Mechanisms Behind Vaccine Side-Effects: The Science That Causes That Sore Arm

After receiving a vaccination shot, it’s likely that we’ll feel some side-effects. These can range from merely a sore arm to swollen lymph nodes and even a fever. Which side-effects to expect depend on the exact vaccine, with each type and variant coming with its own list of common side-effects. Each person’s immune system will also react differently, which makes it hard to say exactly what one can expect after receiving the vaccination.

What we can do is look closer at the underlying mechanisms that cause these side-effects, to try and understand why they occur and how to best deal with them. Most relevant here for the initial response is the body’s innate immune system, with dendritic cells generally being among the first to come into contact with the vaccine and to present the antigen to the body’s adaptive immune system.

Key to the redness, swelling, and fever are substances produced by the body which include various cytokines as well as prostaglandin, producing the symptoms seen with inflammation and injury.

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Interactive Clips For Game Boy: Sit Back And Watch Or Take Control

How often does this happen to you? You find yourself describing something that happened in a game to someone, and they’re not sure they know what part of the map you’re talking about, or they’ve never gotten that far. Wouldn’t it be cool to make a bookmark in a video game so you can jump right to the beginning of the action and show your friend what you mean using the actual game?

That’s the idea behind [Joël Franusic] and [Adam Smith]’s fantastic Playable Quotes for Game Boy — clip-making that creates a 4-D nugget of gameplay that can either be viewed as a video, or played live within the bounds of the clip. The system is built on a modified version of the PyBoy emulator.

Game Boy game ROM -- complete and partial
Left: the full game ROM. Right: a bookmarked slice of the game ROM with the rest set to zero.

Basically, a Playable Quote is made up of a save state and all that entails, plus a slice of the game’s ROM that includes just enough game data to recreate an interactive clip. Everything is zipped up and steganographically encoded into a PNG file. Here’s a Tetris quote you can play (or watch) right now — you might recognize it from the post thumbnail. You’ll find the others on the games site, which allows people to create and share and build on each other’s work.

There’s so much more that can be done with this type of immersive and interactive tool outside the realm of games, and we’re excited to see where this leads and what people do with it.

Haven’t heard of PyBoy before? Let us introduce you.

Up Close And Personal With An Unusual 3D Printer Kit

While there are still plenty of folks out there tinkering with custom 3D printers, it’s safe to say that most people these days are using a commercially-available machine. The prices are just so low now, even on the resin printers, that unless you have some application that requires exacting specifications, it just doesn’t make a whole lot of sense to fiddle around with a homebrew machine.

As it so happens, [Nicolas Tranchant] actually does have such an application. He needs ultra-high resolution 3D prints for his jewelry company, but even expensive printers designed for doing dental work weren’t giving him the results he was looking for. Rather than spend five-figures on a machine that may or may not get the job done, he decided to check out what was available in kit form. That’s when he found the work of [Frédéric Lautré].

A look at the heavy-duty Z axis.

He purchased the unique “Top-Down” SLA kit from him back in 2017, and now after four years of working with the machine, [Nicolas] decided he would share his experiences with the rest of the class. The basic idea with this printer is that the light source is above the resin vat, rather than below. So instead of the print bed being pulled farther away from the resin on each new layer, it actually sinks deeper into it.

Compared to the “Bottom-Up” style of resin printers that are more common for hobbyists, this approach does away with the need for a non-stick layer of film at the bottom of the tank. Printing is therefore made faster and more reliable, as the part doesn’t need to be peeled off the film for each new layer.

[Nicolas] goes into quite a bit of detail about building and using the $700 USD kit, including the occasional modifications he made. It sounds like the kit later went through a few revisions, but the core concepts are largely the same. It’s worth noting that the kit did not come with the actual projector though, so in his case the total cost was closer to $1,400. We were also surprised to see that [Frédéric] apparently developed the software for this printer himself, so the tips on how to wrangle its unfamiliar interface for slicing and support generation may be particularly helpful.

Unfortunately, it sounds like [Frédéric] has dropped off the radar. The website for the kit is gone, and [Nicolas] has been unable to get in touch with him. Which is a shame, as this looks to be a fascinating project. Perhaps the Hackaday community can help track down this mysterious SLA maestro?