stem mammal

Hey, look, I’m actually alive! I’m still neck deep into painting, redecorating, and so on, but I did manged to paint a lazy Dimetrodon sunbathing on a Walchia trunk, and found some time to upload it, so there’s that.

I’m still not going to post anywhere near regularly here, as also, life happened, and it turned out I have to write myself a website, get a hosting, and go through a lot of changes in the business I’m trying to run, and it’s all still in progress, and I’ll be focusing on this for now. I’ll try to pop up here from time to time, and maybe even get some new artwork done. Life’s pesky like that, and there’s this little issue of earning money to stay alive, or something…

I hope you’re all doing alright, and I now I got a bunch of new followers, so hello to you :)

As for this Dimetrodon, contrary to a whole lot of palaeoart, you can’t spend your life roaring, hunting, chasing, and snapping at everything that moves. Sometimes you just have to take a break, and take a nap in the sun.

I don’t know why, but the painting looks weird: it looks fine when I look at it in krita, the .kra file looks also good, but when I save it as png it turns out really dark. No idea why. I did play a bit with levels, to get it to look closer to what the painting before conversion looks like, and this is the best result I got, but I’m still not 100% happy with it. That’s the first time something like that happened, and I hope it’s the last. And also tumblr doing something atrocious to it doesn’t help…

Based on Scott Hartman’s skeletal.

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introductory bios? for my ocs?

yeah, so I’ve got quite a few of them that I’ve accumulated over the years. I still need to throw a character page up so people can have an idea of who/what they are…

they do not all exist in the same universe (or at least, these versions of them don’t). Sam, Ike, Terry, and Mira all exist in a sci-fantasy dystopia with psychic people and lycomorphs (aka werewolves if werewolves were humans rapidly devolving/re-evolving into a stem mammal-like beast form), Roach is from a dumpy vampire world, Mauve is from an edgy Pokemon AU me and my gf made, and Ancha (sometimes also called Alice in AUs) exists in a surreal seapunk Atlantis and Dylan tags along.

I like, have thought way too much about these guys and welcome questions about them.

Geikia elginensis, a dicynodont synapsid from the Late Permian of Scotland (~254-252 mya). Known only from a single skull discovered in the 1890s, it would have measured around 50cm long and was closely related to South African forms like Bulbasaurus.

It had an unusually shortened snout and forward-facing eyes – sort of like a pug with a beak – and a pair of protruding nasal bosses on its snout. It was probably a selective browser, biting off small pieces of vegetation at a time, and its large eyes and stereoscopic vision suggest it may have been nocturnal.

4

I’ve finally uploaded synapsid evolution to my redbubble (link to my shop is in my blog description, apparently tumblr now hides posts with outgoing links from search. Not cool.)

As always with things without background, I wasn’t sure what background color to add, and finally ended up going with the default white. It’d be great if there was option for customers to choose  background colors on all sorts of things, like they can do with t-shirts now.

I was tempted to make the background black on things where you the buyer can’t choose  background color themselves, but then I’m aware of the fact that not everyone shares my obsession with black.

Now I’m thinking about uploading this again, so I’ll have to listings for it: one with white background, and one with black.

And as an aside, adding artwork to redbubble is a pain. It literally took well over an hour to get this done.

Lystrosaurus murrayi, a non-mammalian therapsid from the Early Triassic of Southern Pangaea (an area that later became Africa, India, and Antarctica), living about 250 million years ago.

Only about 50cm long (~19.5in), these tubby little creatures were one of the few survivors of the worst mass extinction in Earth’s history. For a few million years after the extinction the various species of Lystrosaurus were so successful that they were the single most common land vertebrate in the world, making up 95% of the population.

The name Tetraceratops (“four-horned face”) sounds like it should belong to some sort of large horned dinosaur, doesn’t it? Perhaps a relative of Triceratops or Pentaceratops.

Well, nope! Tetraceratops was actually a small synapsid (a “proto-mammal”) from the Early Permian of Texas, USA, living about 279-272 million years ago. Known only from a 9cm long skull (3.5″), it had two sets of saber teeth in its jaws and a total of six horns on its face instead of four – two on its snout, two in front of its eyes, and two at the back of its jaws.

It’s unclear exactly what the rest of its body looked like, or even where it belongs in the synapsid family tree – but currently it’s thought to be the earliest known member of the therapsids. I’ve reconstructed it here to look similar to other basal therapsids like Herpetoskylax.

Researchers observe stem cell specialization in the brain

Adult stem cells are flexible and can transform themselves into a wide variety of special cell types. Because they are harvested from adult organisms, there are no ethical objections to their use, and they therefore open up major possibilities in biomedicine. For instance, adult stem cells enable the stabilization or even regeneration of damaged tissue. Neural stem cells form a reservoir for nerve cells. Researchers hope to use them to treat neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease. Tübingen researchers led by Professor Olga Garaschuk of the University of Tübingen’s Institute for Physiology, working with colleagues from Yale University, the Max Planck Institute of Neurobiology in Martinsried and the Helmholtz Center in Munich, studied the integration of these cells into the pre-existing neural network in the living organism. The results of their study have been published in the latest edition of Nature Communications.

There are only two places in the brains of adult mammals where stem cells can be found – the lateral ventricles and the hippocampus. These stem cells are generating neurons throughout life. The researchers focused on a stem cell zone in the lateral ventricle, from where progenitors of the nerve cells migrate towards the olfactory bulb. The olfactory nerves which start in the nasal tissue run down to this structure, which in mice is located at the frontal base of the brain. It is there that the former stem cells specialized in the task of processing information on smells detected by the nose. “Using the latest methods in microscopy, we were for the first time able to directly monitor functional properties of migrating neural progenitor cells inside the olfactory bulb in mice,” says Olga Garaschuk. The researchers were able to track the cells using special fluorescent markers whose intensity changes according to the cell’s activity.

The study showed that as little as 48 hours after the cells had arrived in the olfactory bulb, around half of them were capable of responding to olfactory stimuli. Even though the neural progenitor cells were still migrating, their sensitivity to odorants and their electrical activity were similar to those of the surrounding, mature neurons. The mature pattern of odor-evoked responses of these cells strongly contrasted with their molecular phenotype which was typical of immature, migrating neuroblasts. “Our data reveal a remarkably rapid functional integration of adult-born cells into the pre-existing neural network,” says Garaschuk, “and they show that sensory-driven activity is in a position to orchestrate their migration and differentiation as well as their decision of when and where to integrate.”