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Memristor Breakthrough: First Single Device To Act Like a Neuron

2020-09-01 Samuel K. Moore

It combines resistance, capacitance, and what’s called a Mott memristor all in the same device. Memristors are devices that hold a memory, in the form of resistance, of the current that has flowed through them. Mott memristors have an added ability in that they can also reflect a temperature-driven change in resistance. Materials in a Mott transition go between insulating and conducting according to their temperature. It’s a property seen since the 1960s, but only recently explored in nanoscale devices.

The transition happens in a nanoscale sliver of niobium oxide in the memristor. Here when a DC voltage is applied, the NbO2 heats up slightly, causing it to transition from insulating to conducting. Once that switch happens, the charge built up in the capacitance pours through. Then the device cools just enough to trigger the transition back to insulating. The result is a spike of current that resembles a neuron’s action potential.

https://spectrum.ieee.org/nanoclast/semiconductors/devices/memristor-first-single-device-to-act-like-a-neuron

Also: https://www.nature.com/articles/s41586-020-2735-5.epdf?sharing_token=B11PDbIH67ccrQscLpqM19RgN0jAjWel9jnR3ZoTv0OdeNphDinnZf2DfBr6sMtOQnlA9ClIX5PlqiQovl5PS67A1_SeUDz_GOTcpm9U8FJOwFmzPM8n_1wR_XcVzo9nasoynqgc04XmOkuXv1UxU95v5wjS-eNBbDS0aEI6zvz9aX0jlTRX9soTeiiWwoHX-JFpZUeYiamNdcA3x8Vr8eOQFWRjS7vQ0Ji-WYiQAvIhdiylBLMCTx5sY6HEBVNO2EAlUzWxg8JW4JFhkFf9Fd_P8V18BwKJ_k_eJ2TofXNsyjmPTa-r98OT104dU21Eev4zf-LFX6_7z34scRoUTA%3D%3D&tracking_referrer=spectrum.ieee.org

Why has college gotten so expensive in the last 30 years? Probably because the government handed them a blank check in 1993.

2020-09-01 Andrew Ghobrial

the federal government pays the universities/colleges up front, and the student then owes the government that money.

This represented a large shift in the alignment of incentives. When the loans come from the federal gov, there’s much less pressure on schools to compete on price.

https://medium.com/@andrewghobrial/why-has-college-gotten-so-expensive-in-the-last-30-years-3505af9aded8

Artificial brains may need sleep too

2020-06-08 James Riordon

States that resemble sleep-like cycles in simulated neural networks quell the instability that comes with uninterrupted self-learning in artificial analogs of brains

Watkins and her research team found that the network simulations became unstable after continuous periods of unsupervised learning. When they exposed the networks to states that are analogous to the waves that living brains experience during sleep, stability was restored. “It was as though we were giving the neural networks the equivalent of a good night’s rest,” said Watkins.

https://www.lanl.gov/discover/news-release-archive/2020/June/0608-artificial-brains.php

Trump admits he ‘often’ regrets tweets, retweets get him ‘into trouble’, in interview with Barstool Sports founder

2020-07-25 Joseph A. Wulfsohn

“Do you sometimes — because I follow you on Twitter and I know I do this… do you ever tweet out and be like — you wake up and, ‘Aw man, I wish I didn’t send that one out’?” Portnoy asked.

“Often, too often,” Trump responded. “It used to be in the old days before this, you’d write a letter and you’d say this letter is very big. You put it on your desk and then you go back tomorrow and you say, ‘Oh, I’m glad I didn’t send it,’ right? But we don’t do that with Twitter, right? We put it out instantaneously, we feel great, and then you start getting phone calls — ‘Did you really say this?’ I say, ‘What’s wrong with that?’ and you find out a lot of things.”

https://www.foxnews.com/politics/trump-admits-often-regrets-tweets-barstool-sports-ceo

What We Believe – Black Lives Matter

2020-07-11 Black Lives Matter Foundation, Inc

We disrupt the Western-prescribed nuclear family structure requirement by supporting each other as extended families and “villages” that collectively care for one another, especially our children, to the degree that mothers, parents, and children are comfortable.

https://blacklivesmatter.com/what-we-believe/

Wayback Machine copy:
http://web.archive.org/web/20200822193504/https://blacklivesmatter.com/what-we-believe/

Behind the dead-water phenomenon

2020-07-06 CNRS

What makes ships mysteriously slow down or even stop as they travel, even though their engines are working properly?

…In 1904, the Swedish physicist and oceanographer Vagn Walfrid Ekman showed in a laboratory that waves formed under the surface at the interface between the and freshwater layers that form the upper portion of this area of the Arctic Ocean interact with the ship, generating drag.

This phenomenon, called dead water, is seen in all seas and oceans where waters of different densities (because of salinity or temperature) mix. It denotes two drag phenomena observed by scientists. The first, Nansen wave-making drag, causes a constant, abnormally low speed. The second, Ekman wave-making drag, is characterized by speed oscillations in the trapped boat. The cause of this was unknown.

https://phys.org/news/2020-07-dead-water-phenomenon.html