“Ahead-of-time” snowmelt triggers chains of events in the Mormon Fritillary butterfly
Early snowmelt caused by climate change in the Colorado Rocky Mountains snowballs into two chains of events: a decrease in the number of flowers, which, in turn, decreases available nectar. The result is decline in a population of the Mormon Fritillary butterfly, Speyeria mormonia.
Using long-term data on date of snowmelt, butterfly population sizes and flower numbers at the Rocky Mountain Biological Laboratory, Carol Boggs, a biologist at Stanford University, and colleagues uncovered multiple effects of early snowmelt on the growth rate of an insect population. (more…)
AUSTIN, TX — Researchers from The University of Texas at Austin’s Department of Chemical Engineering are the first to show that mechanical property changes in cells may be responsible for cancer progression — a discovery that could pave the way for new approaches to predict, treat and prevent cancer.
Postdoctoral student Parag Katira and his adviser, Roger T. Bonnecaze, department chair in the Cockrell School of Engineering and T. Brockett Hudson Professor, worked with Muhammad Zaman of Boston University to devise a 3-D cancer model that shows the softening of cells and changes in cell binding cause cancerous behavior in cells. These mechanical property changes cause cells to divide uncontrollably — making them less likely to die and resulting in malignant tumor growth. The findings present a unique physics-based perspective on understanding cancer progression and were published recently in the American Physical Society’s journal Physical Review Letters. (more…)
The green Voorwerp in the foreground remains illuminated by light emitted up to 70,000 years ago by a quasar in the center of the background galaxy, which has since died out. Image credit: WIYN/William Keel/Anna Manning
While sorting through hundreds of galaxy images as part of the Galaxy Zoo citizen science project two years ago, Dutch schoolteacher and volunteer astronomer Hanny van Arkel stumbled upon a strange-looking object that baffled professional astronomers. Two years later, a team led by Yale University researchers has discovered that the unique object represents a snapshot in time that reveals surprising clues about the life cycle of black holes.
In a new study, the team has confirmed that the unusual object, known as Hanny’s Voorwerp (Hanny’s “object” in Dutch), is a large cloud of glowing gas illuminated by the light from a quasar-an extremely energetic galaxy with a supermassive black hole at its center. The twist, described online in the Astrophysical Journal Letters, is that the quasar lighting up the gas has since burned out almost entirely, even though the light it emitted in the past continues to travel through space, illuminating the gas cloud and producing a sort of “light echo” of the dead quasar. (more…)
