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SPONSORED BY  | | | | June 10, 2024: A misunderstood kind of insomnia, how whiteflies became so prolific, and spongy moth caterpillars are eating their way through U.S forests. —Andrea Gawrylewski, Chief Newsletter Editor | | | Lymantria dispar caterpillar. This is the larva of the Spongy Moth, an invasive species in America. Antje Schulte - Insects/Alamy Stock Photo | | | • Millions of very hungry spongy moth caterpillars are munching their way through U.S. forests, enabled by drought. | 5 min read | | | • High blood pressure affects men and women differently. It may be time to have separate guidelines for healthy blood pressure. | 6 min read | | | • Researchers are developing AI tools that can quickly detect and debunk false or misleading claims about climate change. | 4 min read | | | People with so-called subjective insomnia (also called paradoxical insomnia) report that they've been awake all night, even when the polysomnography, the gold standard for sleep measurement, says they've been asleep. Now, scientists have taken more extensive measurements of the condition and found that this type of insomnia involves spurts of arousal–fast brain waves–during rapid eye movement (REM) sleep. The typical "quiescent" state of REM (immersive dream state) dissolves emotional distress that has accumulated throughout the daytime. People who experience interrupted REM never reach a deep state of REM and report poor sleep (though technically they have been sleeping).
Why this matters: Interrupted REM is strongly linked to disorders such as post-traumatic stress disorder (PTSD) and anxiety. If two people experience the same level of trauma, a good sleeper is probably less likely to develop PTSD than someone with disturbed sleep. And those with disturbed sleep are therefore more vulnerable to developing PTSD–a vicious cycle.
What the experts say: "Sound REM sleep is the only state during which the brain has a 'time-out' of noradrenaline [norepinephrine]," which is a stress hormone, says Eus van Someren, a sleep scientist at the Netherlands Institute for Neuroscience. "The neurons are not firing anymore, so they don't release noradrenaline downstream in the brain." | | | Sap-eating whiteflies wreak havoc on the nearly 500 plant species they feed on by spreading plant viruses and leaving mold-attracting goop on everything they touch. Researchers have discovered that a secret to the flies' success might be a genetic advantage: Millions of years ago, whiteflies incorporated two nitrogen-recycling genes, likely from bacteria, into their own DNA.
How it works: A virus likely transferred the nitrogen-recycling genes from bacteria into whiteflies, in a process called horizontal gene transfer. The genes enable the flies to convert amino acids into waste if they have too much nitrogen in their blood, OR to recycle that waste back into amino acids if they need more nitrogen. Plants hold a wide variety of amino acids, so whiteflies are uniquely suited to thrive on many plant varieties thanks to their nitrogen management.
What the experts say: The transferred genes have served the flies well, but could end up being their Achilles' heel, says Ted Turlings, a chemical ecologist at Switzerland's University of Neuch├вtel. Modifying plants to disrupt the flies' genes could be an effective form of targeting whitefly-control, without harming other organisms. | | | A CUSTOM PUBLICATION SPONSORED BY DAVOS ALZHEIMER'S COLLABORATIVE | The Heartbreak and Hazards of Alzheimer's Caregiving | Most caregivers of people with Alzheimer's find themselves behaving in ways they know are counterproductive. The disease affects their brains, too. Read More | | | • Numerous studies of news coverage of protests--including both left-wing and right-wing protests--show that journalists follow an uninformative template of ignoring the actual issues of the protest, writes Douglas M. McLeod, a professor of journalism and mass communication at the University of Wisconsin–Madison. Rather than report on issues, mass media follows a kind of "protest paradigm," by highlighting rude or violent behavior, disparaging non-normative personalities among protestors, and minimizing the effectiveness of protests. | 5 min read | | | It's fascinating that multiple phases of sleep contribute to "cleaning out" parts of the brain. While immersive dream REM sleep serves to wash away some emotional distress overnight, researchers also think that cerebral spinal fluid flushes out toxins from the brain during non-REM sleep. I hope you spent solid time in all phases of sleep this weekend. | Thank you for your notes, questions and comments. It's an honor to be part of such a science-loving community! Keep the emails coming: newsletters@sciam.com. Have a great week! | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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