Five colors of Cast21 on five different wrists.

Cast21 Brings Healing Into 2024

It takes but an ill-fated second to break a bone, and several long weeks for it to heal in a cast. And even if you have one of those newfangled fiberglass casts, you still can’t get the thing wet, and it’s gonna be itchy under there because your skin can’t breathe. Isn’t it high time for something better?

Enter Cast21, co-founded by Chief Technical Officer [Jason Troutner], who has been in casts more than 50 times due to sports injuries and surgeries. He teamed up with a biomedical design engineer and an electrical engineer to break the norms associated with traditional casts and design a new solution that addresses their drawbacks.

A medical professional fills a Cast21 with purple resin.So, how does it work already? The latticework cast is made from a network of silicone tubes that harden once injected with resin and a catalyst mixture. It takes ten seconds to fill the latticework with resin and three minutes for it to cure, and the whole process is much faster than plaster or fiberglass.

This new cast can be used along with electrical stimulation therapy, which can reduce healing time and prevent muscle atrophy.

Cast21 is not only breathable, it’s also waterproof, meaning no more trash bags on your arm to take a shower. The doctor doesn’t even need a saw to remove it, just cut in two places along the seam. It can even be used as a splint afterward.

It’s great to see advancements in simple medical technologies like the cast. And it looks almost as cool as this 3D-printed exoskeleton cast we saw ten years ago.

Thanks to [Keith Olson] for the tip!

An Earth-Bound Homage To A Martian Biochemistry Experiment

With all the recent attention on Mars and the search for evidence of ancient life there, it’s easy to forget that not only has the Red Planet been under the figurative microscope since the early days of the Space Race, but we went to tremendous effort to send a pair of miniaturized biochemical laboratories there back in 1976. While the results were equivocal, it was still an amazing piece of engineering and spacefaring, one that [Marb] has recreated with this Earth-based version of the famed Viking “Labeled Release” experiment.

The Labeled Release experimental design was based on the fact that many metabolic processes result in the evolution of carbon dioxide gas, which should be detectable by inoculating a soil sample with a nutrient broth laced with radioactive carbon-14. For this homage to the LR experiment, [Marb] eschewed the radioactive tracer, instead looking for a relative increase in the much lower CO2 concentration here on Earth. The test chamber is an electrical enclosure with a gasketed lid that holds a petri dish and a simple CO2 sensor module. Glands in the lid allow an analog for Martian regolith — red terrarium sand — and a nutrient broth to be added to the petri dish. Once the chamber was sterilized, or at least sanitized, [Marb] established a baseline CO2 level with a homebrew data logger and added his sample. Adding the nutrient broth — a solution of trypsinized milk protein, yeast extract, sugar, and salt — gives the bacteria in the “regolith” all the food they need, which increases the CO2 level in the chamber.

More after the break…

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Pong In A Petri Dish: Teasing Out How Brains Work

Experimental setup for the EAP hydrogel free energy principle test. (Credit: Vincent Strong et al., Cell, 2024)
Experimental setup for the EAP hydrogel free energy principle test. (Credit: Vincent Strong et al., Cell, 2024)

Of the many big, unanswered questions in this Universe, the ones pertaining to the functioning of biological neural networks are probably among the most intriguing. From the lowliest neurally gifted creatures to us brainy mammals, neural networks allow us to learn, to predict and adapt to our environments, and sometimes even stand still and wonder puzzlingly how all of this even works. Such puzzling has led to a number of theories, with a team of researchers recently investigating one such theory, as published in Cell. The focus here was that of Bayesian approaches to brain function, specifically the free energy principle, which postulates that neural networks as inference engines seek to minimize the difference between inputs (i.e. the model of the world as perceived) and its internal model.

This is where Electro Active Polymer (EAP) hydrogel comes into play, as it features free ions that can migrate through the hydrogel in response to inputs. In the experiment, these inputs are related to the ball position in the game of Pong. Much like experiments involving biological neurons, the hydrogel is stimulated via electrodes (in a 2 x 3 grid, matching the 2 by 3 grid of the game world), with other electrodes serving as outputs. The idea is that over time the hydrogel will ‘learn’ to optimize the outputs through ion migration, so that it ‘plays’ the game better, which should be reflected in the scores (i.e. the rally length).

Based on the results some improvement in rally length can be observed, which the researchers present as statistically significant. This would imply that the hydrogel displays active inference and memory. Additional tests with incorrect inputs resulted in a marked decrease in performance. This raises many questions about whether this truly displays emergent memory, and whether this validates the free energy principle as a Bayesian approach to understanding biological neural networks.

To the average Star Trek enthusiast the concept of hydrogels, plasmas, etc. displaying the inklings of intelligent life would probably seem familiar, and for good reason. At this point, we do not have a complete understanding of the operation of the many billions of neurons in our own brains. Doing a bit of prodding and poking at some hydrogel and similar substances in a dish might be just the kind of thing we need to get some fundamental answers.

This Week In Security: Malicious Rollback, WHOIS, And More

It’s time to talk about Microsoft’s patch Tuesday, and the odd vulnerability rollback that happened. CVE-2024-43491 has caught some attention, as it’s a 9.8 on the CVSS scale, is under active exploitation, and results in Remote Code Execution (RCE). Yikes, it sounds terrible!

First off, what actually happened? The official statement is that “build version numbers crossed into a range that triggered a code defect”. We don’t know the exact details, but it’s something like an unsigned integer that was interpreted as a signed integer. A build number could have rolled over 32767, and what was intended to be 32768 or higher suddenly became −32767. Lots of “if greater than or equal” logic breaks down in that situation. Because of a logic flaw like this, certain versions of Windows 10 were unintentionally opting out of some historical security fixes.

And that’s where the high CVSS score and active exploitation descriptor comes from. This is simply the highest score of the resurgent flaws, and an acknowledgement that they have been exploited in the past. The good news is that this only applies to Windows 10 build 1507, so either the original install without any of the major updates installed, or one of the Windows 10 Enterprise Long-Term Servicing Branch (LTSB) versions. It seems that the March 2024 monthly security update introduced the problem, and it wasn’t fixed until this month’s updates. Continue reading “This Week In Security: Malicious Rollback, WHOIS, And More”

IBM’s 1969 Educational Computing

IBM got their PCs and PS/2 computers into schools in the 1980s and 1990s. We fondly remember educational games like Super Solvers: Treasure Mountain. However, IBM had been trying to get into the educational market long before the PC. In 1969, the IBM Schools Computer System Unit was developed. Though it never reached commercial release, ten were made, and they were deployed to pilot schools. One remained in use for almost a decade! And now, there’s a new one — well, a replica of IBM’s experimental school computer by [Menadue], at least. You can check it out in the video below.

The internals were based somewhat on the IBM System/360’s technology. Interestingly, it used a touch-sensitive keypad instead of a traditional keyboard. From what we’ve read, it seems this system had a lot of firsts: the first system to use a domestic TV as an output device, the first system to use a cassette deck as a storage medium, and the first purpose-built educational computer. It was developed at IBM Hursley in the UK and used magnetic core memory. It used BCD for numerical display instead of hexadecimal or octal, with floating point numbers as a basic type. It also used 32-bit registers, though they stored BCD digits and not binary. In short, this thing was way ahead of its time.

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Credit: Silversea cruises

Cruise Ship-Lengthening Surgery: All The Cool Companies Are Doing It

Sliding in an extra slice of cruise ship to lengthen it. (Credit: Silversea cruises)
Sliding in an extra slice of cruise ship to lengthen it. (Credit: Silversea cruises)

The number of people going on cruises keeps rising year over year, with the number passengers carried increasing from just over 3.7 million in 1990 to well over 28 million in 2023. This has meant an increasing demand for more and also much larger cruise ships, which has led to an interesting phenomenon where it has become more economical to chop up an existing cruise ship and put in an extra slice to add many meters to each deck. This makes intuitively sense, as the segment added is fairly ‘dumb’, with no engine room, control systems, but mostly more rooms and cabins.

The current top-of-the-line cruise ship experience is exemplified by the Icon class that’s being constructed for the Royal Caribbean Group. The first in this line is the Icon of the Seas, which is the largest cruise ship in the world with a length of 364.75 meters and a gross tonnage of 248,663. All of this cost €1.86 billion and over two years of construction time, compared to around $80 million and a few months in the drydock. When combined with a scheduled maintenance period in the drydock, this ‘Jumboization’ process can be considered to be a great deal that gives existing cruise ships a new lease on life.

Extending a ship in this manner is fairly routine as well, with many ships beyond cruise ships seeing the torch before being split. A newly built segment is then slid in place, the metal segments are welded together, wires, tubing and more are spliced together, before the in and outside are ready for a new coat of paint that makes it seem like nothing ever happened to the ship.

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Why Have Seven Segments When You Can Have 21?

IO user [monte] was pointed towards an 1898 display patent issued to a [George Mason] and liked the look of the ‘creepy’ font it defined. The layout used no less than 21 discrete segments to display the complete roman alphabet and numerals, which is definitely not possible with the mere seven segments we are all familiar with. [monte] then did the decent thing and created a demonstration digit using modern parts.

For the implementation, [monte] created a simple PCB by hand (with an obvious mistake) and 3D-printed an enclosure and diffuser to match. After a little debugging, a better PCB was ordered from one of the usual overseas factories. There isn’t a schematic yet, but they mention using a CH32V003 Risc-V micro, which can be seen sitting on the rear of the PCB.

Maximum flexibility is ensured by storing every glyph as a 32-bit integer, with each LED corresponding to a single bit. It’s interesting to note the display incorporates serifs, which are definitely optional, although you could display sans-serif style glyphs if you wanted to. There is now a bit of a job to work out how to map character codes to glyph codes, but you can have a go at that yourself here. It’s still early doors on this project, but it has some real potential for a unique-looking display.

We love displays—every kind. Here’s a layout reminiscent of a VFD digit but done purely mechanically. And if you must limit yourself to seven digits, what about this unique thing?

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