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1
Arnold, L. J. "Mass spectra and the Macintosh: Isotope pattern calculator. A program to calculate isotopic ratios for molecular fragments." Journal of Chemical Education 69, no. 10 (1992): 811. http://dx.doi.org/10.1021/ed069p811.1.
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Behrmann-Godel, J., and E. Yohannes. "Multiple isotope analyses of the pike tapeworm Triaenophorus nodulosus reveal peculiarities in consumer–diet discrimination patterns." Journal of Helminthology 89, no. 2 (2014): 238–43. http://dx.doi.org/10.1017/s0022149x13000849.
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AbstractPrevious studies of dietary isotope discrimination have led to the general expectation that a consumer will exhibit enriched stable isotope levels relative to its diet. Parasite–host systems are specific consumer–diet pairs in which the consumer (parasite) feeds exclusively on one dietary source: host tissue. However, the small numbers of studies previously carried out on isotopic discrimination in parasite–host (ΔXP-HT) systems have yielded controversial results, showing some parasites to be isotopically depleted relative to their food source, while others are enriched or in equilibrium with their hosts. Although the mechanism for these deviations from expectations remains to be understood, possible influences of specific feeding niche or selection for only a few nutritional components by the parasite are discussed. ΔXP-HT for multiple isotopes (δ13C, δ15N, δ34S) were measured in the pike tapeworm Triaenophorus nodulosus and two of its life-cycle fish hosts, perch Perca fluviatilis and pike Esox lucius, within which T. nodulosus occupies different feeding locations. Variability in the value of ΔXP-HT calculated for the parasite and its different hosts indicates an influence of feeding location on isotopic discrimination. In perch liver ΔXP-HT was relatively more negative for all three stable isotopes. In pike gut ΔXP-HT was more positive for δ13C, as expected in conventional consumer–diet systems. For parasites feeding on pike gut, however, the δ15N and δ34S isotope values were comparable with those of the host. We discuss potential causes of these deviations from expectations, including the effect of specific parasite feeding niches, and conclude that ΔXP-HT should be critically evaluated for trophic interactions between parasite and host before general patterns are assumed.
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Popa-Lisseanu, Ana G., Karin Sörgel, Anja Luckner, et al. "A Triple-Isotope Approach to Predict the Breeding Origins of European Bats." PLoS ONE 7, no. 1 (2012): e30388. https://doi.org/10.5281/zenodo.13435391.
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(Uploaded by Plazi for the Bat Literature Project) Despite a commitment by the European Union to protect its migratory bat populations, conservation efforts are hindered by a poor understanding of bat migratory strategies and connectivity between breeding and wintering grounds. Traditional methods like mark-recapture are ineffective to study broad-scale bat migratory patterns. Stable hydrogen isotopes (dD) have been proven useful in establishing spatial migratory connectivity of animal populations. Before applying this tool, the method was calibrated using bat samples of known origin. Here we established the potential of dD as a robust geographical tracer of breeding origins of European bats by measuring dD in hair of five sedentary bat species from 45 locations throughout Europe. The dD of bat hair strongly correlated with well-established spatial isotopic patterns in mean annual precipitation in Europe, and therefore was highly correlated with latitude. We calculated a linear mixed-effects model, with species as random effect, linking dD of bat hair to precipitation dD of the areas of hair growth. This model can be used to predict breeding origins of European migrating bats. We used d13C and d15N to discriminate among potential origins of bats, and found that these isotopes can be used as variables to further refine origin predictions. A triple-isotope approach could thereby pinpoint populations or subpopulations that have distinct origins. Our results further corroborated stable isotope analysis as a powerful method to delineate animal migrations in Europe.
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Popa-Lisseanu, Ana G., Karin Sörgel, Anja Luckner, et al. "A Triple-Isotope Approach to Predict the Breeding Origins of European Bats." PLoS ONE 7, no. 1 (2012): e30388. https://doi.org/10.5281/zenodo.13435391.
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(Uploaded by Plazi for the Bat Literature Project) Despite a commitment by the European Union to protect its migratory bat populations, conservation efforts are hindered by a poor understanding of bat migratory strategies and connectivity between breeding and wintering grounds. Traditional methods like mark-recapture are ineffective to study broad-scale bat migratory patterns. Stable hydrogen isotopes (dD) have been proven useful in establishing spatial migratory connectivity of animal populations. Before applying this tool, the method was calibrated using bat samples of known origin. Here we established the potential of dD as a robust geographical tracer of breeding origins of European bats by measuring dD in hair of five sedentary bat species from 45 locations throughout Europe. The dD of bat hair strongly correlated with well-established spatial isotopic patterns in mean annual precipitation in Europe, and therefore was highly correlated with latitude. We calculated a linear mixed-effects model, with species as random effect, linking dD of bat hair to precipitation dD of the areas of hair growth. This model can be used to predict breeding origins of European migrating bats. We used d13C and d15N to discriminate among potential origins of bats, and found that these isotopes can be used as variables to further refine origin predictions. A triple-isotope approach could thereby pinpoint populations or subpopulations that have distinct origins. Our results further corroborated stable isotope analysis as a powerful method to delineate animal migrations in Europe.
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Pracht, Hilde, Brett Metcalfe, and Frank J. C. Peeters. "Oxygen isotope composition of the final chamber of planktic foraminifera provides evidence of vertical migration and depth-integrated growth." Biogeosciences 16, no. 2 (2019): 643–61. http://dx.doi.org/10.5194/bg-16-643-2019.
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Abstract. The translation of the original seawater signal (i.e. ambient temperature and δ18Osw) into distinct chambers of a single shell of a foraminifer during calcification can influence our interpretation of surface ocean conditions of the past, when based upon oxygen and carbon stable isotope geochemistry. In this study three different hypotheses were tested to gain more insight into biological and ecological processes that influence the resultant composition of stable isotopes of oxygen (δ18O) in the shells of planktonic foraminifera. These hypotheses were related to the shell size; the differences in isotopic composition between the final chamber and the remaining shell; and the differences between different species. Shells of Trilobatus sacculifer, Globigerinoides ruber white and Neogloboquadrina dutertrei were picked from the top of multi-core GS07-150-24, of modern age, offshore of north-eastern Brazil (3∘46.474′ S, 37∘03.849′ W) and analysed for single-shell and single-chamber stable isotope analysis. We show that the mean value of δ18O of the final chambers (δ18OF) is 0.2 ‰ ± 0.4 ‰ (1σ) higher than the mean value δ18O of the test minus the final chamber (δ18O<F) of T. sacculifer. The formation of the final chamber happens at temperatures that are approximately 1 ∘C cooler than the chambers formed prior, suggesting both ontogenetic depth migration to deeper water and a potential offset from the surface signal. Furthermore, we show that there is no statistical difference in the δ18Osacculifer values of shells of three different size classes of T. sacculifer, although the pattern between the different size classes indicates depth migration during the life and growth of T. sacculifer. Comparison of vital effect corrected δ18Oshell between T. sacculifer, G. ruber white and N. dutertrei suggests that G. ruber has a slightly shallower depth habitat (∼90–120 m) compared to the other two species (∼100–130 m). Disentangling depth vs. seasonal habitat is complicated given the commonality between isotope values from similar depths but different seasons; for instance, the same average isotope value will have a shallower depth habitat in May than September. Calculation of seasonal-depth habitat was therefore tested. Our results highlight the complicated nature of interpreting oxygen isotopes even for the modern record.
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van der Velde, I. R., J. B. Miller, K. Schaefer, G. R. van der Werf, M. C. Krol, and W. Peters. "Terrestrial cycling of <sup>13</sup>CO<sub>2</sub> by photosynthesis, respiration, and biomass burning in SiBCASA." Biogeosciences 11, no. 23 (2014): 6553–71. http://dx.doi.org/10.5194/bg-11-6553-2014.
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Abstract. We present an enhanced version of the SiBCASA terrestrial biosphere model that is extended with (a) biomass burning emissions from the SiBCASA carbon pools using remotely sensed burned area from the Global Fire Emissions Database (GFED), (b) an isotopic discrimination scheme that calculates 13C signatures of photosynthesis and autotrophic respiration, and (c) a separate set of 13C pools to carry isotope ratios into heterotrophic respiration. We quantify in this study the terrestrial exchange of CO2 and 13CO2 as a function of environmental changes in humidity and biomass burning. The implementation of biomass burning yields similar fluxes as CASA-GFED both in magnitude and spatial patterns. The implementation of isotope exchange gives a global mean discrimination value of 15.2‰, ranges between 4 and 20‰ depending on the photosynthetic pathway in the plant, and compares favorably (annually and seasonally) with other published values. Similarly, the isotopic disequilibrium is similar to other studies that include a small effect of biomass burning as it shortens the turnover of carbon. In comparison to measurements, a newly modified starch/sugar storage pool propagates the isotopic discrimination anomalies to respiration much better. In addition, the amplitude of the drought response by SiBCASA is lower than suggested by the measured isotope ratios. We show that a slight increase in the stomatal closure for large vapor pressure deficit would amplify the respired isotope ratio variability. Our study highlights the importance of isotope ratio observations of 13C to assess and improve biochemical models like SiBCASA, especially with regard to the allocation and turnover of carbon and the responses to drought.
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Corcoran, Loretta, and Antonio Simonetti. "Geochronology of Uraninite Revisited." Minerals 10, no. 3 (2020): 205. http://dx.doi.org/10.3390/min10030205.
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Identification of uraninite provenance for the purpose of nuclear forensics requires a multifaceted approach. Various geochemical signatures, such as chondrite normalized rare earth element patterns, help identify and limit the potential sources of uraninite based on the geological setting of the uranium ore mineralization. The inclusion of accurate age determinations to discriminate geochemical signatures for natural uranium ores may help to potentially restrict geographical areas for provenance consideration. Determining a robust age for uraninite formation is somewhat difficult, due to well known, inherent difficulties associated with open system behavior that involve either uranium and/or lead loss or gain. However, open system behavior should not perturb their Pb isotopic compositions to the same degree as Pb isotopes should not fractionate during alteration processes. Here, a suite of pristine and altered samples of uraninite was examined for their Pb isotope compositions, and these yielded geologically meaningful secondary Pb–Pb isochron ages. The degree of alteration within individual uraninite samples, which is extremely variable, does not appear to affect the calculated ages. The approach adopted here yields insightful age information, and hence, is of great value for source attribution in forensic analyses of raw nuclear materials.
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Ohlanders, N., M. Rodriguez, and J. McPhee. "Stable water isotope variation in a Central Andean watershed dominated by glacier- and snowmelt." Hydrology and Earth System Sciences Discussions 9, no. 10 (2012): 12227–69. http://dx.doi.org/10.5194/hessd-9-12227-2012.
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Abstract. Central Chile is an economically important region for which water supply is dependent on snow- and ice melt. Nevertheless, the fraction of water supplied by each of those two sources remains largely unknown. This study represents the first attempt to estimate the region's water balance using stable isotopes of water in streamflow and its sources; isotopic ratios of both H and O were monitored during one year in a high-altitude basin with a relatively high glacial cover (11.5%). We found that the steep altitude gradient of the studied catchment caused a corresponding gradient in snowpack isotopic composition and that this spatial variation had a profound effect on the temporal evolution of streamflow isotopic composition during snowmelt. Glacier- and snowmelt contributions to streamflow in the studied basin were calculated using a quantitative analysis of the isotopic composition of streamflow and its sources, resulting in a glacier melt contribution of 50–80% for the unusually dry melt year of 2011/12. This suggests that in (la Niña) years with little precipitation, glacier melt is an important water source for Central Chile. Predicted decreases in glacier melt due to global warming may therefore have a negative impact on water availability in the Central Andes as well as in comparable semi-arid regions of the world; this impact is non-commensurable with areal glacial cover or with the relative areal influence coverage of glacier versus seasonal snowpack. The pronounced seasonal pattern in streamflow isotope composition and its close relation to the evolution of snow cover and to discharge presents a potentially powerful tool for relating discharge evolution in mountainous, melt-dominated catchments with related factors such as contributions of sources to streamflow and snowmelt transit times.
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Winemiller, Kirk O., Steven C. Zeug, Clinton R. Robertson, Brent K. Winemiller, and Rodney L. Honeycutt. "Food-web structure of coastal streams in Costa Rica revealed by dietary and stable isotope analyses." Journal of Tropical Ecology 27, no. 5 (2011): 463–76. http://dx.doi.org/10.1017/s0266467411000277.
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Abstract:Food webs of streams draining tropical rain forests on Costa Rica's Pacific and Caribbean coasts were examined in the 1980s via dietary analyses, and the same streams were surveyed again in 2004 to compare trophic structure based on analysis of stable isotope ratios of fish, macro-invertebrate and plant tissues. Estimates of species’ trophic positions (TP) were calculated from stomach-contents data (51 species; 5420 specimens) and compared with TP estimates derived from analysis of nitrogen isotope ratios (82 taxa; 240 samples). Coefficients of determination for TP based on dietary versus isotopic analysis ranged from 0.18 (Quebrada Camaronal, Corcovado) to 0.73 (Quebrada Estacion, Tortuguero). Consumer taxa within all four streams spanned a broad range of carbon isotope values, indicating assimilation of variable proportions of carbon from periphyton and terrestrial vegetation that in all but one of the streams had similar δ13C values. Approximately half the consumers in all four streams had carbon ratios heavier than any of the in situ production sources examined. This pattern could be explained by consumption of other production sources that were not sampled, including periphyton taxa with variable carbon isotope signatures, or migration of prey and/or consumers between these freshwater and coastal marine habitats.
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Zeng, Jie, Guilin Han, and Jian-Ming Zhu. "Seasonal and Spatial Variation of Mo Isotope Compositions in Headwater Stream of Xijiang River Draining the Carbonate Terrain, Southwest China." Water 11, no. 5 (2019): 1076. http://dx.doi.org/10.3390/w11051076.
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The dissolved molybdenum (Mo) contents and Mo isotope in water samples from the upper Xijiang River (XJR), draining the carbonate terrain, southwest China, are reported to investigate the seasonal and spatial variations, sources, ion budget, and isotopic fractionation of dissolved Mo. The results show that the Mo concentrations (5.3–18.9 nmol/L) exhibit an extensive variation along the mainstream without significant spatial pattern, but the Mo concentrations are slightly higher in the dry season than in the wet season caused by the dilution effect. There is a slight spatial tendency for δ98/95Mo to become higher along the mainstream (0.51–1.78%), while the seasonal variations in δ98/95Mo values of NPR (Nanpanjiang River) reach and BPR (Beipanjiang River) reach can be identified higher in the dry season but lower in the wet season. Based on the hydro-geochemical analysis, the sources of dissolved Mo are identified as the carbonates and sulfide/sulfate minerals weathering with a seasonal contribution. Moreover, our results suggest there is no significant Mo isotopic fractionation during weathering and riverine transportation. The calculation of Mo budget demonstrates that the dissolved δ98/95Mo of river draining the carbonate terrain is underestimated, which could significantly influence the redox history of oceans by Mo isotope model.
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Zajączkowski, Marek, Witold Szczuciński, Birgit Plessen, and Patrycja Jernas. "Benthic foraminifera in Hornsund, Svalbard: Implications for paleoenvironmental reconstructions." Polish Polar Research 31, no. 4 (2010): 349–75. http://dx.doi.org/10.2478/v10183-010-0010-4.
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Benthic foraminifera in Hornsund, Svalbard: Implications for paleoenvironmental reconstructions Modern hydrology of a typical Arctic fjord (Hornsund, SW Spitsbergen, Svalbard) was investigated and compared with commonly used in paleoceanography proxies: benthic foraminiferal assemblages and their stable isotope (Δ18O and Δ13C) composition. The benthic foraminifera from Hornsund comprised 45 species and 28 genera. Their spatial variations follow the zonation pattern, resulting from the influence of Atlantic water at the fjord mouth and glacial meltwaters at the fjord head. At the mouth of the fjord, the total number of species and the contribution of agglutinating species were the highest. In the inner part of fjord, the foraminiferal faunas were poor in species and individuals, and agglutinating species were absent. "Living" (stained) foraminifera were found to be common throughout the short sediment cores (~10 cm long) studied. The stable isotope values of Δ18O and Δ13C were measured on tests of four species: Elphidium excavatum forma clavata, Cassidulina reniforme, Nonionellina labradorica and Cibicides lobatulus. The results confirmed the importance of species-specific vital effects, particularly in the case of C. lobatulus. The variability in the isotopic composition measured on different individuals within a single sample are comparable to isotopic composition of the same species test between sampling stations. The temperatures and bottom water salinities calculated from Δ18O values in different foraminifera tests mirrored those recorded for bottom waters in the central and outer fjords relatively well. However, in the case of the inner fjord, where winter-cooled bottom waters were present, the calculated values from Δ18O were systematically higher by about 2°C. The obtained results imply that particular caution must be taken in interpretation of fjord benthic foraminifera assemblages in high resolution studies and in selection of material for isotope analyses and their interpretation in cores from inner fjords or silled fjords, where winter-cooled waters may be present.
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Wang, Xin, David Depew, Sherry Schiff, and Ralph E. H. Smith. "Photosynthesis, respiration, and stable isotopes of oxygen in a large oligotrophic lake (Lake Erie, USA–Canada)." Canadian Journal of Fisheries and Aquatic Sciences 65, no. 11 (2008): 2320–31. http://dx.doi.org/10.1139/f08-134.
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Dissolved oxygen (DO) concentration, isotopic composition (18:16O), and respiratory fractionation (αr) were measured in the east basin of Lake Erie to determine the patterns of planktonic photosynthesis (P) and respiration (R) and to assess a dual isotope, steady-state model for P/R ratios. Values of αr varied significantly between months but averaged close to a widely accepted norm for planktonic respiration (0.982). Isotope dynamics in situ predicted that 33%–53% of hypolimnetic oxygen consumption was by the sediments, consistent with previous knowledge. Except during fall turnover, DO was generally above, and 18:16O below, atmospheric equilibrium in the surface mixed layer (SML), suggesting P/R is usually >1 and agreeing with independent estimates by incubation experiments. P/R ratios calculated from the oxygen isotope model were often inconsistent with the DO and 18:16O data, likely because of uncertainties in αr and nonsteady-state conditions in the SML. The autumnal transition to P/R < 1 was captured better in the DO and 18:16O data than in the incubation experiments. Despite problems with the steady-state model, the isotope data were able to reveal spatial and temporal variations in lake metabolism and indicated a strong autochthonous basis for community metabolism in the SML.
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Taylor, C. B. "On the Isotopic Composition of Dissolved Inorganic Carbon in Rivers and Shallow Groundwater: A Diagrammatic Approach to Process Identification and A More Realistic Model of the Open System." Radiocarbon 39, no. 3 (1997): 251–68. http://dx.doi.org/10.1017/s0033822200053248.
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Rivers and shallow groundwater are deep groundwater precursors. Their dissolved inorganic carbon content (DIC) and its isotopic composition are end members in the evolution of these properties in confined situations, and are therefore essential information when applying carbon isotopes as tracers of groundwater processes and determining aquifer residence times using 14C.During studies of regional aquifer systems in New Zealand, a simple model has been developed to explain the isotopic compositions of DIC encountered in rivers and shallow groundwater. The model format incorporates a diagrammatic approach, providing a framework for tracing the subsequent evolution of DIC in both precipitation- and river-recharged aquifers under closed conditions.DIC concentration of rivers continuously adjusts toward chemical and isotopic equilibrium between direct addition of CO2 to the water (via plant respiration and decay of dead organic material) and exchange of CO2 across the river-air interface. In the shallow groundwater situation, the gaseous reservoir is soil CO2, generally at significantly higher partial pressure. In both cases, calcite dissolution or other processes may be an additional source of DIC directly added to the bicarbonate and dissolved CO2 components; while these may add or remove DIC, steady-state isotopic concentrations are considered to be determined only by the dynamic balance between directly added CO2 and gas exchange. This model allows the calculation of steady states, using selectable parameters in river or groundwater situations. These appear as straight lines in 13C or 14C vs. 1/DIC, or total 14C vs. DIC plots, into which the experimental data can be inserted for interpretation. In the case of 14C, the steady-state balance is very often complicated by the presence of an old component in the directly added DIC; the understanding achieved via the 13C patterns is helpful in recognizing this.Data from four contrasting aquifer systems in New Zealand. The success of the approach has depended crucially on DIC concentrations measured very accurately on the isotope samples, rather than separate chemical analyses.
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Hellerstein, Marc K., and Richard A. Neese. "Mass isotopomer distribution analysis at eight years: theoretical, analytic, and experimental considerations." American Journal of Physiology-Endocrinology and Metabolism 276, no. 6 (1999): E1146—E1170. http://dx.doi.org/10.1152/ajpendo.1999.276.6.e1146.
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Mass isotopomer distribution analysis (MIDA) is a technique for measuring the synthesis of biological polymers. First developed approximately eight years ago, MIDA has been used for measuring the synthesis of lipids, carbohydrates, and proteins. The technique involves quantifying by mass spectrometry the relative abundances of molecular species of a polymer differing only in mass (mass isotopomers), after introduction of a stable isotope-labeled precursor. The mass isotopomer pattern, or distribution, is analyzed according to a combinatorial probability model by comparing measured abundances to theoretical distributions predicted from the binomial or multinomial expansion. For combinatorial probabilities to be applicable, a labeled precursor must therefore combine with itself in the form of two or more repeating subunits. MIDA allows dilution in the monomeric (precursor) and polymeric (product) pools to be determined. Kinetic parameters can then be calculated (e.g., replacement rate of the polymer, fractional contribution from the endogenous biosynthetic pathway, absolute rate of biosynthesis). Several issues remain unresolved, however. We consider here the impact of various deviations from the simple combinatorial probability model of biosynthesis and describe the analytic requirements for successful use of MIDA. A formal mathematical algorithm is presented for generating tables and equations ( ), on the basis of which effects of various confounding factors are simulated. These include variations in natural isotope abundances, isotopic disequilibrium in the precursor pool, more than one biosynthetic precursor pool, incorrect values for number of subunits present, and concurrent measurement of turnover from exogenously labeled polymers. We describe a strategy for testing whether isotopic inhomogeneity (e.g., an isotopic gradient or separate biosynthetic sites) is present in the precursor pool by comparing higher-mass (multiply labeled) to lower-mass (single- and double-labeled) isotopomer patterns. Also, an algebraic correction is presented for calculating fractional synthesis when an incomplete ion spectrum is monitored, and an approach for assessing the sensitivity of biosynthetic parameters to measurement error is described. The different calculation algorithms published for MIDA are compared; all share a common model, use overlapping solutions to computational problems, and generate identical results. Finally, we discuss the major practical issue for using MIDA at present: quantitative inaccuracy of instruments. The nature and causes of analytic inaccuracy, strategies for evaluating instrument performance, and guidelines for optimizing accuracy and reducing impact on biosynthetic parameters are suggested. Adherence to certain analytic guidelines, particularly attention to concentration effects on mass isotopomer ratios and maximizing enrichments in the isotopomers of interest, reduces error. Improving instrument accuracy for quantification of isotopomer ratios is perhaps the highest priority for this field. In conclusion, MIDA remains the “equation for biosynthesis,” but attention to potentially confounding factors and analytic performance is required for optimal application.
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Drăguşin, V., M. Staubwasser, D. L. Hoffmann, V. Ersek, B. P. Onac та D. Veres. "Constraining Holocene hydrological changes in the Carpathian–Balkan region using speleothem δ<sup>18</sup>O and pollen-based temperature reconstructions". Climate of the Past 10, № 4 (2014): 1363–80. http://dx.doi.org/10.5194/cp-10-1363-2014.
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Abstract. Here we present a speleothem isotope record (POM2) from Ascunsă Cave (Romania) that provides new data on past climate changes in the Carpathian–Balkan region from 8.2 ka until the present. This paper describes an approach to constrain the effect of temperature changes on calcite δ18O values in stalagmite POM2 over the course of the middle Holocene (6–4 ka), and across the 8.2 and 3.2 ka rapid climate change events. Independent pollen temperature reconstructions are used to this purpose. The approach combines the temperature-dependent isotope fractionation of rain water during condensation and fractionation resulting from calcite precipitation at the given cave temperature. The only prior assumptions are that pollen-derived average annual temperature reflects average cave temperature, and that pollen-derived coldest and warmest month temperatures reflect the range of condensation temperatures of rain above the cave site. This approach constrains a range of values between which speleothem δ18O changes should be found if controlled only by surface temperature variations at the cave site. Deviations of the change in δ18Ocspel values from the calculated temperature-constrained range of change are interpreted towards large-scale variability of climate–hydrology. Following this approach, we show that an additional ∼0.6‰ enrichment of δ18Oc in the POM2 stalagmite was caused by changing hydrological patterns in SW Romania across the middle Holocene, most likely comprising local evaporation from the soil and an increase in Mediterranean moisture δ18O. Further, by extending the calculations to other speleothem records from around the entire Mediterranean basin, it appears that all eastern Mediterranean speleothems recorded a similar isotopic enrichment due to changing hydrology, whereas all changes recorded in speleothems from the western Mediterranean are fully explained by temperature variation alone. This highlights a different hydrological evolution between the two sides of the Mediterranean. Our results also demonstrate that during the 8.2 ka event, POM2 stable isotope data essentially fit the temperature-constrained isotopic variability. In the case of the 3.2 ka event, an additional climate-related hydrological factor is more evident. This implies a different rainfall pattern in the Southern Carpathian region during this event at the end of the Bronze Age.
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Kern, Z., B. Kohán, and M. Leuenberger. "Precipitation isoscape of high reliefs: interpolation scheme designed and tested for monthly resolved precipitation oxygen isotope records of an Alpine domain." Atmospheric Chemistry and Physics 14, no. 4 (2014): 1897–907. http://dx.doi.org/10.5194/acp-14-1897-2014.
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Abstract. Stable oxygen isotope composition of atmospheric precipitation (δ18Op) was scrutinized from 39 stations distributed over Switzerland and its border zone. Monthly amount-weighted δ18Op values averaged over the 1995–2000 period showed the expected strong linear altitude dependence (−0.15 to −0.22‰ per 100 m) only during the summer season (May–September). Steeper gradients (~ −0.56 to −0.60‰ per 100 m) were observed for winter months over a low elevation belt, while hardly any altitudinal difference was seen for high elevation stations. This dichotomous pattern could be explained by the characteristically shallower vertical atmospheric mixing height during winter season and provides empirical evidence for recently simulated effects of stratified atmospheric flow on orographic precipitation isotopic ratios. This helps explain "anomalous" deflected altitudinal water isotope profiles reported from many other high relief regions. Grids and isotope distribution maps of the monthly δ18Op have been calculated over the study region for 1995–1996. The adopted interpolation method took into account both the variable mixing heights and the seasonal difference in the isotopic lapse rate and combined them with residual kriging. The presented data set allows a point estimation of δ18Op with monthly resolution. According to the test calculations executed on subsets, this biannual data set can be extended back to 1992 with maintained fidelity and, with a reduced station subset, even back to 1983 at the expense of faded reliability of the derived δ18Op estimates, mainly in the eastern part of Switzerland. Before 1983, reliable results can only be expected for the Swiss Plateau since important stations representing eastern and south-western Switzerland were not yet in operation.
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Drăguşin, V., M. Staubwasser, D. L. Hoffmann, V. Ersek, B. P. Onac та D. Veres. "Constraining Holocene hydrological changes in the Carpathian-Balkan region using speleothem δ<sup>18</sup>O and pollen-based temperature reconstructions". Climate of the Past Discussions 10, № 1 (2014): 381–427. http://dx.doi.org/10.5194/cpd-10-381-2014.
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Abstract. Here we present a new speleothem isotope record (POM2) from Ascunsă Cave (Romania) that provides new data on past climate changes in the Carpathian-Balkan region from 8.2 ka until present. This paper describes an approach towards constraining the effect of temperature changes on calcite δ18O values in stalagmite POM2 over the course of the Middle Holocene (6–4 ka), and across the 8.2 and 3.2 ka rapid climate change events. Independent pollen temperature reconstructions are used to constrain the temperature-dependent component of total isotopic change in speleothem calcite. This includes the temperature-dependent composition of rain water attained during vapour condensation and during calcite precipitation at the given cave temperature. The only prior assumptions are that pollen-derived average annual temperature reflects average cave temperature, and that pollen-derived coldest and warmest month temperatures reflect the range of condensation temperatures of rain at the cave site. This approach constrains a range of values between which speleothem isotopic changes should be found if controlled only by surface temperature variations at the cave site. Deviations of measured δ18Oc values from the calculated range are interpreted towards large-scale hydrologic change independent of local temperature. Following this approach, we show that an additional 0.6‰ enrichment of δ18Oc in the POM2 stalagmite was caused by changing hydrological patterns in SW Romania during the Middle Holocene. Further, by extending the calculations to other speleothem records from around the entire Mediterranean Basin, it appears that all Eastern Mediterranean speleothems recorded a similar isotopic enrichment due to changing hydrology, whereas all changes recorded in speleothems from the Western Mediterranean are fully explained by temperature variation alone. This highlights a different hydrological evolution between the two sides of the Mediterranean. Our results also demonstrate that during the 8.2 ka event, POM2 stable isotope data fit the temperature-constrained isotopic variability, with only little hydrologic change at most. In the case of the 3.2 ka event, the hydrological factor is more evident. This implies a potentially different rainfall pattern in the Southern Carpathian region during this event at the end of the Bronze Age. This study brings new evidence for disturbances in Eastern Mediterranean hydrology during the Holocene, bearing importance for the understanding of climate pressure on agricultural activities in this area.
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Saurer, M., A. S. H. Prévôt, J. Dommen, J. Sandradewi, U. Baltensperger, and R. T. W. Siegwolf. "The influence of traffic and wood combustion on the stable isotopic composition of carbon monoxide." Atmospheric Chemistry and Physics Discussions 8, no. 6 (2008): 19561–604. http://dx.doi.org/10.5194/acpd-8-19561-2008.
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Abstract. Carbon monoxide in the atmosphere is originating from various combustion and oxidation processes. Recently, the proportion of CO resulting from the combustion of wood for domestic heating may have increased due to political measures promoting this renewable energy source. Here, we used the stable isotope composition of CO (δ13C and δ18O) for the characterization of different CO sources in Switzerland, along with other indicators for traffic and wood combustion (NOx-concentration, aerosol light absorption at different wavelengths). We assessed diurnal variations of the isotopic composition of CO at 3 sites during winter: a village site dominated by domestic heating, a site close to a motorway and a rural site. The isotope ratios of wood combustion emissions were studied at a test facility, indicating significantly lower δ18O of CO from wood combustion compared to traffic emissions. At the village and the motorway site, we observed very pronounced diurnal δ18O-variations of CO with an amplitude of up to 8‰. Solving the isotope mass balance equation for three distinct sources (wood combustion, traffic, clean background air) resulted in diurnal patterns consistent with other indicators for wood burning and traffic. The average night-time contribution of wood-burning to total CO was 70% at the village site, 47% at the motorway site and 28% at the rural site based on the isotope mass balance. As this analysis showed a strong sensitivity towards the pure source isotope values, we additionally applied a combined CO/NOx-isotope model for verification. Here, we separated the CO emissions into different sources based on different CO/NOx emissions ratios for wood combustion and traffic, and inserted this information in the isotope mass balance equation. Accordingly, a highly significant agreement between measured and calculated δ18O-values of CO was found (r=0.67, p<0.001). While different proxies for wood combustion all have their uncertainties, our results indicate that the oxygen isotope ratio of CO (but not the carbon isotope ratio) is an independent sensitive tool for source attribution studies.
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Saurer, M., A. S. H. Prévôt, J. Dommen, J. Sandradewi, U. Baltensperger, and R. T. W. Siegwolf. "The influence of traffic and wood combustion on the stable isotopic composition of carbon monoxide." Atmospheric Chemistry and Physics 9, no. 9 (2009): 3147–61. http://dx.doi.org/10.5194/acp-9-3147-2009.
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Abstract. Carbon monoxide in the atmosphere is originating from various combustion and oxidation processes. Recently, the proportion of CO resulting from the combustion of wood for domestic heating may have increased due to political measures promoting this renewable energy source. Here, we used the stable isotope composition of CO (δ13C and δ18O) for the characterization of different CO sources in Switzerland, along with other indicators for traffic and wood combustion (NOx-concentration, aerosol light absorption at different wavelengths). We assessed diurnal variations of the isotopic composition of CO at 3 sites during winter: a village site dominated by domestic heating, a site close to a motorway and a rural site. The isotope ratios of wood combustion emissions were studied at a test facility, indicating significantly lower δ18O of CO from wood combustion compared to traffic emissions. At the village and the motorway site, we observed very pronounced diurnal δ18O-variations of CO with an amplitude of up to 8‰. Solving the isotope mass balance equation for three distinct sources (wood combustion, traffic, clean background air) resulted in diurnal patterns consistent with other indicators for wood burning and traffic. The average night-time contribution of wood-burning to total CO was 70% at the village site, 49% at the motorway site and 29% at the rural site based on the isotope mass balance. The results, however, depend strongly on the pure source isotope values, which are not very well known. We therefore additionally applied a combined CO/NOx-isotope model for verification. Here, we separated the CO emissions into different sources based on distinct CO/NOx emissions ratios for wood combustion and traffic, and inserted this information in the isotope mass balance equation. Accordingly, a highly significant agreement between measured and calculated δ18O-values of CO was found (r=0.67, p<0.001). While different proxies for wood combustion all have their uncertainties, our results indicate that the oxygen isotope ratio of CO (but not the carbon isotope ratio) is an independent sensitive tool for source attribution studies.
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Dührkop, Kai, Franziska Hufsky, and Sebastian Böcker. "Molecular Formula Identification Using Isotope Pattern Analysis and Calculation of Fragmentation Trees." Mass Spectrometry 3, Special_Issue_2 (2014): S0037. http://dx.doi.org/10.5702/massspectrometry.s0037.
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Jiang, Zhuang, Becky Alexander, Joel Savarino, and Lei Geng. "An inverse model to correct for the effects of post-depositional processing on ice-core nitrate and its isotopes: model framework and applications at Summit, Greenland, and Dome C, Antarctica." Atmospheric Chemistry and Physics 24, no. 8 (2024): 4895–914. http://dx.doi.org/10.5194/acp-24-4895-2024.
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Abstract. Comprehensive evaluation of the effects of post-depositional processing is a prerequisite for appropriately interpreting ice-core records of nitrate concentration and isotopes. In this study, we developed an inverse model that uses archived snow/ice-core nitrate signals to reconstruct primary nitrate flux (i.e., the deposition flux of nitrate to surface snow that originates from long-range transport or stratospheric input) and its isotopes (δ15N and Δ17O). The model was then applied to two polar sites, Summit, Greenland, and Dome C, Antarctica, using measured snowpack nitrate concentration and isotope profiles in the top few meters. At Summit, the model successfully reproduced the observed atmospheric δ15N(NO3-) and Δ17O(NO3-) and their seasonality. The model was also able to reasonably reproduce the observed snowpack nitrate profiles at Dome C as well as the skin layer and atmospheric δ15N(NO3-) and Δ17O(NO3-) at the annual scale. The calculated Fpri at Summit was 6.9 × 10−6 kgN m2 a−1, and the calculated Δ17O(NO3-) of Fpri is consistent with atmospheric observations in the Northern Hemisphere. However, the calculated δ15N(NO3-) of Fpri displays an opposite seasonal pattern to atmospheric observations in the northern mid-latitudes, but it is consistent with observations in two Arctic coastal sites. The calculated Fpri at Dome C varies from 1.5 to 2.2 × 10−6 kgN m−2 a−1, with δ15N(NO3-) of Fpri varying from 6.2 ‰ to 29.3 ‰ and Δ17O(NO3-) of Fpri varying from 48.8 ‰ to 52.6 ‰. The calculated Fpri at Dome C is close to the previous estimated stratospheric denitrification flux in Antarctica, and the high δ15N(NO3-) and Δ17O(NO3-) of Fpri at Dome C also point towards the dominant role of stratospheric origin of primary nitrate to Dome C.
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Mass Spectrometric Analysis of Isotopic Abundance Ratio in Biofield Energy Treated Thymol." World Journal of Applied Chemistry 1, no. 1 (2016): 001–8. https://doi.org/10.11648/j.wjac.20160101.11.
Full textAbstract:
Thymol is a natural monoterpenoid phenol possessing various pharmacological activities such as antimicrobial, antioxidant, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, metabolism, medical research, etc. An investigation of the effect of the biofield energy treatment (The Trivedi Effect®) on the isotopic abundance ratios of PM+1/PM and PM+2/PM in thymol using gas chromatography - mass spectrometry was attempted in this study. The sample, thymol was divided into two parts - one part was denoted as control and another part was referred as biofield energy treated sample that was given Mr. Trivediꞌs unique biofield energy. T1, T2, T3, and T4 were represented to different time interval analysis of the biofield treated thymol. The GC-MS spectra of the both control and biofield treated thymol indicated the presence of molecular ion peak [M+] at m/z 150 (calculated 150.10 for C10H14O) along with the similar pattern of fragmentation. The relative intensities of the parent molecule and other fragmented ions of the biofield treated thymol were enhanced as compared to the control thymol. The percentage change of the isotopic abundance ratio of PM+1/PM in the biofield treated thymol at T1, T2, T3 and T4 was increased by 3.25, 6.31, 96.75, and 140.25%, respectively as compared to the control thymol. In addition, the percentage change of the isotopic abundance ratio of PM+2/PM was increased in the biofield treated thymol at T1, T2, T3, and T4 by 5.33, 8.00, 101.33, and 140.00%, respectively with respect to the control sample. In summary, 13C, 2H, and 17O contributions from (C10H14O)+ to m/z 151 and 18O contribution from (C10H14O)+ to m/z 152 in the biofield treated thymol were significantly increased gradually with respect to the time and was found that biofield energy treatment has time dependent effect on it. Hence, the biofield energy treated thymol might display altered isotope effects such as physicochemical and thermal properties, binding energy and the reaction kinetics with respect to the control sample. So, biofield energy treated thymol could be advantageous for designing the synthetic scheme for the preparation of pharmaceuticals through its kinetic isotope effects. Besides, biofield treated thymol might be useful to overcome the problems associated with thymol for e.g. pungent flavor, high dose requirement for the activity through understanding its isotope effects and the determination of its pharmacokinetic profile, bioavailability. <strong>Source:</strong> https://www.trivedieffect.com/science/mass-spectrometric-analysis-of-isotopic-abundance-ratio-in-biofield-energy-treated-thymol http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=206&doi=10.11648/j.wjac.20160101.11
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Mass Spectrometric Analysis of Isotopic Abundance Ratio in Biofield Energy Treated Thymol." World Journal of Applied Chemistry 1, no. 1 (2016): 001–8. https://doi.org/10.5281/zenodo.196892.
Full textAbstract:
Thymol is a natural monoterpenoid phenol possessing various pharmacological activities such as antimicrobial, antioxidant, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, metabolism, medical research, etc. An investigation of the effect of the biofield energy treatment (The Trivedi Effect®) on the isotopic abundance ratios of PM+1/PM and PM+2/PM in thymol using gas chromatography - mass spectrometry was attempted in this study. The sample, thymol was divided into two parts - one part was denoted as control and another part was referred as biofield energy treated sample that was given Mr. Trivediꞌs unique biofield energy. T1, T2, T3, and T4 were represented to different time interval analysis of the biofield treated thymol. The GC-MS spectra of the both control and biofield treated thymol indicated the presence of molecular ion peak [M+] at m/z 150 (calculated 150.10 for C10H14O) along with the similar pattern of fragmentation. The relative intensities of the parent molecule and other fragmented ions of the biofield treated thymol were enhanced as compared to the control thymol. The percentage change of the isotopic abundance ratio of PM+1/PM in the biofield treated thymol at T1, T2, T3 and T4 was increased by 3.25, 6.31, 96.75, and 140.25%, respectively as compared to the control thymol. In addition, the percentage change of the isotopic abundance ratio of PM+2/PM was increased in the biofield treated thymol at T1, T2, T3, and T4 by 5.33, 8.00, 101.33, and 140.00%, respectively with respect to the control sample. In summary, 13C, 2H, and 17O contributions from (C10H14O)+ to m/z 151 and 18O contribution from (C10H14O)+ to m/z 152 in the biofield treated thymol were significantly increased gradually with respect to the time and was found that biofield energy treatment has time dependent effect on it. Hence, the biofield energy treated thymol might display altered isotope effects such as physicochemical and thermal properties, binding energy and the reaction kinetics with respect to the control sample. So, biofield energy treated thymol could be advantageous for designing the synthetic scheme for the preparation of pharmaceuticals through its kinetic isotope effects. Besides, biofield treated thymol might be useful to overcome the problems associated with thymol for e.g. pungent flavor, high dose requirement for the activity through understanding its isotope effects and the determination of its pharmacokinetic profile, bioavailability. https://www.trivedieffect.com/science/mass-spectrometric-analysis-of-isotopic-abundance-ratio-in-biofield-energy-treated-thymol http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=206&doi=10.11648/j.wjac.20160101.11
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Vasil'chuk, Yurij Kirillovich. "Possible changes of the isotopic composition of ice wedge as a result of self-diffusion." Арктика и Антарктика, no. 3 (March 2021): 44–56. http://dx.doi.org/10.7256/2453-8922.2021.3.36603.
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&nbsp; The subject of this research is the assessment of changes of the isotopic composition of ice wedge as a result of self-diffusion. The author offers a relatively simple method of considering the impact of the process of self-diffusion upon redistribution of paleo-isotopic composition that allows accurately and quickly estimating the changes in the values&nbsp;&delta;18О and &delta;2H values in ice wedges at different periods of the quaternary (1000 years, 10,000 years, 100,000 years, and 1,000,000 years). The patterns of diffusion process in physico-chemical systems&nbsp;are described by two differential forms of Fick's diffusion laws, which are transformed into Gaussian integral, using six-digit Chambers&nbsp;charts for calculation of the&nbsp;threshold values&nbsp;&delta;18О. The article applies the experimentally determined real values of&nbsp;self-diffusion coefficient in the ice &ndash;&nbsp;D=(2&ndash;10)&times;10-15 m2/s. The values of the Gaussian integral are calculated for time intervals, at different distances between samples with different concentration; for the period of 1,000 years its values in all cases&nbsp;exceed 0.99. For longer time intervals, these values change significantly. The calculated probabilistic values of changes in the concentration of heavy oxygen isotopes in ice wedge&nbsp;under the impact&nbsp;of&nbsp;self-diffusion at different distances and concentration gradients are noticeable only for&nbsp;the time period&nbsp;of over 100,000 years. &nbsp;
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Yartsev, E. I., I. V. Vikentyev, and N. I. Eremin. "Isotopic composition and geochemical features of ores of Dzhusa pyrite-polymetallic deposit (South Urals)." Moscow University Bulletin. Series 4. Geology, no. 4 (August 28, 2019): 78–83. http://dx.doi.org/10.33623/0579-9406-2019-4-78-83.
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The sulfur isotopic composition was studied for the main morphological types and generation of sulfides composing the ore of the Dzhusinsky deposit, and the content of trace elements was analyzed using the highly sensitive method of mass spectrometry with inductively coupled plasma and laser sampling (LA-ICP-MS). Both types of studies were performed for ore deposits for the first time. According to the geochemistry of sulfur isotopes, its deep magmatic source was reconstructed, which made a predominant contribution to the ore-forming fluid. Using the modules of the STATISTICA, correlations were calculated and the patterns of distribution of micro impurities in sulfide minerals were revealed.
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Ramaley, Louis, and Lisandra Cubero Herrera. "Software for the calculation of isotope patterns in tandem mass spectrometry." Rapid Communications in Mass Spectrometry 22, no. 17 (2008): 2707–14. http://dx.doi.org/10.1002/rcm.3668.
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Isotopic Abundance Ratio Analysis of 1,2,3-Trimethoxybenzene (TMB) After Biofield Energy Treatment (The Trivedi Effect®) Using Gas Chromatography-Mass Spectrometry." American Journal of Applied Chemistry 4, no. 4 (2016): 132–40. https://doi.org/10.11648/j.ajac.20160404.13.
Full textAbstract:
1,2,3-Trimethoxybenzene (TMB) is one of the most versatile chemical used for the synthesis of several pharmaceuticals, dyes, polymers, organic compounds, etc. The stable isotope ratio analysis has increased attention day-by-days in several fields such as agricultural, food authenticity, biochemistry, medical research, etc. The current study was aimed to evaluate the effect of the biofield energy treatment on the isotopic abundance ratios of 13C/12C or 2H/1H or 17O/16O (PM+1/PM) and 18O/16O (PM+2/PM) in TMB using Gas chromatography - mass spectrometry (GC-MS) technique. TMB was divided into two parts - one part was denoted as control and another part was referred as biofield energy treated sample that was received through Mr. Trivediꞌs unique biofield energy (The Trivedi Effect®). The GC-MS of the biofield treated TMB was characterized at different time intervals considered as T1, T2, T3, and T4 to examine the impact of the biofield energy treatment on isotopic abundance ratio with respect to the time. The GC-MS spectra of the both control and biofield treated TMB exhibited the presence of molecular ion peak [M+] at m/z 168 (calculated 168.08 for C9H12O3) along with similar pattern of fragmentation. The relative peak intensities of the fragmented ions in the biofield treated TMB, particularly at T2 and T3 was altered from the control sample. The isotopic abundance ratio analysis in the biofield treated TMB exhibited that the isotopic abundance ratio of PM+1/PM in the biofield treated TMB at T2 and T3 was significantly enhanced by 128.13 and 117.99%, respectively with respect to the control sample. Consequently, the percentage change in isotopic abundance ratio of PM+2/PM was significantly increased in the biofield treated TMB at T2 and T3 by 125.93 and 116.67%, respectively as compared with the control TMB. The isotopic abundance ratios (PM+1/PM and PM+2/PM) in the biofield treated TMB at T1 and T4 was altered with respect to the control TMB. In summary, 13C, 2H, and 17O contributions from (C9H12O3)+ to m/z 169 and 18O contribution from (C9H12O3)+ to m/z 170 for the biofield treated TMB, particularly at T2 and T3 were significantly improved and biofield treated TMB might exhibit changed isotope effects as compared to the control sample. The biofield treated TMB might assist to develop new chemicals and pharmaceuticals through using its kinetic isotope effects like understanding the reaction mechanism, the enzymatic transition state and all aspects of enzyme mechanisms. <strong>Source:</strong> https://www.trivedieffect.com/science/isotopic-abundance-ratio-analysis-of-123-trimethoxybenzene-tmb-after-biofield-energy-treatment-the-trivedi-effect-using-gas-chromatography-mass-spectrometry http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=227&doi=10.11648/j.ajac.20160404.13
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Isotopic Abundance Ratio Analysis of 1,2,3-Trimethoxybenzene (TMB) After Biofield Energy Treatment (The Trivedi Effect®) Using Gas Chromatography-Mass Spectrometry." American Journal of Applied Chemistry 4, no. 4 (2016): 132–40. https://doi.org/10.5281/zenodo.196902.
Full textAbstract:
1,2,3-Trimethoxybenzene (TMB) is one of the most versatile chemical used for the synthesis of several pharmaceuticals, dyes, polymers, organic compounds, etc. The stable isotope ratio analysis has increased attention day-by-days in several fields such as agricultural, food authenticity, biochemistry, medical research, etc. The current study was aimed to evaluate the effect of the biofield energy treatment on the isotopic abundance ratios of 13C/12C or 2H/1H or 17O/16O (PM+1/PM) and 18O/16O (PM+2/PM) in TMB using Gas chromatography - mass spectrometry (GC-MS) technique. TMB was divided into two parts - one part was denoted as control and another part was referred as biofield energy treated sample that was received through Mr. Trivediꞌs unique biofield energy (The Trivedi Effect®). The GC-MS of the biofield treated TMB was characterized at different time intervals considered as T1, T2, T3, and T4 to examine the impact of the biofield energy treatment on isotopic abundance ratio with respect to the time. The GC-MS spectra of the both control and biofield treated TMB exhibited the presence of molecular ion peak [M+] at m/z 168 (calculated 168.08 for C9H12O3) along with similar pattern of fragmentation. The relative peak intensities of the fragmented ions in the biofield treated TMB, particularly at T2 and T3 was altered from the control sample. The isotopic abundance ratio analysis in the biofield treated TMB exhibited that the isotopic abundance ratio of PM+1/PM in the biofield treated TMB at T2 and T3 was significantly enhanced by 128.13 and 117.99%, respectively with respect to the control sample. Consequently, the percentage change in isotopic abundance ratio of PM+2/PM was significantly increased in the biofield treated TMB at T2 and T3 by 125.93 and 116.67%, respectively as compared with the control TMB. The isotopic abundance ratios (PM+1/PM and PM+2/PM) in the biofield treated TMB at T1 and T4 was altered with respect to the control TMB. In summary, 13C, 2H, and 17O contributions from (C9H12O3)+ to m/z 169 and 18O contribution from (C9H12O3)+ to m/z 170 for the biofield treated TMB, particularly at T2 and T3 were significantly improved and biofield treated TMB might exhibit changed isotope effects as compared to the control sample. The biofield treated TMB might assist to develop new chemicals and pharmaceuticals through using its kinetic isotope effects like understanding the reaction mechanism, the enzymatic transition state and all aspects of enzyme mechanisms. https://www.trivedieffect.com/science/isotopic-abundance-ratio-analysis-of-123-trimethoxybenzene-tmb-after-biofield-energy-treatment-the-trivedi-effect-using-gas-chromatography-mass-spectrometry http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=227&doi=10.11648/j.ajac.20160404.13
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Senger, Moritz, Stefan Mebs, Jifu Duan, et al. "Stepwise isotope editing of [FeFe]-hydrogenases exposes cofactor dynamics." Proceedings of the National Academy of Sciences 113, no. 30 (2016): 8454–59. http://dx.doi.org/10.1073/pnas.1606178113.
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The six-iron cofactor of [FeFe]-hydrogenases (H-cluster) is the most efficient H2-forming catalyst in nature. It comprises a diiron active site with three carbon monoxide (CO) and two cyanide (CN−) ligands in the active oxidized state (Hox) and one additional CO ligand in the inhibited state (Hox-CO). The diatomic ligands are sensitive reporter groups for structural changes of the cofactor. Their vibrational dynamics were monitored by real-time attenuated total reflection Fourier-transform infrared spectroscopy. Combination of 13CO gas exposure, blue or red light irradiation, and controlled hydration of three different [FeFe]-hydrogenase proteins produced 8 Hox and 16 Hox-CO species with all possible isotopic exchange patterns. Extensive density functional theory calculations revealed the vibrational mode couplings of the carbonyl ligands and uniquely assigned each infrared spectrum to a specific labeling pattern. For Hox-CO, agreement between experimental and calculated infrared frequencies improved by up to one order of magnitude for an apical CN− at the distal iron ion of the cofactor as opposed to an apical CO. For Hox, two equally probable isomers with partially rotated ligands were suggested. Interconversion between these structures implies dynamic ligand reorientation at the H-cluster. Our experimental protocol for site-selective 13CO isotope editing combined with computational species assignment opens new perspectives for characterization of functional intermediates in the catalytic cycle.
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Robb, G. N., S. Woodborne, P. R. de Bruin, K. Medger, and N. C. Bennett. "The influence of food quantity on carbon and nitrogen stable isotope values in southern African spiny mice (Acomys spinosissimus)." Canadian Journal of Zoology 93, no. 5 (2015): 345–51. http://dx.doi.org/10.1139/cjz-2014-0134.
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Stable isotope analysis is frequently applied as a tool to examine dietary patterns in animals. However, some of the underlying assumptions associated with using this approach are increasingly being questioned. We carried out a controlled diet experiment on the southern African spiny mouse (Acomys spinosissimus Peters, 1852) to test a number of aspects relating to these assumptions and also examine the hypothesis that stable isotopes, especially δ15N, can be used to provide evidence of nutritional stress. We compared the δ13C and δ15N values of livers and blood from animals that were fed ad libitum with animals undergoing a 10% reduction in food supply. Food-restricted animals showed no significant difference in δ15N; however, δ13C values of both liver and blood were depleted. Restricted animals also had a significantly lower C:N ratio. We examined the role of lipids and found following lipid extraction that both livers and lipids still showed the same separation in carbon values. Tissue–diet discrimination values were also calculated and found to be higher for both Δ13C and Δ15N compared with other mice species. Empirical values for discrimination rates were then compared with values calculated using an alternative method based on employing generic values and were found to be dissimilar, suggesting the use of generic values are not always appropriate. Our results highlight the need for greater understanding of the assumptions associated with using stable isotope analysis to examine diet and we suggest that studying a single species under captive conditions presents an ideal method to begin to test these hypotheses.
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Ning, Yongqiang, Bizheng Yang, Shaochen Yang, et al. "Application of Pb Isotopes and REY Patterns in Tracing Heavy Metals in Farmland Soils from the Upper-Middle Area of Yangtze River." International Journal of Environmental Research and Public Health 20, no. 2 (2023): 966. http://dx.doi.org/10.3390/ijerph20020966.
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Farmland heavy metal pollution—caused by both human activity and natural processes—is a major global issue. In the current study, principal component analysis (PCA), cluster analysis (CA), rare earth elements and yttrium (REY) analysis, and isotope fingerprinting were combined to identify sources of heavy metal pollution in soil from different farmland types in the upper-middle area of the Yangtze River. The concentrations of Zn and Cu were found to be higher in the vegetable base and tea plantation soil compared with their concentrations in the orangery soil. On the other hand, greater accumulation of Cd and Pb was observed in the orangery soil versus the vegetable base and tea plantation soils. Influenced by the type of bedrock, REY was significantly enriched in the orangery soil and depleted in the vegetable base soil, as compared with the tea plantation soil. The Pb isotopic compositions of the tea plantation (1.173–1.193 for 206Pb/207Pb and 2.070–2.110 for 208Pb/206Pb) and vegetable base (1.181–1.217 for 206Pb/207Pb and 2.052–2.116 for 208Pb/206Pb) soils were comparable to those of coal combustion soil. The compositions of 206Pb/207Pb (1.149–1.170) and 208Pb/206Pb (2.121–2.143) in the orangery soil fell between those observed in soils obtained from coal combustion and ore smelting sites. Using the IsoSource model, the atmospheric Pb contributions of the vegetable base, tea plantation, and orangery soils were calculated to be 66.6%, 90.1%, and 82.0%, respectively, and the bedrock contributions of Pb were calculated to be 33.3%, 9.90%, and 18.1%, respectively. Based on the PCA, CA, and REY results, as well as the Pb isotope model, it appears that heavy metals in the orangery soil may be derived from atmospheric deposition and bedrock weathering, while heavy metals in the vegetable base and tea plantation soils may be derived from mining and the use of fertilizer.
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Hellerstein, M. K., and R. A. Neese. "Mass isotopomer distribution analysis: a technique for measuring biosynthesis and turnover of polymers." American Journal of Physiology-Endocrinology and Metabolism 263, no. 5 (1992): E988–1001. http://dx.doi.org/10.1152/ajpendo.1992.263.5.e988.
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Mass isotopomer distribution analysis (MIDA) is a technique for measuring biosynthesis and turnover of polymers in vivo. A stable isotopically enriched precursor is administered, and the relative abundances of different mass isotopomers in the polymer of interest are measured by mass spectrometry (MS). By comparison of statistical distributions predicted from the binomial or multinomial expansion to the pattern of excess isotopomer frequencies observed in the polymer, the enrichment of the biosynthetic precursor subunits (p) for newly synthesized polymers is calculated. MIDA thereby provides a solution to the problem of determining the isotope content in the actual precursor molecules that entered a particular polymeric product (the “true” precursor). The fraction of polymer molecules in a mixture that were newly synthesized during an isotopic experiment (fractional synthesis) can then be calculated. We describe some mathematical characteristics of MIDA and point out certain advantageous features. For example, mathematical estimates of p remain valid even if there does not exist a single anatomic or functional precursor pool. The interpretation of decay curves of endogenously labeled polymers may be improved by the use of higher mass isotopomers, which better fulfill the assumption of flash labeling. By combining fractional synthesis values with rate constants of decay, absolute endogenous synthesis rates can be calculated. Thus, by using probability logic combined with MS analysis, MIDA allows dynamic measurements to be made through analyses on a polymer alone during both isotopic incorporation and decay phases. The method has been applied to fatty acids, cholesterol, and glucose and is potentially applicable to nucleic acids, porphyrins, perhaps proteins, and many other classes of polymers.
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Qi, Chong. "Shell model description of heavy nuclei and abnormal collective motions." EPJ Web of Conferences 178 (2018): 02015. http://dx.doi.org/10.1051/epjconf/201817802015.
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In this contribution I present systematic calculations on the spectroscopy and electromagnetic transition properties of intermediate-mass and heavy nuclei around 100Sn and 208Pb. We employed the large-scale configuration interaction shell model approach with realistic interactions. Those nuclei are the longest isotopic chains that can be studied by the nuclear shell model. I will show that the yrast spectra of Te isotopes show a vibrational-like equally spaced pattern but the few known E2 transitions show rotational-like behaviour. These kinds of abnormal collective behaviors cannot be reproduced by standard collective models and provide excellent background to study the competition of single-particle and various collective degrees of freedom. Moreover, the calculated B(E2) values for neutron-deficient and heavier Te isotopes show contrasting different behaviours along the yrast line, which may be related to the enhanced neutron-proton correlation when approaching N=50. The deviations between theory and experiment concerning the energies and E2 transition properties of low-lying 0+ and 2+ excited states and isomeric states in those nuclei may provide a constraint on our understanding of nuclear deformation and intruder configuration in that region.
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Gulson, Brian L., Karen J. Mizon, and Brian T. Atkinson. "Source and timing of gold and other mineralization in the Red Lake area, northwestern Ontario, based on lead-isotope investigations." Canadian Journal of Earth Sciences 30, no. 12 (1993): 2366–79. http://dx.doi.org/10.1139/e93-205.
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The problems of the timing and source of gold mineralization and the sulfidation mechanism in the Red Lake area, north-western Ontario, have been addressed using more than 300 Pb-isotope analyses of more than 250 samples of sulfides, oxides, gold, and potential source rocks. Base metals and some gold from the Campbell and Dickenson mines are interpreted to have been mainly derived from the mafic–intermediate and felsic volcanic rocks of the lower sequence at ca. 2865 Ma, the model age calculated for samples of gold, chalcopyrite, pyrite, and galena. Other samples of gold are considered to have formed at younger ages, perhaps at ca. 2700 Ma. Differences in isotopic patterns for deposits in possibly different deformation zones but hosted by rocks of the same age and composition, e.g., Campbell–Dickenson, McFinley, Cochenour Willans, are interpreted to mean that some of the deposits formed at different times or from different sources or both (i.e., by multistage processes). The older period of gold mineralization is supported by a 2865 ± 10 Ma Pb–Pb isochron age (mean square of weighted deviates (MSWD) 2.9) for Cu–Ni and Fe sulfides and a similar model age for pyrite from the Bridget Lake prospect in the western sector. Younger mineralization at ca. 2700 Ma is represented by, for example, disseminated sulfides in the Dome stock, Balmer Lake arsenopyrite, the Red Summit mine in the Red Crest stock, sulfides and gold from the McFinley mine, and the model age for the Abino galena. A well-constrained Pb–Pb line for magnetites, mainly from 2700–2730 Ma felsic intrusions, gives an apparent age of 2660 ± 10 Ma (MSWD 3.7). This event may represent late-stage hydrothermal activity. Analyses of gold grains yield very complex isotopic patterns possibly because of remobilization and the very low contents of Pb in the gold grains. In environments such as Red Lake, Pb-isotope analyses of gold appear to give unreliable estimates of genesis and timing.
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Saito, K., and S. Ogawa. "FRACTAL DIMENSIONS FOR RADIOISOTOPE POLLUTION PATTERNS BY NUCLEAR POWER PLANT ACCIDENTS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-7/W3 (April 30, 2015): 919–25. http://dx.doi.org/10.5194/isprsarchives-xl-7-w3-919-2015.
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The radioisotope pollution shows two types of patterns: dry and wet deposits for nuclear power plant accidents. Two surface pollution patterns were analysed by fractal. In Fukushima nuclear power plant accident, surface pollution by wet deposits was estimated to occur. However, actually it was no rain and white crystals were observed on the surface. Then, fractal analysis was carried out for the spatial distribution patterns of radio isotopes on the surface to judge the types of deposits. As a reference, Chernobyl nuclear power plant accident was checked for the spatial distribution patterns of radioisotopes on the surface. The objective patterns by fractal analysis were the surface pollution maps in Fukushima and Chernobyl, Abukuma river watershed map, and NOAA/AVHRR. The calculation of fractal dimensions was carried out with the box counting for binarized images. Fractal analysis results suggested the next conclusions. The radioisotope pollution in Fukushima might occur in both dry and wet deposits. The dry deposit might make the pollution pattern similar to the watershed, while the wet deposit might make the pollution pattern similar to cloud images. Moreover, most radioisotope contaminants might flow on the road in the forest valley and deposit on forest with and without rainfall in Fukushima.
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Chang, Yunhua, Yanlin Zhang, Chongguo Tian, et al. "Nitrogen isotope fractionation during gas-to-particle conversion of NO<sub><i>x</i></sub> to NO<sub>3</sub><sup>−</sup> in the atmosphere – implications for isotope-based NO<sub><i>x</i></sub> source apportionment." Atmospheric Chemistry and Physics 18, no. 16 (2018): 11647–61. http://dx.doi.org/10.5194/acp-18-11647-2018.
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Abstract. Atmospheric fine-particle (PM2.5) pollution is frequently associated with the formation of particulate nitrate (pNO3−), the end product of the oxidation of NOx gases (NO + NO2) in the upper troposphere. The application of stable nitrogen (N) (and oxygen) isotope analyses of pNO3− to constrain NOx source partitioning in the atmosphere requires knowledge of the isotope fractionation during the reactions leading to nitrate formation. Here we determined the δ15N values of fresh pNO3− (δ15N–pNO3−) in PM2.5 at a rural site in northern China, where atmospheric pNO3− can be attributed exclusively to biomass burning. The observed δ15N–pNO3− (12.17±1.55 ‰; n = 8) was much higher than the N isotopic source signature of NOx from biomass burning (1.04±4.13 ‰). The large difference between δ15N–pNO3− and δ15N–NOx (Δ(δ15N)) can be reconciled by the net N isotope effect (εN) associated with the gas–particle conversion from NOx to NO3−. For the biomass burning site, a mean εN( ≈ Δ(δ15N)) of 10.99±0.74 ‰ was assessed through a newly developed computational quantum chemistry (CQC) module. εN depends on the relative importance of the two dominant N isotope exchange reactions involved (NO2 reaction with OH versus hydrolysis of dinitrogen pentoxide (N2O5) with H2O) and varies between regions and on a diurnal basis. A second, slightly higher CQC-based mean value for εN (15.33±4.90 ‰) was estimated for an urban site with intense traffic in eastern China and integrated in a Bayesian isotope mixing model to make isotope-based source apportionment estimates for NOx at this site. Based on the δ15N values (10.93±3.32 ‰; n = 43) of ambient pNO3− determined for the urban site, and considering the location-specific estimate for εN, our results reveal that the relative contribution of coal combustion and road traffic to urban NOx is 32 % ± 11 % and 68 %± 11 %, respectively. This finding agrees well with a regional bottom-up emission inventory of NOx. Moreover, the variation pattern of OH contribution to ambient pNO3− formation calculated by the CQC module is consistent with that simulated by the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), further confirming the robustness of our estimates. Our investigations also show that, without the consideration of the N isotope effect during pNO3− formation, the observed δ15N–pNO3− at the study site would erroneously imply that NOx is derived almost entirely from coal combustion. Similarly, reanalysis of reported δ15N–NO3− data throughout China and its neighboring areas suggests that NOx emissions from coal combustion may be substantively overestimated (by > 30 %) when the N isotope fractionation during atmospheric pNO3− formation is neglected.
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Ipsen, Andreas. "Efficient Calculation of Exact Fine Structure Isotope Patterns via the Multidimensional Fourier Transform." Analytical Chemistry 86, no. 11 (2014): 5316–22. http://dx.doi.org/10.1021/ac500108n.
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Smith, Devin F., W. Berry Lyons, Tiernan Henry, Raymond Flynn, and Anne E. Carey. "Irish surface water response to the 2018 drought." PLOS Water 2, no. 11 (2023): e0000197. http://dx.doi.org/10.1371/journal.pwat.0000197.
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Intense weather events are projected to increase as a consequence of climate change. The summer 2018 drought in Europe impacted human health, ecosystems, and economic prosperity. Even locations with an abundance of fresh water, like Ireland, faced water restrictions due to depleted supplies. To characterize the effect of the 2018 drought on Irish rivers, we collected surface water samples from rivers across the island at the drought onset and termination. We analyzed samples for stable water isotopes δ18O and δ2H and calculated the fraction of evaporation from river groundwater and precipitation inflow (E/I) of rivers. We extended river δ18O and δ2H analysis to 2020 for rivers in two catchments, Corrib and Shannon, to investigate how Irish river systems respond to high precipitation events, and the role of loughs (lakes) in the system. River δ18O and δ2H values showed progressive depletion from west to east in response to precipitation depletion from airmasses arriving off the Atlantic Ocean. From onset to termination of the 2018 drought, river δ18O and δ2H values were enriched and the calculated E/I value increased for most rivers. D-excess were negatively correlated with E/I value, providing support for E/I calculations. Extended analysis of loughs along the Corrib and Shannon river systems showed that lough Corrib consistently induced isotopic enrichment, while loughs in the Shannon catchment inconsistently caused isotopic enrichment. Both systems exert control over river isotopic composition in hydrologic extremes. Findings promote additional research in hydrologic patterns in response to increasing frequency of floods and droughts.
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Pollock, J. C., P. J. Sylvester, and S. M. Barr. "Lu–Hf zircon and Sm–Nd whole-rock isotope constraints on the extent of juvenile arc crust in Avalonia: examples from Newfoundland and Nova Scotia, Canada." Canadian Journal of Earth Sciences 52, no. 3 (2015): 161–81. http://dx.doi.org/10.1139/cjes-2014-0157.
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Avalonia, the largest accreted crustal block in the Appalachian orogen, consists of Neoproterozoic magmatic arc sequences that represent protracted and episodic subduction-related magmatism before deposition of an Ediacaran–Ordovician cover sequence including siliciclastic rocks. Zircon crystals were obtained from arc-related magmatic rocks and from clastic sedimentary sequences and analyzed in situ for their Hf-isotope composition. The majority of magmatic and detrital zircons are dominated by initial 176Hf/177Hf values that are more radiogenic than chondritic uniform reservoir (CHUR) with calculated crust formation Hf–TDM model ages that range from 0.84 to 1.30 Ga. These results suggest formation by partial melting of juvenile mantle in a Neoproterozoic continental arc. Some zircons have Hf–TDM model ages ca. 1.39–3.09 Ga with εHf values of –33.9 to –0.5 and more clearly indicate involvement of older lithosphere in their petrogenesis. Whole-rock Sm–Nd isotopic compositions from felsic volcanic rocks are characterized by positive initial εNd values with Mesoproterozoic depleted mantle model ages consistent with juvenile extraction. Results suggest a dominant mantle component with long-term light rare earth element (LREE) depletion mixed with an older crustal component with long-term LREE enrichment. The pattern of TDM model ages and variations in Lu–Hf and Sm–Nd isotopic character are compatible with a ca. 1.0–1.2 Ga igneous tectonomagmatic event that formed basement to Neoproterozoic magmatic arcs in Avalonia. The presence of evolved isotopic signatures, however, indicates that significant older Proterozoic crust is present locally beneath Avalonia, suggesting that Avalonia formed in a single Neoproterozoic arc system that generated juvenile mantle-derived crust, coupled with lesser anatectic reworking of significantly older crust.
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Hansen, Poul Erik, and Fadhil S. Kamounah. "Multiple Intramolecular Hydrogen Bonding in Large Biomolecules: DFT Calculations and Deuterium Isotope Effects on 13C Chemical Shifts as a Tool in Structural Studies." Chemistry 5, no. 2 (2023): 1317–28. http://dx.doi.org/10.3390/chemistry5020089.
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Large biomolecules often have multiple intramolecular hydrogen bonds. In the cases where these interact, it requires special tools to disentangle the patterns. Such a tool could be deuterium isotope effects on chemical shifts. The use of theoretical calculations is an indispensable tool in such studies. The present paper illustrates how DFT calculations of chemical shifts and deuterium isotope effects on chemical shifts in combination with measurements of these effects can establish the complex intramolecular hydrogen bond patterns of rifampicin as an example) The structures were calculated using DFT theoretical calculations, performed with the Gaussian 16 software. The geometries were optimized using the B3LYP functional and the Pople basis set 6-31G(d) and the solvent (DMSO) was taken into account in the PCM approach. Besides the 6-31G(d) basis set, the 6-31 G(d,p) and the 6-3111G(d,p) basis sets were also tested. The nuclear shieldings were calculated using the GIAO approach. Deuteriation was simulated by shortening the X-H bond lengths by 0.01 Å.
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Determination of Isotopic Abundance of 13C/12C or 2H/1H and 18O/16O in Biofield Energy Treated 1-Chloro-3-Nitrobenzene (3-CNB) Using Gas Chromatography-Mass Spectrometry." Science Journal of Analytical Chemistry 4, no. 4 (2016): 42–51. https://doi.org/10.11648/j.sjac.20160404.11.
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1-Chloro-3-nitrobenzene (3-CNB) is an aromatic halo-amine compound used as chemical intermediate for the production of several fine chemicals like pharmaceuticals, dyes, agricultural chemicals, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, etc. The objective of the current research was to investigate the impact of the biofield energy treatment on the isotopic abundance ratios of PM+1/PM, PM+2/PM and PM+3/PM in 3-CNB using gas chromatography - mass spectrometry (GC-MS). The sample, 3-CNB was divided into two parts - one part was denoted as control and another part was referred as biofield energy treated sample that was treated with biofield energy (The Trivedi Effect®). T1, T2, T3, and T4 were represented to different time interval analysis of the biofield treated 3-CNB. The GC-MS spectra of the both control and biofield treated 3-CNB indicated the presence of molecular ion peak [M+] at m/z 157 (calculated 156.99 for C6H4ClNO2) along with same pattern of fragmentation. The relative intensities of the parent molecule and other fragmented ions of the biofield treated 3-CNB were improved as compared to the control 3-CNB. The percentage change of the isotopic abundance ratio of PM+1/PM was significantly increased in the biofield treated 3-CNB at T1, T2 and T3 by 11.62, 18.50, and 29.82%, respectively with respect to the control 3-CNB. Accordingly, the isotopic abundance ratio of PM+2/PM in the biofield treated 3-CNB at T2 and T3 was significantly improved by 15.22 and 35.09%, respectively as compared to the control sample. The isotopic abundance ratios of PM+1/PM and PM+2/PM in the biofield treated 3-CNB at T1 and T4 were changed as compared to the control sample. The percentage change of the isotopic abundance ratio of PM+3/PM was enhanced in the biofield treated 3-CNB at T1, T2, T3, and T4 by 4.67, 18.69, 31.31 and 6.08%, respectively as compared to the control 3-CNB. The isotopic abundance ratios of PM+1/PM, PM+2/PM and PM+3/PM in the biofield treated 3-CNB changed with the time. So, the biofield energy treated 3-CNB might exhibit the altered isotope effects such as altered physicochemical and thermal properties, binding energy, and the rate of the chemical reaction as compared to the control sample. The biofield energy treated 3-CNB might assist in designing for the synthesis of pharmaceuticals, agricultural chemicals, dyes, corrosion inhibitors and other several useful industrial chemicals. <strong>Source:</strong> https://www.trivedieffect.com/science/determination-of-isotopic-abundance-of-13c-12c-or-2h-1h-and-18o-16o-in-biofield-energy-treated-1-chloro-3-nitrobenzene-3-cnb-using-gas-chromatography-mass-spectrometry http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=223&doi=10.11648/j.sjac.20160404.11
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Determination of Isotopic Abundance of 13C/12C or 2H/1H and 18O/16O in Biofield Energy Treated 1-Chloro-3-Nitrobenzene (3-CNB) Using Gas Chromatography-Mass Spectrometry." Science Journal of Analytical Chemistry 4, no. 4 (2016): 42–51. https://doi.org/10.5281/zenodo.196927.
Full textAbstract:
1-Chloro-3-nitrobenzene (3-CNB) is an aromatic halo-amine compound used as chemical intermediate for the production of several fine chemicals like pharmaceuticals, dyes, agricultural chemicals, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, etc. The objective of the current research was to investigate the impact of the biofield energy treatment on the isotopic abundance ratios of PM+1/PM, PM+2/PM and PM+3/PM in 3-CNB using gas chromatography - mass spectrometry (GC-MS). The sample, 3-CNB was divided into two parts - one part was denoted as control and another part was referred as biofield energy treated sample that was treated with biofield energy (The Trivedi Effect®). T1, T2, T3, and T4 were represented to different time interval analysis of the biofield treated 3-CNB. The GC-MS spectra of the both control and biofield treated 3-CNB indicated the presence of molecular ion peak [M+] at m/z 157 (calculated 156.99 for C6H4ClNO2) along with same pattern of fragmentation. The relative intensities of the parent molecule and other fragmented ions of the biofield treated 3-CNB were improved as compared to the control 3-CNB. The percentage change of the isotopic abundance ratio of PM+1/PM was significantly increased in the biofield treated 3-CNB at T1, T2 and T3 by 11.62, 18.50, and 29.82%, respectively with respect to the control 3-CNB. Accordingly, the isotopic abundance ratio of PM+2/PM in the biofield treated 3-CNB at T2 and T3 was significantly improved by 15.22 and 35.09%, respectively as compared to the control sample. The isotopic abundance ratios of PM+1/PM and PM+2/PM in the biofield treated 3-CNB at T1 and T4 were changed as compared to the control sample. The percentage change of the isotopic abundance ratio of PM+3/PM was enhanced in the biofield treated 3-CNB at T1, T2, T3, and T4 by 4.67, 18.69, 31.31 and 6.08%, respectively as compared to the control 3-CNB. The isotopic abundance ratios of PM+1/PM, PM+2/PM and PM+3/PM in the biofield treated 3-CNB changed with the time. So, the biofield energy treated 3-CNB might exhibit the altered isotope effects such as altered physicochemical and thermal properties, binding energy, and the rate of the chemical reaction as compared to the control sample. The biofield energy treated 3-CNB might assist in designing for the synthesis of pharmaceuticals, agricultural chemicals, dyes, corrosion inhibitors and other several useful industrial chemicals. https://www.trivedieffect.com/science/determination-of-isotopic-abundance-of-13c-12c-or-2h-1h-and-18o-16o-in-biofield-energy-treated-1-chloro-3-nitrobenzene-3-cnb-using-gas-chromatography-mass-spectrometry http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=223&doi=10.11648/j.sjac.20160404.11
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Putman, Annie L., Patrick C. Longley, Morgan C. McDonnell, et al. "Isotopic evaluation of the National Water Model reveals missing agricultural irrigation contributions to streamflow across the western United States." Hydrology and Earth System Sciences 28, no. 13 (2024): 2895–918. http://dx.doi.org/10.5194/hess-28-2895-2024.
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Abstract. The National Water Model (NWM) provides critical analyses and projections of streamflow that support water management decisions. However, the NWM performs poorly in lower-elevation rivers of the western United States (US). The accuracy of the NWM depends on the fidelity of the model inputs and the representation and calibration of model processes and water sources. To evaluate the NWM performance in the western US, we compared observations of river water isotope ratios (18O / 16O and 2H / 1H expressed in δ notation) to NWM-flux-estimated (model) river reach isotope ratios. The modeled estimates were calculated from long-term (2000–2019) mean summer (June, July, and August) NWM hydrologic fluxes and gridded isotope ratios using a mass balance approach. The observational dataset comprised 4503 in-stream water isotope observations in 877 reaches across 5 basins. A simple regression between observed and modeled isotope ratios explained 57.9 % (δ18O) and 67.1 % (δ2H) of variance, although observations were 0.5 ‰ (δ18O) and 4.8 ‰ (δ2H) higher, on average, than mass balance estimates. The unexplained variance suggest that the NWM does not include all relevant water fluxes to rivers. To infer possible missing water fluxes, we evaluated patterns in observation–model differences using δ18Odiff (δ18Oobs−δ18Omod) and ddiff (δ2Hdiff-8⋅δ18Odiff). We detected evidence of evaporation in observations but not model estimates (negative ddiff and positive δ18Odiff) at lower-elevation, higher-stream-order, arid sites. The catchment actual-evaporation-to-precipitation ratio, the fraction of streamflow estimated to be derived from agricultural irrigation, and whether a site was reservoir-affected were all significant predictors of ddiff in a linear mixed-effects model, with up to 15.2 % of variance explained by fixed effects. This finding is supported by seasonal patterns, groundwater levels, and isotope ratios, and it suggests the importance of including irrigation return flows to rivers, especially in lower-elevation, higher-stream-order, arid rivers of the western US.
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Kiss, G. G., A. Vitéz-Sveiczer, Y. Saito та ін. "Measuring the β-decay Properties of Neutron-rich Exotic Pm, Sm, Eu, and Gd Isotopes to Constrain the Nucleosynthesis Yields in the Rare-earth Region". Astrophysical Journal 936, № 2 (2022): 107. http://dx.doi.org/10.3847/1538-4357/ac80fc.
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Abstract The β-delayed neutron-emission probabilities of 28 exotic neutron-rich isotopes of Pm, Sm, Eu, and Gd were measured for the first time at RIKEN Nishina Center using the Advanced Implantation Detector Array (AIDA) and the BRIKEN neutron detector array. The existing β-decay half-life (T 1/2) database was significantly increased toward more neutron-rich isotopes, and uncertainties for previously measured values were decreased. The new data not only constrain the theoretical predictions of half-lives and β-delayed neutron-emission probabilities, but also allow for probing the mechanisms of formation of the high-mass wing of the rare-earth peak located at A ≈ 160 in the r-process abundance distribution through astrophysical reaction network calculations. An uncertainty quantification of the calculated abundance patterns with the new data shows a reduction of the uncertainty in the rare-earth peak region. The newly introduced variance-based sensitivity analysis method offers valuable insight into the influence of important nuclear physics inputs on the calculated abundance patterns. The analysis has identified the half-lives of 168Sm and of several gadolinium isotopes as some of the key variables among the current experimental data to understand the remaining abundance uncertainty at A = 167–172.
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Daoutidis, J., and G. A. Lalazissis. "Superdeformation in Pb isotopes with large neutron excess." HNPS Proceedings 14 (December 5, 2019): 197. http://dx.doi.org/10.12681/hnps.2272.
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Covariant Density Functional theory (CDFT) is used to investigate superdeformation in Pb isotopes on the neutron rich side of the periodic table. Energy surfaces and deformation parameters in this region are calculated by solving the constrained Relativistic Hartree Bogoliubov (RHB) equations. We use the parameter set DDME2, which has an explicit density dependence as well in the isoscalar as in the isovector channel together with the finite range pairing force DIS of Gogny. With increasing neutron number we find a characteristic pattern for superdeformed minima in these nuclei.
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Mamberti, Marc, Henriette Lapierre, Delphine Bosch, Etienne Jaillard, Jean Hernandez, and Mireille Polvé. "The Early Cretaceous San Juan Plutonic Suite, Ecuador: a magma chamber in an oceanic plateau?" Canadian Journal of Earth Sciences 41, no. 10 (2004): 1237–58. http://dx.doi.org/10.1139/e04-060.
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Sections through an oceanic plateau are preserved in tectonic slices in the Western Cordillera of Ecuador (South America). The San Juan section is a sequence of maficultramafic cumulates. To establish that these plutonic rocks formed in an oceanic plateau setting, we have developed criteria that discriminate intrusions of oceanic plateaus from those of other tectonic settings. The mineralogy and crystallization sequence of the cumulates are similar to those of intra-plate magmas. Clinopyroxene predominates throughout, and orthopyroxene is only a minor component. Rocks of intermediate composition are absent, and hornblende is restricted to the uppermost massive gabbros within the sequence. The ultramafic cumulates are very depleted in light rare-earth elements (LREE), whereas the gabbros have flat or slightly enriched LREE patterns. The composition of the basaltic liquid in equilibrium with the peridotite, calculated using olivine compositions and REE contents of clinopyroxene, contains between 16% and 8% MgO and has a flat REE pattern. This melt is geochemically similar to other accreted oceanic plateau basalts, isotropic gabbros, and differentiated sills in western Ecuador. The Ecuadorian intrusive and extrusive rocks have a narrow range of εNdi (+8 to +5) and have a rather large range of Pb isotopic ratios. Pb isotope systematics of the San Juan plutonic rocks and mineral separates lie along a mixing line between the depleted mantle (DMM) and the enriched-plume end members. This suggests that the Ecuadorian plutonic rocks generated from the mixing of two mantle sources, a depleted mid-oceanic ridge basalt (MORB) source and an enriched one. The latter is characterized by high (207Pb/204Pb)i ratios and could reflect a contamination by recycled either lower continental crust or oceanic pelagic sediments and (or) altered oceanic crust (enriched mantle type I, EMI). These data suggest that the San Juan sequence represents the plutonic components of an Early Cretaceous oceanic plateau, which accreted in the Late Cretaceous to the Ecuadorian margin.
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Vermeeren, Bart, and Hubert Druenne. "Development of a MOX equivalence Python code package for ANICCA." EPJ Nuclear Sciences & Technologies 7 (2021): 25. http://dx.doi.org/10.1051/epjn/2021023.
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The basis of the MOX (Mixed OXide) energy equivalence principle is keeping the in-core fuel management characteristics (cycle length, feed size, etc.) of a nuclear reactor unchanged when replacing UOX (Uranium OXide) fuel assemblies by MOX. If the effect of the loading pattern is neglected, such an equivalence is obtained by tuning the Pu content in the MOX fuel, while considering the specific Pu isotopic vector at the time of the core reload to obtain a crossing of the reactivity curves of UOX and MOX at the end-of-cycle core average burnup. It is proposed in this work to extend the fuel cycle analysis tool ANICCA (Advanced Nuclear Inventory Cycle Code) with a MOX equivalence Python code package, which automatically governs the supply and demand of Pu vector isotopes required to obtain MOX equivalence. This code package can determine the reactivity evolution for any given Pu vector by means of a multidimensional interpolation on a directive grid of pre-calculated data tables generated by WIMS10, covering the physically accessible Pu vector space. A fuel cycle scenario will be assessed for a representative evolution of the Pu vector inventory available in spent UOX fuel as a demonstration case, defining the interim fuel storage building dimensional requirements for different reprocessing strategies.
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Wang, Tiantian, Bo Sun, Xueyuan Tang, et al. "Spatio-temporal variability of past accumulation rates inferred from isochronous layers at Dome A, East Antarctica." Annals of Glaciology 57, no. 73 (2016): 87–93. http://dx.doi.org/10.1017/aog.2016.28.
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ABSTRACTStudies of palaeo-accumulation rates at Dome A, East Antarctica, are entirely absent. Here, spatio-temporal variations in ice accumulation rates for the past ~161 ka are calculated from isochronous internal layering, traced from radio-echo sounding (RES) data collected by the Polar Research Institute of China (PRIC) during the 21st CHINARE. The layers are dated by linking them to the site of Vostok ice core along an RES profile, which was flown by the Alfred-Wegener-Institut (AWI) in the Dome Connection East Antarctica (DoCo) project. The Dansgaard-Johnsen model is used to determine the spatial and temporal pattern of ice accumulation in Dome A region. The results show that there is a slight increasing pattern of ice accumulation from south to north along the 216 km radar profile at Dome A. The lowest ice accumulation rates were calculated around the Dome A zone. In the past ~90 ka, there were relatively high accumulation rates during the time period 34–47 ka (Marine Isotope Stage 3) at Dome A.
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Schönfeld, Joachim, and Hermann-Rudolf Kudrass. "Hemipelagic Sediment Accumulation Rates in the South China Sea Related to Late Quaternary Sea-Level Changes." Quaternary Research 40, no. 3 (1993): 368–79. http://dx.doi.org/10.1006/qres.1993.1090.
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AbstractSediments of 13 piston cores from opposite continental slopes of the South China Sea, off southern China and Sabah (northern Borneo), were analyzed by sedimentological methods and dated by oxygen isotope stratigraphy. Sediments mostly consist of hemipelagic clay with 20% carbonate off Sabah and 40% off China. We calculated terrigenous and carbonate accumulation rates for up to 11 time-slices from the Holocene to oxygen-isotope stage 6. Terrigenous accumulation rates generally increase with water depth and reach a maximum at the middle slope off Sabah and at the lower continental slope off China. During glacial and interglacial times this distribution pattern did not markedly change, despite an increase of accumulation rates for glacial periods by a factor of 2 to 5 compared to interglacial periods. Rates are negatively correlated with positions of sea level, which controls the partition of fluviatile terrigenous material for deposition on shelf, slope, and abyssal plain. Carbonate accumulation rates are higher off China by a factor of 2 compared to Sabah, probably indicating higher calcareous plankton productivity.
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Elmore, David, Nicholas J. Conard, Peter W. Kubik, Harry E. Gove, Martin Wahlen, and Juerg Beer. "Measurements of 36CI in Polar Ice." Annals of Glaciology 10 (1988): 202. http://dx.doi.org/10.3189/s0260305500004481.
Full textAbstract:
We are measuring 36Cl in the upper part of the 1966 Camp Century deep core, using the tandem-accelerator mass-spectrometry facility at the University of Rochester. There are two primary motivations for measuring 36Cl in ice. The first is to look for correlations between 36Cl concentrations and changes in solar activity. Previous studies of 10Be and 14C (Stuiver and Quay 1980, Raisbeck and others 1981, Beer and others 1983) have demonstrated that the production of these radio-isotopes increases during periods of low solar activity. When the sun is active, the magnetic field induced by the solar wind deflects galactic cosmic rays from the inner solar system and thereby lowers the production of radio-isotopes. Our study of 36Cl in ice dating back to A.D. 1550, from Camp Century, Greenland, shows that there was an increase in 36Cl production during the Maunder Minimum (1650–1715). However, climatic variations introduce fluctuations of a factor of 2 or more over short periods and the Maunder Minimum peak is only readily apparent when the data are smoothed mathematically.The second motivation for measuring 36Cl in ice is to test the possibility that the ratio of 36Cl to 10Be will provide a means for dating ice over 50 000 years old (Nishiizumi and others 1983). The dependence on both solar activity and climatic fluctuations mentioned above precludes dating with a single radio-isotope. If, however, the production rates of 36Cl and 10Be are each proportional to the cosmic-ray flux and are transported identically to the ice sheet, these fluctuations would cancel and the ratio of 36Cl to 10Be would provide a radiometric means of dating very old ice. The half-lives for 36Cl (3.0 × 105 years) and 10Be (1.6 × 106 years), combine to give a “half-life” for the 36Cl/10Be ratio of 3.7 × 105 years.Unfortunately, preliminary results from Camp Century, Greenland, show that it will almost certainly not be possible to use the 10Be/36Cl ratio for dating. 10Be and 36Cl have been measured in more than 20 samples; the 10Be/36Cl ratio varied, without any obvious pattern, from below 5 to over 15. Additional evidence comes from Antarctica. We found that the 10Be/36Cl ratio changed significantly within a short depth interval within a single block of ice and that the calculated age of ice based on 10Be/36Cl differed from the age of an embedded meteorite, ALHA82102 (personal communication from K. Nishiizumi).A variation in the 10Be/36Cl ratio may be caused by climatic effects: for example, changes in air circulation between the stratosphere and the troposphere in the polar region, in combination with chemical processes that affect aerosol chlorine and beryllium differently. Also, the 10Be/36Cl ratio is smaller than expected, indicating that there may be additional sources of 36Cl. If there is a source of 36Cl that varies independently from the galactic cosmic-ray flux, this would result in variations in the isotope ratio. Discovery of the cause of the variations may result in a new tool for understanding paleoclimate.