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The Effects Of Different Gases On Excystation Of Coccidian Oocysts, James B. Jensen
The Effects Of Different Gases On Excystation Of Coccidian Oocysts, James B. Jensen
Theses and Dissertations
Excystation of coccidian oocysts is a diphasic process where CO2 and suitable reducing agents cause changes in oocyst wall permeability (phase I) allowing the entrance of trypsin and bile which activate the sporozoites (phase II). This project was an indirect study of the mechanism of CO2 action by the substitution of NO, NO2, N2O, H2S, SO2 , CH4, NH3 and 8M urea in place of CO2. Changes in oocyst wall permeability of Eimeria stiedae, E. bovis and E. tenella were determined by incubation with the reagents and cysteine HCl followed by treatment with trypsin and bile to initiate activation of …
The Effects Of Temperatures And Chemicals On The Oocysts Of Eimeria Stiedae, Charles Larry Keehner
The Effects Of Temperatures And Chemicals On The Oocysts Of Eimeria Stiedae, Charles Larry Keehner
Theses and Dissertations
A study was made of the effects of temperatures and chemicals on the unsporulated and sporulated oocysts of Eimeria stiedae. In general, oocysts were affected by temperatures lower than -10 C and above +39 C, while normal development occurred between these temperatures. Unsporulated oocysts were more tolerant to temperature extremes, as they survived up to 8 days at 39 C and 12 days at -28 C. Sporulated oocysts were killed after 24 hours storage at 39 C and 4 days at -28 C. Oocyst resistance to low temperatures was not improved if unsporulated and sporulated oocysts were conditioned before and …
The Reproductive Biology Of The Leech Helobdella Stagnalis (Linnaeus) In Utah Lake, David L. Tillman
The Reproductive Biology Of The Leech Helobdella Stagnalis (Linnaeus) In Utah Lake, David L. Tillman
Theses and Dissertations
The reproductive biology of the brooding leech Helobdella stagnalis (Linnaeus) in Utah Lake was studied for an 18 month period from June 1970 to December 1971. In determining the annual reproductive cycle, the number of adult leeches carrying eggs or young were counted at weekly intervals during the reproductive season and monthly during the rest of the year. Gonadal staging data from histological sections were correlated with the field collection data. It was found that two broods of young were produced by the adult animals during the reproductive season. Continuous water temperatures were recorded at the study site throughout the …