A planet rebuilt from a dead star, cells that nibble Parkinson's clumps

Hubble first captured its light in the late 1990s and showed aluminium, titanium and nickel, metals that don't belong in a white dwarf's atmosphere 18. A study published October 5 in Nature Astronomy used Hubble's updated instruments and other observatories' data to find more: zinc, copper, and niobium, which had never turned up in a white dwarf before 18. The team's reading is that these elements came from the red giant's death throes, clumped into a "second-generation" planet, and are now raining back onto the star as stellar winds strip that planet's atmosphere 18. Follow-up observations caught a recurring dip in the star's brightness, consistent with something crossing in front of it every 4.4 Earth days. From the transit duration, the researchers estimate the planet is about the size of Jupiter 18. The star is giving itself away by eating its planet's atmosphere.

Each person did both interventions in random order, at least 72 hours apart. One was 30 minutes chest-deep in 40 °C (104 °F) water. The other was 30 minutes on a stationary bike at 60 to 70 percent of maximum heart rate 95. The soak changed the blood vessels beneath the skin in ways that in some respects exceeded moderate exercise, and it lowered blood pressure more than the cycling did, according to the paper in the European Journal of Applied Physiology 95.

A University of Oxford team grew human stem-cell-derived dopamine neurons together with microglia and watched a subset of the microglia remove alpha-synuclein aggregates by trogocytosis, from the Greek for "to gnaw" 103. They nibbled the clumped segments off living neurons while the neurons stayed alive and connected 103. The process depends on a protein called GPNMB, which genome-wide studies had already tied to Parkinson's risk and which binds alpha-synuclein directly. Two further signals act as sensors and brakes, with an interleukin-10 loop keeping the response from tipping into damaging inflammation 103. "What is striking is the precision of this response," said first author Hung-Ju Chueh 103.

An NYU Langone team led by NYU Grossman School of Medicine used the fruit fly, whose connectome is fully mapped, and published in Nature 102. They found a "split attractor network": PFG neurons carry the content of the memory (which direction the fly is heading, from its internal compass), while hΔK neurons control when memory forms 102. The two stay apart until an odour cue lifts an inhibitory gate. Flies given a whiff of apple cider vinegar then kept steering toward it for seconds after the scent plume was gone 102.

The virus was only identified in 1989. Today's once-a-day pills cure more than 95 percent of chronic cases in eight to twelve weeks 119. England, Egypt and Norway are making the fastest progress. England's approach combined opt-out testing for HIV, hepatitis B and hepatitis C in emergency departments, mobile testing vans and care teams for underserved communities, free at-home test kits, and free NHS medication for anyone who tests positive 119. England aims to eliminate the virus by 2030 and has already hit its target of treating 80 percent of infections 119.

With no predators in the enclosure, the animals can feed, breed and explore, and the panels provide shade that is 8 to 18 degrees cooler than open ground 260. Mountain gazelles and Arabian hares were released into the park last October, and males were added in May to start a self-sustaining herd 260. Reserve director Andrew Zaloumis calls the approach "ReWildingVoltaics" 260.

Saplings, with shallow roots, are flagged first 275. Volunteers log a watering, see when someone last watered the same tree, and find public water pumps 275. When Berlin hit an all-time high of 39.9 °C on June 27, people poured 8,000 litres onto trees in a single day 275. The project began in 2020 at the start of lockdown, and the biggest annual peak, nearly half a million litres, came in those first pandemic months 275. One volunteer, Amanda Gläser-Bligh, hauls 20 litres up and down the stairs each week to Linda, an eight-year-old linden outside her building 275.