News bits: Petition to remove judge; Ukraine war update; Brain mapping update

MoveOn is gathering signatures to asking Trump judge Aileen Cannon to be removed from the Mar-a-Lago stolen documents case, Trump v. U.S. As discussed here yesterday, Cannon halted the case, claiming she has too much work to do. Cannon's decision protects DJT from prosecution until after the 2024 elections. And if he wins, it protects him forever.

I signed the petition. If you are interested, you can sign at this link. I recommend signing, even if it has no impact.

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The Ukraine military has started using an ancient war device called caltrops (crow's feet) to stop Russian military convoys.

Interesting Engineering reports:

The caltrops are scattered in the path of a Russian convoy, blowing out their tires and leaving them more vulnerable. Once disabled, the vehicles are finished off using low-cost quadcopter explosive-laden drones or artillery.

However, unlike in the past, specialist drones were used to deploy the caltrops under the cover of the night—a simple yet very effective tactic. Once scattered, wheeled vehicles have their tires blown out, making them sitting ducks.

Even if not destroyed outright, the loss of multiple, or all, tires seriously hampers the movement of Russian personnel and materiel until recovery or repairs are carried out.

This 1 minute video shows the kind of damage that caltrops are inflicting on Russian vehicles. Maybe the Russians will start dropping their own caltrops to stop Ukrainian vehicles. 

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Nature News reports that scientists using artificial intelligence for data analysis have mapped 1 cubic millimeter (0.000061 cubic inch) of human cerebral cortex tissue at nanometer scale resolution (1 nm = 0.000000094 inch) (neuron cell body size is ~4-100 micrometers in diameter, 0.00016 to 0.0039 inch). The research paper is entitled, A petavoxel fragment of human cerebral cortex reconstructed at nanoscale resolution (peta = 1 x 10^15):

Rendering based on electron-microscope data, showing 

the positions of neurons in a fragment of the brain cortex --

neuron color indicates cell body size

Researchers have mapped a tiny piece of the human brain in astonishing detail. The resulting cell atlas, which was described today in Science and is available online, reveals new patterns of connections between brain cells called neurons, as well as cells that wrap around themselves to form knots, and pairs of neurons that are almost mirror images of each other.

The 3D map covers a volume of about one cubic millimeter, one-millionth of a whole brain, and contains roughly 57,000 cells and 150 million synapses — the connections between neurons. It incorporates a colossal 1.4 petabytes (1,400 terabytes) of image data. “It’s a little bit humbling,” says Viren Jain, a neuroscientist at Google in Mountain View, California, and a co-author of the paper. “How are we ever going to really come to terms with all this complexity?”

The brain fragment was taken from a 45-year-old woman when she underwent surgery to treat her epilepsy. It came from the cortex, a part of the brain involved in learning, problem-solving and processing sensory signals. The sample was immersed in preservatives and stained with heavy metals to make the cells easier to see. Neuroscientist Jeff Lichtman at Harvard University in Cambridge, Massachusetts, and his colleagues then cut the sample into around 5,000 slices — each just 34 nanometers thick (0.0000013 inch) — that could be imaged using electron microscopes. 

Jain’s team then built artificial-intelligence models that were able to stitch the microscope images together to reconstruct the whole sample in 3D. “I remember this moment, going into the map and looking at one individual synapse from this woman’s brain, and then zooming out into these other millions of pixels,” says Jain. “It felt sort of spiritual.”

A single neuron (white) shown with 5,600 of the axons (blue) that connect to it 

The synapses that make these connections are shown in green

A range of histological features in 1 mm3 of human brain were rendered, including neuropil (A) and its segmentation (B) at nanometer resolution, annotated synapses (C), excitatory neurons (D), inhibitory neurons (E), astrocytes (F), oligodendrocytes (G), myelin (H), and blood vessels (I). A previously unrecognized neuronal class (J) and multisynaptic connections (K) were also identified.

Rendering showing cortex neuron layers

When examining the model in detail, the researchers discovered unconventional neurons, including some that made up to 50 connections with each other. “In general, you would find a couple of connections at most between two neurons,” says Jain. Elsewhere, the model showed neurons with tendrils that formed knots around themselves. “Nobody had seen anything like this before,” Jain adds.

The team also found pairs of neurons that were near-perfect mirror images of each other. “We found two groups that would send their dendrites in two different directions, and sometimes there was a kind of mirror symmetry,” Jain says. It is unclear what role these features have in the brain.  

Proofreaders needed

The map is so large that most of it has yet to be manually checked, and it could still contain errors created by the process of stitching so many images together. “Hundreds of cells have been ‘proofread’, but that’s obviously a few per cent of the 50,000 cells in there,” says Jain. He hopes that others will help to proofread parts of the map they are interested in. The team plans to produce similar maps of brain samples from other people — but a map of the entire brain is unlikely in the next few decades, he says.

This is a truly amazing accomplishment. Other groups are working to map an entire mouse brain, but that will probably take several years. As time passes, maybe some improvements in data gathering protocols will speed up the mapping process.