The Student News Site of University of Arizona

The Daily Wildcat

Tucson, AZ

The Daily Wildcat

The Daily Wildcat


    This Week in Science Aug. 25

    The reproductive hormone testosterone and stress hormone cortisol have been found to encourage and reinforce unethical behavior.

    According to researchers at Harvard University and the University of Texas at Austin, increased levels of testosterone decrease the fear of punishment and heighten the valuation of reward. Simultaneously, increased cortisol creates a state of debilitating and uncomfortable stress that acts as incentive to behave unethically.

    The study published in the Journal of Experimental Psychology asked 117 participants to perform a math test, and then to self-grade and self-report their number of correct answers. The more problems the participant answered correctly, the more money they would earn.

    The researchers collected saliva samples before and after the test. They found that participants with high levels of testosterone and cortisol were more likely to overstate the number of problems solved correctly.

    Participants who cheated had lower cortisol levels on the day of the experiment and reported less emotional distress after the test. The results seem to indicate that cheating provided stress reduction. Dishonorable behavior is reinforced because stress reduction stimulates the brain’s reward centers.

    Cheating is a prominent issue not only on college campuses, but also in businesses and agencies everywhere. Researchers are hopeful that further research can help to create effective interventions for unethical behavior.


    By recalculating the dates at which melting glaciers exposed boulders during the end of the last Ice Age, researchers have found that increasing levels of carbon dioxide and other greenhouse gases caused the disappearance of glaciers.

    Due to the Industrial Revolution and human impact, current CO2 levels are substantially higher than they were during the end of the last Ice Age almost 19,000 years ago. Then, atmospheric CO2  levels increased from 180 parts per million to 280 parts per million.

    The levels have risen from 280 to about 400 parts per million in just the past 150 years.

    The findings confirm the prediction that the world’s glaciers will continue to disappear within the next few centuries if greenhouse gases continue to increase at the current rate. Future glacial loss will contribute to rising sea levels and influence local water supplies.

    Researchers noted that glacial melting on a regional scale could also be caused by changes in the Earth’s orbit around the sun, or shifts in ocean heat distribution. However, only the change in greenhouse gas levels could cause a simultaneous global retreat of glaciers.


    Inspired by nature, researchers have created an ultrasound sensor that can detect dangerous cracks in structures like aircraft engines, oil and gas pipelines and nuclear plants.

    The ultrasound sensor, or transducer, identifies structural defects by emitting ultrasonic frequencies. Before, man-made transducers could only send out a narrow range of frequencies, thus restricting their ability to find defects in structures that were of a more varied size or geometry.

    The newly developed transducer is founded upon a natural mathematical phenomenon called fractals. Fractals are irregular shapes that form repeatedly to create complex-looking objects like ferns, snowflakes or cauliflower.

    By using fractals to design the transducers, complicated sound waves with different frequencies can be sent out to improve safety of structures and to lower financial costs due to early detection of structural defects and less need for inspection.

    Follow Kimberlie Wang on Twitter

    More to Discover
    Activate Search