Parity operator and quantization of δ-functions

In the Weyl quantization scheme, the -function at the origin of phase space corresponds to the parity operator. The quantization of a functionf() on phase space is the operator f(/2)W()dM, whereM is the parity andW() the Weyl operator.     

Accuracy and precision of a laser-spectroscopy approach to the analysis of δ²H and δ¹⁸O in human urine

The isotope ratio analysis of body water often involves large sample numbers and lengthy sample processing. Here we demonstrate the ability of isotope ratio infrared spectroscopy (IRIS) to rapidly and accurately analyse the isotope ratios of water in urine. We analysed water extracted from human urine using traditional isotope ratio mass spectrometry (IRMS) and compared those values with IRIS-analysed extracted water and un-extracted urine. Regression analyses for δ2H and δ1?O values between (1) extracted water analysed via IRMS and IRIS and (2) urine and extracted water analysed via IRIS were significant (R2=0.99). These results indicate that cryogenic distillation of urine was not required for an accurate estimate of the isotopic composition of urine when using IRIS.     

Products of distributions and collision of a δ-wave with a δ′-wave in a turbulent model

We study the possibility of collision of a δ-wave with a stationary δ′-wave in a model ruled by equation f (t)u _t+[u²?β(x?γ(t))u]_x = 0, where f, β and γ are given real functions and u = u(x, t) is the state variable. We adopt a solution concept which is a consistent extension of the classical solution concept. This concept is defined in the setting of a distributional product, which is not constructed by approximation processes. By a convenient choice of f, β and γ, we are able to distinguish three distinct dynamics for that collision, to which correspond phenomena of solitonic behaviour, scattering, and merging. Also, as a particular case, taking f = 2 and β = 0 we prove that the referred collision is impossible to arise in the setting of the inviscid Burgers equation. To show how this framework can be applied to other physical models, we included several results already obtained.     

High-precision measurements of δ2H, δ18O and δ17O in water with the aid of cavity ring-down laser spectroscopy

A thorough evaluation of measurement uncertainty together with control of short-term and long-term precision of measurements should be a basis of any successful quality assurance/quality control (QA/QC) strategy aimed at maintaining a high quality of the analytical process. Here we present the results of a comprehensive assessment of the analytical performance of a Picarro L2140-i CRDS laser spectrometer analysing δ²H, δ¹⁸O and δ¹⁷O in water. The assessment is based on results obtained during 15 months of continuous operation of this instrument (February 2017 to May 2018). The short-term precision of measured and derived quantities was 0.11, 0.036, 0.028, 0.23 ‰ and 11 per meg, for δ²H, δ¹⁸O, δ¹⁷O, d-excess and Δ¹⁷O, respectively, and is comparable to the precision reported by the manufacturer. The long-term precision of the L2140-i, defined as standard uncertainty of the time series of 153 analyses of a laboratory standard conducted throughout 15 months, was roughly two times lower (0.24, 0.053, 0.038, 0.37 ‰ and 21 per meg, for δ²H, δ¹⁸O, δ¹⁷O, d-excess and Δ¹⁷O). In-depth assessment of the measurement uncertainty of a single analysis revealed that assigned uncertainty of the calibration standards is an important component of the uncertainty budget, especially in case of δ²H analysis.     

Integrability and PT-Symmetry of N-Body Systems with Spin-Coupling δ-Interactions

We study the PT-symmetric boundary conditions for "spin"-related -interactions and the corresponding integrability for both bosonic and fermionic many-body systems. The spectra and bound states are discussed in detail for 1/2-spin particle systems.     

Comparison of δ81Br and δ37Cl composition of volatiles,salt precipitates,and associated water in terrestrial evaporative saline lake systems

This study provides the first characterization of the variability of bromine and chlorine stable isotopic composition in evaporites, associated residual brines, and shoreline gases in terrestrial evaporative saline lakes. The lakes investigated here are groundwater discharge locations, and include both potash-rich alkaline lakes and sodic-dominated neutral pH lakes at a variety of salinities and evaporative stages. The chlorine and bromine isotope systems behave consistently different during evaporative salt precipitation, with ³⁷Cl more enriched in the salt than in the fluid, but ⁸¹Br more enriched in the fluid compared with the precipitated salt. The ⁸¹Br concentration of shore off-gassing was even smaller than mineral precipitate compositions. The trends observed for bromine isotopes are surprising compared with published laboratory studies, indicating that a process besides inorganic mineral precipitation is affecting δ⁸¹Br. Additional processes explored include diffusion, salt deflation, microbial and photolytic conversion to the gas phase, and oxidative bromination of organic matter.

Dedicated to Professor Peter Fritz on the occasion of his 80th birthday     

Hydrogen-Bond Symmetrization of δ-AlOOH

The δ-AIOOH can transport water into the deep mantle along cold subducting slab geothenn. We investigate the hydrogen-bond symmetrization behavior of δ-AIOOH under the relevant pressure-temperature condition of the lower mantle using ab initio molecular dynamics(AID). The static symmetrization pressure of 30.0 GPa can be reduced to 17.0 GPa at 300 K by finite-temperature(T) statistics, closer to the experimental observation of-10.0 GPa. The symmetrization pressure obtained by MD simulation is related to T by P(GPa) = 13.9(GPa) +0.01(GPa/K) × T(K). We conclude that δ-AIOOH in the lower mantle exists with symmetric hydrogen bond from its birthplace, or someplace slightly deeper, to the core-mantle boundary(CATB) along cold subducting slab geotherm. The bulk modulus decreases with T and increases anomalously upon symmetrization: K_o(GPa) =181(GPa)-0.013(GPa/K) × T(K) for δ-AIOOH with asymmetric hydrogen bond, and K_o(GPa) = 216(GPa)-0.013(GPa/K) × T(K) for δ-AIOOH with symmetric hydrogen bond. Our results provide an important insight into the existent form and properties of δ-AIOOH in the lower mantle.     

The impact of solar and atmospheric parameter uncertainties * on the measurement of θ13 and δ

We present in this paper the analysis of the measurement of the unknown PMNS parameters θ₁₃ and δ at future LBL facilities performing complete three parameters fits, each time fully including in the fit one of the atmospheric and solar oscillation parameters within its present (future) error. We show that, due to the presence of degeneracies, present uncertainties on θ₂₃ and worsen significantly the precision on (θ₁₃,δ) at future LBL experiments. Only if a precision on the atmospheric parameters at least similar to what expected at T2K-I is reached, then the sensitivities to θ₁₃ and δ that have been presented in the literature for many facilities (where θ₂₃ and are generally considered as fixed external inputs) can indeed be almost recovered. On the other hand, the impact on this measurement of the uncertainties on the solar parameters, θ₁₂ and is already negligible. Our analysis has been performed using three reference setups: the SPL Super-Beam and the standard low-γ β-Beam, both aiming toward a Mton Water Čerenkov detector located at L = 130 km; the 50 GeV Neutrino Factory with a 40 kton Magnetized Iron Detector to look for the "golden channel" ν_e → ν_μ with baseline L = 3000 km and a 4 kton Emulsion Cloud Chamber to look for the "silver channel" ν_e → ν_τ with baseline L = 732 km. Received: 19 July 2005, Revised: 30 September 2005, Published online: 11 November 2005 PACS: 14.60.Pq, 14.60.Lm     

Isoscalar magnetic moments and the role of the δ-hole excitation

Expectation values of the total spinS of nucleons in nuclei are very quenched. This quenching is shown to be hardly explained by the mixture of-hole states. The quenching thus provides the best evidence for the role of non-central parts of the nucleon-nucleon interaction, especially the tensor interaction.     

Effects of pressure and/or magnetism on superconductivity of δ-MoN single crystal

Effects of pressure and/or magnetism on the critical superconducting temperature(Tc)ofδ-Mo N single crystal were investigated using a Maglab system.Theδ-Mo N single crystal was synthesized at extreme conditions of high pressure and high temperature.The carrier density ofδ-Mo N single crystal as a function of applied pressure was determined using Hall coefficient measurement.     

Diurnal variability of δ13C and δ18O of atmospheric CO2 in the urban atmosphere of Kraków,Poland

This article presents the results of measurements of the isotopic composition and concentration of atmospheric carbon dioxide, performed on air samples from Kraków (Southern Poland) in different seasons of the year. A simple isotope mass balance model has been applied to determine the contributions of different sources of CO₂ to the urban atmosphere of Kraków city: the latitudinal/regional background, biospheric contributions and anthropogenic emissions. The calculations show that during the summer and early autumn the dominant contribution to local CO₂ peaks is the biosphere, making up to 20% of atmospheric CO₂ during the nocturnal temperature inversion in the lower troposphere. During early spring and winter, anthropogenic emissions are the main local source.     

A robust and fast method of sampling and analysis of δ13C of dissolved inorganic carbon in ground waters

The stable carbon isotopic composition of dissolved inorganic carbon (δ¹³C_DIC) is traditionally determined using either direct precipitation or gas evolution methods in conjunction with offline gas preparation and measurement in a dual-inlet isotope ratio mass spectrometer. A gas evolution method based on continuous-flow technology is described here, which is easy to use and robust. Water samples (100–1500 μl depending on the carbonate alkalinity) are injected into He-filled autosampler vials in the field and analysed on an automated continuous-flow gas preparation system interfaced to an isotope ratio mass spectrometer. Sample analysis time including online preparation is 10 min and overall precision is 0.1 ‰. This method is thus fast and can easily be automated for handling large sample batches.     

Effect of the phonon and magnetic anharmonicity on the thermal and elastic properties of nearly magnetic δ-plutonium

The temperature dependences of the total heat capacity and the lattice components of the bulk modulus, the volume thermal expansion coefficient, and the mean-square deviation of atoms from the equilibrium positions of nearly magnetic δ-plutonium (using the Pu_0.96Ga_0.04 alloy as an example) have been calculated within the framework of the self-consistent thermodynamic model. The electronic heat capacity has been calculated using the results obtained in terms of the self-consistent spin-fluctuation theory based on the inclusion of the strong magnetic anharmonicity, which leads to a splitting of the electronic spectra by fluctuating exchange fields. On this basis, the effect of phonon anharmonicity not only on the lattice heat capacity but also on other thermal and elastic properties has been considered.     

The Effect of Diet Quality on δ13C and δ15N in the Tissues of Locusts,Locusta migratoria L

Abstract

Locust nymphs were raised from hatching to adult locusts on either seedling wheat (C₃) or maize (C₄), to determine whether relative enrichments/depletions of ¹⁵N and ¹³C within body tissues are influenced by diet. The maize contained less hexose sugars and protein per gram than wheat.

The isotopic spacing between the food and the whole insect was found to differ between the two diets. The lower quality maize diet showed an overall +5.1‰ enrichment in δ¹⁵N compared to + 2.8‰ for wheat, possibly due to increased fractionation due to protein recycling.

The maize diet resulted in increased depletion in lipid and trehalose and depletion in chitin relative to diet. The results for both δ¹⁵N and δ¹³C suggest that substrate recycling was occurring on the low quality maize diet. Therefore diet quality determines the enrichment/depletion in δ¹⁵N and δ¹³C within organisms.     

The effect of different fish feed compositions on δ13C and δ15N signatures of sea bass and its potential value for tracking mariculture-derived nutrients

Increasing demand for fish and seafood calls for an expansion of aquaculture production. At the same time, the status of the marine environment must not be jeopardised. Stable isotopes are potential markers for tracking feed-based nutrient flows from aquaculture into marine biota. Here, we demonstrate how four experimental diets (main protein components: fishmeal, soya protein concentrate, wheat gluten, and Jatropha kernel meal) and a commercial diet induce characteristic δ¹³C and δ¹⁵N signals in sea bass (Dicentrarchus labrax) during nine weeks of laboratory feeding under replicate conditions. The plant-protein-based diets containing wheat gluten and soya, and the commercial feed consistently induced the largest isotopic differentiation of the fish, both from the feed source and from the pre-experimental condition. The large difference of the fish on plant-protein-based diets compared to the range of natural isotopic variation in the macrozoobenthos of the North Sea lends support to the idea that plant-based feeds are suitable for tracing mariculture-derived organic matter under practical conditions. The commercial feed had a similar effect as the experimental feeds and would be a cost-effective option for an offshore aquaculture experiment.     

Expression of classic cadherins and δ-protocadherins in the developing ferret retina

Background  

Cadherins are a superfamily of calcium-dependent adhesion molecules that play multiple roles in morphogenesis, including proliferation, migration, differentiation and cell-cell recognition. The subgroups of classic cadherins and δ-protocadherins are involved in processes of neural development, such as neurite outgrowth, pathfinding, target recognition, synaptogenesis as well as synaptic plasticity. We mapped the expression of 7 classic cadherins (CDH4, CDH6, CDH7, CDH8, CDH11, CDH14, CDH20) and 8 δ-protocadherins (PCDH1, PCDH7, PCDH8, PCDH9, PCDH10, PCDH11, PCDH17, PCDH18) at representative stages of retinal development and in the mature retina of the ferret by in situ hybridization.     

Ground State Energy of One-Dimensional δ-Function Interacting Bose and Fermi Gas

The ground state energy curves of one-dimensional ＆function interacting bose and fermi gas are fitted with simple algebraic approximations according to their asymptotic behaviors.     

Synthesis of peptidomimetics, δ- and {\varepsilon}-lactam tetrazoles

A concise two-step procedure for the synthesis of novel δ-lactam tetrazoles has been established via the Ugi-azide reaction using 5-oxohexanoic acid along with primary amines, isocyanides, and azidotrimethylsilane followed by 1,1'-carbonyldiimidazole-mediated intramolecular amide formation. Expansion to [Formula: see text]-lactam tetrazole scaffolds was accomplished using methyl 6-oxoheptanoate via the same Ugi-azide reaction followed by basic hydrolysis and SOCl(2) activation to enable lactam formation.     

Effect of different lipid extraction methods on δ13C of lipid and lipid-free fractions of fish and different fish feeds

For many ecological applications of stable carbon isotope techniques, it is necessary to separate the lipid and lipid-free fractions. The effect of different lipid extraction methods on the isotope signature of the remaining lipid-free matter as well as the lipid fraction was tested. A hot extraction form of the Soxhlet method using petrol-ether was compared with two liquid-liquid extraction methods for lipid determination described by Bligh and Dyer and Smedes. Solid samples of fish and different natural food items were subjected to extraction and the carbon isotope ratios in lipid and lipid-free matter determined by IRMS. All methods were suitable for lipid extraction from all samples analysed here and did not cause biologically relevant differences (>1) in carbon isotopic ratios, except the Bligh and Dyer extraction method using chloroform which caused systematic errors for δ ¹³C when applied to diatoms.