Researchers

From U of T’s Department of Geology, lead authour Gopalan Srinivasan et. al.

Method

The subjects of the study were tiny zircon crystals found in volcanically produced meteorites (eucrites). The team used an ion microprobe located at the Swedish National Museum to determine the amount of hafnium-128 that had decayed into tungsten-182 and used the known half-life of 9 million years to infer the age of crystallization of the zircon crystals present. These eucrites were collected in Antarctica and are believed to have originated from Vesta, a sizeable asteroid located in the asteroid belt present between the orbits of Jupiter and Mars.

Variables

It is thought that Vesta most likely formed in a method similar to Earth. A rapid heating process, caused by a high amount of radiation present, cooked Vesta and caused it to melt into a core made up of metal and silicates. The missing piece of information was the exact point at which this event occurred.

Findings The team concluded that Vesta was melted down less than 10 million years after the solar system’s formation 4.5 billion years ago. The steady and measurable decay of hafnium allowed the team to pinpoint this date of formation rather accurately–especially considering the length of time involved.

Implications

Knowing when an object such as Vesta formed provides us with another event we can place on the time line of our solar system. As well, it provides further information on how and under what conditions planets and smaller space objects form.

Future Steps

Further study of meteorites from the asteroid belt between Mars and Jupiter could corroborate and expand upon the team’s fi ndings. As a vast majority of asteroids in our solar system are found in this ancient scrap yard of space debris, understanding when and how it formed is an important step in fully describing our solar system’s history.

Source

Science 317 (5836): pages 345–347, July 20, 2007

Researchers

Professor Marla Sokolowski and postdoctoral fellow Ken Dawson-Scully of UTM.

Findings

The team discovered that a single genetic pathway could be manipulated to protect fruit fl ies and locusts from neural damage due to extreme heat stress.

Method A gene responsible for foraging behaviour in fruit fl ies also produces a protein known as PKG. The team increased temperature levels by 5 degrees Celsius per minute starting at close to room temperature (22 degrees).

Results The flies that had higher levels of PKG experienced neural problems at lower temperatures compared to flies with lower levels of PKG. Additional work by Gary Armstrong and Mel Robertson of Queen’s University showed that locusts injected with a PKG inhibitor while under rising heat exhibited quickly increased protection of their neural areas.

Implications A fever is the body’s natural and benefi – cial response to some form of infection. A higher temperature makes it diffi cult for invaders to carry out their work and allows the body’s immune system to take care of the threat. In small children, a long-lasting, severe fever (over 42 degrees Celsius) can sometimes result in brain damage. The PKG pathway exists in other organisms besides fl ies and locusts. It is conceivable that this pathway, or a similar one, may function in much the same way in humans. If this is the case, when a child is undergoing a severe fever and risks neurological damage, inhibitors to reduce the proteins created by the pathway may reduce damage like in the fl ies studied.

Source http://www.news.utoronto.ca/ bin6/070827-3364.asp