Cholesterol Content of Bull Spermatozoa Alters Survival at Ultra-Low Temperatures

Anaerobic heat production and fructolysis of bull spermatozoa at different temperatures.

Bull spermatozoa are regularly preserved in a viable condition at low temperatures, but few experiments have been done on their metabolism at different temperatures. The most systematic examination was that of Blackshaw, Salisbury and van Demark (1957), who reported that the Q10 of aerobic fructolysis was 4-0 between 37 0 and 21 C. and i-6 between 37 and 5 C, for bull semen diluted 1/5 (v/v) wi...

Heat capacity of adsorbed Helium-3 at ultra-low temperatures

SHPM imaging of LiHoF 4 at ultra low temperatures

In the first part of this thesis we describe the functioning principle of the scanning hall probe microscope (SHPM), and we present a summary of the theoretical and experimental knowledge on the dipolar-coupled Ising ferromagnet LiHoF4. In the second chapter we present the experimental setup that allows us to perform SHPM imaging at ultra low temperatures. The main components; microscope head, ...

Study of Bull Spermatozoa

The electron microscope has been used to determine the characteristic dimensions and the distribution of the dry mass in bull spermatozoa. The most important result is that all characteristic data are occurring in logarithmic distributions. Furthermore, no correlation between such parameters as head weight and tail weight or head length and tail length was found. The occurrence in logarithmic d...

Survival of Clostridium difficile spores at low temperatures.

Clostridium difficile's presence has been reported in meat products stored typically at low temperatures. This study evaluated the viability in phosphate buffer saline (PBS) of spores from epidemic C. difficile strain R20291 (4.6 log CFU/ml) and M120 (7.8 log CFU/ml). Viability was assessed during 4 months at -80 °C, -20 °C, 4 °C (refrigeration), and 23 °C (room temperature), and after 10 freez...