The Effect of Diet Quality on δ(13)C and δ(15)N in the Tissues of Locusts, Locusta migratoria L

Abstract Locust nymphs were raised from hatching to adult locusts on either seedling wheat (C(3)) or maize (C(4)), to determine whether relative enrichments/depletions of (15)N and (13)C 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 δ(15)N 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 δ(15)N and δ(13)C suggest that substrate recycling was occurring on the low quality maize diet. Therefore diet quality determines the enrichment/depletion in δ(15)N and δ(13)C within organisms.     

(RBaCo2O5 δ(Pr,Sm,Y)体系的滞弹性内耗研究

本文对双钙钛矿结构RBaCo2O5 δ(Pr, Sm, Y)化合物进行了内耗研究.随稀土元素R的不同该材料体系存在着不同的晶体结构, 并导致了氧缺陷不同的驰豫行为.体系内耗谱图中呈现的一个驰豫型内耗峰被认为是由于[Roδ]层中额外氧的运动引起的.SmBaCo2O5 δ体系中在360 K附近还观察到一个相变型内耗峰,它伴随有模量的变化.     

Quantum size effects in δ-Pu (110) films

First-principles full-potential linearized-augmented-plane-wave (FP-LAPW) calculations have been carried out for δ-Pu (110) films up to seven layers. The layers have been studied at the non-spin-polarized-no-spin-orbit coupling (NSP-NSO), non-spin-polarized-spin-orbit coupling (NSP-SO), spin-polarized-no-spin-orbit coupling (SP-NSO), spin-polarized-spin-orbit coupling (SP-SO), antiferromagnetic-no-spin-orbit coupling (AFM-NSO), and antiferromagnetic-spin-orbit-coupling (AFM-SO) levels of theory. The ground state of δ-Pu (110) films is found to be at the AFM-SO level of theory and the surface energy is found to rapidly converge. The semi-infinite surface energy for δ-Pu (110) films is predicted to be 1.41 J/m², while the magnetic moments show an oscillating behavior, gradually approaching the bulk value of zero with increase in the number of layers. Work functions indicate a strong quantum size effect up to and including seven layers. The work function of the seven-layer δ-Pu (110) film at the ground state is found to be 2.99 eV.     

RBaCo_2O_(5 δ)(Pr,Sm,Y)体系的滞弹性内耗研究

本文对双钙钛矿结构RBaCo2O5 δ(Pr,Sm,Y)化合物进行了内耗研究。随稀土元素R的不同该材料体系存在着不同的晶体结构,并导致了氧缺陷不同的驰豫行为。体系内耗谱图中呈现的一个驰豫型内耗峰被认为是由于[ROδ]层中额外氧的运动引起的。SmBaCo2O5 δ体系中在360 K附近还观察到一个相变型内耗峰,它伴随有模量的变化。     

WULI(Physics, Monthly)TOTAL CONTENTS,Vol.ll,No.1-l2,l982

SubieCt Writer No. p.No nIinear Optica and SpeCtro5copy -...............'.......-.....- .-........-.........'...' N. Blotmberyen 7 (385)SpeCtroscopy in a New Light -'.........--.'...-...-......-- ..---.--.--....--.-..-...-.' Arthuf L. SchandoW 9 (5l3)AnowIedge ed Progres.Demonstration of Spinor Character of Spin--1 /2 Nucleus via Magnetic Resonance Method -.....-.-.-...............--..-....--.....-..-..--'-'-- Ye Chaohui, Zhn Xiwen l (l )Microwave Parameters for PoIycrystaIline F…     

Isotope (δ13C, δ15N, δ2H) diet–tissue discrimination in African grey parrot Psittacus erithacus: implications for forensic studies

Diet–tissue isotopic relationships established under controlled conditions are informative for determining the dietary sources and geographic provenance of organisms. We analysed δ¹³C, δ¹⁵N, and non-exchangeable δ²H values of captive African grey parrot Psittacus erithacus feathers grown on a fixed mixed-diet and borehole water. Diet–feather Δ¹³C and Δ¹⁵N discrimination values were +3.8?±?0.3?‰ and +6.3?±?0.7?‰ respectively; significantly greater than expected. Non-exchangeable δ²H feather values (?62.4?±?6.4?‰) were more negative than water (?26.1?±?2.5?‰) offered during feather growth. There was no positive relationship between the δ¹³C and δ¹⁵N values of the samples along each feather with the associated samples of food offered, or the feather non-exchangeable hydrogen isotope values with δ²H values of water, emphasising the complex processes involved in carbohydrate, protein, and income water routing to feather growth. Understanding the isotopic relationship between diet and feathers may provide greater clarity in the use of stable isotopes in feathers as a tool in determining origins of captive and wild-caught African grey parrots, a species that is widespread in aviculture and faces significant threats to wild populations. We suggest that these isotopic results, determined even in controlled laboratory conditions, be used with caution.     

Wild Rabbit Host and Some Parasites Show Trophic-Level Relationships for δ(13)C and δ(15)N: A First Report

Abstract We report the first isotopic study of an animal host-parasite system. Parasitic, intestinal nematodes, Graphidium strigosum and Passalurus ambiguus, were (15)N-enriched relative to their host, the European rabbit Oryctolagus cuniculus, while parasitic cestodes, Cittataenia denticulata and Mosgovoyia pectinata, were (15)N-depleted, suggesting different trophic relationships. Host embryos were more similar in their δ(13)C and δ(15)N values to maternal muscle than were any of the parasites. Coprophagy, the direct recycling of food by the rabbit eating its own faeces, did not lead to isotopic differences between stomach contents and faeces, suggesting that the major point for isotopic discrimination in lagomorph nitrogen metabolism is in the animal rather than in the gut. We conclude that bulk δ(13)C and δ(15)N can reveal valuable new information about host-parasite relationships, and these could be explored further at the biochemical level using compound-specific isotopic analyses.     

In memory of A.M. Dykhne (October 27, 1933–January 6, 2005)

Chronicle

In memory of A.M. Dykhne (October 27, 1933–January 6, 2005)     

In memory of V.A. Robsman (March 18, 1937–January 9, 2005)

Chronicle

In memory of V.A. Robsman (March 18, 1937–January 9, 2005)     

Synthesis of monolayers and bilayers of cobalt oxyhydrates (Na,K) x (H2O) y CoO2− δ

Potassium sodium cobalt oxyhydrates (Na,K)_x(H₂O)_yCoO_{2? δ} were synthesized from γ-Na_0.7CoO₂ by using aqueous KMnO₄ solution in a one-pot process. Chemical and structural analyses revealed that a partial or even almost complete replacement of K⁺ for Na⁺ in the alkaline layers occurs. Direct formation of the c ≈ 13.9 Å phase is apparently associated with the larger size of K⁺ (～1.4 Å) as compared to Na⁺ (～1.0 Å). Formation of (Na,K) _x (H₂O) _y CoO_{2? δ} not only involves de-intercalation, oxidation and hydration processes, but also an ion exchange reaction. Based on a systematic study, the phase formation of (Na,K) _x (H₂O) _y CoO_{2? δ} with c ≈ 19.6 Å is a slow process, particularly when using aqueous KMnO₄ solution with low molar ratio of KMnO₄/Na. When comparing the Co K-edge X-ray absorption spectra of (Na,K) _x (H₂O) _y CoO_{2? δ} with those of Na _x (H₂O) _y CoO₂ obtained from Br₂/CH₃CN solution, the edge energy of the main peak of the bilayered hydrate is found to be 3.5 eV higher than that of the monolayered hydrate for (Na,K) _x (H₂O) _y CoO_{2? δ}. In contrast, the edge energy of the main peak of the bilayered hydrate is 0.4 eV lower than that of the monolayered hydrate for Na _x (H₂O) _y CoO₂. In addition, the hydration behavior of monolayered of (Na,K) _x (H₂O) _y CoO_{2? δ} is different from that of Na _x (H₂O) _y CoO₂. These results seem to suggest that they are two different systems.     

In memory of L.M. Brekhovskikh (May 6, 1917–January 15, 2005)

Chronicle

In memory of L.M. Brekhovskikh (May 6, 1917–January 15, 2005)