Science Friday Folgen

Fully Vaccinated Can Unmask Often, CDC Says As the number of vaccinated Americans continues to rise and evidence mounts that the vaccines may reduce viral transmission in addition to lessening disease severity, the CDC announced Thursday that fully-vaccinated people may be able to go mask-free except in specific crowded indoor situations. The announcement caused celebration in some circles and anxiety in others, with people wondering how the new guidelines fit into their personal risk assessments. Sarah Zhang, staff writer at The Atlantic, joins Ira to talk about the latest news in the pandemic and beyond, including a WHO committee report discussing the early days of the outbreak, the latest on the Colonial gas pipeline shutdown, research into cats’ love of sitting in boxes, and more.   Can An Algorithm Explain Your Knee Pain? In an ideal world, every visit to the doctor would go something like this: You’d explain what brought you in that day, like some unexplained knee pain. Your physician would listen carefully, run some tests, and voila—the cause of the issue would be revealed, and appropriate treatment prescribed. Unfortunately, that’s not always the result. Maybe a doctor doesn’t listen closely to your concerns, or you don’t quite know how to describe your pain. Or, despite feeling certain that something is wrong with your knee, tests turn up nothing. A new algorithm shows promise in reducing these types of frustrating interactions. In a new paper published in Nature, researchers trained an algorithm to identify factors often missed by x-ray technicians and doctors. They suggest it could lead to more satisfying diagnoses for patients of color. Dr. Ziad Obermeyer, associate professor of Health Policy and Management at the University of California, Berkley joins Ira to describe how the algorithm works, and to explain the research being done at the intersection of machine learning and healthcare.   Ever Wonder Why Big Cereal Chunks Are Always On Top? You may not have heard of it, but you’ve probably seen the “brazil nut effect” in action—it’s the name for the phenomenon that brings larger nuts or cereal chunks to the top of a container, leaving tinier portions at the bottom of the mix. But the process by which granular materials mix is weirdly hard to study, because it’s difficult to see what’s going on away from the visible surfaces of a container. In recent work published in the journal Scientific Reports, researchers turn the power of three-dimensional time-lapse x-ray computer tomography onto the problem. By using a series of CT scans on a mixed box of nuts as it sorted itself by size, the researchers were able to capture a movie of the process—finally showing how the large Brazil nuts turn as they are forced up to the top of the mix by smaller peanuts percolating downwards. Parmesh Gajjar, a research associate in the Henry Moseley X-ray Imaging Facility at the University of Manchester, talks with SciFri’s Charles Bergquist about the imaging study, and the importance of size segregation in mixing of materials—with applications from the formation of avalanches to designing drug delivery systems.   This Alaskan Glacier Is Moving 100 Times Faster Than Usual One of the glaciers on Alaska’s Denali mountain has started to “surge.” The Muldrow Glacier is moving 10-100 times faster than usual, which is about three feet per hour. About 1% of glaciers “surge,” which are short periods where glaciers advance quickly. Geologist Chad Hults has been on the glacier to study it during this surge period. He talks about how the glacier’s geometry and hydrology contribute to this surge period.           Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

A Beetle’s Chemical (And Plastic) Romance For many species of beetle, the key to finding a mate is scent: Both females and males give off pheromones that signal their species, their sex, and even their maturity level. How do researchers know? In experiments with dead beetles that have been sprayed with female pheromones, live males reliably attempt to mate with the dead insects. But when one team of researchers based at the Chinese Academy of Sciences in Beijing and Syracuse University in New York tried to investigate whether this was true for the flea beetle Altica flagariae, they got a strange result. Males seemed confused when presented with scented dead beetles, leaving the team wondering if the dead beetles were still exuding their original chemicals. What is a research team to do? They attempted the same experiment, but with 3D-printed replicas. This time, the male beetles seemed clearly attracted to the female scent, the researchers wrote in the journal Chemoecology last month. Producer Christie Taylor talks to Syracuse University biologist Kari Segraves about the intricacies of studying beetle intimacy, and the implications for evolutionary biology. Nature’s Early Warning Signs For A Bad Wildfire Season Last year, California saw a record breaking wildfire season. Nearly 10,000 fires burned over four million acres in the state.  Now, wildfire researcher Craig Clements is investigating natural indicators, like the chamise plant, for clues to predict what this wildfire season might look like. Normally, the wildfire season peaks during the late summer. This year, he’s observed a lower moisture content in these plants, possibly indicating the fire season may begin earlier.  Clements joins SciFri to explain how landscape, temperatures, drought, and atmospheric conditions all play a role in wildfire risk.  Arctic Wildfires Are Burning An Important Carbon Sink California wildfires have made national headlines for the last several years, but important—and large—wildfires have also been burning in the forests above the U.S. Canadian border and near the Arctic circle.  A group of researchers wanted to know how these fires affected the northern forests and how this impacted their ability to store carbon. Their results were recently published in the journal Nature Climate Change. Jonathan Wang, an author on that study, discusses what this might mean for future climate change predictions.  Can Woodchips Help The Gulf Of Mexico’s Dead Zone? In the Gulf of Mexico is an ecological dead zone, caused by algal blooms at the mouth of the Mississippi River. Warmer ocean temperatures provide the perfect conditions for algae to grow out of control, suffocating seagrass beds and killing fish, dolphins, and manatees. Fueling this toxic algae’s growth is nitrogen. The Mississippi river empties into the gulf, and drainage water from farms along it carries fertilizer ingredients—straight into the marine ecosystem.  While farmers have tried using practices to reduce fertilizer runoff, like cover crops, no-till farming and conservation buffers, for decades, the problem has only gotten worse. According to a new paper published in the journal Transactions of the American Society of Agricultural and Biological Engineers, a creative new approach involves denitrifying bioreactors—a system that allows bacteria to help convert nitrate in the water to harmless dinitrogen gas. “It’s a complicated name, but it’s really a very simple idea,” says Laura Christianson, assistant professor of crop sciences at the University of Illinois at Urbana Champaign, and lead author on the study. She talks with SciFri producer Katie Feather about how a simple system involving woodchips in a trench can help keep nitrogen out of drainage water from farms across the midwest. Katie also speaks to Shirley Johnson, a farm-owner from Peoria, Illinois, about why she adopted the bioreactor technology, and what farmers can do to help their downstream neighbors.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Weighing COVID-19 Vaccinations For Teens Federal officials are reporting that the Food and Drug Administration is poised to authorize Pfizer’s COVID-19 vaccine for children ages 12 to 15 by early next week—just as Canada became the first country to do so on Wednesday of this week. Pfizer has said they will seek out emergency authorization for even younger kids by the fall. But as most countries still lag far behind the United States in vaccine access for adults, public health officials are questioning the ethics of prioritizing American teens over adults from other countries. Science writer Maggie Koerth joins Ira with more on the accessibility of COVID-19 vaccines for children, new projections of rapid sea level rise under climate change, and other stories from the week. Is COVID-19 Herd Immunity Even Possible Anymore? Since the start of the pandemic, we’ve equated getting out of this mess with the concept of herd immunity—when a certain percentage of the population is immune to a disease, mostly through vaccination. With COVID-19, experts have said we need somewhere around 70 to 90% of the population to be immunized to meet this goal. Now that all adults in the U.S. are eligible for the vaccine, how far are we from that goal? And what is our trajectory? Some experts now say with variants and vaccine hesitancy, herd immunity may not be possible here in the U.S. Joining Ira to break down this and other coronavirus quandaries is Angela Rasmussen, research scientist at VIDO-InterVac, the University of Saskatchewan’s vaccine research institute in Saskatoon, Saskatchewan. This Computer Won The 2021 American Crossword Puzzle Tournament In 2012, a computer program named Dr. Fill placed 141st out of some 660 entries in that year’s American Crossword Puzzle Tournament, a competition for elite crossword puzzle solvers. This year, the algorithm beat the human competition, completing the final playoff puzzle in just 49 seconds.  The A.I. relies on a collection of different techniques to make sense of a puzzle. Sometimes, a simple fact is needed—who was the First Lady before Eleanor Roosevelt? (Lou Henry Hoover.) More often, however, crossword puzzle solutions rely not just on factual knowledge, but an ability to recognize themes that puzzle constructors have embedded in the crosswords, along with an understanding of puns, homonyms, and word play. (Think: Five letters, “dining table leaves”—SALAD!) The program makes a series of statistical calculations about likely answers, then tries to fit those possibilities into the puzzle squares.  This year, researchers from the Berkeley Natural Language Processing group added their expertise to Dr. Fill’s algorithms—a contribution that may have helped push Dr. Fill to its crowning victory.  But the program isn’t infallible. This year, it made three mistakes solving puzzles during the tournament, while some human solvers completed the puzzles perfectly. It can make these errors with any unique puzzle form it’s never seen before.  Matt Ginsberg, the computer programmer behind Dr. Fill, joins Ira to talk about the competition and the advances his program has made over the years.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.