#235In very rare cases, Alzheimer’s disease could be transmitted from person to person during medical procedures. This finding comes as five people have developed the disease after receiving contaminated human growth hormone injections in the late 1950s to early 1980s – a practice that is now banned. What this finding means for medical settings and why most people don’t need to be concerned.  Elon Musk’s mind-reading brain implant company Neuralink is carrying out its first human trial. The volunteer who has received the surgically implanted device and is now, Musk said earlier this week, “recovering well”. Neuralink promises to connect users to their smartphones and computers, reading brain signals and translating a person’s intentions into text or other functions. While this isn’t the first device of its kind, it is the only one being marketed as a consumer technology device, as opposed to a medical device. Contrails, the streams of white vapour that form behind planes in the sky, are to blame for a huge proportion of air travel’s impact on the climate. But there’s good news. Small changes in altitude may be sufficient to reduce their formation – and implementing these changes may be easier than we thought. Plus why flying at night has a bigger climate impact.Tiny tornadoes have been discovered inside the egg cells of fruit flies. These twisters circulate the jelly-like cytoplasm inside the cells and could be essential to the successful reproduction of these fruit flies. Excitingly, these tornadoes may be happening in the cells of other animals too – just not humans.Plus: Revealing which dogs live the longest; how an army of Twitter bots spreaded fake news about 2023’s Chinese spy balloon incident; an ancient gadget that turns fibres into rope.Hosts Timothy Revell and Christie Taylor discuss with guests Chen Ly, Matt Sparkes, James Dinneen and Alex Wilkins. To read more about these stories, visit newscientist.com. Hosted on Acast. See acast.com/privacy for more information.