Overcast tests with clock-shifted pigeons

In order to investigate the pigeon's compass mechanism, a series of overcast tests with clock-shifted birds were run at two familiar release sites. While controls were able to assume a correct homeward direction, the experimental birds' initial orientation cannot be explained either on the basis of a time-compensated sun compass or of a time-independent magnetic compass. Speculative explanations of our paradoxical results are attempted.     

Precipitating immunoenzyme revealed tests on cellulose acetate. Use of ELIEDA (enzyme-linked-immuno-electro-diffusion assay) and ELIDEPA (enzyme-linked-immuno-double-electrophoresis-assay) in parasitology]

Precipitating tests carried out on cellulose acetate membrane were revealed by treating the immune complexes with enzyme linked anti-immunoglobulin antibodies. We insist on the importance of ELIEDA (enzyme-linked-immuno-electro-diffusion-assay) and ELIDEPA (enzyme-linked-immuno-double-electro-phoresis-assay) for the study of antibody classes involved in the immune response.     

Cadmium in foods and the diet

Summary Information on the sources of cadmium in food are presented and the effects of raised environmental levels of cadmium on the concentration of cadmium in plant based foods, fish and shellfish, meat and offals, and dairy produce are discussed. Information is also presented on normal dietary intakes of cadmium and how these intakes may be elevated by environmental pollution or atypical dietary habits. The estimation of dietary intakes of cadmium using data about extreme intakes of specific foods is described.The author wishes to thank the Ministry of Agriculture, Fisheries and Food for permission to publish this paper.     

Interaction of molybdate with copper(II)-histidine

Summary Molybdate and copper(II)-histidine form an insoluble complex of empirical formula Cu₂(His)₃(MoO₄)₂(H₂O)₂. ESR-spectroscopy indicated that the complex had tetragonal symmetry. IR-spectroscopy showed the presence of a carboxylate anion and suggested that the molybdate ion formed an ammonium-type salt with the nitrogens of the imidazole. The complex did not form following dissociation of the protonated imidazole (above a pH of approximately 6).Acknowledgments. Drs C. Tennant, D. McGavin and B. Cleverly, Chemistry Division, D.S.I.R., Petone, for the computer simulated ESR spectrum and for help in interpreting ESR- and IR-spectra; Prof. A. D. Campbell, Department of Chemistry, University of Otago, Dunedin, for C,H,N- and H₂O-microanalyses.     

One-sided Simultaneous Prediction Intervals for AR(1) and MA(1) Processes with Exponential Innovations

This paper is concerned with the determination of simultaneous confidence regions for some types of time series models. We derive recursive formulas which allow the determination of the probability for an AR(1) stationary process based on exponential inputs to lie under any sequence of constants during N steps. Also, probabilities of the same form are derived for an MA(1) process, based on an exponentially distributed white noise. Numerical results are obtained and comparison of prediction regions for different values of ϕ or θ is made. The results show how the use of the correlation structure of the models can reduce the confidence regions area. © 1997 by John Wiley & Sons, Ltd.     

On combined effects of deoxyfluorouridine (FUDR) with radiations and ethyl methane sulphonate (EMS) on chromosomes

Résumé Des graines deNigella damascena et des graines d'orge ont été irradiés par les rayons du Co⁶⁰ ainsi que par des neutrons rapides. Ils ont ensuite été traités par la déoxyfluorouridine (FUDR) après différents temps de prégermination. On a observé que FUDR accroissait de manière nette les effets totaux des rayons sur les chromosomes (taux d'aberrations en anaphase). Par contre les effets des neutrons rapides n'ont été que faiblement modifés. Des effets synergiques ont également été obtenus chez l'orge après des traitements consécutifs FUDREMS.     

Immuno-cyto-adherence tests inXenopus laevis daud

Riassunto Si è studiata la natura delle cellule immunologicamente competenti della milza diX. laevis Daud. Mediante la tecnica della immuno-cito-aderenza, si è potuto constatare che tali cellule estratte da milze di animali immunizzati con globuli rossi di pollo e coniglio, rispondono ad uno solo o ad ambedue gli antigeni, che la percentuale delle cellule che reagiscono sia contro le emazie di coniglio che di pollo è di molto superiore a quella dei mammiferi e che tale percentuale non varia al variare delle dosi di antigene somministrato.     

Paradoxical findings in ouchterlony tests

Zusammenfassung Mit Präzipitationsversuchen im Agargel wird gezeigt, dass Präzipitine ausRicinus communis-oderAbrus precatorius-Samen und die spezifischen Anti-PnXIV-Präzipitine des Pferdeserums mit verschiedenen Seitenästen der Strukturformel von PnXIV-Kapselpolysaccharid reagieren können.     

RNA in planarians (Dugesia lugubris) treated with LSD

Riassunto Se si mantengono Planarie (Dugesia lugubris) per otto giorni in una soluzione di LSD (0,02 mg/ml), si nota un aumento di RNA nella parte cefalica del soggetto rispetto ai corpi e anche rispetto alle teste dei controlli. Anche l'incorporazione di uridina triziata segue lo stesso andamento. Vengono proposte alcune ipotesi.     

Interaction of molybdate with copper(II)-histidine.

Molybdate and copper(II)-histidine form an insoluble complex of empirical formula Cu2(His)3(MoO4)2(H2O)2ESR-spectroscopy indicated that the complex had tetragonal symmetry. IR-spectroscopy showed the presence of a carboxylate anion and suggested that the molybdate ion formed an ammonium-type salt with the nitrogens of the imidazole. The complex did not form following dissociation of the protonated imidazole (above a pH of approximately 6).     

Development of in vitro toxicity tests with cultures of freshly isolated rat hepatocytes

Summary Freshly isolated and cultured hepatocytes were analyzed by two-parameter flow cytometry. The combined analysis of DNA and cellular protein content allowed the contribution of ploidy classes and of subpopulations within a ploidy class to be defined. Analysis of hepatocytes during exposure to dimethylsulfoxide (DMSO), phenobarbital (PB), low oxygen tension (5% O₂) or fetal calf serum (FCS), provided insight into the dynamic response of individual ploidy classes as a function of culture time. By analogy with the age-dependent ploidy shifts in vivo, hepatocyte-cultures shift towards adult animals during exposure to DMSO and towards young animals when cultured at low pO₂ (4% O₂). FCS and phenobarbital disturb this constitutive ploidy balance. FCS increased the 2 N cell population, where stem cells probably respond to the proliferative stimuli provided by growth factors in the serum. Phenobarbital affects the liver-specific 4 N hepatocytes, which agrees with effects seen in liver after exposure in vivo. It is suggested that drug-induced pathological alterations in ploidy in hepatocyte cultures could serve as indicators of compounds, such as liver tumor promoters, which interfere with cell differentiation in liver. The heterotypic cell-cell interaction of freshly isolated hepatocytes with isolated, in vitro cultured, rat liver epithelial cells in co-cultures proved to be a valuable concept in toxicity testing: aldrin epoxidase, an enzyme system involved in xenobiotic metabolism, was stabilized for more than two weeks. After exposure to the three chemicals, 2-acetylaminofluoren, procarbazine and cyproterone-acetate, a preferential toxicity for each compound and cell population was established. Thus heterotypic cell cultures can considerably increase the amount of information available from in vitro studies.The final concept, combining monitoring of cellular DNA (ploidy) and protein content in hepatocyte cultures during and after exposure to a given test compound at tissue oxygen tension with the heterotypic cell-cell interaction, would create a more in vivo-like culture system. This would enhance the predictability of hepatocyte cultures and contribute to a more widespread use of the test system and as a result help to reduce the number of whole-animal tests.     

Development of in vitro toxicity tests with cultures of freshly isolated rat hepatocytes

Freshly isolated and cultured hepatocytes were analyzed by two-parameter flow cytometry. The combined analysis of DNA and cellular protein content allowed the contribution of ploidy classes and of subpopulations within a ploidy class to be defined. Analysis of hepatocytes during exposure to dimethylsulfoxide (DMSO), phenobarbital (PB), low oxygen tension (4% O2) or fetal calf serum (FCS), provided insight into the dynamic response of individual ploidy classes as a function of culture time. By analogy with the age-dependent ploidy shifts in vivo, hepatocyte-cultures shift towards adult animals during exposure to DMSO and towards young animals when cultured at low pO2 (4% O2). FCS and phenobarbital disturb this constitutive ploidy balance. FCS increased the 2 N cell population, where stem cells probably respond to the proliferative stimuli provided by growth factors in the serum. Phenobarbital affects the liver-specific 4 N hepatocytes, which agrees with effects seen in liver after exposure in vivo. It is suggested that drug-induced pathological alterations in ploidy in hepatocyte cultures could serve as indicators of compounds, such as liver tumor promoters, which interfere with cell differentiation in liver. The heterotypic cell-cell interaction of freshly isolated hepatocytes with isolated, in vitro cultured, rat liver epithelial cells in co-cultures proved to be a valuable concept in toxicity testing: aldrin epoxidase, an enzyme system involved in xenobiotic metabolism, was stabilized for more than two weeks. After exposure to the three chemicals, 2-acetylaminofluoren, procarbazine and cyproterone-acetate, a preferential toxicity for each compound and cell population was established. Thus heterotypic cell cultures can considerably increase the amount of information available from in vitro studies. The final concept, combining monitoring of cellular DNA (ploidy) and protein content in hepatocyte cultures during and after exposure to a given test compound at tissue oxygen tension with the heterotypic cell-cell interaction, would create a more in vivo-like culture system. This would enhance the predictability of hepatocyte cultures and contribute to a more widespread use of the test system and as a result help to reduce the number of whole-animal tests.     

聚合质量比对Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19／PAn复合体系微波吸收性能的影响

用原位聚合法制备了Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19铁氧体／聚苯胺（PAn）复合材料。采用X射线衍射（XRD）、扫描电子显微镜（SEM）对样品的结构、微观表面形貌和粒子大小进行了表征,用微波矢量网络分析仪测量样品在2～12．4GHZ频率范围内复介电常数和复磁导率,根据测量数据计算微波反射率R与频率f的关系。研究结果表明：PAn包覆于掺杂锶铁氧体表面,PAn／Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19复合材料具有良好的吸波性能,随着掺杂锶铁氧体含量的增加,微波吸收匹配厚度和吸收带宽发生变化：当Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19聚合质量比为40％时,最佳匹配厚度为2．6mm,吸收峰值接近-40dB,峰值频率高于12．4GHz,大于10dB吸收带宽预计达到55GHz。     

Interaction of N-(DL-seryl)N′-(2,3,4-trihydroxybenzyl)-hydrazine with L-Dopa decarboxylase from pig kidney

Summary Interaction of seryl trihydroxy-benzyl-hydrazine with a highly purified preparation of Dopa decarboxylase from pig kidney has been studied. This compound was found not to be a powerful inhibitor in vitro. Kinetic and spectral data suggest some possibilities on the binding nature of the inhibitor and substrates.