🎓 Doc Freemo 🇳🇱 @freemo@qoto.org

#introduction I’m a Prof at the Centre for Cognitive Neuroimaging (CCNi), UofG, Scotland, studying human memory. My lab uses a range of tools, including behaviour, EEG/MEG, fMRI and intracranial (single unit + LFP) EEG recordings, trying to understand how the human brain reconstructs past experiences from memory, and how our memories change over time and when we repeatedly remember something.

Interesting fact of the day: The same effect that cuased light in a prism to split up into different colors is what ultimately caused the first transatlantic telegraphic wire in 1858 to fail.

Morse code is transmitted as on-off signals, effectively square waves. Square waves are in fact made up of many different frequencies. Like in a prism different frequencies move at different speeds through a wire. Therefore as the on-off pulses traveled through the transatlantic telegraph wire the signal spread out like it does in a prism and ultimately the pulses would overlap and be indistinguishable.

The effect was so extreme that it took a message of only 98 words (the first message sent) over 67 minutes to send one way and a whopping 16 hours to confirm the message.

Whitehouse, a doctor with little mathematical understanding, thought he could solve the problem by increasing voltage, which we now know was a futile effort. He increased the voltage to the point he managed to short out the cable entirely and made it useless. However Lord Kelvin had already warned of the problem as was ignored and he came up with the law of squares to describe the problem which later was refined to give us the telegraphers equation. The telegraphers equation is still used today to model feedlines in radio transmitters and receivers.

#Science #STEM #Physics #History @Science #QOTOJournal

One of the nicest things about Mastodon so far is having a very scientific and academia focused feed where I can discover and follow those working in fields where I don't have a background.

It is wonderful for seeing the diversity of research and being inspired by the works of others.

Hey - this place seems interesting. Hope that the distributed nature can keep up with the near-certain influx of new users - like me.

I am trying to work out the strengths and weaknesses of messaging platforms from fully decentralized to federated to centralized. I am only a user on Mastodon/activitypub and IRC, but I have in the past hosted usenet and currently host:

smtp (email)
XMPP
Matrix
SSB (Secure ScuttleButt)
SIP (fully decentralized)

The impressive feature of twitter and it's totalitarian centralized ilk is that a single id can have millions of followers - and know that. SSB supports unlimited secure (signed) broadcasting, but there is no mechanism for knowing how many followers there are. Of course, TV was in the same boat, and you could get an estimate by polling. BBC broadcasts on SSB.

Counting followers is essential for monetizing content via advertising and sponsors in a decentralized manner - i.e. not subject to cancellation at a whim by a global centralized platform.

Matrix seems ideal for many of the purposes people use Teams or Substack or Slack. Private conversations e2e encrypted, logging with controlled retention (HIPPA compliant), voice and video calls, voice and video conferencing, media. But performance of small personal servers drops with number of participants in a room - I don't think it can support a million followers.

XMPP has inconsistent state for multiple devices, and is terrible at group chats. I do use it a backup for matrix and for voice/video calls. Open XMPP clients supporting VOIP and IPv6 are easier to find than SIP clients. (And SIP is even worse at state for multiple devices.)

Usenet has no authentication (not worth tacking on GPG header schemes).

Email is not designed to be "instant" (as in IM), but can be coaxed into resembling that by clients such as DeltaChat.

Ok, so now I should make a feature matrix (which includes Matrix), but have I missed any open and federated/decentralized protocols? Any other features? Current feature list:

broadcast (million+ followers)
follower count
p2p voice/video
e2e encryption
authentication
federated
decentralized (or federated that can be practically fully decentralized, like SMTP)

Did I miss any?

bad news fedibros, you are very likely terrorists

https://www.nzsis.govt.nz/assets/media/Know-the-signs.pdf

@freemo It definitly is. Sorry I didn’t respond at the time. I lost my login and couldn’t be bothered. Now I’m giving Mastodon another shot and am slowly getting the hang of it.

I am a liar & a sorcerer
I am so fickle that I scorn the bridle.
I am unchaste, voluptuous and idle.
I am a bully & a tyrant crass,
I am as dull & as stubborn as an ass;
I am untrusty, cruel & insane,
I am a fool & frivolous & vain.
I am a weakling & a coward; I cringe,
I am a catamite & cunnilinge.
I am a glutton, a besotted wight;
I am a satyr & a sodomite.
I am as changeful & selfish as the Sea.
I am a thing of vice & vanity.
I am not violent & I vaccilate,
I am a blind man & esmasculate.
I am a raging fire of wrath no wiser!
I am a blackguard, spendthrift & a miser.
I am obscene & devious & null.
I am ungenerous & base & dull.
I am not marked with the white Flame of Breath.
I am a Traitor! die the traitor's death!

-- Aliester Crowley, Liber DCLXXI

Also called: A Ritual of Self Initiation based upon the Formula of the Neophyte.

This was just an exceprt.

#Occult #Thelema #OTO #Crowley #magic #magick

It's fun that QOTO is a techie place, because a few people will read about the adventures with an AS400 and realize the state of a lot of the worlds' computer systems.

The collarary to that is that 25% of America LITERALLY doesn't know how to use a computer even in this day and age.

Hi, Mastodon!

Admittedly, I'm here not because of a deep interest in the Fediverse, but because I'm repulsed from Twitter by the Elon takeover. But hopefully I'll enjoy it here in its own right!

Time for my #introduction!

Hello, Mastodon! My name is Alan Johnson. I have a deep interest in many topics, including tech, management, business, politics, music, history, econ, education, etc. I expect I'll probably use Mastodon in a similar way as I use Twitter -- a place to put thoughts from my very scattered brain out into the world, so that I can learn from the feedback I get. Hopefully I occasionally inspire people with some of my better thoughts, too.

My current profession is running the Data department for an insurance company, and I'm more broadly interested in tech strategy.

The fact that there's even a culture of #introductions here is pretty cool, and different from Twitter.

@freemo

Hold on a minute...

He called it a toot in his toot. Referring to his own toot, he said post or toot.

That's what he said in his toot. Or post, as I won't call it.

"Post-embryonic remodeling of the C. elegans motor circuit" by Ben Mulcahy et al. 2022 (Mei Zhen's lab https://zhenlab.com/)

... in which the authors show, using #vEM and #connectomics, that while the nematode #celegans nervous system grows from ~200 neurons in the hatchling to ~300 in the adult, the addition of new neurons doesn't disrupt existing motor function, but new circuits are formed that endow the animal with new behaviors such as bending.

Interestingly, in the course of larval maturation one neuron type inverts its polarity: what was the dendrite becomes the axon, and viceversa. And this is accomplished not with retraction and regrowth of the arbor, but rather, by flipping the synapses in situ.

URL: https://doi.org/10.1016/j.cub.2022.09.065

#readingpapers #science #neuroscience #development

In my course MCB111 "mathematics in biology", we just learned about Hopfield networks and the Hebbian learning. Can anyone give a critical reading of this paper for us?

@freemo @Waldemar I'm talking about following hashtags, here: