Clever, no further explanation needed.

Clever, no further explanation needed.

Via Reddit

teded: Despite what many may think, handedness…

teded:

Despite what many may think, handedness is not a choice. It can be predicted even before birth based on the fetus’ position in the womb. So, if handedness is inborn, does that mean it’s genetic? 

Well, yes and no. Identical twins, who have the same genes, can have different dominant hands. In fact, this happens as often as it does with any other sibling pair.

From the TED-Ed Lesson Why are some people left-handed? – Daniel M. Abrams

Animation by TED-Ed

Happy Left Hander’s Day!

Proud to be a lefty? Grab yourself a Left Hand, Best Hand t-shirt, designed by TED-Ed! 

Poison dart frogs have evolved a resistance to…

Poison dart frogs have evolved a resistance to their own toxins. These tiny animals defend themselves using hundreds of bitter-tasting compounds called alkaloids that they accumulate from consuming small arthropods like mites and ants. One of their most potent alkaloids is the chemical epibatidine, which binds to the same receptors in the brain as nicotine but is at least ten times stronger. 

An amount barely heavier than a grain of sugar would kill you. So what prevents poison frogs from poisoning themselves? Think of the molecular target of a neurotoxic alkaloid as a lock, and the alkaloid itself as the key. When the toxic key slides into the lock, it sets off a cascade of chemical and electrical signals that can cause paralysis, unconsciousness, and eventually death. But if you change the shape of the lock, the key can’t fit. For poison dart frogs and many other animals with neurotoxic defenses, a few genetic changes alter the structure of the alkaloid-binding site just enough to keep the neurotoxin from exerting its adverse effects.

From the TED-Ed Lesson Why don’t poisonous animals poison themselves? – Rebecca D. Tarvin

Animation by Giulia Martinelli

A Perseids meteor catched while photographing …

A Perseids meteor catched while photographing the Andromeda galaxy in 2016.

Via APOD: Meteor before Galaxy

Image Credit: Fritz Helmut Hemmerich

Simulation of groups of positrons being concen…

Simulation of groups of positrons being concentrated into a beam and accelerated.

Credit: Aakash Sahai

Via Phys.org: Mini antimatter accelerator could rival the likes of the Large Hadron Collider

Paper: DOI: 10.1103/PhysRevAccelBeams.21.081301 (PDF)

teded: Happy Book Lover’s Day! Get lost in a …

teded:

Happy Book Lover’s Day! Get lost in a good book. Need some ideas?

31 great books for students, chosen by students

40+ books recommended by our educators

From the TED-Ed lesson The contributions of female explorers – Courtney Stephens

Animation by @lizziakana

Alluvial fans at Roddy crater on Mars.

Alluvial fans at Roddy crater on Mars.

Via NASA: Fans of Roddy Crater (Image credit: NASA/JPL-Caltech/Univ. of Arizona)

virtual-artifacts: auricaedus: Vatican Museums…

virtual-artifacts:

auricaedus:

Vatican Museums , March 2017.

I had a lunch in this hallway. Me, small PhD student among biggest minds of Egyptology, eating pasta, drinking prosecco and… feeling fulfilled. Good memory. 

Why don’t poisonous animals poison themselves?

In fact, how do any toxic animals survive their own secretions? The answer is that they use one of two basic strategies: securely storing these compounds or evolving resistance to them. Snakes employ both strategies – they store their flesh-eating, blood-clotting compounds in specialized compartments that only have one exit: through the fangs and into their prey or predator and they have built-in biochemical resistance. Rattlesnakes and other types of vipers manufacture special proteins that bind and inactivate venom components in the blood.

image

Poisonous and venomous animals aren’t the only ones that can develop this resistance: their predators and prey can, too. The garter snake, which dines on neurotoxic salamanders, has evolved resistance to salamander toxins through some of the same genetic changes as the salamanders themselves.

image

That means that only the most toxic salamanders can avoid being eaten— and only the most resistant snakes will survive the meal. The result is that the genes providing the highest resistance and toxicity will be passed on in greatest quantities to the next generations.

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As toxicity ramps up, resistance does too, in an evolutionary arms race that plays out over millions of years. This pattern appears over and over again. Grasshopper mice resist painful venom from scorpion prey through genetic changes in their nervous systems. Horned lizards readily consume harvester ants, resisting their envenomed sting with specialized blood plasma. And sea slugs eat jellyfish nematocysts, prevent their activation with compounds in their mucus, and repurpose them for their own defenses.

From the TED-Ed Lesson Why don’t poisonous animals poison themselves? – Rebecca D. Tarvin

Animation by Giulia Martinelli

Refreshing vocabulary lesson: ‘petrichor’ /ˈpɛ…

Refreshing vocabulary lesson: ‘petrichor’ /ˈpɛtrɪkɔːr/

petrichor = the smell of rain on dry ground

example: ‘I love the smell of petrichor in the morning’