To investigate the scale, and to determine the origin of the nitrogen isotope heterogeneity (source vs. fractionation during diamond-formation) shown for populations of mantle diamonds we have determined multiple δ13C-δ15N values and nitrogen abundances from 14 monocrystalline (MCDs) and 25 polycrystalline diamonds (PCDs) using step-wise oxidation gas sourced mass spectrometry. These data show that the heterogeneity shown for carbon and nitrogen isotope values from single diamond samples presented here is typically ,5‰ and ,8‰ respectively, both of which are comparable to the standard deviation for the mean mantle δ13C and δ15N values (±3 and ±4‰). However, there are samples that show much larger heterogeneities for δ13C and δ15N values (≤ 23‰ and ≤ 33‰ respectively), which cannot be generated by equilibrium stable isotope fractionation during, or prior to diamond-formation. These data suggest that isotopic heterogeneity may be present within the diamond-forming fluid on ...

Article Estimation of nitrogen stable isotope turnover rate of Oncorhynchus nerka. Estimation of the isotopic turnover rate in the tissues of organisms allows us to estimate the temporal relationship between the isotope ratio of an organism and its p...

Comparative studies on manual and automatic backbone chemical shift assignments of 2H-13C-15N-labeled Ube2g1. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.

Nicole is interested in developing new applications of stable isotopes and other source-sink tracers to the study of plants and mycorrhizal fungi. For her Ph.D she focused mainly on the use of stable isotopes to examine mycoheterotrophic food-webs. The physiology of mycoheterotrophic plants remained nearly entirely unexplained until the relatively recent application of stable isotope analyses to plant ecology. The analysis of the natural abundance of carbon (13C:12C) and nitrogen (15N:14N) stable isotopes in plants are powerful tools to infer strategies of resource acquisition and metabolic pathways in plants. The stable isotope signatures of mycoheterotrophic plants seem to best fit an isotope food-chain model where the plants stable isotope signatures reflect those of their host fungi, their ultimate nutrient source. Generally, the source of a nutrient is left depleted in the heavy isotope compared to its sink. For instance, previous work has shown that fully mycoheterotrophic plants that ...

In the Southern part of Hanoi, high ammonium (NH4+) concentrations in reducing groundwater have been an issue over the last 25 years. Elevated NH4+ concentrations in groundwater, in general, are an indicator of influences from anthropogenic sources, but the buried peat layers in the Red River delta formation are also hypothesized to contribute to the high NH4+ levels (up to 100 mg/l). We traced the sources of NH4+ at the Nam Du well field of the Hanoi water works by means of isotope ratios (N-15/N-14). The delta N-15 values were determined for total sedimentary N and exchangeable NH4+ of the peat material, and for NH4+ dissolved in deep and shallow groundwater, sewage, and surface water. Groundwater NH4+ of the upper (Holocene) and the lower (Pleistocene) aquifers had higher delta N-15 values than did total N and NH4+ of the sediments, and were somewhat higher than the delta N-15 values of NH4+ in sewage and surface water. We conclude that the present conditions of temperature and pH tend to ...

As many of you have heard, I have a project in the 4th SciFund Challenge, a scientific research crowdfunding organization. My project, entitled You are what you eat: non-lethal feeding ecology to help conserve threatened sharks, is part of my Ph.D. dissertation research. Youll be hearing a lot more about it over the new few weeks here, on twitter, and on my Facebook page once the challenge officially starts on February 1st. Id really appreciate your support of my research!. Ill be using a research technique called stable isotope analysis to study the diet and food web interactions of shark species in Florida. My project (and the research technique) will be briefly explained on my SciFund site, but I wanted to go into more detail about the type of research questions that stable isotope analysis can answer, as well as why this kind of data is significant.. Feeding ecology is important to the conservation and management of sharks.. An emerging trend in marine conservation is ecosystem based ...

The hydrothermal vent zoarcid fish Thermarces cerberus is a top predator that inhabits deep-sea hydrothermal vents on the East Pacific Rise (EPR). Bacterial chemoautotrophy at these sites supports abundant animal communities. Paradoxically, these chemoautotrophic bacteria are not known to produce polyunsaturated fatty acids (PUFA), dietary nutrients essential for all marine vertebrates. To understand how T cerberus successfully exploits the vent environment and obtains essential PUFA, we compared its fatty acid composition to those of its invertebrate prey. Levels of 20 : 5(n - 3) and 22 : 6(n - 3) in muscle and ovary tissues of T. cerberus were low and contained higher amounts of 20 : 5(n - 3) than 22 : 6(n - 3). This is in contrast to most marine fish where 22 : 6(n - 3) typically dominates. Prey items include the limpet (Lepetodrilus elevates) and amphipods (Halice hesmonectes and Ventiella sulfuris) and all contained PUFA dominated by 20: 5(n - 3) in amounts likely to support the ...

Compound-specific isotope analyses are a very promising method for reconstructing aspects of past diets, especially by combining nitrogen and carbon isotope analyses on single amino acids to clearly distinguish aquatic and terrestrial sources of proteins, and to estimate with more precision the contribution of plants in individual diets. Our application of CSIA to two Neandertals has shown that both were high trophic level consumers, with large herbivores being the main protein source. Therefore, there is no reason to invoke myriad dietary interpretations such as the consumption of mushrooms, putrid animal flesh, mammoths, or freshwater fish to explain their high bulk bone collagen nitrogen isotope values of Neandertals in relation to carnivores from the same site. However, we acknowledge that our isotopic study does not rule out the occasional consumption of these foods. Instead, the differing high N values between Neandertals and associated carnivores is likely due to the consumption of ...

The chitin-active 19.2 kDa lytic polysaccharide monooxygenase BlLPMO10A from Bacillus licheniformis has been isotopically labeled and recombinantly expressed. In this paper, we report the 1H, 13C, 15N resonance assignment of BlLPMO10A ...

In large lakes around the world, shifts in ecological communities are often associated with water depth. This suggests that there may be concomitant changes in patterns of resource allocation. Using Lake Superior as an example, we explored this idea through stable isotope analyses of 14 major fish taxa. Patterns in carbon and nitrogen isotope ratios revealed use of littoral and profundal benthos among individuals of most taxa analyzed. Use of benthos was strongest among nearshore demersal species and weakest among planktivores, and declined with depth of habitat. Isotope mixing model results indicated that benthic food web pathways were most important in nearshore fish species, whereas offshore pelagic and profundal species used planktonic pathways. These patterns appear to be governed by two key processes: high benthic production in nearshore waters and diel vertical migration among offshore invertebrates and fish. These characteristics are shared with the Great Lakes of Africa, Russia, and ...

The biosynthesis of the opine agropine in transformed Nicotiana tabacum L. root cultures was studied using in vivo 15N nuclear magnetic resonance (NMR) spectroscopy. Roots were incubated with [15N]ammonium and/or [15N]nitrate, and the incorporation of the label into agropine, conjugated polyamines, γ-aminobutyric acid (GABA), glutamate (Glu), glutamine (Gln) and nicotine was monitored by NMR. The largest labelled pool was agropine in cells grown on a 15N-enriched medium and its synthesis was maintained, to the detriment of the Gln pool, under conditions of nitrogen (N) starvation. These observations indicate that the synthesis of agropine is not tightly regulated and that it represents a significant sink for carbon (C) and N in the plant. The addition of α-naphthaleneacetic acid (NAA) and kinetin to the growth medium caused de-differentiation of the root cultures and perturbation of secondary N metabolism. The amount of agropine relative to Gln increased but the total accumulation of agropine

This study analyses the response of the carbon and nitrogen isotopic composition of sedimentary organic matter to rapid human-induced eutrophication and meromixis as well as subsequent restoration efforts [in-lake phosphorus (P)-Precipitation, P-remediation of the well inflow and multiannual destratification] in a 46-yr sediment core sequence (1963-2009) from Fischkaltersee, a small hard-water lake (S-Germany). In addition, the sediment record was compared with detailed data on water column chemistry during almost (1977-2009) the recorded history of eutrophication and trophic recovery of the named lake. While the onset of eutrophication resulted in an abrupt positive excursion (+2.4‰), the overall reaction of δ13CSOM to ongoing eutrophication and meromixis as well as to permanent hypolimnion aeration and trophic recovery is a continous negative trend (-3.7‰) with the most depleted signatures (-38.8‰) present in the youngest part of the core. This negative trend was not influenced by ...

Fingerprint Dive into the research topics of Variability of the ,sup,15,/sup,N chemical shift anisotropy in Escherichia coli ribonuclease H in solution. Together they form a unique fingerprint. ...

The usefulness of Stable Isotope Analysis in Archaeology (Theme 3-Subsistence and diet). Key facts:. · Every chemical in nature has isotopes.. · The main difference is their atomic mass.. · Different isotopes have different amounts of protons and neutrons but still remain stable.. · C14 is an unstable isotope due to the radioactive nature of the neutrons and protons.. · This means that whilst C14 decays at the rate of the half life, stable isotopes do not decay so are useful in the archaeological record.. · Key isotopes to analyse: Carbon, Nitrogen and Sulphur-all link to diet.. · Analysis takes place using collagen (bone) or tooth enamel.. How do discuss it within an essay:. 1. When food is eaten and digested it already has a carbon and/or nitrogen trace within it.. 2. Human bones reflect the amount of plants ingested during the lifetime based on the C13 ratio.. 3. The nitrogen ratio can distinguish which plants were or were not eaten at a particular time in prehistory.. 4. Analysing the ...

ABSTRACT: In 2007 a ceremonial complex representing the Globular Amphora Culture was discovered in Kowal (the Kuyavia region, Poland). Radiocarbon dating demonstrated that the human remains associated with the complex are of similar antiquity, i.e. 4.105 ± 0.035 conv. and 3.990 ± 0.050 conv. Kyrs. After calibration, this suggests a period between 2850 and 2570 BC (68.2% likelihood), or more specifically, 2870 to 2500 BC (95.4% likelihood). Morphological data indicate that the skeleton belonged to a male who died at 27-35 years of age. The unusual morphology of his hard palate suggests this individual may have had a speech disorder. Stable oxygen isotope values of the individuals teeth are above the locally established oxygen isotope range of precipitation, but due to sample limitations we cannot conclusively say whether the individual is of non-local origin. Stable carbon and nitrogen isotope ratios were analyzed to reconstruct the diet of the studied individual, and show a terrestrial-based ...

Differences in δ15N among ten white spruce [ Picea glauca (Moench) Voss] families were examined in hydroponic experiments testing (1) three N sources [100 μM N as (i) NH4+, (ii) NO3− or (iii) NH4NO3]

Background. The pattern of protein intake following exercise may impact whole-body protein turnover and net protein retention. We determined the effects of different protein feeding strategies on protein metabolism in resistance-trained young men. Methods. Participants were randomly assigned to ingest either 80g of whey protein as 8x10g every 1.5h (PULSE; n=8), 4x20g every 3h (intermediate, INT; n=7), or 2x40g every 6h (BOLUS; n=8) after an acute bout of bilateral knee extension exercise (4x10 repetitions at 80% maximal strength). Whole-body protein turnover (Q), synthesis (S), breakdown (B), and net balance (NB) were measured throughout 12h of recovery by a bolus ingestion of [15N]glycine with urinary [15N]ammonia enrichment as the collected end-product. Results. PULSE Q rates were greater than BOLUS (~19%, P Conclusion. We conclude that the pattern of ingested protein, and not only the total daily amount, can impact whole-body protein metabolism. Individuals aiming to maximize NB would likely ...

Imbrie, John D; McIntyre, Andrew; Mix, Alan C (1997): Stable isotope data (adjusted) of sediment core RC13-228 (specmap.003). PANGAEA, https://doi.org/10.1594/PANGAEA.52118

Compound-specific carbon and hydrogen isotope ratios are routinely measured on extractable organic matter to decipher biogeochemical processes and events in Earth history. To deliver accurate interpretations, it is paramount that isotopic values are derived from indigenous compounds and are not the result of contamination. However, distinguishing between compounds from these different provenances can be difficult, especially if a degree of mixing occurred. In this study, we assess the impact of hydrocarbon contamination on the carbon and hydrogen isotopic composition of n-alkanes from similar to 820 Ma Precambrian evaporitic drill core samples through exterior/interior (E/I) rock extraction experiments. In these experiments, exterior and interior portions of the same rock samples were separately crushed to powder, extracted and processed. Compound-specific isotope values of n-alkanes from the different rock portions were subsequently measured and compared. In most cases, n-alkanes from exterior ...

In the last year, the stable isotope ratio analysis has become a useful tool with many applications in different scientific area. In particular the characteristic isotope signature of materials has permitted to identify authenticity and traceability of food sample and isotope composition has become a valuable marker in environmental studies. This work shows the applicability of analytical methods for isotopic carbon determination in food and environmental samples and the innovative use of δ13C in cultural heritage as valuable tool to trace pollutant fate. The first part is dedicated to the improvement of spectroscopic methods as Fourier Transform Infrared (FT-IR) and Non-Dispersive Infrared spectroscopy (NDIRS) and their application to identify geographical origin in sample like pasta, cocoa, olive oil. The results conducted in order to assess the robustness of the two alternative methods respecting IRMS showed a strong correlation like a demonstration of the positive relationship between the ...

On Australian semiarid floodplains, large herbivores such as kangaroos have a role in the cycling of energy (carbon) through the mechanism of feeding and defaecation of vegetative material. The degree to which kangaroos are vectors of energy within this system is not fully understood. This study describes the stable carbon isotope signature of floodplain plants and kangaroo scats at two close study sites. Kangaroos were found to deposit scats that mirrored the forage composition at each particular feeding site. Scats were 3.94‰ higher in δ13C values at the site where C4 grasses were available, indicating that this grass contributed ~25-30% of the diet of these kangaroos. The difference in diet due to the relative availability of C3 and C4 forage, detectable in the carbon stable isotope signature of scats, is used to demonstrate that kangaroos are recycling and redistributing energy locally, rather than transporting it more broadly across the floodplain. © 2010, CSIRO ...

Résumé: Stable isotope ratios for six size fractions of zooplankton (80 to >2000 μm) were analyzed in the Gulf of Lion in spring 2010 and winter 2011. Environmental and plankton community variables were also recorded. The originality of this study is the use of a Lagrangian transport modeling system to determine the origin of the water masses and the assessment of the proportion of detritus in the plankton samples. The highest δ15N values were observed in the 1000-2000 μm fraction in January and in the 500-1000 μm fraction in May. The largest size class (>2000 μm), dominated by salps, had lower δ15N values owing to the low isotopic signatures of these organisms. The history of the water masses resulted in two main patterns with different isotopic signatures: the water masses which resided on the shelf and the waters masses carried onto the shelf from off-shelf region by the Northern Current. The δ13C values varied strongly between January and May, mainly owing to changes in hydrographic ...

Otoliths of king threadfin, Polydactylus macrochir were collected from 2007 to 2009 at nine locations across northern Australia representing most of their distributional range and areas where fisheries are active. Measurement of the stable isotope ratios of δ18O and δ13C in the sagittal otolith carbonate from assemblages of P. macrochir revealed location-specific signatures and indicated that adult fish sampled from representative sites across their range were significantly different. The significant differences in the isotopic signatures of P. macrochir demonstrated that population subdivision is evident and there is unlikely to be substantial movement of fish among these distinct adult assemblages. The stable isotopic signatures for the fish from the different locations were persistent through time, and therefore it could be concluded that they comprise separate stocks for many of the purposes of fisheries management. The spatial separation of these populations indicates a complex stock ...

Abstract. The balance between denitrification and nitrogen fixation is the key control of the availability of nitrogen in coastal ecosystems and thus the primary productivity of these environments. However, evaluating the importance of denitrification and nitrogen fixation over large spatial and temporal scales is problematic. In this study, a combined mass and stable isotope balance of nitrogen was used to constrain the cycling of nitrogen in Western Port, Victoria - a temperate, intertidal embayment in south-eastern Australia. This method is a more effective approach compared to the extrapolation of discrete measurements and geochemical approaches. The validity of the isotope and mass balance model has been tested by comparing the output of the model with the average measured isotopic signature of the sediment in Western Port. Using previously measured rates of nitrogen fixation and denitrification in combination with the isotopic signature of nitrogen inputs from the catchment, atmosphere and ...

Aerosol nitrate is an important fraction of the mass of the fine particles (PM) in atmosphere. Moreover, aerosol nitrogen species are predominantly anthropogenic over Europe (traffic, industry and farming). In the view of the increasingly drastic constraints of the European air quality standard for PM, the understanding of these sources has become crucial in France. Indeed, during the months of March and April, several high concentration of PM are observed on a large scale throughout the national territory. During these specific events, the ammonium nitrate (NH4NO3) is a predominant component of the airborne PM. There are two main ways that produces NH4NO3 in air with many precursors as NH3 from specific primary sources (agricultural activity). The presence of these species in PM is the result of complex primary and secondary processes which are always investigated. In literature, many studies propose the nitrogen stable isotope ratio (?15N) of NOx as an indicator for NOx source apportionment ((Walters,

TY - JOUR. T1 - Chemical shift assignments of the C-terminal Eps15 homology domain-3 EH domain. AU - Spagnol, Gaelle. AU - Reiling, Calliste. AU - Kieken, Fabien. AU - Caplan, Steve. AU - Sorgen, Paul L.. PY - 2014/10/1. Y1 - 2014/10/1. N2 - The C-terminal Eps15 homology (EH) domain 3 (EHD3) belongs to a eukaryotic family of endocytic regulatory proteins and is involved in the recycling of various receptors from the early endosome to the endocytic recycling compartment or in retrograde transport from the endosomes to the Golgi. EH domains are highly conserved in the EHD family and function as protein-protein interaction units that bind to Asn-Pro-Phe (NPF) motif-containing proteins. The EH domain of EHD1 was the first C-terminal EH domain from the EHD family to be solved by NMR. The differences observed between this domain and proteins with N-terminal EH domains helped describe a mechanism for the differential binding of NPF-containing proteins. Here, structural studies were expanded to include ...

Background: Information on larval diet of many holometabolous insects remains incomplete. Carbon (C) and nitrogen (N) stable isotope analysis in adult wing tissue can provide an efficient tool to infer such trophic relationships. The present study examines whether moth feeding guild affiliations taken from literature are reflected in isotopic signatures. Results: Non-metric multidimensional scaling and permutational analysis of variance indicate that centroids of dietary groups differ significantly. In particular, species whose larvae feed on mosses or aquatic plants deviated from those that consumed vascular land plants. Moth δ15N signatures spanned a broader range, and were less dependent on species identity than δ13C values. Comparison between moth samples and ostensible food sources revealed heterogeneity in the lichenivorous guild, indicating only Lithosia quadra as an obligate lichen feeder. Among root-feeding Agrotis segetum, some specimens appear to have developed on crop plants in ...

Background: Information on larval diet of many holometabolous insects remains incomplete. Carbon (C) and nitrogen (N) stable isotope analysis in adult wing tissue can provide an efficient tool to infer such trophic relationships. The present study examines whether moth feeding guild affiliations taken from literature are reflected in isotopic signatures. Results: Non-metric multidimensional scaling and permutational analysis of variance indicate that centroids of dietary groups differ significantly. In particular, species whose larvae feed on mosses or aquatic plants deviated from those that consumed vascular land plants. Moth δ15N signatures spanned a broader range, and were less dependent on species identity than δ13C values. Comparison between moth samples and ostensible food sources revealed heterogeneity in the lichenivorous guild, indicating only Lithosia quadra as an obligate lichen feeder. Among root-feeding Agrotis segetum, some specimens appear to have developed on crop plants in ...

We have developed a transportable spectroscopic nitrogen isotopic analyzer. The spectrometer is based on dual-modulation Faraday rotation spectroscopy of nitric oxide isotopologues with near shot-noise limited performance and baseline-free operation. Noise analysis indicates minor isotope (15NO) detection sensitivity of 0.36 ppbv·Hz−1/2, corresponding to noise-equivalent Faraday rotation angle (NEA) of 1.31 × 10−8 rad·Hz−1/2 and noise-equivalent absorbance (αL)min of 6.27 × 10−8 Hz−1/2. White-noise limited performance at 2.8× the shot-noise limit is observed up to ~1000 s, allowing reliable calibration and sample measurement within the drift-free interval of the spectrometer. Integration with wet-chemistry based on acidic vanadium(III) enables conversion of aqueous nitrate/nitrite samples to gaseous NO for total nitrogen isotope analysis. Isotopic ratiometry is accomplished via time-multiplexed measurements of two NO isotope transitions. For 5 μmol potassium nitrate samples, the

A team of researchers found something rather peculiar tucked in the dental tartar of a Mesolithic forager from the 8th millennium B.C., who was excavated from Vlakno Cave on the Croatian island of Dugi Otok. Using carbon and nitrogen stable isotope analysis, the researchers uncovered several microfossils of plants, fish scales, and fish muscle fibers. This is a find never seen in the human remains of Mediterranean people from this age.. Theres substantial archaeological evidence demonstrating that people in the Central Mediterranean caught and ate fish, but this is the first time we have direct evidence that humans consumed these resources, or used their teeth for de-scaling activities, which is very unique, University of York archaeologist Dr. Harry Robson said in a press statement.. Finding skeletal remains with both plant and fish microfossils gives researchers greater clues into how Adriatic and Mediterranean foragers lived, and the similarities between their diet and that of modern ...

ABSTRACT: Epilithic bacterial communities play a major role in biogeochemical cycles of rivers; however, distributional patterns and controls of epilithic communities remain unclear. The objective of the present study was to examine possible environmental factors that affect longitudinal distributional patterns of epilithic bacterial communities in 2 rivers (Yasu and Ado Rivers) draining the Lake Biwa basin, Japan. Phylogenetic analyses were conducted using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes and fluorescence in situ hybridization (FISH) with oligonucleotide probes targeted to small subunit rRNA. Non-metric multidimensional scaling and canonical correspondence analysis of the DGGE profile indicated that a clear shift in community composition occurred at the middle reach of the Yasu River. This shift was most closely related to variation in the nitrogen stable isotope ratio (δ15N) of epilithic materials (BIOENV analysis, ρw = 0.512), which is an indicator of the ...

The research reported in this manuscript was conducted by a National Academy of Sciences, NRC Post-Doctoral Fellow, and a fellow of the Scientist Committee of NATO, both of whom were located at WED. The research was also funded by the National Science Foundation, Environmental Biology. The research contributed to the WED project Extrapolating Anthropogenic Stress Effects: Individuals to Forests, Ecosystems, and Regions (INFER). One overarching objective of INFER was to develop the capabilities to scale ecosystem processes across gradients of space, time and biological complexity to inform predictions of consequences of anthropogenic stresses. The overall objective of this collaborative research was to use stable isotope signatures of nitrogen and carbon to provide a mechanistic understanding of the taxanomic variation in how a dominant (in terms of biomass) functional group of soil microbiota (higher fungi) assimilate and partition nitrogen and carbon across a large geographic range within the ...

The present work reports the first data set on particulate organic carbon (POC) and nitrogen (PON), and the highresolution modelling of their stable isotope variability in the Patagonian Cold Estuarine System (PCES), with focus on particulate organic matter (POM) origin and distribution in dependence on physical, chemical and biological parameters. POC, PON, stable carbon (δ13C) and nitrogen isotopes (δ15N), dissolved organic nitrogen, phaeopigments, diatom, dinoflagellate and heterotrophic bacteria (HB) abundance are reported for 17 stations in different waters masses in the southern end of the Argentine shelf in late summer 2012. Most parameters denote clear differences between Beagle-Magellan Water (BMW), Subantarctic ShelfWater (SSW) and Subantarctic Water (SAW). POC and PON decreased frommaxima in BMWto intermediate values in SSWandminima in SAW. There was a highly significant correlation among POC, PON and fluorescence indicators of diagenetic maturity of dissolved humic matter. This, ...

Solid state NMR:. Any researcher who needs solid state spectroscopy is able to request time on this spectrometer. There are two solid state NMR probes available, each triple resonance with fixed 1H, 13C, and 15N channels: Probe 1: E-free 3.2 mm probe (MAS up to 24 kHz) ; and Probe 2: CMP probe (MAS up to 15 kHz).e probes having fixed 1H, 13C, 15N channel.. Probe #1: E-free 3.2 mm probe (MAS up to 24kHz): This is a top-loading E-Free triple resonance Magic Angle Spinning probe for solid state NMR of biological samples. It has been optimized for 13C and/or 15N observation / decoupling and 1H high-power decoupling. A special coil configuration minimizes the electric field at the sample, and strongly reduces RF heating when dielectric samples are studied. Active volume that is required can be varied from 10 to 30µL using special inserts and 24 kHz maximum spinning speed. VT range -80o C to +80o C. MAS heat exchanger system BCU-II is available for VT below ambient. Triple resonance experiments are ...

Analysis of stable carbon and nitrogen isotopes in the bones of early humans from the Buran Kaya caves on the Crimean Peninsula, Russia-occupied Ukraine, and

Sequence specific resonance assignment constitutes an important step towards high-resolution structure determination of proteins by NMR and is aided by selective identification and assignment of amino acid types. The traditional approach to selective labeling yields only the chemical shifts of the particular amino acid being selected and does not help in establishing a link between adjacent residues along the polypeptide chain, which is important for sequential assignments. An alternative approach is the method of amino acid selective `unlabeling or reverse labeling, which involves selective unlabeling of specific amino acid types against a uniformly C-13/N-15 labeled background. Based on this method, we present a novel approach for sequential assignments in proteins. The method involves a new NMR experiment named, {(CO)-C-12 (i) -N-15 (i+1)}-filtered HSQC, which aids in linking the H-1(N)/N-15 resonances of the selectively unlabeled residue, i, and its C-terminal neighbor, i + 1, in ...

For example, carbonate apatite - a primary constituent of both skeletal bones and dentition in vertebrates - is incorporated into organisms through diet and water uptake. Some conservationists use the isotopic signatures recovered from this apatite to better decipher the life histories of contemporary species in expectation of aiding in their continued preservation. As a case in point, remains from the worlds largest cavefish (Milyeringa veritas) have been used by Australian conservationists to better examine and comprehend the environment and ecosystem inhabited by the fish. The cavefish resides in deep water columns that are rich in dissolved limestone. Due to relative densities and variable solubility, different depths in the water column are correlated to specific concentrations of dissolved materials. By examining the isotopic signatures of the cavefishs skeletal apatite, conservationists were able to discover the exact depth the fish occupies ...

This material is based upon work supported by the National Science Foundation under grant DEB#1545288, 10/1/2015-9/30/19 and DEB#1929393, 09/01/2019-08/31/2024. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.. ...

The main aim of this thesis is to show how scientific methods may be used to look at migration in prehistory on the basis of archaeological material. The individuals examined represent the period 4 000 BC to 1 000 AD and have their geographical origins in various parts of Sweden.. Ancient DNA analysis is employed in three cases. The first is an investigation of the genetic profiles of the two main cultural groups, which existed in Sweden during the Neolithic, the Funnel Beaker (TRB) and Pitted Ware (PWC) cultures. We can deduce from these genetic data that they were two separate populations, and can see that the TRB genetic profiles continue into the Bronze Age whereas the PWC profiles seem to disappear. In a second analysis based on the same material we explore the ability of adults to digest milk, i.e. lactose tolerance, a genetic trait found in high frequencies in northern Europe. We can see that the TRB population had a higher frequency of this allele than the PWC population. The last paper ...

Stable isotope analysis is often used to investigate the trophic ecology of marine systems. However, a lack of standardization of the treatment of samples prior to analysis, hampers comparisons of res

This material is based upon work supported by the National Science Foundation under grant DEB#1545288, 10/1/2015-9/30/19 and DEB#1929393, 09/01/2019-08/31/2024. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.. ...

Documentary evidence and artistic representations have traditionally served as the primary sources of information about Byzantine diet. According to these sources, Byzantine diet was based on grain (primarily wheat and barley), oil, and wine, supplemented with legumes, dairy products, meat, and marine resources. Here, we synthesize and compare the results of stable isotope ratio analyses of eight Greek Byzantine populations (6th-15th centuries AD) from throughout Greece. The δ13C and δ15N values are tightly clustered, suggesting that all of these populations likely consumed a broadly similar diet. Both inland and coastal Byzantine populations consumed an essentially land-based C3 diet, significant amounts of animal protein, and possibly some C4 plants, while no evidence of a general dependence on low-δ15N legumes was observed. One interesting result observed in the isotopic data is the evidence for the consumption of marine protein at both coastal sites (a reasonable expectation given their ...

Stable isotopes are widely used to identify trophic interactions and to determine trophic positions of organisms in food webs. Comparative studies have provided general insights into the variation in isotopic composition between consumers and their diet (discrimination factors) in predator-prey and herbivore-plant relationships while other major components of food webs such as host-parasite interactions have been largely overlooked.

Tardani, D., Reich, M., Roulleau, E., Takahata, N., Sano, Y., Perez-Flores, P., Sanchez-Alfaro, P., Cembrano, J., and Arancibia, G., 2016: Geochimica Et Cosmochimica Acta, v. 184, p. 193-211.. Abstract:. There is a general agreement that fault-fracture meshes exert a primary control on fluid flow in both volcanic/magmatic and geothermal/hydrothermal systems. For example, in geothermal systems and epithermal gold deposits, optimally oriented faults and fractures play a key role in promoting fluid flow through high vertical permeability pathways. In the Southern Volcanic Zone (SVZ) of the Chilean Andes, both volcanism and hydrothermal activity are strongly controlled by the Liquine-Ofqui Fault System (LOFS), an intra-arc, strike-slip fault, and by the Arc-oblique Long-lived Basement Fault System (ALFS), a set of transpressive NW-striking faults. However, the role that principal and subsidiary fault systems exert on magma degassing, hydrothermal fluid flow and fluid compositions remains poorly ...

Reptile growth is influenced by many ecological processes that can cumulatively give rise to divergent somatic growth rates within spatially structured populations. As somatic growth variation can strongly influence a species population dynamics, identifying proximate drivers can be critical to the conservation and management of protected species. Kemps ridley sea turtles (Lepidochelys kempii) exhibit spatial variation in both diet composition and growth, but whether components of this variation are linked has not been evaluated. Through an integration of skeletochronological and stable isotope analyses of stranded turtle humerus bones we characterized regional variation in Kemps ridley diet composition and potential relationships with somatic growth rates. Turtles were divided among five regions within the United States Gulf of Mexico (GoM) and Atlantic Coast based on location of stranding, and humerus bones were sampled for stable carbon (δ13C) and nitrogen (δ15N) isotope ratios. These data were

Biomolecular NMR Assignments provides a forum for publishing sequence-specific resonance assignments for proteins and nucleic acids as Assignment Notes. Chemical shifts for NMR-active nuclei in macromolecules contain detailed ...

Barbers and salon owners were supportive, Ehleringer says. They would then let us go to the trash bin and pull out a handful or two of hair, which we then sort into identifiable clusters representing individuals. This sampling technique was blind, he adds, to the individuals age, gender, income, health status or any other factor, except for the isotope record. All together, they collected samples representing nearly 700 people.. The results showed variations in hair isotope ratios, both locally and nationally, but within a relatively narrow range. Within that variation, the researchers found, carbon isotope values correlated with the cost of living in the ZIP codes where the samples were collected. Previous studies provided the expected isotope values from the ends of the diet spectrum, from vegans to meat-prominent omnivores.. The samples collected from the Salt Lake Valley offered an opportunity to examine in greater detail the factors behind the isotope variation. Surprisingly, carbon ...

Breast cancer is the most common cancer in women worldwide. Despite the information provided by anatomopathological assessment and molecular markers (such as receptor expression ER, PR, HER2), breast cancer therapies and prognostics depend on the metabolic properties of tumor cells. However, metabolomics have not provided a robust and congruent biomarker yet, likely because individual metabolite contents are insufficient to encapsulate all of the alterations in metabolic fluxes. Here, we took advantage of natural 13 C and 15 N isotope abundance to show there are isotopic differences between healthy and cancer biopsy tissues or between healthy and malignant cultured cell lines. Isotope mass balance further suggests that these differences are mostly related to lipid metabolism, anaplerosis and urea cycle, three pathways known to be impacted in malignant cells. Our results demonstrate that the isotope signature is a good descriptor of metabolism since it integrates modifications in C partitioning and N

Highlights: ► The isotopic signature of δ{sup 13}C-DIC of leachates is linked to the reactivity of MSW. ► Isotopic signatures of leachates depend on aerobic/anaerobic conditions in landfills. ► In situ aeration of landfills can be monitored by isotope analysis in leachate. ► The isotopic analysis of leachates can be used for assessing the stability of MSW. ► δ{sup 13}C-DIC of leachates helps to define the duration of landfill aftercare. - Abstract: Stable isotopic signatures of landfill leachates are influenced by processes within municipal solid waste (MSW) landfills mainly depending on the aerobic/anaerobic phase of the landfill. We investigated the isotopic signatures of δ{sup 13}C, δ{sup 2}H and δ{sup 18}O of different leachates from lab-scale experiments, lysimeter experiments and a landfill under in situ aeration. In the laboratory, columns filled with MSW of different age and reactivity were percolated under aerobic and anaerobic conditions. In landfill simulation reactors, ...

C4 grasses form the foundation of warm-climate grasslands and savannas and provide important food crops such as corn, but their Neogene rise to dominance is still not fully understood. Carbon isotope ratios of tooth enamel, soil carbonate, carbonate cements, and plant lipids indicate a late Miocene-Pliocene (8-2 Ma) transition from C3 vegetation to dominantly C4 grasses at many sites around the world. However, these isotopic proxies cannot identify whether the C4 grasses replaced woody vegetation (trees and shrubs) or C3 grasses. Here we propose a method for reconstructing the carbon isotope ratio of Neogene grasses using the carbon isotope ratio of organic matter trapped in plant silica bodies (phytoliths). Although a wide range of plants produce phytoliths, we hypothesize that in grass-dominated ecosystems the majority of phytoliths will be derived from grasses, and will yield a grass carbon isotope signature. Phytolith extracts can be contaminated by non-phytolith silica (e.g., volcanic ash). ...

This study analyses deciduous dental pathology and stable carbon and nitrogen isotopes to investigate the relationship between dietary composition, feeding practices, and oral health in a subadult skeletal sample from the Greek colonial site of Apollonia Pontica, Bulgaria (5th to 3rd century BC). Stable isotope analysis of 74 bone collagen samples indicates that weaning began between the ages of 6 months and 1 year, and was complete by the age of 4. The stable isotope data are consistent with a diet of primarily terrestrial C3 resources. The deciduous dentitions of 85 individuals aged between 8.5 months and 10.5 years were examined for evidence of a number of pathological conditions. The presence of dental caries, calculus, occlusal tooth wear and an abscess indicate that foods introduced early in life affected the oral health of these individuals. Overall, the deciduous dental data correlate well with the stable isotope data and ancient textual sources regarding infant and childhood dietary ...

Analysis of stable carbon and nitrogen isotope values (δ13C and δ15N) of animal tissues can provide important information about diet, physiology, and movements. Interpretation of δ13C and δ15N values, however, is influenced by factors such as sample lipid content, tissue-specific isotope discrimination, and tissue turnover rates, which are typically species- and tissue-specific. In this study, we generated lipid normalization models for δ13C and investigated the effects of chemical lipid extractions on δ13C and δ15N in Pacific walrus (Odobenus rosmarus divergens) muscle, liver, and skin. We also evaluated tissue-specific isotope discrimination in walrus muscle, liver, skin, and bone collagen. Mean δ13Clipid-free of skin and bone collagen were similar, as were mean δ15N of muscle and liver. All other tissues differed significantly for both isotopes. Differences in δ13Clipid-free and δ15N among tissues agreed with published estimates of marine mammal tissue-specific isotope discrimination

ABSTRACT: We studied the diet of sperm whales Physeter macrocephalus by measuring carbon and nitrogen isotope ratios in 106 sloughed skin samples and 10 squid beaks (Histioteuthidae spp.), the latter collected from sperm whale defecations. Samples were collected during 8 studies conducted between 1989 and 2000 in the South Pacific Ocean. We examined diet variation across region, year, social group and vocal clan. The isotopic signatures of groups and acoustic clans of sperm whales were compared using a nested analysis of variance (ANOVA) and the absolute distances between each pair of samples were calculated. The δ13C and δ15N values ranged from 17.8 to 14.5 and from 8.5 to 22.3 , respectively. The δ15N values of defecated squids were about 3 lower than values of the sperm whale, corresponding to a trophic difference of one level. There was a significant difference in both the δ15N and δ13C values between groups (nested within clans and the studies) and clans (nested within studies). Most ...

Abstract. Fire frequency exerts a fundamental control on productivity and nutrient cycling in savanna ecosystems. A single fire event often increases short-term nitrogen (N) availability to individual plants, but repeated burning causes ecosystem carbon and N losses and can ultimately decrease soil organic matter and N availability. However, these effects remain poorly understood due to limited long-term biogeochemical data. Here, we leveraged one of the longest running prescribed burn experiments (established in 1964) to evaluate how fire frequency and changing vegetation composition influenced wood stable N isotopes (δ15N) across space and time. We developed multiple δ15N records across a burn frequency gradient from precisely dated Quercus macrocarpa tree-rings in an oak savanna at Cedar Creek Ecosystem Science Reserve, Minnesota, USA. Sixteen trees were sampled across four treatment stands that varied in temporal onset of burning and burn frequency, but were consistent in overstory species ...

Using stable isotopes of carbon (δ13C) and nitrogen (δ15N), I investigate the trophic ecology and niche overlap of Yellow Perch (Perca flavescens) and White Perch (Morone americana) across the western basin of Lake Erie. Stable isotopes varied spatially and temporally in lower trophic level organisms, which are used to estimate carbon sources and trophic position of consumers. These variations inhibit our ability to assess trophic relationships, particularly in large lakes. Yellow Perch relied on benthic food sources, while White Perch occupied higher trophic positions and had larger niche widths. Trophic positions of yellow and white perch were related to size however a lack of δ13C- length relationship suggests these species exhibit no changes in carbon source. Significant differences in δ 13C/ δ15N and high niche overlap among Yellow and White Perch indicated that the species are utilizing different forage bases, however, have the potential to compete if resources become limited.

Sandberg P.A., M. Sponheimer, J. A Lee-Thorp, D. van Gerven 2014. Intra-tooth stable isotope analysis of dentine: a step toward addressing selective mortality in the reconstruction of life history in the archaeological record. Am. J. Phys. Anthrop. 55:281-293. Le Roux P.J., J.A. Lee-Thorp, S.R. Copeland, M. Sponheimer, D.J. de Ruiter 2014. Strontium isotope analysis of curved tooth enamel surfaces by laser-ablation multi-collector ICP-MS. Palaeogeog. Palaeoclimatol. Palaeoecol. 416:142-149. Snoeck C., Lee-Thorp J.A., Schulting R.J. 2014 From bone to ash: compositional and structural studies of burned bone. Palaeogeog. Palaeoclimatol. Palaeoecol. 416: 55-68. Vaiglova, P., C. Snoeck, E. Nitsch, A. Bogaard, J.A. Lee-Thorp. 2014. Impact of contamination and pre-treatment on stable carbon and nitrogen isotope composition of charred plant remains. Rapid Commun. Mass Spectrom. 28: 2497-2510.. Buckberry J., J. Montgomery, J. Towers, G. Muldner, M. Holst, J. Evans, A. Gledhill, N. Neale, J.A. Lee-Thorp ...

Weinelt, Mara (2005): Stable isotope data of benthic foraminifera of ODP Site 162-984B. PANGAEA, https://doi.org/10.1594/PANGAEA.319265

Stable carbon isotope analyses of the humin fraction of the soil organic matter were conducted on more than 160 soil profiles from Tikal, Guatemala. The profiles were collected from near areas associated with the earthworks of Tikal; an ancient ditch and parapet construction hypothesized to have formed ancient boundaries of the polity. In addition to the isotope analyses, the physical and chemical characteristics of the horizons were determined. Maize, a C4 plant, formed an integral part of the ancient Maya diet and is the only known C4 plant cultivated by the Maya. Prior to and subsequent to the ancient Maya occupation of Tikal, the landscape was dominated by C3 forest vegetation. Over the centuries C4 plant biomass including rhizodeposition decomposed to form soil organic matter that contains a distinct C4 signature reflecting the vegetation history of the area. Forested areas anciently cleared for agriculture were identified through interpretation of significant isotopic shifts that signaled past

Data & statistics on Chile Plant 3 Total Organic Carbon: Chile Plant 3 - Total Organic Carbon, Soil organic carbon (total and C-GRSP) in soil from four plant species from a Mediterranean ecosystem in central Chile. Abbreviations: R = rhizospheric soil; NR = non-rhizospheric soil. Different letters indicate significant difference according to the orthogonal contrasts test (p b 0.05). Bars denote mean ± S.E. (n = 4)., Nitrogen isotope ratios (δ15N) of the different categories of organic and synthetic fertilizer. The dashed line denotes the threshold value, based on the natural isotopic abundance of different materials; an organic fertilizer with a ratio below the line may warrant investigation for adulteration. Based on 99% confidence intervals, seaweed, algae, Chilean nitrate and soybean fertilizers and their blends ......

The giant protein titin is the third most abundant protein of vertebrate striated muscle. The titin molecule is , 1 ?m long and spans half the sarcomere, from the Z-disk to the M-line, and has important roles in sarcomere assembly, elasticity and intracellular signaling. In the A-band of the sarcomere titin is attached to the thick filaments and mainly consists immunoglobulin-like and fibronectin type III-like domains. These are mostly arranged in long-range patterns or super-repeats. The large super-repeats each contain 11 domains and are repeated 11 times, thus forming nearly half the titin molecule. Through interactions with myosin and C-protein, they are involved in thick filament assembly. The importance of titin in muscle assembly is highlighted by the effect of mutations in the A-band portion, which are the commonest cause of dilated cardiomyopathy, affecting ~1 in 250 (Herman et al. in N Engl J Med 366:619-628, 2012). Here we report backbone (15)N, (13)C and (1)H chemical shift and ...

TY - GEN. T1 - Carbon isotope signatures and their possible link to upwelling, Middle Mississippian crinoidal-bryozoan carbonates, Illinois Basin. AU - Lasemi, Z.. N1 - hand-typed from author-received information. PY - 2018. Y1 - 2018. KW - ISGS. M3 - Conference contribution. SP - 88. BT - Book of Abstracts. CY - Quebec City, Canada. ER - ...

Monooxygenation is an important route of nitroaromatic compound (NAC) biodegradation and it is widely found for cometabolic transformations of NACs and other aromatic pollutants. We investigated the C and N isotope fractionation of nitrophenol monooxygenation to complement the characterization of NAC (bio)degradation pathways by compound-specific isotope analysis (CSIA). Because of the large diversity of enzymes catalyzing monooxygenations, we studied the combined C and N isotope fractionation and the corresponding C-13- and N-15-apparent kinetic isotope effects (AKIEs) of four nitrophenol-biodegrading microorganisms (Bacillus spharericus JS905, Pseudomonas sp. 1A, Arthrobacter sp. JS443, Pseudomonas putida B2) in the pH range 6.1-8.6 with resting cells and crude cell extracts. While the extent of C and N isotope fractionation and the AKIE-values varied considerably for the different organisms, the correlated C and N isotope signatures (delta N-15 vs delta C-13) revealed trends, indicative of ...

This study investigates the isotopic signatures of human skeletal remains that were recovered from several sites along the coast and inland in the north-central Patagonian region of Argentina. Human skeletal remains, dating from 2500 BP through the early historic period, are examined to determine the relative significance of terrestrial and aquatic food resources and subsequently, the extent to which coastal food resources were exploited by indigenous Argentinians. Carbon and nitrogen isotopes contained within human bone collagen and apatite are measured quantitatively to determine the relative significance of marine and terrestrial foods. This study, one of the first isotopic studies of indigenous diet on the Atlantic coast of Argentina, is significant because it provides initial results to be used for the reconstruction of aboriginal subsistence patterns prior to and after European contact.

Antigens, Bacterial, CHEMISTRY, GENETICS, Bacterial Outer Membrane Proteins, CHEMISTRY, GENETICS, Borrelia burgdorferi, CHEMISTRY, IMMUNOLOGY, Carbon Isotopes, Escherichia coli, GENETICS, Nitrogen Isotopes, Nuclear Magnetic Resonance, Biomolecular, Protons, Recombinant Proteins, CHEMISTRY, Solutions, Support, U.S. Govt, P.H.S ...

Elements with multiple isotopes have varied isotopic compositions in nature as a result of isotope fractionation. Biomedical applications relying on isotopic analysis have become more popular. Cu, Fe and Zn isotopic analysis in blood has shown potential as a diagnostic tool for a number of diseases. Furthermore, the natural variations of these elements on healthy individuals can provide useful information.. Frank Vanhaecke and colleagues from Ghent University and Ghent University Hospital compared the isotopic values of Cu, Fe and Zn between men, menstruating women and two groups of non-menstruating women, women in their menopause and women with an intra-uterine device (IUD) used for contraception. The results indicated that Cu and Fe isotopic composition of whole blood is affected by menstruation, since the results for both groups of non-menstruating women were significantly different from those of menstruating women and much like those for men. On the other hand, Zn isotopic composition seems ...

Laboratory experiments with stable isotopes (13C and 15N) were conducted to determine the importance of bacteria and algae as food sources for free-living nematodes. All tested bacterivorous nematodes (Caenorhabditis elegans, Acrobeloides tricornis, Poikilolaimus sp. and Panagrolaimus sp.) were found to be depleted in δ13C (on average by −1.71 ± 0.56‰) and enriched in δ15N (on average by 3.17 ± 1.27‰) relative to their bacterial diets of Escherichia coli and Matsuebacter sp. The nematode species showed considerable differences in their stable isotope composition with respect to food sources. Moreover, they differed significantly in δ13C and δ15N values when placed on the same bacterial diet of E. coli, consistent with differences in their trophic shifts. Conversely, no differences in δ13C values were observed among nematode species placed on the same Matsuebacter sp. diet. In mixed food sources of E. coli and Matsuebacter sp., E. coli contributed 71% of the carbon to C. elegans and

The irons display a range in values which is to too large to be the result of fractionation processes in the nebula. An explanation involving primordial heterogeneity is favoured, with the iron meteorite parent bodies having sampled at least four isotopically distinct nitrogen reservoirs. One of the factors controlling the variation may be an input of 1%-rich nitrogen, together with 26Al, from a nova event prior to solar nebula collapse. The behaviour of nitrogen during core formation processes is also considered and compared with the observed nitrogen variation in the non-magmatic group lAB. Other secondary processes affecting nitrogen in the iron meteorites are also identified. The isotopic composition of nitrogen has been used to identify genetic links between iron and stony meteorites, thereby enhancing the normal technique based on oxygen isotopic composition (prohibited by the rarity of oxygen bearing minerals ...

Abstract : MC1 is the most abundant architectural protein present in Methanosarcina thermophila CHTI55 in laboratory growth conditions and is structurally unrelated to other DNA-binding proteins. MC1 functions are to shape and to protect DNA against thermal denaturation by binding to it. Therefore, MC1 has a strong affinity for any double-stranded DNA. However, it recognizes and preferentially binds to bent DNA, such as four-way junctions and negatively supercoiled DNA minicircles. Combining NMR data, electron microscopy data, biochemistry, molecular modelisation and docking approaches, we proposed recently a new type of DNA/protein complex, in which the monomeric protein MC1 binds on the concave side of a strongly bent 15 base pairs DNA. We present here the NMR chemical shifts assignments of each partner in the complex, 1H 15N MC1 protein and 1H 13C 15N bent duplex DNA, as first step towards the first experimental 3D structure of this new type of DNA/protein complex.. ...

We describe a new fivefold symmetric approach to homonuclear recoupling in rotating solids that is based on rotor-synchronized, spin-lock rf irradiation of the type employed previously in MELODRAMA and C7 ~and their derivative sequences! for C- C recoupling. The fivefold sequence, like its sevenfold relatives, is g-encoded, and therefore exhibits a theoretical efficiency of ;73% for double quantum filtering ~2QF!. However, since the ratio of rf field strength, v rf/2p , to spinning frequency, vr/2p , is lower, it is possible to operate the sequence at higher spinning rates, and we have investigated the 2QF efficiency as a function of H decoupling field strength at high spinning frequencies. We observe dramatic oscillations of the recoupled signal with a period ;vr/2p indicating that the H reservoir is behaving partially inhomogeneously. This kind of double quantum recoupling is explored in multiple spin systems and we derive analytical forms for polarization transfer and double quantum excitation

White-tailed kite (Elanus leucurus) populations in the 1930s were close to extirpation in the United States. But by the 1940s, an upward trend towards recovery was apparent and continued to their current stable population levels. These dramatic fluctuations in kite numbers may have been related to changes in rodent prey populations due to the conversion of native habitats to agriculture. To address this question, we evaluated the use of stable isotope analysis in determining if a shift in diet could be isotopically differentiated in current and historic kite populations. We first compared δ 13C, δ 15N, and δ 34S values from present-day kite flight feathers and prey fur samples from four locations in California. The total ranges of isotope values for kite and their rodent prey were similar within each site. Carbon isotope values ranged from m 27.1 to m 22.2 in Arcata, m 26.1 to m 16.9 in Davis,...

The development started with our industry performance proven MTM 742R dual belt spin trimer that is great for necks above 6, but its only capable of trimming them vertically and only single up.. Our all NEW MTM 2225 Horizontal N2N Spin Trimmer will spin trim logs with over 6 necks while exceeding 100 logs per minute. Our neck finish quality exceeds any other on the market today.Your customers will love this finish!!!. The new MTM 2225 N2N spin trimmer fits in the same small foot print of our single belt MTM 2025, 50 wide and 60 long. It comes with an infeed chute fully adjustable to fit most log designs.. Our exclusive upper and lower dual drive belt system allows perfect control of the rolling speed and direction the container will roll through the spin trimmer. This provides the perfect cut. Our speeds and rotational direction can be controlled via our color touch HMI.. Setup is easy, accurate and repeatable with our new blade holder design. This allows blade changes without any ...

The radiogenic isotopic composition of both detrital and Fe-Mn fractions in marine sediments can be used in paleoceanography to infer changes of bottom-water circulation. We have examined various chemical techniques for the analysis of Sr and Nd isotope ratios in these fractions and present a robust method that can be used to separate both the Fe-Mn oxides and the detrital fraction from a marine sediment sample for isotopic analysis. Our sequential leaching procedure involves the use of 10% acetic acid, followed by 1 M hydroxylamine hydrochloride in 25% acetic acid to remove the carbonate component and the Fe-Mn oxide fraction, respectively. The applicability of our chemical procedure is illustrated with examples from a marine sediment core raised from the northern Cape Basin, southeast Atlantic Ocean.. ...

article{4144201, abstract = {Based on promising results obtained in earlier work on antimony ores, we have investigated the use of natural variation in the isotopic composition of Sb as determined using multi-collector ICP-mass spectrometry (MC-ICP-MS) for provenancing Roman glasses. In antiquity, Sb was used either as a decolourizer or as an opacifier and thus, colourless and opaque coloured glasses from different regions and periods were selected for investigation. Both, the sample digestion and isolation of Sb preceeding isotopic analysis via MC-ICP-MS have been optimized and validated for this type of materials. For this purpose, NIST SRM 610 glass reference material and an in-house standard were employed. Isotope ratio determinations were carried out by MC-ICP-MS, relying on In as an internal standard for correction for instrumental mass discrimination. The merits of external calibration in a sample-standard bracketing approach and the so-called {\textacutedbl}revised Russells ...

Here we present a novel method which allows the measurement of the stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) from much smaller samples of dentine than previously possible without affecting the quality parameters. The reconstruction of the diet of past populations using isotopic analysis of bone collagen is a well-established tool. However, because of remodelling of bone throughout life, this gives a blurred picture of the diet. The analysis of δ13C and δ15N from tiny increments of dentine utilizes tissue that does not remodel and permits comparison, at the same age, of those who survived infancy with those who did not at high temporal resolution. This new method has been tested on archaeological teeth from two sites: three molar teeth from the 19th Century Kilkenny Union Workhouse Famine cemetery, Ireland; and three from the Anglian (5-7th centuries AD) cemetery at West Heslerton, Yorkshire, England, selected on the basis of their varied preservation. The methods of ...

The stable carbon isotopic analysis of tree-rings for environmental, plant physiological and archaeological applications using conventional methods is occasionally limited by physical constraints (narrow rings) or administrative concerns (requirement for non-destructive sampling) that prevent researcher access to scientifically valuable wood samples. Analysis of such archives by laser-ablation can potentially address these issues and facilitate access to restricted archives. Smaller quantities of wood are required for analysis by laser ablation, hence the approach may be considered less-invasive and is virtually non-destructive compared to standard preparation methods. High levels of intra-annual isotopic variability reported elsewhere mean that a single measurement may not faithfully represent the inter-annual isotopic signal, so before such an approach can be used with confidence it is necessary to compare the stable carbon isotopic data produced using these two methods. This paper presents ...

The project SIGNAL addresses the crucial question of the eutrophication sources and what impact additional nitrogen has on the productivity in remote regions. The investigation will be carried out in the Baltic sea where the impact of eutrophication is one of the main threats to the ecosystem due to the 80 million people living in its watershed. The nitrogen input from the rivers, the atmosphere and N2 fixing cyanobacteria will be qualitatively and quantitatively assessed. This task will be accomplished through regular measurements in the mouths of several rivers, and in the precipitation. Stable isotope ratios of the most important elements are indicating eutrophication from various sources and have not been used simultaneously. However previous studies proved the utility of stable isotope ratios as indicators of external nitrogen inputs(.eg. fertilizer and soil runoff) and that they allow the identification of pathways through the ecosystem. Finally the role of the imported nitrogen for the ...

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In contrast with artefactual studies of long-distance trade and exchange in South Asia during the Prehistoric and Early Historic periods ( Ardika et al. 1993; Gogte 1997; Krishnan and Coningham 1997; Tomber 2000; Gupta et al. 2001; Ford et al. 2005), few scientifically orientated analyses have focused on artefacts from the regions Historic period. During excavations at the ancient city of Anuradhapura, Sri Lanka, a number of buff ware ceramics with a putative organic coating on the interior were recovered ( Coningham 2006). Dated stylistically to between the third and ninth centuries ad, analysis of the coatings using gas chromatography-mass spectrometry (GC-MS) and stable isotope analysis (carbon and deuterium) confirmed that the coatings are bitumen-an organic product associated with petroleum deposits. There are no known bitumen sources in Sri Lanka, and biomarker distributions and isotopic signatures suggest that the majority of the samples appear to have come from a single bitumen source ...

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EPPICH, Gary R. and PECK, William H., Department of Geology, Colgate University, 13 Oak Drive, Hamilton, NY 13346, [email protected]. The Kilmar magnesite deposits are a series of lenticular, km-scale ore deposits within granulite-facies metasediments of the Morin terrane, Quebec. The terrane is dominated by the 1.15 Ga Morin Anorthosite-Mangerite-Charnockite-Granite suite which intrudes the metasedimentary sequence, and has experienced a polymetamorphic history. The study site, the Dobbie mine, contains magnesite ore surrounded by dolomitic marble. Now removed, this ore body reached a thickness of approximately 20 m and extended ca. 350 m along strike. The ore contains magnesite + dolomite + serpentine while host marble contains dolomite + serpentine magnesite strontianite celestine. Stable isotope ratios of magnesite and dolomite from ore samples and host dolomite suggest minimal influence of metamorphic fluids and preservation of sedimentary values. Carbon isotope ratios of the magnesite ...

TY - JOUR. T1 - Structural details of aqueous attack on a phosphate glass by 1H/31P cross-polarization NMR. AU - Wenslow, R. M.. AU - Mueller, K. T.. PY - 1998/11/5. Y1 - 1998/11/5. N2 - One- and two-dimensional heteronuclear correlation solid-state nuclear magnetic resonance experiments allow a direct study of the chemistry of water incorporation into a simple phosphate glass network. One main pathway for water incorporation into phosphate glass networks is through the formation of P-OH groups, and previous 1H magic-angle-spinning NMR investigations of proton environments in silicate and phosphate glasses suggest that hydroxyl groups are involved in multiple hydrogen-bonding motifs with backbone units within the glass networks. The presence of multiple proton environments presents more complex structural issues for aqueous incorporation into glass systems, which have yet to be explained unambiguously. The spectral editing capabilities of two-dimensional cross-polarization NMR identify specific ...

Burkhardt, C., Dauphas, N., Tang, H., Fischer-Gödde, M., Qin, L., Chen, J. H., Rout, S. S., Pack, A., Heck, P. R. and Papanastassiou, D. A.. Meteoritics & Planetary Science. doi: 10.1111/maps.12834. LINK. High-precision isotope data of meteorites show that the long-standing notion of a chondritic uniform reservoir is not always applicable for describing the isotopic composition of the bulk Earth and other planetary bodies. To mitigate the effects of this isotopic crisis and to better understand the genetic relations of meteorites and the Earth-forming reservoir, we performed a comprehensive petrographic, elemental, and multi-isotopic (O, Ca, Ti, Cr, Ni, Mo, Ru, and W) study of the ungrouped achondrites NWA 5363 and NWA 5400, for both of which terrestrial O isotope signatures were previously reported. Also, we obtained isotope data for the chondrites Pillistfer (EL6), Allegan (H6), and Allende (CV3), and compiled available anomaly data for undifferentiated and differentiated meteorites. The ...

Authors: van Mierlo, Carlo; Darby, Nigel; Keeler, James; Neuhaus, David; Creighton, Thomas. Citation: van Mierlo, Carlo; Darby, Nigel; Keeler, James; Neuhaus, David; Creighton, Thomas. Partially folded conformation of the (30-51) intermediate in the disulphide folding pathway of bovine pancreatic trypsin inhibitor. 1H and 15N resonance assignments and determination of backbone dynamics from 15N relaxation measurements. J. Mol. Biol. 229, 1125-1146 (1993).. Assembly members: ...

TY - ABST. T1 - ¤In vivo¤ studies of nitrogen fixation and assimilation in pea-¤Rhizobium¤ nodules by 15N NMR spectroscopy. AU - Scharff, A.M.. AU - Hansen, P.E.. AU - Rosendahl, L.. N1 - Conference code: 3. PY - 1998. Y1 - 1998. KW - Planteproduktion og stofomsætning. M3 - Conference abstract for conference. T2 - 3rd European Nitrogen Fixation Conference. Y2 - 20 September 1998 through 24 September 1998. ER - ...

In normal and lathyritic chick embryos bone collagen was synthesized primarily in the periosteum of the femurs, and was organized as radioactive spicules in these bones. Saline extraction of the lathyritic bones removed the radioactive spicules, although they eventually seemed to become non-extractable. Normal bone seemed to be unaffected by saline extraction. Marked variation in the degree of isotope incorporation was seen in collagenous and non-collagenous tissues. All the tissues of any one embryo, however, showed a similar degree of isotope incorporation. Tritiated ß-aminopropionitrile was diffusely distributed throughout bone and was completely removed by saline extraction. This autoradiographic study supports the postulate that a portion of extractable lathyritic collagen is recently synthesized and is organized in fibrous structures in bone.. ...

Authors: Samson, Camille; Herrada, Isaline; Celli, Florian; Theillet, Francois-Xavier; Zinn-Justin, Sophie. Citation: Samson, Camille; Herrada, Isaline; Celli, Florian; Theillet, Francois-Xavier; Zinn-Justin, Sophie. 1H, 13C and 15N backbone resonance assignment of the intrinsically disordered region of the nuclear envelope protein emerin Biomol. NMR Assign. 10, 179-182 (2016).. Assembly members: ...

Abstract: Biological assemblies with specific function or pathogenicity are widespread within organisms; however, their insolubility, amorphous properties, and large size are the major obstacles for structure determination via solution NMR spectroscopy and X-ray crystallography. In contrast, solid-state NMR (ssNMR) spectroscopy is not limited by the solubility or crystallinity of the sample and is a potent method to determine the structure of protein assemblies at atomic resolution. High magnetic field, fast magic-angle spinning (MAS), isotope labeling schemes, and improved methodology in ssNMR have enabled resonance assignment and restraints in structure determination among protein assemblies. This review first discusses methods of obtaining structural restraints by ssNMR. Optimization of sample preparation is an effective approach to increase homogeneity in the conformation, thus also improving the resolution of ssNMR spectra. Furthermore, the resolution of 13C spectra can be further improved ...

Nitrogen-15 Determination in Tissues of Laying Hens Fed on Different Levels of Chloride () Diets - Atom Percentage Excess Nitrogen-15;Delta Nitrogen-15 Excess;Laying Hen Tissues;Nitrogen-15;

To test whether the PDZ domain is required for DVL rescue activity, we designed two point mutations in its ligand-binding cleft (V334E and D331A R338A, called DARA; see below) that are expected to block ligand access, based on structural information on this cleft and its interaction with cognate physiological ligands (Cheyette et al., 2002; Lee et al., 2015). To confirm that these mutations affect ligand binding, we used a sensitive in vitro binding assay based on nuclear magnetic resonance (NMR) spectroscopy, which is capable of detecting low-affinity binding in the high micromolar Kd range. We purified 15N-labelled minimal wt or mutant PDZ domains of DVL2 after bacterial expression, and acquired 1H-15N correlation spectra, alone or after incubation with a well-validated C-terminal peptide from Dvl1 (DVL-C; Lee et al., 2015). As expected, this peptide induced exchange broadening or shift perturbation of numerous cross peaks in the spectrum of the wt domain (Fig. 3A), as previously observed (Lee ...

Following the entry of Zea mays to northeast North America, there are indications of human population growth, suggesting crop intensification. Isotopic values from bone collagen have been inconsistent with this hypothesis, showing temporal and regional fluctuations that have led to hypotheses of sporadic overreliance on this super-crop. Following Katzenbergs suggestion that intake of this carbohydrate should be measured through apatite rather than protein tissue, and with the permission of the Huron-Wendat Nation of Wendake, Quebec, we measured tooth enamel δ13C from 167 permanent tooth crowns (most M1), retained after reburial of the skeletons. Enamel values encapsulate diet from early childhood (3 to 4 years of age). The teeth represent 16 ancestral Huron-Wendat sites in southern Ontario. Isotopic values show a gradual increase in reliance on maize from the 14th to 17th centuries, perhaps reflecting development of crop strains that were more reliable at higher latitudes. This pattern of δ13C

The Tonian Period (1000 - c.720 Ma) followed a long interval of relative stasis, in terms of climate, carbon isotopes and biological evolution, and led into the Cryogenian Period of environmental extremes and instability. Despite its pivotal situation, the Tonian Period is still relatively understudied, and this is partly due to the lack of robust age constraints in key Proterozoic successions around the world. The fossiliferous Neoproterozoic strata of the North China craton were until recently thought to be of Ediacaran age. However, fossil evidence and new geochronological constraints combine to show that most of the Qingbaikou System, which reaches a great thickness in some areas, was deposited between c. 980 and c. 920 Ma. The isotopic signature of these strata confirms their Tonian age, showing typical moderately high 13C values together with low 87Sr/87Sr ratios, < 0.7065. Another characteristically Tonian feature is the unusually widespread abundance of early diagenetic ...

The discovery of c. 1.77 Ga A-type granite in the Tarim Craton (TC) provides the first evidence that supports an extensional event related to fragmentation of the Columbia supercontinent in the late Palaeoproterozoic. We present laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb ages, Lu-Hf isotopic data and the whole-rock geochemical and Nd isotopic data of A-type granites in the Dunhuang area in the SE Tarim Craton. Zircon U-Pb dating for three granite samples indicate that they were emplaced at c. 1.77 Ga. Zircons from these granites have εHf(t) values ranging from -5.9 to 8.7, corresponding to two-stage model ages of 1.9-2.7 Ga. These granites exhibit the following petrological geochemical characteristics that are typical of A-type granite: (a) high content of SiO2 and alkalis (i.e. high K2O + Na2O with K2O/Na2O > 1), enrichment of high-field-strength elements (HFSE) and rare Earth elements (REE) (except for Eu) and extreme depletion of Ba, Sr, P, Ti and Eu; ...

For decades, archaeologists have debated how farming spread to Stone Age Europe, setting the stage for the rise of Western civilization.

Deep continental subsurface fracture water systems, ranging from 1.1 to 3.3 km below land surface (kmbls), were investigated to characterize the indigenous microorganisms and elucidate microbial carbon sources and their cycling. Analysis of phospholipid fatty acid (PLFA) abundances and direct cell counts detected varying biomass that was not correlated with depth. Compound-specific carbon isotope analyses (δ13C and Δ14C) of the phospholipid fatty acids (PLFAs) and carbon substrates combined with genomic analyses did identify, however, distinct carbon sources and cycles between the two depth ranges studied.. In the shallower boreholes at circa 1 kmbls, isotopic evidence indicated microbial incorporation of biogenic CH4 by the in situ microbial community. At the shallowest site, 1.05 kmbls in Driefontein mine, this process clearly dominated the isotopic signal. At slightly deeper depths, 1.34 kmbls in Beatrix mine, the isotopic data indicated the incorporation of both biogenic CH4 and dissolved ...

Deep continental subsurface fracture water systems, ranging from 1.1 to 3.3 km below land surface (kmbls), were investigated to characterize the indigenous microorganisms and elucidate microbial carbon sources and their cycling. Analysis of phospholipid fatty acid (PLFA) abundances and direct cell counts detected varying biomass that was not correlated with depth. Compound-specific carbon isotope analyses (δ13C and Δ14C) of the phospholipid fatty acids (PLFAs) and carbon substrates combined with genomic analyses did identify, however, distinct carbon sources and cycles between the two depth ranges studied. In the shallower boreholes at circa 1 kmbls, isotopic evidence indicated microbial incorporation of biogenic CH4 by the in situ microbial community. At the shallowest site, 1.05 kmbls in Driefontein mine, this process clearly dominated the isotopic signal. At slightly deeper depths, 1.34 kmbls in Beatrix mine, the isotopic data indicated the incorporation of both biogenic CH4 and dissolved ...