A key brain chemical is the reason we enjoy rewards more when they are difficult to achieve. Plus, genetics might play a bigger part in longevity than we thought and a holistic view of eating well.
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Researchers compared the similarity of lifespans of fraternal twins with that of identical twins like Raymonde Saumade and Lucienne Grare — shown here aged 98 — who both lived to over 105 years old. (Pierre Andrieu/AFP via Getty)
According to a new analysis, about 55% of the observed variation in longevity across a population is attributable to genetics — challenging previous estimates of 10–25%. Researchers say that earlier numbers were much too low because they did not effectively separate deaths caused by extrinsic factors, such as accidents, from intrinsic ones such as the gradual decline of organ function. Not all intrinsic causes of death are equally heritable, the researchers found — and the results don’t indicate a genetically encoded ‘destiny’ for lifespan, because so much is determined by environment and lifestyle choices.
Nature | 5 min read
Reference: Science paper
Scientists have identified a distinctive brain-wave pattern that marks the slide into unconsciousness during general anaesthesia with the drug propofol. Data taken from people about to have surgery show that, as anaesthesia takes hold, a specific type of activity in brain areas such as the parietal cortex and deeper structures slips out of synchronicity. If verified in studies that gather deep-brain data, and use other anaesthetics, this shift could serve as a biomarker of loss of consciousness that doctors could use to avoid sedating patients too deeply — or not deeply enough.
Nature | 4 min read
Reference: Cell Reports Medicine paper
“The synthesis of small molecules is the slow step in drug discovery and a number of other important areas,” says chemist Timothy Newhouse, co-author of a new paper about an AI system called MOSAIC. Instead of researchers having to trawl through millions of known chemical reactions and then test whether it is possible to synthesize them, MOSAIC recommends conditions to make potentially useful substances. In tests, researchers could successfully produce 35 of the 52 that the system suggested.
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