The effect of K+, Ca2+, and Mg2+ on sperm motility in the perch,Perca fluviatilis

This study investigated the effect of 0.25–5 mM K⁺, Ca²⁺, and Mg²⁺ on sperm motility in the perch, Perca fluviatilis. In 75 mM NaCl, the used motility-activating solution, motility rate, and swimming velocity decreased within the first 4 min after activation, and the rate of locally motile sperm increased. Thereafter, the motility parameters remained constant for periods >20 min. Based on the decrease in sperm motility, two types of semen samples could be distinguished. Semen samples of type I retained a high motility rate of >65 % after 20 min, and the rate of locally motile sperm was <20 %. In semen samples of type II, the motility rate decreased to values <30 % after 20 min, and the rate of locally motile sperm exceeded >50 %. Ca²⁺ and Mg²⁺ concentrations of 0.25–0.5 mM had no effect on the sperm motility parameters 10 s after activation, while 0.25 mM K⁺ increased the swimming velocity. K⁺, Ca²⁺, and Mg²⁺ concentrations ≥1.5 mM had suppressive effects on the sperm motility 10 s after activation. No differences were found between the two semen types. Twenty minutes after activation, type I semen was not affected by the tested cations. On the contrary, 0.25–2.5 mM K⁺, 0.25 mM Mg²⁺, and 0.25–2.5 mM Ca²⁺ significantly increased the sperm motility rate and/or sperm velocity of type II semen. Therefore, supplementation of saline solution with cations might stabilize the motility of perch sperm, which can be a benefit for experimental purposes and for specific handling procedures in aquaculture.     

Die gegenwärtige Situation der biologischen Schädlingsbekämpfung in Deutschland

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Die gegenwärtige Situation der biologischen Schädlingsbekämpfung in Deutschland

Zusammenfassung Vor drei Jahren setzten in der Bundesrepublik Deutschland amtliche Bestrebungen ein, die schwierigen Aufgaben der biologischen Schädlingsbekämpfung zu sichten und die vordringlichsten von ihnen einer Lösung zuzuführen. Die Schriftleitung erachtete es für notwendig, einen Überblick über die Aufgaben und den Stand der Arbeiten zu vermitteln, und hat daher den Verfasser um einen Bericht über die in der Bundesrepublik laufenden Untersuchungen. In seiner Eigenschaft als deutscher Fachvertreter und zugleich Vizepräsident der internationalen Kommission für biologische Bekämpfung (CILB) ist Herr Regierungsrat Dr. J. Franz unserem Wunsche nachgekommen, in kurzen Zügen auch auf die internationalen Beziehungen und Zusammenarbeit einzugehen.     

Conventional and alternative housing systems for poultry--point of view of infectious disease medicine

The use of conventional battery cages for hens will be prohibited in Germany in 2007. Only few studies, however, have considered the differences between battery cages and alternative systems with regard to infectious diseases. The existing gaps in the current knowledge need to be closed by research and measures must be developed that will prevent the spread of viral, bacterial, and parasitic infections in alternative poultry housing systems.With regard to virus infections, avian influenza requires particular attention. Since wild birds, particularly anseriformes, represent a reservoir for avian influenza viruses, free-ranging poultry is much more at risk of infection than birds in closed hen-houses. Appropriate measures must prevent direct contact with wild birds and transmission via contaminated water, feed, or equipment. Several bacterial infections of poultry represent zoonoses. Salmonella and Campylobacter are considered as particularly important. To avoid a potential increase in the risk of infection for consumers due to poultry keeping systems that might favour infections with bacterial zoonotic agents, there is a special need for research in this area. With regard to parasitic infections, coccidioses may cause problems in alternative poultry housing systems, and lead to considerable economic consequences. The epidemiological situation concerning infections with Histomonas meleagridis needs to be analysed. Since all compounds that had been used for prophylactic or therapeutic purposes in the past have been banned, there is a need to develop new drugs which are safe for animals and humans.     

Oesophagogastroduodenoscopy in swine--technique, methods, indications

The aim of this study was to investigate in 20 healthy pigs the practicability of the oesophagogastroduodenoscopic examination technique in regard to equipment, method of examination, indications and its suitability as a diagnostical tool for the assessment of the oesophagus, stomach and upper duodenum in one procedure. Preparation of the patient for endoscopy, the procedure of the endoscopic examination as well as the topographical findings of the upper intestinal tract including the duodenum until the flexura duodenojejunalis are described. Flexible oesophagogastroduodenoscopy is a suitable method for the observation and natural visualisation of mucosal surfaces and for the digital documentation of peristaltic movements. The procedure is easy to perform in anaesthetized animals, is in most cases completed within 15 min, and can be repeated in the same animal. Indications of this interesting diagnostic imaging technique are discussed.     

Prüfung der Auswirkungen von Pflanzenschutzmitteln auf Nutzarthropoden und deren Einbeziehung in die Zulassung

Tests of side-effects of pesticide on beneficial arthropods and their incorporation into registrationSimulated by the expences of integrated plant protection and based on the plant protection law of the Federal Republic of Germany, a German working group (directed by the Biologische Bundesansalt) since 1970 and an International (WPRS) Working Group since 1974 intiated a systematic study of side-effects of pesticides on beneficial (entomophagous) arthropods. The present status of this work is being reported which intends to obtain guide-lines for tests following standardized principles, which will allow, at first ona voluntary basis, acceptance os a test complementary to the protocol for registration as presently applied. This was officially started in the Fed, Rep. of Germany on October 1, 1975, covering, at first, 3 common and important species of entomophagous parasites (in the laboratory) and one field test developed for the surveys of the fauna of apple trees. Some details of the test, the evaluation of results, and the contributions of experts from member countries of WPRS/IOBC are reported upon. This complementary test, geared from the beginning at an international cooperation, will lesd in all co-operating countries to an enlarged basis for a correct assessment of the total impact of pesticides as it is needed for an effective applicaton of integrated plant protection.     

Übersicht und Bestimmungstabelle der europäischen nadelholzbewohnenden Siriciden (Hymenoptera,Symphyta)

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