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Abstract  

This pape discusses the use, of stable Cs as an activatable tracer for measuring performance of plant root intrusion barriers for solid waste disposal site cover systems. Experiments conducted at small-scale demonstrate the effectiveness and practicality of the technique and suggest that the methodology has application to a better understanding of plant root ecology.

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Abstract  

Nuclear chemistry is usually associated with great disasters, especially the atomic bomb; this without reflecting that knowledge of nuclear chemistry has also had many benefits in the field of medicine and health. Whereas in technologically advanced countries, nuclear chemistry is considered to be an important part of the syllabus, including topics such as radioactivity with the emphasis in making conscience in the common citizen of the inherent benefits.

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Previously described and alternative methods of the induction of sexual maturation in the European eel were investigated. Weekly administrations of a gonadoliberin agonist (GnRH-A=D-Phe6-GnRH-Ea) did not induce statistically significant effect on the gonads of treated eels in none of the dosages used (0.1 mg and 10 mg/fish). Carp pituitary extract and carp pituitary extract together with a dopamine antagonist caused considerable external changes (increase in eye size) and significant gonadal development in two treatment groups: wild and cultivated stocks. The induction of the ovulation by double amount of CP and gonadoliberin agonist with dopamine antagonist mixture was not successful in a wild stock. Fertilisation of stripped eggs of farm eel was attempted unsuccessfully in, due to low egg quality. An advanced phase of the sexual maturation process could be induced in specimen infected by Anguillicola crassus indicating, that nematode infection is not a limiting factor in the artificial propagation of the European eel.

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Acta Veterinaria Hungarica
Authors: A. Vos, T. Müller, P. Schuster, T. Selhorst, and U. Wenzel

The objective of the study was to examine possible maternally transferred antibodies (maAb) against rabies in raccoon dogs. Ten cubs born from a rabiesimmune animal were bled on days 31, 36, 43, 50, 57 and 64 post partum. The geometric mean titres of the cubs were 1.19, 1.18, 0.45, 0.25, 0.25 and 0.16 IU/ml, respectively. Up to 36 days post partum maAb were detected in all cubs at levels ≥ 0.5 IU/ml and at day 56 post partum all animals had maAb levels < 0.5 IU/ml. Based on the results of this study, it is suggested that vaccine baits should not be distributed before July if the vaccination campaign is aimed at immunizing young raccoon dogs as well.

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The aim of present study was to survey the fatty acid composition and fat content in common carp (Cyprinus carpio L.) fillet captured in five different fish farms located in Hungary. Lipid peroxidation characteristics (conjugated dienes and malondialdehyde levels) were also determined in fish muscle. Data on fatty acid composition of common carp has shown that different methods of rearing and feeding cause significant differences in the proportions of n-6 and n-3 polyunsaturated fatty acids of this fish species. According to present results, it seems that the feeding practice of the last month before capture has determined the fatty acid profile of fillet, therefore the technology of carp nutrition should be divided into two main periods: first a growth and weight gain period; and a second one when the nutritional quality of the fillet composition can be improved.

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Acta Veterinaria Hungarica
Authors: T. Müller, T. Molnár, Éva Szabó, R. Romvári, Cs. Hancz, M. Bercsényi, and P. Horn

Female European eels were kept in artificial seawater for a trial period of 14 weeks. Three fish were injected intra-abdominally with carp pituitary suspension (twice a week) and human chorionic gonadotropin (every 2nd week), with the aim to induce artificial maturation. Three further fish were not treated (control). Fish were not fed during the trial. The treated fish were scanned by computed tomography (CT) every second week (the controls only at the start and at the end of the trial) to follow changes in body composition. Notable decreases were shown in total body pixel number (body volume), total body fat content, total fillet volume and fillet fat content during the experiment. Changes were more pronounced in the treated group than in the control. The abdominal volume strongly increased in the responding fish throughout the trial. The ovary volume increased measurably, while its fat content increased only until the 8th week, after which a decrease was measured. Tissue volumetric estimations of the ovary were also supported by histological results. A so-called volumetric gonadosomatic index (gonad volume/total body volume × 100) was developed for the quantitative characterisation of eel maturation.

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Experiments were carried out on sperm cryopreservation of two European percid fish species, the pikeperch (Sander lucioperca) and the Volga pikeperch (S. volgensis) . Two experiments were conducted on pikeperch sperm. In the first, the effects of three extenders (Glucose, KCl, Sucrose) and two cryoprotectants (dimethyl-sulfoxide: DMSO, methanol: MeOH) were tested on motility and fertilization. In the second, the effects of two dilution ratios (1: 1, 1: 9) and two cryoprotectants (DMSO, MeOH) on hatching were investigated. In the experiment on Volga pikeperch the suitability of using cryopreservation for fertilization was investigated. In the first experiment on pikeperch the highest post-thaw motility (28 ± 21%) and fertilization rate (43 ± 12%) was found with DMSO as cryoprotectant in combination with Glucose extender. In the second, the highest hatch rate (41 ± 22%) was observed with MeOH as cryoprotectant and 1: 1 sperm dilution ratio, however no significant difference was found among the results. In the experiment on Volga pikeperch hatch rates with cryopreserved sperm (60 ± 2%) did not significantly differ from the control (60 ± 6%). Contamination of sperm with urine seems to be a key problem in the success of sperm cryopreservation of these species.

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Acta Archaeologica Academiae Scientiarum Hungaricae
Authors: D. Gáspár, T. Kemenczei, M. Szabó, N. Dávid, R. Müller, and I. Holl
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Fatty acid (FA) composition of the fillet and the intestinal content of dwarf common carp (Cyprinus carpio carpio) living in Lake Hévíz was determined in wintertime collected samples and results were compared to widespread literature data on carp. Fillet FA profile of the thermally adapted (28 °C) Hévíz dwarf carps differed from profiles originated from divergent culture and feeding conditions in the overall level of saturation. Fillet myristic acid proportions largely exceeded all literature data in spite of poor dietary supply. Fillet fatty acid results indicate the effects of thermal adaptation (high saturation level) and the correlative effects of feed components rich in omega-3 fatty acids, with special respect to docosahexaenoic acid. With the application of discriminant factor analysis the Hévíz sample was accurately differentiated from the literature data on carp fillet fatty acid profile, mostly based on C14:0, C18:1 n9, C18:2 n6, C20:1 n9 and C20:4 n6 FAs. In summary, fillet FA profile suggested thermal adaptation, location specificity and the ingestion of algal and bacterial material.

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