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A neuron (green) from a person with Alzheimer’s disease includes an unusual protein complex (pink) encircling the nucleus (yellow).Credit: Thomas Deerinck, NCMIR/SPL
How an Alzheimer’s gene ravages the brain
No gene variant is a bigger risk factor for Alzheimer’s disease than one called APOE4. But exactly how the gene spurs brain damage has been a mystery. A study has now linked APOE4 with faulty cholesterol processing in the brain, which in turn leads to defects in the insulating sheaths that surround nerve fibres and facilitate their electrical activity. Preliminary results hint that these changes could cause memory and learning deficits. And the work suggests that drugs that restore the brain’s cholesterol processing could treat the disease.
Reference: Nature paper
Why a bat virus keeps infecting people
Researchers have identified the environmental conditions that spark spillovers of a virus from bats to humans. Scientists can now predict probable spillovers of the deadly Hendra virus up to two years in advance — giving them the opportunity to intervene to prevent them. Drought, habitat loss and food stress are key drivers. When food is in short supply, bats shed more Hendra virus, and more horses — an intermediate host — get sick. The work “underscores the enhanced risk we are likely to see” with climate change and increasing habitat loss, says conservation biologist Alice Hughes.
References: Nature paper & Ecology Letters paper
COP27 climate conference
Image of the day
At the centre of Ukraine’s striking, somber COP27 pavilion is a funnel-shaped enclosure meant to evoke the bomb craters that dot the country because of Russian shelling. Inside, more than 500 cubes contain 16 types of Ukrainian soil. The text accompanying the display notes that the country is home to more than one-third of Earth’s chernozem — extremely fertile soil that is also called black soil. The shells compress, uproot and pollute the soil, damaging arable land in one of the world’s breadbaskets. Read more: Ukraine COP27 websiteCredit: Flora Graham for Nature
TODAY AT COP27
Brazilian president-elect Luiz Inácio Lula da Silva got a hero’s welcome at COP yesterday, gathering a cheering crowd chanting “olé olé olé”. “We’re so glad to be part of the conversation again,” one Brazilian youth activist told me. Inside Brazil’s glittering pavilion, the busy coffee bar felt lively and celebratory (especially in contrast to others, some of which are starting to pack up or have already been abandoned). But there are downsides to being the belle of the ball. “There is a lot of pressure, the whole world is looking at us,” one delegate told me. “But we can’t do anything. We have to wait until we have our new president.” Lula won’t be sworn in until 1 January 2023.
Today, Egypt, which is hosting COP27, released a 20-page first draft of the final text. “This is a significant moment in the life cycle of a COP because it’s an indication of areas of agreement and disagreement,” says Nature’s Ehsan Masood. The majority of uncertainties are related to one of the most contentious issues at the conference: climate finance for poorer countries, including loss-and-damage funding. “Fossil fuel” is mentioned only once, in a section on renewable energy — which has incensed campaigners who want acknowledgement that fossil fuels must be phased out to halt global warming.
Facing a Friday deadline, the gulf between countries is still too wide for a successful outcome. But brinkmanship is not necessarily unusual at this point in a COP. Last year at this time, the feeling at COP26 was also one of pregnant pause. Delegates have a long night ahead as negotiators will work without sleep to deliver the final texts that must be agreed on by all parties.
Flora Graham, Senior Editor, Nature Briefing
Features & opinion
Short-circuiting the electronic-waste crisis
The computers, smartphones and other technologies that define modern life are creating waste across the world. A combination of technological and policy solutions could help to limit the damage.
Nature Outlook: The circular economy is an editorially independent supplement produced with the financial support of Google.
Video: how to recycle a building
Sand — specifically river and beach sand, which is needed for building — is running out. Without it, the construction industry is facing a crisis. A fresh framework for thinking about construction and the economy could help. A circular model, designed to keep materials in use for as long as possible, would mean that less sand ends up in landfill and less energy is wasted during construction, leading to a more sustainable industry that benefits businesses and the planet.
