extended to predict α-decay half-lives of nuclei with Z=119, 120 isotopes. The results of the predicted α-decay half-lives indicate that N=184 appears to be the next magic number beyond N=126. [ABSTRACT FROM AUTHOR]

This paper analyzes the analytical expressions available in the literature for calculating the coefficient of viscosity and thermal conductivity obtained from the Chapman–Enskog kinetic theory. A modification of the expressions is proposed taking into account the calculated value of the compressibility factor Z = PV/RT, obtained as a result of thermodynamic calculations using a theoretical model of the equation of state based on perturbation theory. To validate the modified expressions, the Green–Kubo model for modeling transport properties by the molecular dynamics method is considered. This model enables simultaneous calculation of both the viscosity and thermal conductivity within one calculation, having previously performed the statization of the system in the NpT ensemble. Molecular dynamics and thermodynamic simulation of the transport properties of individual helium and hydrogen isotopes are carried out in the pressure range of 1–2000 atm and in the temperature range of 200–3000 K. The viscosity and thermal conductivity coefficients are determined in the considered pressure and temperature range. It is shown that the use of modified analytical expressions for transfer coefficients makes it possible to calculate the viscosity and thermal conductivity of helium and hydrogen isotopes, taking the real pressure in the system in accordance with experimental data and the results of molecular dynamics simulation in a wide range of pressures and temperatures, including the supercritical region, into account. [ABSTRACT FROM AUTHOR]

Methane, a greenhouse gas and energy source, is commonly studied using stable isotope signals as proxies for its formation processes. In subsurface environments, methane often exhibits equilibrium isotopic signals, but the equilibration process has never been demonstrated in the laboratory. We cocultured a hydrogenotrophic methanogen with an H2-producing bacterium under conditions (55°C, 10 megapascals) simulating a methane-bearing subsurface. This resulted in near-complete reversibility of methanogenesis, leading to equilibria for both hydrogen and carbon isotopes. The methanogen not only equilibrated kinetic isotope signals of initially produced methane but also modified the isotope signals of amended thermogenic methane. These findings suggest that hydrogenotrophic methanogenesis can overwrite the isotope signals of subsurface methane, distorting proxies for its origin and formation temperature-insights crucial for natural gas exploration. [ABSTRACT FROM AUTHOR]

In this paper, we model the fission process by assuming that at certain elongation, after crossing the fission barrier, a fissile nucleus can be treated as a superposition of dinuclear systems (DNS). The distribution of primary fission fragments is described as a result of competition between evolution of initially formed DNS and its decay in relative distance. The level densities required for the calculations were microscopically derived accounting for deformation and excitation energy effects. The calculations performed for even 244−260Fm isotopes give overall good description of mass and neutron multiplicity distributions. To describe sudden onset of symmetric fission in 258Fm, the fissile nucleus is treated as superposition of DNS at smaller elongations than for lighter Fm isotopes, which is in line with significant reduction of half-life for 258Fm. Our results indicate the presence of bimodality due to coexistence of spherical and deformed mass symmetric fission modes. [ABSTRACT FROM AUTHOR]

The oceanic chromium (Cr) cycle is mainly governed by the interconversion and the distribution of Cr(VI) and Cr(III) species and their stable isotopic ratios (δ53Cr) in the water column. As a result, the Cr cycle generates a strong correlation between the natural logarithm of its dissolved concentration and δ53Cr regardless of the location of sampling. A few studies have reported the Cr composition of certain regions falling off the global Cr array, highlighting the local prevalence of underlying mechanisms participating in the Cr cycle in the oceans. In an effort to better constrain the global Cr array, this study presents an extensive dataset for total dissolved Cr concentration ([Cr] T) and δ53Cr in the Arctic Ocean in regions meeting the environmental conditions where Cr was observed to fall off the global Cr array (e.g. continental shelves, restricted water circulation, sea ice melting). We find that more than 70% of the Arctic seawater collected plot below the global Cr array due to a small addition of highly fractionated Cr (−2.8 ‰ to −1.1 ‰) and its transport across all the Arctic regions sampled. We identify the Chukchi Shelf as the region where highly fractionated Cr is produced, from where a Cr shuttle could work in tandem with the Arctic Fe and Mn shuttles to explain the production and widespread export of isotopically light Cr in the Arctic waters. We identify a second non-reductive release of highly fractionated Cr in the Canadian Arctic Archipelago, Baffin Bay and potentially the Labrador Sea via sediment resuspension, alongside addition of isotopically light Cr originating from crustal rocks. These findings demonstrate that the Arctic-modified outflow signature of Cr isotopes modify the Cr isotopic signature of the North Atlantic waters, and that the North Atlantic waters may deviate from the global Cr array depending on whether the isotopically light Cr added to the Arctic Ocean is Cr(III) that has not been scavenged or Cr(III) that has oxidized to Cr(VI). [ABSTRACT FROM AUTHOR]

Two diterpene synthases from the bacterium Chitinophaga pinensis were characterised. The first enzyme mainly produced the rearranged diterpene palmatol, a compound known from octocorals, while the second enzyme made the new coral‐type eunicellane chitinol. The mechanisms of both enzymes were deeply studied through isotopic labelling experiments, DFT calculations, and with a substrate analog containing a saturated double bond, resulting in the formation of derailment products that gave additional insights into the nature of the cyclisation cascade intermediates. The formation of coral‐type diterpenes poses interesting questions on the functions of these compounds in organisms as different as bacteria and corals. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Aim Methods Results Conclusions Main transformation pathways of low molecular weight organic substances (LMWOS) are understood, but only limited knowledge exists on their transformations in different soils and on their interactions with biochar.Objectives were to study short‐term pathways of 13C‐labelled LMWOS with different functional groups in the presence and absence of biochar in arable loess soils.Soils from three sites were incubated with or without artificially aged biochar and 13C‐labelled acetate, alanine or glucose at different rates (10 or 50 µmol C g−1 soil) at 60% water holding capacity and 15°C for 5 days, and total and substrate‐derived CO2‐C and microbial biomass C (MBC) were determined and analyses of variance were calculated.Cumulative CO2‐C (ΣCO2‐C) emission was significantly (p ≤ 0.05) affected by substrate rate and type and their interaction. Biochar significantly stimulated total, but not substrate‐derived ΣCO2‐C (ΣCO2‐CSD) emission. Box‐Cox transformed MBC was significantly affected by site, substrate rate and type, whereas biochar had no significant effect. Substrate‐derived MBC (MBCSD) and carbon use efficiency (CUE) were significantly affected by site, substrate rate and type and their interaction.MBCSD and CUE results at low addition rate confirmed the greater importance of glucose for the build‐up of MBC compared to acetate and alanine, whereas the latter were mineralized to a greater extent. Biochar, once it is aged, which is the typical biochar form in soil, did not significantly affect build‐up of MBCSD and CUE and only slightly increased total, but not ΣCO2‐CSD emission. [ABSTRACT FROM AUTHOR]