Geological glass discovery could lead to increased knowledge about Mars
When an asteroid or comet collides with Earth, soil and rock melt. Once these materials cool, they can form glass. A research team led by Professor Emeritus of Geological Sciences Peter Schultz recently discovered that such glass can contain preserved plant parts that hold information about life forms and climate at the time of impact, according to a University press release.
The team discovered glass fragments in Argentinian soil, Schultz said in the press release. One piece of glass contained plant parts from an impact 3 million years ago, while the other dated back 9 million years. The findings from this discovery, published online, will be featured in the May edition of the journal Geology.
After finding the glass, the research team tried replicating this type of glass preservation to determine the necessary conditions for the process. They found that plant parts were preserved in glass most successfully when the glass was quickly heated to over 1,500 degrees Celcius, according to the release.
This quick and extreme heating preserves the inside layers of the plant due to the water it holds. "Its a little like deep frying," Schultz said in the release. "The outside fries up quickly, but the inside takes much longer to cook."
The findings also suggest that if the same process of preservation occurred on Mars, glass fragments in Mars' soil could provide information about the planet millions of years ago.
Soil on Mars is similar to that the researchers examined in Argentina, suggesting that areas of Mars may contain similar fragments, according to the release.
"Impact glass may be where the 4 billion-year-old signs of life are hiding," Schultz said in the release.
Medical marijuana legalization does not increase adolescent use
The legalization of medical marijuana does not lead to an increase in use of the substance by adolescents, according to a study published this month in the Journal of Adolescent Health.
The study, led by Esther Choo, assistant professor of emergency medicine at the Alpert Medical School, was conducted due to "raised concerns about increased accessibility and appeal of the drug" resulting from legalization of medical marijuana over the past few years, according to the study.
Choo, along with her fellow researchers, aimed to evaluate these concerns by comparing the rates of adolescent marijuana use in states where medical marijuana has and has not been legalized, according to the study.
The data used in the analysis came from the Youth Risk Behavior Survey between the years 1991 and 2011 and included data from over 11.5 million adolescents.
Through these comparisons, the researchers found no statistically significant increase in the probability of adolescent marijuana use due to medical marijuana legalization.
Researchers examine link between compound presence and high blood pressure during pregnancy
Organochlorines — organic compounds that may be toxic to humans — have been suggested to lead to high blood pressure and related disorders during pregnancy. But this alleged association had not been directly explored until University researchers published a study in the journal Environmental Research earlier this month.
Hypertensive disorders, caused by high blood pressure, can cause harm to both the fetus and the mother.
The study, led by David Savitz, vice president for research and professor of community health and obstetrics and gynecology, evaluated the potential relationship between these disorders and organochlorines, by looking specifically at the impact of the insecticidal organochloride DDE, the chemical PCB and other similar compounds, according to the study.
Organochlorines occur naturally and can be found in some man-made substances, like pesticides.
After examining the records of over 2,000 women, the researchers found the alleged association between these compounds and hypertensive disorders during pregnancy to be false.
They obtained information for the study from the Collaborative Perinatal Project, a U.S. birth cohort study completed during the 1960s.
This finding suggests that similar toxins are also not linked to hypertensive diseases during pregnancy, according to the study.
Source : http://www.browndailyherald.com/2014/04/21/science-research-roundup-april-21-2014/
