WATCH: These are the top 5 deadliest substances on Earth

What not to drink.

Have you heard the one about Bulgarian journalist, Georgi Markov? Like a plot-line straight out of a Bond film, says Hank Green in the episode of SciShow above, Markov was just walking across a bridge in London one day, minding his own business, when all of a sudden, he felt a slight sting in his right thigh. The well-known Communist defector, who was at the time working for the BBC, turned around, and saw a man behind him picking an umbrella up off the ground. 

That evening, Markov had developed a severe fever, and four days later, he was dead. Turns out, Markov had been assassinated for his political views by the man with the umbrella, which was specifically designed to shoot a pellet laced with one of the most powerful natural toxins in the world, that's not produced by an animal - ricin. (And no, Walter White wasn't the assassin.)

"Just 500 micrograms of the stuff - that's five ten thousandths [0.0005] of what a paper clip weighs - is enough to kill a man," says Hank. 

But even that isn't close to the deadliest substance that Earth has managed to dish up. And the best thing is it's not produced by some complex organism that's evolved over millions of years to hunt and kill its prey with the efficiency of some kind of Freddy-Jason-The Predator super-hybrid. Nope, the most deadly substance known to science is produced by a simple, tiny species of bacterium. I'll let Hank explain to you just how potent this substance is in the episode of SciShow above, but let's just say... I'm glad I'm not a lab mouse. Because those poor bastards never even saw it coming. 

Source: SciShow

Scientists have created insulin-producing cells that could replace injections

                                      Artificial pancreases are on their way.

Australian scientists from the University of Technology, Sydney (UTS), have created a line of insulin-producing cells that could eliminate the need for Type 1 diabetics to inject themselves with insulin. 

The development on its own is pretty impressive, but the cells, which are derived from liver cells, are now on their way to being incorporated to a world-first bio-artificial pancreas after being licensed by US biotechnology company PharmaCyte Biotech last October.

PharmaCyte Biotech has already acquired something called the Cell-in-a-Box® system, which is basically a tiny cellulose-based ‘capsule’ that can house artificial cells and integrate them into a human body. This platform can be used to develop treatments for any disease where cells aren’t releasing the molecules they’re supposed to, but after acquiring the license to the insulin-producing cells, it's clear that PharmaCyte Biotech has set their sites on targeting Type 1 diabetes.

Type 1 diabetes or juvenile-onset diabetes is an autoimmune disease that occurs when a person’s immune system attacks their pancreas’s islet cells and prevents it from properly regulating the body’s blood glucose levels by releasing insulin.

The new cell line, called “Melligen” cells, is derived from human liver cells, which have been genetically modified to take over the role of the pancreas's insulin-producing islet cells. 

"When a foetus develops, the liver and the pancreas form from the same endodermal origin," explained Ann Simpson from UTS:Science, who has been developing the cells over the past 20 years, in a press release. Which means that they should have the potential to do the same things as one another.

Early lab trials have shown that the genetically modified Melligen cells are able to release insulin in direct response to the amount of glucose in their surroundings - something that could help type 1 diabetics to live without daily injections and regulate their blood sugar levels naturally.

"My team and I are excited by the prospect of working with PharmaCyte Biotech to eliminate daily injections for insulin-dependent diabetic patients,” said Simpson in the release.

The next step for the company is for PharmaCyte Biotech to embed clusters of the Melligen cells into the Cell-in-a-Box® capsule, which is around the size of a pin head.

These artificial pancreases will then be transplanted into animals to test whether they can effectively integrate into the body and regulate insulin levels. After that, they can begin testing the technology in humans.

Several other groups are now working on artificial pancreases that use sensors under the skin, or even temporary tattoos to monitor blood glucose levels. But these systems all require a pump to control the amount of insulin required in response to these levels, rather than biologically sensitive cells.

It’s pretty exciting to see all the ground-breaking work on diabetes and insulin-producing cells finally be commercialised into a product that could directly change people’s lives.

Watching porn may boost a man's performance in bed

And no, it doesn't lead to erectile dysfunction.

It’s hard to argue that pornography, especially the hardcore stuff, is healthy viewing for men. It objectifies women and it perpetuates myths about how sex actually goes down in the real world, where not every guy is hung like an argentine duck or has the sexual stamina of an olympic triathlete.

But there’s an amazing, epic, and obscene (pun intended) amount of free porn online, so inevitably, people will indulge. The question is, aside from the social stigma of watching these sex films, are there any real physical repercussions?

There has been a lot of speculation that over-exposure to porn can lead to erectile dysfunction (ED). The basic argument is this: men get desensitised, or come to expect way more variety in the sack than most monogamous relationships offer, and therefore, can't get it up.

But a recent study, focussed exclusively on men and published in the online journalSexual Medicine, says porno viewing is unlikely to hinder someone's ability to have an enduring erection, and suggests that men who regularly watch porn may actually perform better in bed, becuase they enjoy greater desire and arousal with their partners.

The researchers from Concordia University in Canada and UCLA in the US, saytheir study is the first to actually test the relationship between how much porn men are watching and the likelihood that they’ll experience erectile dysfunction. 

“The study shows that if there is erectile dysfunction in a relationship, it’s probably not the porn that’s causing it — it’s more likely the quality of the sex,” Neurobiologist Jim Pfaus from Concordia University told Karen Seidman at The Montreal Gazette.  

“This shows that all the dire predictions about porn addiction leading to erectile dysfunction aren’t necessarily true,” he added.

Pfaus, along with his co-author Nicole Prause from UCLA, analysed data collected from 280 male volunteers during previous studies in Prause’s lab. Of the 280 volunteers, 127 had regular sex partners.

The men were questioned about their sexual behaviour, both with partners and flying solo, about their porn viewing habits, and about their erectile functioning. The men, who regularly watched between zero and 25 hours of porn per week, were all shown a vanilla porn film, referred to as visual sexual stimuli (VSS), in the lab and asked to measure their arousal levels.

Men who watch more porno in their daily lives reported feeling more aroused during the lab viewing, as well as feeling higher levels of desire for both partnered sex and masturbation. Furthermore, “self-reported erectile functioning with a partner was not related to the hours of VSS viewed weekly,” the team wrote.

“Viewing more sex films was associated with a stronger sex drive, including the desire to have sex with a partner, so sex films may be able to 'stoke the fire’,”Prause told The Huffington Post.

While the researcher acknowledged that some men might simply have higher sex drives, they’re adamant that porn doesn’t deserve the bad reputation it’s received, and list in their conclusion a number of positive effects that regular porn viewing (or VSS) can have on a man’s sex drive.

For instance, they say “regular VSS use may prime sexual thoughts and, hence, sexual response… VSS may suggest or normalise sexual behaviors, providing a wider repertoire of stimuli for which men may experience desire. Finally, VSS use has been associated with more positive attitudes about sex. If this is causal from VSS use, VSS use might be reducing some anxieties about sexual interactions that are a common cause of erectile problems."

In other words, porn, rather than limiting your erectile function, could have just the opposite effect. The researchers say "erectile dysfunction is most likely caused by the same issues that have been known for some time, such as performance anxiety, poor cardiovascular health, or side-effects from substance abuse."

The study has already garnered some criticism from an online forum called Reboot Nation, which is essentially a community of anti-porn activists. They say the study doesn’t adequately investigate men who have complained of erectile dysfunction or people who have developed serious addictions, and is flawed because it doesn’t “assess actual erections”. Meaning, the researchers haven't done a thorough inspection of the men's penises to back-up their self-reported claims of good showing.  

Still, the issue of porn addiction is an interesting one. In a previous study, researchers at Cambridge University showed that the activity in the brains of people claiming to be porn addicts resembles some of the activity happening in the brains of drug addicts, which is somewhat alarming.

For a refresher on the science of pornography addiction check out the below ASAP Science video.

Sources: The Montreal Gazette, The Huffington Post

NASA has spotted a strange aurora on Mars

And it was so much cooler than the aurora on Earth.

It's been a big week for the skies, with pretty much all of us who live remotely close to a pole scanning for signs of super-powerful aurorae, or preparing to witness the solar eclipse. And over at NASA, researchers reported that their MAVEN probe had spotted an aurora glowing over Mars in mid-December last year - and it's like nothing seen on the Red Planet before.

Aurorae are caused when charged particles that have been blasted out of the Sun interact with a planet's atmosphere. On Earth, these light up the skies above the north and south magnetic poles, but on Mars, scientists have only ever seen aurorae over the Red Planet's southern hemisphere, where the magnetic field is the strongest.

However, this newly described aurora, which researchers are calling the "Christmas lights", as it was spotted between the 8th and 23rd of December last year, occurred all across the northern hemisphere, and at far lower altitudes than any previous aurorae.

"We're seeing it not connected to magnetic regions," the MAVEN mission leader, Bruce Jakosky, told New Scientist. "We don't know if it is occurring only at the places we're observing, or if it is globally distributed."

Around the same time, the Sun was pouring out electrons at high enough energies to penetrate the Martian atmosphere, as Jacob Aron explains for New Scientist. So it's likely that this played a role in triggering the strange event, but so far the team has no answers for exactly how it occurred.

The MAVEN probe is now lining up to look at the entire northern hemisphere of the Red Planet in the hopes of finding some answers.

Source: New Scientist

WATCH: The rocket booster that will take humans to Mars in action

All we can say is whoa. Seriously, whoa.

In case you missed it, NASA has grand plans to send humans to Mars by mid-2030s. And by the looks of it, they’ll be powered there by a fire demon that’ll light up the sky.

All poetic imagery aside, this is the most powerful rocket booster ever built, and you can see it in action in the video above, taken at the first test of the system earlier this week.

The booster, which will propel NASA’s Space Launch System (SLS) and Orion spacecraft deep into space, including to Mars and an asteroid, fired for a total of two minutes - the same amount of time it would take to blast off the launch pad. In that time, it is capable of producing around 1.6 MILLION kilograms of thrust (3.6 million pounds).

This was one of two necessary tests before the booster is qualified for flight, and was conducted in the middle of the Utah desert, where it would have left some serious scorch marks.

In this trial, the booster was heated to 32 degrees Celsius (90 Fahrenheit) to test it at the top range of its temperature limit. The next test, which is scheduled for early 2016, will make sure it works just as well at the bottom end of the temperature scale, at 4 degrees Celsius (40 Fahrenheit).

"The work being done around the country today to build SLS is laying a solid foundation for future exploration missions, and these missions will enable us to pioneer far into the solar system," said William Gerstenmaier, NASA’s associate administrator for human exploration and operations, in a press release. 

"The teams are doing tremendous work to develop what will be a national asset for human exploration and potential science missions." 

We can’t wait to see this bad boy unleash all its fire and brimstone on a launch pad in the coming years. If nothing else is certain about a mission to Mars, at least it looks like we’ve got enough fire power.

Driverless Mercedes spotted zooming around San Francisco

Welcome to the future.

Last week, San Francisco locals got to see first-hand what life could be like when our roads are filled with driverless cars, and I think we can all agree it looks pretty damn great.

Named the F015 Luxury In Motion - that name is probably the only ill-conceived thing about it - the car was first revealed to the public at the Consumer Electronics Show in Las Vegas last September. Since then, Mercedes-Benz has announced that it’s become one of the first car manufacturers in the world to receive authorisation from the state of California to test self-driving cars on public roads. 

The F015 is being billed as a "virtual living room", with seating for up to four people arranged in the back like two sets of couches facing each other. So basically, you could call this thing around after a hard day’s work, hop in, pick the wife up and have a glass of wine on your way home. "And, because its Mercedes, it comes trimmed in walnut veneer, nappa leather, polished aluminium and glass, with soft blue LED lighting,” says Jason Fell at Entrepreneur. 

San Fran residents are now getting their first look at the futuristic curiosity, Reddit user 'GoogleplexStar' posting the pic above, commenting, "This driverless Mercedes is cruising around San Francisco, blowing everyone's minds." It was also spotted driving itself around Twin Peaks, near the city’s geographical centre, for a slick photoshoot. It’s not clear whether or not there’s actually someone inside directing it, or if it’s functioning completely autonomously, but either way, it’s a pretty bold statement. 

So what would the world be like filled with driverless cars? A recent study from researchers in Sweden into the impact of self-driving cars on traffic and daily commutes suggests that they could actually decrease instances of traffic jams and road congestion significantly. 

The report, led by Pierre-Jean Rigole from the KTH Centre for Traffic Research, says that self-driving cars could replace 14 regular cars, so long as people were happy to car pool and allow an average of 15 percent extra commuting time. And on top of that, parking space requirements would drop by 80 percent.

According to David Nield at Digital Trends, the first driverless cars are predicted to hit roads by 2020, but the first iteration will still need some input from a driver. I'm counting down the The F015 is being billed as a "virtual living room", with seating for up to four people arranged in the back like two sets of couches facing each other. So basically, you could call this thing around after a hard day’s work, hop in, pick the wife up and have a glass of wine on your way home. "And, because its Mercedes, it comes trimmed in walnut veneer, nappa leather, polished aluminium and glass, with soft blue LED lighting,” says Jason Fell at Entrepreneur. 

San Fran residents are now getting their first look at the futuristic curiosity, Reddit user 'GoogleplexStar' posting the pic above, commenting, "This driverless Mercedes is cruising around San Francisco, blowing everyone's minds." It was also spotted driving itself around Twin Peaks, near the city’s geographical centre, for a slick photoshoot. It’s not clear whether or not there’s actually someone inside directing it, or if it’s functioning completely autonomously, but either way, it’s a pretty bold statement. 

So what would the world be like filled with driverless cars? A recent study from researchers in Sweden into the impact of self-driving cars on traffic and daily commutes suggests that they could actually decrease instances of traffic jams and road congestion significantly. 

The report, led by Pierre-Jean Rigole from the KTH Centre for Traffic Research, says that self-driving cars could replace 14 regular cars, so long as people were happy to car pool and allow an average of 15 percent extra commuting time. And on top of that, parking space requirements would drop by 80 percent.

According to David Nield at Digital Trends, the first driverless cars are predicted to hit roads by 2020, but the first iteration will still need some input from a driver. I'm counting down the days.

Source: Entrepreneur

You can now turn your brown eyes blue for $5,000

This is actually happening

Thirty-seven patients in Mexico and Costa Rica have successfully undergone a special laser procedure to change the colour of their irises from brown to blue. 

Conducted by a California-based company called Stroma Medical, the procedure costs $5,000, and right now can only be performed in certain countries outside the US. The company is yet to be granted approval from US government officials to practice the procedure locally.

How is all of this possible? Our eye colours are pretty fascinating things, we don’t get them from cells that are pigmented brown, blue, or green, but rather from the very specific structures that make up the two layers of our irises - the epithelium at the back and the stroma at the front. As ScienceAlert editor Fiona MacDonald wrote back in December, the colour of our eyes depends on how the black-brown pigments in our incredibly thin, two-cells-wide epitheliums interact with the dark pigment called melanin in our stromas:

"People with blue eyes have a completely colourless stroma with no pigment at all, and it also contains no excess collagen deposits. This means that all the light that enters it is scattered back into the atmosphere and as a result of the Tyndall effect, creates a blue hue. 

Interestingly, this means that blue eyes don’t actually have a set colour - it all depends on the amount of light available when you look at them."

And according to the same principles, says Stroma Medical chairman, Gregg Homer, under every brown eye is a blue eye. “If you take that pigment away, then the light can enter the stroma - the little fibers that look like bicycle spokes in a light eye - and when the light scatters, it only reflects back the shortest wavelengths and that’s the blue end of the spectrum,” he told Susie Poppick at Time Magazine.

The laser treatment lasts just 20 seconds, and then the patient has to wait a few weeks for their body to remove the dead pigmented tissue, says Poppick.

Now, we're not advocating that you start saving up and plan a jaunt to Mexico to buy yourself some new baby blues, because there are some concerns about the long-term safety of the procedure. But who knows? Maybe changing your eye colour will be as easy, safe, and common in the future as getting laser vision correction is now. Meanwhile, us green-eyed folks can be smug in the knowledge that no money can buy these particular hues... yet.

Source : Time Magazine