May 27, 2022 - Podcast

Episode 273 — Birds and heat, and artificial intelligence

In a warming world, heat waves can be outright lethal to animals. However, there are other effects of climate change that don’t kill animals, but that can influence their ability to thrive. Researchers from Indiana University and the University of Tennessee recently teamed up to examine how heat and behavior interact to affect physiology. Most of what we know about such effects from heat comes from aquatic organisms or cold-blooded animals that are dependent on external sources of body heat, says Sara Lipshutz, a former postdoctoral researcher at Indiana University. Heat could also be a real problem for terrestrial birds and mammals, too, especially if it interferes with reproductive behavior and physiology, she says. To better understand how that interference happens as a first step toward managing these problems, Lipshutz and her colleagues exposed zebra finches to a four-hour heat challenge, similar to what wild birds might experience during the afternoon heat on a summer day. Zebra finches were selected for the study because these songbirds experience extreme temperature fluctuations in their native Australia. The team measured heat effects on thermoregulatory behavior and looked specifically at how heat changed gene activity in tissues that are critical to reproduction. This included the testis, which controls fertility, and the part of the brain that regulates singing, which is how male birds attract mates. The researchers found that heat altered the activity of hundreds of genes in the testis but fewer in the brain, suggesting that the brain may be less responsive to extreme temperatures. However, they also found evidence that dopamine-related signaling was affected in the brain, meaning that even cooler hot temperatures may change a bird’s ability to reproduce because they may not be able to sing, or sing well, and without that, they won’t breed, Lipshutz says. Bird populations have been dramatically declining over the past several decades, and male songbirds need to sing to attract a mate. Coupled with previous studies showing that birds sing less during heat, this project reveals potential underlying mechanisms by which heat may contribute to avian population declines.

In other news, experts at IU participated in a nationwide effort to develop artificial intelligence technology that can accurately identify self-reported race through medical images, something a human radiologist cannot accurately do. Prior to this study, there was no evidence that race was visible in medical imaging. IU researchers Saptarshi Purkayastha and John Burns say that regulations should exist for medical imaging artificial intelligence to be trained and validated on diverse datasets, and that vendors should publish performance metrics by diversity – of race, age, sex and other patient characteristics. This study has proven that there is enough race information available in medical imaging to bias artificial intelligence, they say, but it’s unknown if biased artificial intelligence using this information exists. In pursuit of increasing diversity, Burns and Purkayastha are leading IU’s efforts in federated machine learning for medical imaging. Federated learning allows IU to participate in nationwide artificial intelligence training, without sharing images between collaborators. This reduces the HIPAA risk and time while increasing diversity by opening the patient population from Indiana to the entire world.