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Scientists use Flashes of Light to Investigate Memory

If you’ve seen the Men in Black movies, you might remember the neuralyzer – the flashy thing the agents use to wipe memories? Well this might make you remember. Researchers at the University of California have just used flashes of light to find new evidence about how the brain stores memories.

What were they looking for?

Dr. Brian Wiltgen and Kazumasa Tanaka – a graduate student – were trying to investigate how the brain stores memories. It’s thought that one specific region of the brain – the hippocampus – is what triggers memory recall.

What did they find?

Their study supported their hypothesis. “Our study demonstrates that memory is retrieved when the hippocampus reinstates patterns of cortical activity that were observed during learning,” said Dr. Wiltgen in an email.

How did they do it?

To do this study, the researchers created genetically modified mice that did two specific things. First, their brain cells would light up like Christmas lights when activated by a memory. Secondly, the scientists could also temporarily de-activate cells.

The researchers then tested their hypothesis. If the mice were stimulated to remember a scary event in their past (in this case, an electric shock) they normally froze and their brain cells would light up. However, if the researchers turned off hippocampus cells, the brain cells never lit up and the mice didn’t freeze.

So?

It means that the mice didn’t recall that memory.

They forgot?

Not quite. The memory was still there – the brain cells were still there, after all – they just weren’t able to access it. Without the hippocampus to act like a key, the memory was locked away.

What does this mean?

In an email, Dr. Wiltgen said, “The hope is that once we figure out how these processes work we will be better able to understand (and treat) human disorders that affect memory.”

One caveat of this study is that the research was specifically looking at what’s known as episodic memories – memories of people, places, and events. It’s thought that other types of memory – such as skills or languages – might be controlled differently.

 
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Posted by on October 20, 2014 in Medicine, Natural History

 

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Moonlighting: The Effect of Moonlight on Prey Activity

Image from telegraph.co.uk

Imagine you’re stuck on the African plains at night – would you feel safer with or without the moon? Choose carefully, there are more than just lions out there.

Most people would imagine that moonless nights are safer – after all, lions need to see their prey to catch it, right? The extra light from the moon should make things more dangerous for prey. However, a new study points out a critical flaw in that logic: Wouldn’t the extra light also help the prey as well?

Turns out, each species might decide about that.

Counter to the above logic, lions tended to actually hunt less on moonlit nights, preferring the complete cover of darkness. Rodents and rabbits tended to prefer dark nights as well. Primates didn’t though – full moons correlated with more activity, not less. The researchers had originally thought that activity levels would be organized neatly into a food-chain, but what they found was that the most important factor was possibly a prey animal’s senses, not trophic level.

If you’re a sight-loving primate, for example, bright nights help you spot that creeping lion. If you’re a rabbit and depend on your ears, well, maybe that’s a good night to stay still. 

In fact, some prey species may even vary their choices based on seasonal variations and predation risk. A different study showed that snowshoe hares moved around less during bright, snowy nights than dark, snowy ones, but showed no variation during the snow-free months when, presumably, predator risks are much different.

The take-away message is that prey animals don’t just cower at any possible risk – they base their activity on measurable trade-offs and risks. The moon is bright – is my extra vision worth the risk? The moon is dark – can I depend on my ears to keep me safe?

What’s moving around out there in the night?

 
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Posted by on October 27, 2013 in Natural History

 

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The Knight vs. The Snail

Image from the Gorleston Psalter (14th Century)

This is a doodle from a medieval manuscript. Such manuscripts were written by monks (who, other than nobles and clergy, were really the only ones that could even read after all) and usually included some sort of doodle or artwork in the margins. But some are pretty strange. Like this one. Do you know why the knight is fighting a snail? Because if you read enough 14th century literature this image turns up everywhere. And nobody knows why.

Perhaps its a weird joke – the knight finally facing an equally-armored foe – or maybe it’s a metaphor. Some people have proposed that the snails are references to biblical passages, or political groups, or sex. Here’s a tip – if you don’t know what something represents, sex is always a good guess. Maybe the monks just really hated snails, but then why do the knights always look so worried?

Maybe they know something we don’t. I’m not saying knights battled giant snails in medieval Europe. But I’m not not saying it either.

To see more images, go to the Medieval Manuscripts blog at the British Library. Thanks to io9.com and reddit for the heads up.

 
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Posted by on October 22, 2013 in Anthropology, History

 

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Jökulhlaup

The Ice Age fascinates me. Tectonic plates take millions of years to change the earth, but a few hundred million tons of ice and water can do it in a few thousand. Or sometimes, if the conditions are just right, things happen a lot faster.

When a glacier melts, the water usually flows away as a stream or river from the base of it. However, if the water is dammed and released, or if something like a volcano causes catastrophic melting, that stream can turn into a devastating flood.

This is what is known as a jökulhlaup (pronounced yoo-kul-hloo-ee-p) or glacial outburst flood. They’re well-known in Iceland (where we get “jökulhlaup” from) because of the numerous glaciers and volcanoes, but can occur anywhere where glaciers exist and can be very dangerous. The 1755 Mýrdalsjökull jökulhlaup may have released more cubic meters of water per second than the Amazon river.

During the last ice age these kinds of massive outbursts were very common. As the planet warmed, immense lakes of meltwater formed in the middle of the retreating glaciers, eventually releasing unimaginably large floods. It’s now accepted that the bizarre geology of the channelled scablands was the result of just a handful of these outbursts.

Jökulhlaups – very dangerous, very interesting.

Source: http://en.wikipedia.org/wiki/J%C3%B6kulhlaup

 
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Posted by on October 20, 2013 in Natural History

 

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Tiny, Tiny Porpoise

Photo from whaletrackers.com courtesy of Barb Taylor

Photo from whaletrackers.com courtesy of Barb Taylor

Look at this porpoise. It is so tiny. Even its name – vaquita – means little cow. I bet you didn’t even know this guy existed.

Although, really, it’s not your fault. They’re very rare and are actually the most critically endangered of all the cetaceans (an order that includes whales and dolphins). Vaquitas are only found in the northern bay of the Gulf of California, near where the Colorado River empties out into the sea. The water there is pretty murky and these guys are hard to spot, so there’s not a lot known about them. They weren’t even officially discovered until 1958.

And when I say they’re very rare I mean they’re very rare. As few as 150 of them may be left in the wild.

Check out www.whaletrackers.com to learn more about these guys!

 
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Posted by on September 26, 2013 in Natural History

 

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Molasses Spill Destroys Hawaii Reef

Image from Dailymail.co.uk

Image from Dailymail.co.uk

Sometimes it seems like we can’t even touch the ocean without causing some sort of environmental disaster. British Petroleum poisons the Gulf of Mexico, our ships might be deafening whales, and now even molasses is killing fish. That’s what’s been happening off Honululu’s Sand Island harbor since September 9th, 2013, when a faulty pipe caused over 200,000 gallons of molasses that was supposed to go on a ship to be dumped into the harbor instead.

Turns out, molasses is pretty bad for fish. Instead of sitting on top of the water like oil does, the molasses immediately sank to the bottom of the reef, suffocating anything unlucky enough to be caught in it. Worse still, the sudden influx of pure sugar might be causing an algal and bacterial bloom. These guys suck all the oxygen out of the water and can even be harmful to human health.

Goddamnit molasses, stop accidentally killing things.

Officials say that there’s not much they can do to help out here. It’s not like they can scoop it out or try to contain it like an oil spill, which means they have to sit back and wait for the ocean currents to do the majority of the work. Luckily, most of the fish population should recover quickly as newcomers help repopulate the reef but the immobile animals, like the corals that help build the reef, may take years or even decades to recover.

The company that manages molasses shipping out of the port, Matson Navigation Co, has stepped up and claimed responsibility for the accident, saying that any recovery efforts will be paid out of their pocket and that they will take steps to make sure this never happens again, even if it means abandoning their molasses operations.

Hopefully, the reef will recover quickly. Preliminary fly-overs already look better. Hawaii’s reefs host hundreds of different fish species, including angelfish, bigeyes, blennies, butterflyfish, sunfish and jacks. These species are important to both the fishing and tourism industry in Hawaii. Any large scale disaster has the potential to seriously affect people’s livelihoods.

Not to mention, you know, the fish’s.

 
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Posted by on September 22, 2013 in Modernity

 

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Dogs feel Okay about Robots

Turns out, dogs like robots – if we let they know they’re okay. This is according to a new study from Germany that set out to test how animals would react to robotic helpers. To do this, the researchers put the dogs in a room with a human and a robot, watched, and waited.

As their study concludes, it turns out that the dogs mostly take their cues from us.

If the humans acted like the machines were, well, machines – ignoring it, typing on its keyboard, etc – the dogs weren’t that interested in the robot. Even if it started making noises or using one of it’s insanely creepy mechanical claw-hands to try to point at various dog treats hidden in the room. But if the person acted friendly towards it – talked to it, shook it’s (creepy, fake, monstrous) hand – the dog was much more keen on it. The dogs spent much more time around “friendly” robots and were better at finding hidden food.

These were not good-looking machines, by the way. The dogs were definitely not working off sight. Imagine the front bit of a treadmill on wheels if you taped hospital gloves to it and gave it sentience. And, while the robot was never as successful as a human along was, the researches did show that there was a clear difference.

I’m not sure what the application of this technology is, but it’s pretty cool to think about. Maybe it’s just practice for when robots take over the world. After all, just because we’re all either dead or subjugated doesn’t mean our pets should have to suffer.

 
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Posted by on September 19, 2013 in Modernity

 

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