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We conducted a multicenter, nested case–control study of Alzheimer’s disease biomarkers in cognitively normal participants who were enrolled in the China Cognition and Aging Study from January 2000 through December 2020. A subgroup of these participants underwent testing of cerebrospinal fluid (CSF), cognitive assessments, and brain imaging at 2-year–to–3-year intervals. A total of 648 participants in whom Alzheimer’s disease developed were matched with 648 participants who had normal cognition, and the temporal trajectories of CSF biochemical marker concentrations, cognitive testing, and imaging were analyzed in the two groups.

The median follow-up was 19.9 years (interquartile range, 19.5 to 20.2). CSF and imaging biomarkers in the Alzheimer’s disease group diverged from those in the cognitively normal group at the following estimated number of years before diagnosis: amyloid-beta (Aβ)42, 18 years; the ratio of Aβ42 to Aβ40, 14 years; phosphorylated tau 181, 11 years; total tau, 10 years; neurofilament light chain, 9 years; hippocampal volume, 8 years; and cognitive decline, 6 years. As cognitive impairment progressed, the changes in CSF biomarker levels in the Alzheimer’s disease group initially accelerated and then slowed.

In this study involving Chinese participants during the 20 years preceding clinical diagnosis of sporadic Alzheimer’s disease, we observed the time courses of CSF biomarkers, the times before diagnosis at which they diverged from the biomarkers from a matched group of participants who remained cognitively normal, and the temporal order in which the biomarkers became abnormal. (Funded by the Key Project of the National Natural Science Foundation of China and others; ClinicalTrials.gov number, NCT03653156. opens in new tab.)

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Joe Louca: “Think of it like a realistic video game set on the Moon – we want to make sure the virtual version of moon dust behaves just like the actual thing, so that if we are using it to control a robot on the Moon, then it will behave as we expect.”

After Neil Armstrong took his first steps on the Moon, he said, “It’s almost like a powder”, as he described the lunar regolith, and astronauts on future Apollo missions found working on the lunar surface rather cumbersome and tedious due to the much finer lunar dust compared to Earth’s dirt. Therefore, what steps can be taken to better prepare future rovers and astronauts for NASA’s Artemis program to work on the lunar surface?

This is what a recent study published in Frontiers in Space Technologies hopes to address as a team of researchers led by the University of Bristol developed virtual models of lunar regolith simulants that could provide cost-effective methods to prepare astronauts and robots to work on the lunar surface, someday.

This study builds on an August 2023 study conducted by these same team members that explored the trust between teleoperated robots operating at long distances from Earth with their human controllers. The team found that the human controllers desired to train on increasing difficulty for operating their robots before working the real thing.

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A common belief among astronomers is that galaxy groups and clusters differ mainly in the number of galaxies they contain—there are fewer galaxies in groups and more in clusters. Led by Maret Einasto, astronomers at Tartu Observatory of the University of Tartu decided to look into that and discovered even more differences between groups and clusters.

The structure of the universe can be described as a giant network, a cosmic web, with chains (filaments) of single galaxies and small groups of galaxies connecting rich and clusters that can contain thousands of galaxies. Between galaxy systems, there are giant voids with almost no visible matter (galaxies and gas). Galaxy groups and clusters can, in turn, form even larger systems called superclusters.

In their study, Tartu astronomers used data on galaxy groups, their brightest galaxies (so-called main galaxies), and their surroundings. The aim was to combine these data to see whether it could provide new information about the possible classification of groups of different sizes.

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