Izučavanje morfologije jajnika i citologije jajne ćelije kao osnova za uspostavljanje metoda IVM, IVF i embriotransfera

In three types of domestic animals: cattle, pigs and sheep, morphology of ovary was studied. Results such as differences in shape, size within and between species, number of follicles in maturation, changes in sex cycle, connection of follicles in maturation are presented in figures. By method of aspiration, oocytes were isolated from ovaries and their cytology analyzed as the first step in methods of in vitro maturation (IVM), followed by in vitro fertilization (IVF) and embryo transfer. These methods are wide spread in modern livestock production (cattle, horses) since they have many advantages of which the most important is to obtain more offspring from high quality female heads. Method has disadvantage: potential diminishing of biodiversity, therefore special attention is necessary in order not to endanger biodiversity and still get more offspring with high production abilities and traits. IVM, IVF and embryo transfer represent new approach to selection, fast and with similar effect like in conventional artificial insemination, therefore they should be applied in practice also in our country.Kod tri vrste domaćih životinja: goveda, svinja i ovaca, izučavana je morfologija jajnika. Rezultati: razlika u obliku, veličini inter i intraspecies, broj folikula u zrenju, promene tokom polnog ciklusa, povezanost folikula u zrenju; prikazani su na slikama. Iz jajnika su metodom aspiracije iz jajnika izolovane jajne ćelije i analizirana njihova citologija kao prvi korak u metodi in vitro sazrevanja (IVM), nakon koje slede in vitro oplodnja (IVF) i embriotransfer. Ove metode su široko rasprostranjene u modernom stočarstvu (goveda, konji) jer imaju niz prednosti od kojih je najvažnije dobijanje većeg broja potomaka od kvalitetnih ženskih grla. Metoda ima i nedostatak: moguće smanjenje biodiverziteta, i stoga treba voditi računa da se biodiverzitet ne ugrozi, a da se dobije veći broj potomstva sa visokim proizvodnim osobinama. IVM, IVF i embriotransfer su nov pristup selekciji, brzi, a sa sličnim efektom kao kod klasične veštačke selekcije, i zbog toga bi bilo dobro da nađu primenu i na našim prostorima

A case of excessive lateral vibrations of patrol boat shafting: Failures, analysis and solution

During the endurance trials of three identical patrol boats with "Vee" type main shafting system (3x900 kW each), three (of nine) shaft lines broke. The excessive lateral vibrations of the main shafting (excited by, cardan joints) were recognized as the main cause of the failures, and some corrective measures were proposed. The authors of this paper were engaged a while later to make a thorough vibration measurement of the repaired boats. As the record showed that the improvement was not satisfactory, some additional more effective measures had to be accomplished. The paper discusses the possible additional measures, and identifies the installation of an additional bearing (at the proper location along the shaft line) as the most promising. Such a bearing shifts the first natural frequency out of the working range, and releases the vibrating system of the existing critical. The paper gives the vibration data chronologically (from the first identification of the excessive vibrations to the last measurements, after the installation of the additional bearings), so that the successive steps of the healing action could be followed. Finally, the paper shows that the applied measure did reduce the horizontal (most dangerous) vibrations sufficiently, but also had some negative (unpredictable) effects on the vertical component of the vibrations

STUDY OF THE MORPHOLOGY OF OVARY AND CYTOLOGY OF OOCYTE AS BASIS FOR ESTABLISHING METHODS IVM, IVF AND EMBRYO TRANSFER**

Abstract: In three types of domestic animals: cattle, pigs and sheep, morphology of ovary was studied. Results such as differences in shape, size within and between species, number of follicles in maturation, changes in sex cycle, connection of follicles in maturation are presented in figures. By method of aspiration, oocytes were isolated from ovaries and their cytology analyzed as the first step in methods of in vitro maturation (IVM), followed by in vitro fertilization (IVF) and embryo transfer. These methods are wide spread in modern livestock production (cattle, horses) since they have many advantages of which the most important is to obtain more offspring from high quality female heads. Method has disadvantage: potential diminishing of biodiversity, therefore special attention is necessary in order not to endanger biodiversity and still get more offspring with high production abilities and traits. IVM, IVF and embryo transfer represent new approach to selection, fast and with similar effect like in conventional artificial insemination, therefore they should be applied in practice also in our country. Key words: ovary, follicle, oocyte, in vitro maturation of oocyte (IVM