Prime editing reaches its first patient; mice reveal a sleep counter

Introduced in 2019, prime editing can swap single DNA letters, insert new genetic instructions or delete chunks, with minimal damage to the genome. In theory it could correct up to 89 percent of known disease-linked variants 181. The gene-editing treatment approved in 2024, Casgevy, edits blood stem cells outside the body instead. Last year a baby named KJ Muldoon got a custom base editor, a gentler relative of the original CRISPR cutter, and his symptoms eased within weeks 181.

A third set rose or stayed high as the hours of wakefulness piled up, then dropped once the mice slept. Two of those regions were the median raphe, deep in the brainstem, and the anterior medial preoptic area, which sits farther forward and is involved in sleep regulation. Their activity also followed the mice's ordinary daily rhythm, rising when the animals had been awake longer 107. When researchers turned these cells on in rested mice, the animals slept two to three times more, and the sleep was deeper. Suppressing the cells sharply reduced sleepiness even after hours awake. When two populations were chronically suppressed, the mice slept nearly 70 percent less 107.

They tested adult mice on two adjacent metal plates, one fixed at 33°C and one adjustable. Two temperature-sensing ion channels in peripheral nerves, TRPM2 (warmth) and TRPM8 (coolness), turned out to activate at higher temperatures in females than in males. Core body temperature and paw skin temperature were the same in both sexes, so the difference sits in the sensors rather than in how much heat the body holds 61. Testosterone moved the dial. Lowering it in males shifted their preference toward warmer plates, and giving it to females made them more averse to heat. Estrogen and progesterone showed no direct effect 61.

A new Nature study from David Vilchez's lab at the University of Cologne traces a relay in the roundworm Caenorhabditis elegans. At a mild 15°C (59°F), muscle makes more of an enzyme called CAT-4, which drives production of a metabolite called BH2. Muscle makes, stores and then releases the BH2, and other tissues convert it to BH4, which lets an enzyme called PAH-1 make the amino acid tyrosine 43. Breaking the chain reduced the lifespan benefit, which argues against the older idea that cold just slows everything down. In a worm model of Huntington's disease, the same pathway also suppressed clumping of harmful proteins 43.

Incat Tasmania built it for the operator Buquebus, and the design started as a dual-fuel ship running on liquefied natural gas and diesel before being switched to all-electric partway through the project. The power comes from a 43-megawatt-hour storage system from Wärtsilä and Corvus Energy: more than 5,000 lithium-ion batteries weighing about 286 tons, feeding eight electric motors and eight waterjets 179. The article's estimate is that a comparable diesel ferry on a route like this could burn over a million gallons of marine diesel a year. By that estimate the Zorrilla saves US$4.5 million in fuel and avoids 37,545 tons of carbon dioxide equivalents annually 179.

A city of about 200,000 people had put its own cables in the ground, not Comcast or Spectrum. The network has since been linked to billions of dollars in economic benefits and hundreds of new startups. EPB says it is the single largest source of funding for local public schools 117. It brought 70 percent of households online at the lowest price per megabit in the area, and Consumer Reports regularly ranks EPB among America's best providers. Hundreds of other cities have followed, though many were stymied by opposition from major cable companies 117.

In transmitted light the particles block blue and green and let reds and oranges through; in reflected light they scatter it 203. Lisa Hollands, a glass technical specialist at the University of Sheffield, led an effort to reproduce it. The team first made glass from materials available in Roman times, then spent a long stretch varying oxygen levels, furnace temperatures and other conditions 203. NASA made dichroic glass in the 1960s, but this version is much closer to the cup 203.