By William Raillant-Clark
Hypertension and smoking’s effect on arterial stiffness
Hypertension and smoking were found to increase arterial stiffness independently of each other, according to research published by Dr. Stella Daskalopoulou and Dr. Robert J. Doonan of the Department of Medicine. These findings are important because the measurement of arterial stiffness is being used as a way to evaluate cardiovascular health and the efficacy of treatment. The stiffening of arteries occurs with age, with the development of chronic conditions and in the presence of risk factors, such as smoking. The condition requires the heart to provide a greater amount of force to pump blood around the body. According to the researchers, future studies are needed “to determine the extent to which smoking cessation therapy combined with the appropriate anti-hypertensive medication can lead to stabilization or even reversal of arterial stiffness.”
One man’s trash is another man’s treasure
Dr. Mihaeila Isac, Dr. Zaid Ghouleh, and Dr. Roderick I.L. Guthrie at the McGill Metals Processing Centre are looking to convert “fly ash,” a hazardous by-product of the incineration of waste, into a stable and safe glass-ceramic material that could be used for industrial, structural or ornamental applications. Fly ash, as its name would suggest, is highly-toxic ash that rises up incinerator chimneys. In the past it has been dumped in landfills or simply allowed to escape, but new environmental regulations require authorities and businesses to find new alternatives.
The researchers produced a material with randomly oriented crystals embedded in its residual amorphous matrix. The crystalline phases were identified as Nepheline and Diopside. Confocal Laser Scanning Microscopy was used for real-time in-situ observation of the microstructure under simulated heat treatment conditions.
Wild electric fish and electrical domination
“Animals often use signals to communicate their dominance status and avoid the costs of combat,” explains Dr. Vincent Fugère of McGill’s Department of Biology. Fugère, fellow McGillian Dr. Rüdiger Krahe and a colleague at the Universidad Nacional Mayor de San Marcos in Peru investigated whether the frequency of the electric organ discharge of the Sternarchorhynchus genus of knifefish signals dominance status. The team found a positive correlation between the body size of the fish and the frequency of its electric discharge. They then performed a competition experiment in which they found that higher frequency individuals were dominant over lower frequency ones. An electrical playback experiment showed that subjects more readily approached and attacked stimulus electrodes when they played low-frequency signals than high-frequency ones. These results have led the team to propose that electric organ discharge frequency does indeed communicate dominance status in this species.