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The dog days are over ... almost

August 8, 2019

Sirius heads to the doghouse and we get ready for fall with a research roundup

Editor's note: Aug. 11 marks the end of "the dog days of summer," the most sweltering days of the year. (For those of us in the Northern Hemisphere, anyway.) Over the past several weeks, ASU Now talked to experts from around the university about everything dog, from stars to language to man's best friend. 

We made it! 

The dog days of summer are coming to a close — astronomically speaking, that is. You probably can still bake cookies on your dashboard in Arizona.

With fall semester just around the corner and and temperatures (hopefully) about to start dropping, ASU Now is celebrating the end of the dog days with a look at all the best pup-related stories of the past year. 

ASU prof pinpoints optimal age of puppy cuteness

All dogs are cute (at least we think so), but is there a point where they're most adorable? Clive Wynne, director of ASU’s Canine Science Collaboratory, says yes — and his findings provide insight into the depth and origin of the relationship between humans and dogs, the oldest and most enduring of any human-animal relationship.

Robotic guide dog leads ASU team to 1st prize at Intel Cup

According to Guide Dogs of America, a 16- to 18-month-old puppy will go through four to six months of training before it can become a guide dog. And that doesn’t consider the financial costs of training. A team of students and faculty from the Ira A. Fulton Schools of Engineering, along with visiting scholars, have developed a high-tech alternative that won a first-prize award at the 2018 Intel Cup in Shanghai.

More than a label: Shelter dog genotyping reveals inaccuracy of breed assignments

Dog breed assignments at animal shelters are often used to infer how the dogs might behave and can impact the length of time a dog waits to be adopted. The first step to understanding how breed labels might affect shelter dogs is to identify who shelter dogs actually are, and researchers in the Arizona State University Department of Psychology have done just that. 

Sleepovers reduce stress in shelter dogs

Foster care provides valuable information about dog behavior that can help homeless dogs living in shelters find forever homes. The Arizona State University Canine Science Collaboratory found short-term fostering benefitted shelter dogs in Arizona, Utah, Texas, Montana and Georgia. Stress hormone levels were reduced during one- and two-night sleepovers, and dogs also rested more during and immediately following a sleepover.

World’s largest canine cancer vaccine trial begins

Meet Trilly: The black-and-tan, floppy-eared, 9-year-old Gordon setter may have made medical history by receiving a shot that may also contain the very first vaccine intended to prevent cancer. Trilly is one of 800 dogs participating in ASU Professor Stephen Johnston's Vaccination Against Canine Cancer study.

Thought Huddle podcast: A love like no other

It doesn’t take special insight to recognize dog owners love their dogs. A lot. But the latest episode of ASU Now’s Thought Huddle podcast series digs deeper in an effort to unearth the origin of dogs, explore the purpose of dogs and assess what makes dogs special. 

MORE DOG DAYS OF SUMMER STORIES

ASU researchers study largest impact crater in the US, buried for 35 million years


August 8, 2019

About 35 million years ago, an asteroid hit the ocean off the East Coast of North America. Its impact formed a 25-mile diameter crater that now lies buried beneath the Chesapeake Bay, an estuary in Virginia and Maryland. From this impact, the nearby area experienced fires, earthquakes, falling molten glass droplets, an air blast and a devastating tsunami.

While the resulting “Chesapeake Bay impact crater” is now completely buried, it was discovered in the early 1990s by scientific drilling. It now ranks as the largest known impact crater in the U.S., and the 15th largest on Earth.  An asteroid struck the East Coast of North America 35 million years ago. Ejected material from the impact site was distributed over an area of at least four million square miles. Researchers have found clear traces of the impact and dated them for the first time using the uranium-thorium-helium technique. ODP 1073 on the map refers to the ocean drilling project site where the sample material for this study was collected. Credit: GEBCO world map 2014, www.gebco.net Download Full Image

When the asteroid hit, it also produced an impact ejecta layer, which includes tektites (natural glass formed from debris during meteorite impacts) and shocked zircon crystals which were thrown out of the impact area. Scientists refer to this layer as the “North American tektite strewn field," which covers a region of roughly 4 million square miles, about 10 times the size of Texas. Some ejecta landed on land while the rest immediately cooled on contact with seawater and then sank to the ocean floor.

A team of researchers, including Arizona State University School of Earth and Space Exploration scientist and lead author Marc Biren, along with co-authors Jo-Anne Wartho, Matthijs Van Soest and Kip Hodges, has obtained drilling samples from the Ocean Drilling Project site 1073 and dated them with the “uranium-thorium-helium technique” for the first time.

Their research was recently published in the international journal Meteoritics & Planetary Science.

“Determining accurate and precise ages of impact events is vital in our understanding of the Earth's history,” Biren said. “In recent years, for example, the scientific community has realized the importance of impact events on Earth’s geological and biological history, including the 65 million years old dinosaur mass extinction event that is linked to the large Chicxulub impact crater.”

The team studied zircon crystals in particular because they preserve evidence of shock metamorphism, which is caused by shock pressures and high temperatures associated with impact events. The dated crystals were tiny, about the thickness of a human hair.

“Key to our investigation were zircon — or to be more precise: zirconium silicate — crystals that we found in the oceanic sediments of a borehole, which is located almost 400 kilometers (250 miles) northeast of the impact site, in the Atlantic Ocean,” says co-author Wartho, who began the study when she was a lab manager at the Mass Spectrometry Lab at ASU.

For this study, Biren worked with co-authors Wartho (now working at GEOMAR Helmholtz Centre for Ocean Research Kiel), Van Soest and Hodges to prepare samples for analysis and to date zircon crystals with the uranium-thorium-helium dating method. Biren then identified and processed shocked zircon fragments for imaging and chemical analysis with an electron microprobe.

“This research adds a tool for investigators dating terrestrial impact structures,” Biren said. “Our results demonstrate the uranium-thorium-helium dating method’s viability for use in similar cases, where shocked materials were ejected away from the crater and then allowed to cool quickly, especially in cases where the sample size is small.”

Karin Valentine

Media Relations & Marketing manager, School of Earth and Space Exploration

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