Sexual responses of female canaries at the onset of song stimuli

The salience of a short conspecific song phrase versus a long one or a short heterospecific song phrase was tested in females of the common domesticated canary (Serinus canaria). All phrases were computer-edited. The copulation solicitation displays (CSD) served as an index of female responses. The results support the hypothesis that female canaries are able at the onset of a song phrase stimulus: 1) to respond to a conspecific one by displaying high levels of CSD and 2) to discriminate a conspecific from a heterospecific one. Proximal explanations examine the link between perceptual processes and phonology in the canary. Functional explanations investigate the relations between female responsiveness and the process of pair formation.     

Female canaries display to songs of early isolated males

We tested the sexual responsiveness of female canaries,Serinus canaria, to two sets of different types of male conspecific songs. In each set, three of the male songs had been recorded in a young bird which was isolated at an early age from conspecifics. Each bird was recorded during three stages of the song ontogeny (early plastic songs, late plastic songs and crystallized songs). We used copulation solicitation displays (CSD) as an index of female sexual response. Playbacks were performed during a period of natural sexual responsiveness of the females to song. We demonstrated that, in both experiments, very weak sexual displays of female canaries were recorded to the two stages of isolate plastic songs. Each of the two different types of isolate crystallized songs elicited high levels of CSD. These levels are not significantly different from the adult domesticated control song. Taken together, these results suggest that even isolate songs may convey sexual information. We discuss prominent acoustic features that must be present to ensure female sexual responses.     

Exogenous melatonin accelerates re-entrainment: Attenuation of the circadian rhythm of metabolic rate in the canary,Serinus canaria

Administration of melatonin in the drinking water (200 g/ml in 1% ethanol) decreased the time of re-entrainment of the circadian rhythm of the metabolic rate (measured as oxygen uptake) of domestic canaries (Serinus canaria) after 10-h delay phase shifts of the light-dark (LD) cycle by 1.3 days on average. Associated with faster re-entrainment, the amplitude of the metabolic rhythm was attenuated by 46% on, average on the first day after the shift as compared with about 25% in the controls. After re-entrainment, the amplitude of the metabolic rhythm during melatonin administration was about 23% lower than in the controls. The minimum resting metabolic rate increased by ca 5% on average during treatment with melatonin. The results are consistent with the hypothesis that constant high plasma levels of melatonin act on higher levels of the circadian oscillatory system rather than by directly affecting peripheral or central photoreceptors.     

Weighted Empirical Likelihood Estimator for Vector Multiplicative Error Model

The vector multiplicative error model (vector MEM) is capable of analyzing and forecasting multidimensional non‐negative valued processes. Usually its parameters are estimated by generalized method of moments (GMM) and maximum likelihood (ML) methods. However, the estimations could be heavily affected by outliers. To overcome this problem, in this paper an alternative approach, the weighted empirical likelihood (WEL) method, is proposed. This method uses moment conditions as constraints and the outliers are detected automatically by performing a k‐means clustering on Oja depth values of innovations. The performance of WEL is evaluated against those of GMM and ML methods through extensive simulations, in which three different kinds of additive outliers are considered. Moreover, the robustness of WEL is demonstrated by comparing the volatility forecasts of the three methods on 10‐minute returns of the S&P 500 index. The results from both the simulations and the S&P 500 volatility forecasts have shown preferences in using the WEL method. Copyright © 2012 John Wiley & Sons, Ltd.     

Potentiation of the biological activities of daunomycin and adriamycin by ascorbic acid and dimethylsulfoxide

Summary L-Ascorbic acid (0.57 mM) and dimethylsulfoxide (14.1 mM) were found to potentiate four times the antibacterial activities of daunomycin and adriamycin in theStaphylococcus aureus test. This effect, however, could not be demonstrated against eukaryotic cells and leukemia P388 in mice. The authors thank Dr A. Maráz, Department of Microbiology, J.A. University, Szeged, and Dr Zs. Somfai, Institute of Oncology, Budapest, for collaboration in the experiments with yeast and tumor cells.     

Free amino acid composition of the intestinal contents,intestinal cells and hemolymph ofPhilosamia cynthia larvae

Summary Free amino acid composition of the intestinal contents, intestinal cells and hemolymph has been determined in larvae of the mothPhilosamia cynthia. From the hemolymph/lumen concentration ratio, an active transport could be inferred for neutral and basic amino acids. The values of cell/lumen and hemolymph/cell ratios suggested that the active step in the transport mechanism could be localized at the luminal pole of the enterocyte for neutral amino acids (except aromatic amino acids) and at the basolateral pole of the enterocyte for basic amino acids (except arginine).This work was supported by grants from Italian Consiglio Nazionale delle Ricerche and from Ministero della Pubblica Istruzione, Rome. The authors are indebted to Prof. V. Capraro for helpful discussion.     

Folic acid and the inhibition of brain L-glutamic decarboxylase

Summary Folic acid competitively inhibited brainl-glutamic decarboxylase (K _i=1.62×10^–3 M). This inhibition could possibly be associated with epilepsy.This work was supported by the United Parkinson Foundation.     

Mechanism of neurogenesis in adult avian brain

Summary Adult neurogenesis in birds offers unique opportunities to study basic questions addressing the birth, migration and differentiation of neurons. Neurons in adult canaries originate from discrete proliferative regions on the walls of the lateral ventricles. They migrate away from their site of birth, initially at high rates, along the processes of radial cells. The rates of dispersal diminish as the young neurons invade regions devoid of radial fibers, probably under the guidance of other cues. The discrete sites of birth in the ventricular zone generate neurons that end up differentiating throughout the telencephelon. New neurons may become interneurons or projection neurons; the latter connect two song control nuclei between neostriatum and archistriatum. Radial cells, that in mammals disappear as neurogenesis comes to an end, persist in the adult avian brain. The presence of radial cells may be key to adult neurogenesis. Not only do they serve as guides for initial dispersal, they also divide and may be the progenitors of new neurons.     

Repressible alkaline phosphotase inAspergillus niger

Summary ALP fromA. niger is a) P_i repressible enzyme; b) stimulated by addition of Zn⁺⁺ to the growth medium, and c) that EDTA inhibits the enzyme reversibly, which could be restored by addition of Zn⁺⁺ and perhaps Mg⁺⁺. This property is in contrast to the enzyme fromN. crassa, which is independent of any metal requirement.     

Identification ofTrypanosoma theileri as a contaminant in primary cultures of bovine retina

Summary T. theileri has been isolated from primary cultures of bovine retina and subcultered successfully for 2 passages in sub-confluent cultures. When cultures reached confluency no trypomastigotes or epimastigotes could be detected and attempts to recover trypanosomes from these cultures were unsuccessful. The presence of intracellular forms could not formally be excluded.We wish to thank Dr S. Dershko, Division of Meat Inspection, Health of Animals Branch, Department of Agriculture (Canada) and Intercontinental Packers, Ltd. for their assistance in obtaining the freshest possible specimens. The skillful technical assistance of Mrs J. Graham is also gratefully acknowledged. This investigation was supported by the M. R. C. of Canada.     

Mechanism of neurogenesis in adult avian brain

Adult neurogenesis in birds offers unique opportunities to study basic questions addressing the birth, migration and differentiation of neurons. Neurons in adult canaries originate from discrete proliferative regions on the walls of the lateral ventricles. They migrate away from their site of birth, initially at high rates, along the processes of radical cells. The rates of dispersal diminish as the young neurons invade regions devoid of radial fibers, probably under the guidance of other cues. The discrete sites of birth in the ventricular zone generate neurons that end up differentiating throughout the telencephalon. New neurons may become interneurons or projection neurons; the latter connect two song control nuclei between neostriatum and archistriatum. Radial cells, that in mammals disappear as neurogenesis comes to an end, persist in the adult avian brain. The presence of radial cells may be key to adult neurogenesis. Not only do they serve as guides for initial dispersal, they also divide and may be the progenitors of new neurons.     

The evolutionary history ofDrosophila buzzatii. V. Differential survivorship onOpuntia betweenD. buzzatii andD. serido

Summary Survival time ofDrosophila buzzatii adults on anOpuntia (prickly pear) medium was significantly longer than that of its nearest relativeD. serido. A significant difference was also found betweenD. buzzatii adults from two experimental populations, one of them fed onOpuntia rots for more than two years and another one kept on standardDrosophila medium for the same period of time. These results suggest that adult selection may be taking place in cactiphilicDrosophila in their natural habitats and could be responsible for the niche differentiation betweenD. buzzatii andD. serido.This work has been supported by the Comisión Asesora de investigación Científica y Técnica, Spain, by funds to project 4514/79 awarded to the third author.     

Binding property of rat andLimulus C-reactive proteins (CRP) to mercury

Summary The C-reactive proteins (CRP) from both rat andLimulus were found to bind mercury (Hg) in both in vivo and in vitro conditions. CRP has high-affinity binding sites for Hg as evidenced by the loss of free sulfhydryl groups, arrested mobility in polyacrylamide gel electrophoresis, and the consumption of CRP in the serum after Hg administration. The binding was tight as it could not be inhibited either by the addition of cysteine or EDTA. By using a direct titration method it was shown that binding of Hg to CRP was saturable at a molar ratio of Hg/CRP=13.11. The possibility that CRP may act as a scavenger for Hg is discussed.     

Coaxing bone marrow stromal mesenchymal stem cells towards neuronal differentiation: progress and uncertainties

Multipotent adult stem cells capable of developing into particular neuronal cell types have great potential for autologous cell replacement therapy for central nervous system neurodegenerative disorders and traumatic injury. Bone marrow-derived stromal mesenchymal stem cells (BMSCs) appear to be attractive starting materials. One question is whether BMSCs could be coaxed to differentiate in vitro along neuronal or glial lineages that would aid their functional integration post-transplantation, while reducing the risk of malignant transformation. Recent works suggest that BMSCs could indeed be differentiated in vitro to exhibit some cellular and physiological characteristics of neural cell lineages, but it is not likely to be achievable with simple chemical treatments. We discussed recent findings pertaining to efforts in neuronal differentiation of BMSCs in vitro, and results obtained when these were transplanted in vivo. Received 19 January 2006; received after revision 24 February 2006; accepted 12 April 2006     

Gel-electrophoretic description of European populations ofTerellia virens (Loew) (Diptera,Tephritidae); implications for its use as an agent for the biological control ofCentaurea spp. (Asteraceae) in North America

Allozyme frequencies of 15 enzyme loci, 14 of which were polymorphic, were used to characterize sevenTerellia virens populations originating from three allopatrically distributedCentaurea species. The two populations whose origins were geographically furthest apart, from Israel (onC. iberica) and from Switzerland (onC. vallesiaca), showed relatively high values of genetic distance from the 5 populations sampled in Austria and Hungary (onC. maculosa) (Nei's D>0.07). The latter five displayed a high degree of genetic similarity. No diagnostic (fixed) allelic differences were observed between these three groups ofT. virens populations, but they could be well characterized by significant differences in allelic frequencies at 9 enzyme loci. Independently of this study, the populations from Switzerland (C. vallesiaca) and eastern Austria (C. maculosa) were selected as potential source populations for future introductions into North America for the biological control of introducedC. maculosa andC. diffusa. Based on the observed genetic differences and results from field experiments on the host specificity of these two potential source populations, it is argued that host specificity screening tests should be conducted separately for local (host plant) populations, as such populations might accept a different set of hosts. Biotype mismatch and the risk of spill-overs to native species could thus possibly be reduced.     

De l'emploi d'isotopes radioactifs artificiels,dans le but d'exercer un effet radio-biologique localisé

Summary One of the authors has previously reported on a method which consists in the utilization of an artifical radioactive isotope (Zn⁶³), suspended in a suitably prepared solution ofpectin, for the production oflocalized biological radiation effects.This « macromolecular occlusion » of the radioactive isotope enables one to perform intraperitoneal injections (in cases of cancer of the ovaries with severe metastatic peritoneal extension), evidently also instillations in cavernous organs, and furthermore direct intratumoral injections, without diffusion of the radioactivity outside the treated areas, as shown both by autoradiographs and controls of blood and urine specimens with a Geiger counter.The authors investigated further whether this procedure would also be suitable for obtaining, by means ofintravenous injections, alocalized radiation effect within thelungs, as presumably the radiozinc, held in the large molecules of pectin, could thus be retained in the pulmonary capillaries. Intravenous injections of such a pectin solution containing radiozinc were performed on rabbits, and autoradiographic controls gave evidence of this expected fixation within the lungs.For the purpose of preliminary clinical investigation 40 millicuries of Zn⁶³ suspended in 6 cm³ of a 3 p. c. isotonic pectin solution were injectedintravenously in a female patient with mainly pulmonary metastases of a previously operated hypernephroma. This patient had been also submitted to X-ray therapy. In spite of a poor general condition, the injection was well tolerated. Autoradiographic controls showed quite clearly that the radioactivity remains precisely localized within the pulmonary areas. No radioactivity whatsoever was demonstrated with the counter in the urine eliminated by this patient after the injection, a fact which points to a rather amazing accuracy of the fixation of the radiozinc in the lungs. This first clinical experience seems quite interesting in view of improving the therapeutic possibilities of pathological, especially neoplastic pulmonary conditions.     

Ontogenetische Änderungen im Gehalt an Isoxanthopterin bei verschiedenen Genotypen vonDrosophila melanogaster

Summary The content of isoxanthopterine in different developmental stages and different genotypes ofDrosophila melanogaster has been investigated. In male pupae of the red eyed wild type the isoxanthopterine reaches a high concentration which is maintained during the whole period of imaginal life. It could be shown that the mutantsw (white) andbw (brown) though they are unable to synthesize the red eye pigment do nonetheless accumulate considerable quantities of isoxanthopterine during metamorphosis. This isoxanthopterine, however, disappears gradually from the body ofw andbw during the first 3 days of imaginal life till nothing of it is left in adult flies. The transitory appearance of isoxanthopterine in the two mutants, sets new problems with regard to the pleiotropic effect of thew- andbw-loci in pigment synthesis.     

A simple approach to the toad's (Bufo melanostictus) nerver muscle preparation

Summary A simple and modified dorsal approach method has been made in the toad's (Bufo melanostictus) sciatic gastrocnemius nerve-musle preparation. This method incurs less blood loss, time consumption, nerve damage and visceral spoil compared to conventional ventral approach method.     

Genetic load and effective size of natural populations ofDrosophila melanogaster in Korea

Summary The effect of 750 second chromosomes ofDrosophila melanogaster on viability was studied. 19.3% of them proved letal or semilethal (=drastics) in homozygous condition. Compared to data obtained in previous years at the same sampling site, a significant frequency decrease of drastics during the past decade could be observed. The dynamic processes taking place in the Korean wild populations ofD. melanogaster are discussed.Acknowledgment. This work was supported by a research grant from the Korean Science and Engineering Foundation.