If you can’t find you limbs

We all know our five senses. But, we have many more senses than just those five. We have the sense of proprioception, for example, that helps you keep track of where your body parts are. But, what if you lack that?

Where’s my nose?

Proprioception is, the sense that allows you to touch your nose with your eyes closed, or type without looking at your hands. The reason for this is that your brain knows where your hands and nose are without necessarily having to look at them. And that’s what proprioception does. But what if you don’t have that sense? What if you’re blind, but instead of lacking sight, your proprioception did not work.

Hard to find that sense

Well, it’s quite hard to study that. Because the symptoms of lacking proprioception aren’t as clear as, say, lacking hearing. Another things is that the sense isn’t located at one point in your body, unlike, for example, your eyes. Eyes have a specific place and you know exactly what they do; they see. But with proprioception, the location isn’t really clear. The sense is working all over your body. So you know where all your body parts are hanging out. But this makes it really hard to study this sense.

9 and 19

Fortunately, Carsten Bönnemann and his team have found two people; a nine-year-old girl and a nineteen-year-old woman who totally lack proprioception. With their eyes closed, they can’t tell where they limbs are, or in which way their joints are being moved. With their eyes open, they can tell, but they can only do so if they actually see what’s happening. The researchers considered the situation of the woman and the girl to be so weird that they did a genetic test on both of them. The scientists discovered that both of them have an extreme mutation in a gene called PIEZO2. Scientists already linked this gene to our sense of touch earlier, which made Carsten Bönnemann and his team think that PIEZO2 plays an important role in proprioception.

Whoops, I didn’t mean to…

The discovery of this gene also has another advantage, especially when you’re a bit clumsy. Clumsiness has already been linked to your sense of proprioception not working perfectly. Since proprioception is linked to the PIEZO2 gene, this means that, if you’re clumsy, you may have a mutation in that gene. It doesn’t have to be extreme to the point that you totally lack the sense. But if it malfunctions a bit, this could also be reason enough for you to tip over glasses of water a little more often. So don’t worry, it’s not your fault, it’s just your genetics.

Sources:

http://www.sciencemag.org/news/2016/09/researchers-discover-gene-behind-sixth-sense-humans

http://www.nejm.org/doi/full/10.1056/NEJMoa1602812

https://en.wikipedia.org/wiki/Proprioception

http://www.livescience.com/images/i/000/078/671/original/boys-nose.jpg?interpolation=lanczos-none&downsize=*:1000

http://joshuamhood.com/wp-content/uploads/2016/07/water.jpg

Gaia is mapping the stars

Spacecraft Gaia is going to map our entire galaxy. And with all that data, NASA scientists hope to compose a five-dimensional map of our galaxy, and discover the Milky Way’s past.

spacecraft Gaia

Where are the stars?
Three years ago, spacecraft Gaia was launched. Then the spacecraft, which basically is a giant telescope floating in space, needed the past three years to put together a draft of a map of our galaxy. The reason it took Gaia so long to only turn out a draft is that the spacecraft has already catalogued more than a billion stars for this draft. This is of course an incredible amount, but Gaia isn’t done yet. Our galaxy consists of over 200 billion stars, so the telescope has only catalogued half a percent of all stars. Gaia is going to further map our galaxy for at least another two years. In these five years, Gaia isn’t going to be able to map the other 199 billion stars, instead Gaia is going to focus on refining the data about the billion stars that the spacecraft already mapped.

Gaia's map so far

A look into the future and the past
Gaia has already mapped the position and brightness of over a billion stars, and also the distance and speed of the two million brightest stars. In the next two years, NASA scientists, who control the spacecraft, want to find the distance and speed of way more stars. They’re hoping for a billion. But that’s not all, they also want to map the speeds of the 100 million brightest stars in 3D. While the speeds of the other, dimmer stars are only in 2D, so only sideways. These data will enable scientists to create a five-dimensional model of our galaxy, and essentially predict the Milky Way’s past and future. This could teach us a whole lot about the Milky Way’s possibly violent past, as there are indications that the Milky Way has absorbed quite a lot of smaller galaxies in the past. Which would have caused violent collisions of which we still can see traces today.

Better than the ocean floors
This galaxy-map will also help scientists understand the birth of stars better. Because with the data that will be gathered by Gaia, scientists can calculate the size and also the age of stars, which are essential for finding out how stars actually form. Another thing is that our own Milky Way is a bit like the earth’s ocean floor compared to the moon. We’ve got a better grasp of what’s happening on the moon than on what’s happening on the ocean floor. In a similar way, we know more about some other galaxies than about our own home. That is mainly because the Milky Way is so big, and we’re right in it so we can’t really take overview pictures of it. This makes getting a good, complete view of the Milky Way really hard, but Gaia is changing that. Within a few years, we’ll have the most detailed map of our galaxy yet. And we will, no doubt, have learned all new kinds of cool and interesting things about our own galaxy, thanks to Gaia.

Click here to read more about astronomy.

Sources:
https://www.scientias.nl/miljard-sterren-elkaar-ziet-er-zo/
http://www.cosmos.esa.int/web/gaia/home
http://www.scientificamerican.com/article/upcoming-galaxy-map-could-radically-transform-how-we-see-the-milky-way/
http://blogs.esa.int/gaia/files/2013/07/Gaia_mapping_the_stars_of_the_Milky_Way.jpg
https://cbssanfran.files.wordpress.com/2016/09/gaia_gdr1_sky_map_annotated_hd.png

Ants don’t just smell and count, they also look around

Ants are amazing navigators, they can find their homes even when their quite far away from their nests. This is really impressive, considering the small size of the ants. Scientists have finally found out how the ants can pull it off.

Counting and smelling

A desert ant

Scientists thought they knew all of the tricks ants use to find their way back home. Ants count their steps away from their nests, so they know exactly how far away they are from their home. Ants also have excellent smell, so they can smell other ants and follow them home in the case they accidentally lose count of their steps. This is also the reason ants like to move around in ‘trains’. By moving in trains, they can easily follow each other through their olfactory navigation. Though this method seems flawless, if you were to separate the front and back half of an ant train using a piece of cardboard, for example, the ants in the back half would get utterly disorientated. This would happen because they can’t smell their fellow ants anymore. If you remove the piece of cardboard, the ants will be able to smell their friends again and they can continue their journey back to their nest without any problems. However, a special species of ants called Cataglyphis desert ants are exceptionally good at navigating, better than these two methods can explain. This has left scientists puzzled over the mystery for ages, until now.

How flies see the world

Just use your eyes!
The answer isn’t really weird, or even surprising, desert ants simply look around to estimate distances and find out where they are. It’s the same principle as when you’re driving a car, trying to find your cousin’s new home in a labyrinth-like neighbourhood. Although this seems like a rather obvious answer for humans, it’s somewhat strange for insects like ants since insects have notoriously low vision. The reason for this is that they have so-called facet-eyes made from numerous smaller eyes. These work together to create one big picture. The problem is, insects’ brains aren’t that efficient at putting together all the information from the small eyes. This means that insects see the world in a distorted and pixelated way, which is why you can easily swat a fly with a fly swatter. Due to the holes in the swatter, the fly simply cannot see what’s coming for it. On the other hand, the desert ants can apparently see well enough to find their way back to their nest, even when their step counting and smelling methods fail.

Can the others see too?
Since Cataglyphis desert ants have three different methods of navigating; counting, smelling and looking around, they are some of the best navigators in the realm of insects. This is also due to the fact that they can find their way using each of those methods separately. Scientists already knew that flying insects such as flies, wasps or bees, use their eyes to navigate, but they didn’t know that walking insects, like ants could do the same. This opens all kinds of new, interesting research about the sight of all other kinds of walking insects, for example beetles.

Click here to read more about biology.

Sources:
http://sci-hub.bz/10.1126/science.aaf9754
http://www.sciencemag.org/news/2016/09/video-blindfolded-ants-reveal-clues-insect-navigation
http://www.naturephoto-cz.com/photos/others/desert-ant-87673.jpg
http://8020.photos.jpgmag.com/2851044_245460_1a70698cf0_p.jpg

New giraffe species are endangered

When you think of giraffes, you imagine the long-necked, spotted animal we all know. But German scientists have discovered that there are actually four species of giraffes.

Nubian giraffes

Not nine but four

We used to think that there were nine subspecies of giraffes. The difference tween the different subspecies of giraffes was mostly based on their coat pattern. The Nubian giraffe, for example, has very dark spots on its body, while the Kordofan giraffe has pale spots. These different coat patterns don’t mean that the giraffes are different species. Instead they are different subspecies of an umbrella species of giraffes. This means that, when a giraffe of one subspecies, for example a Kordofan giraffe mates with a Nubian giraffe and they get a baby, that baby giraffe is also fertile. In other words, both giraffes belong to the same species.

That’s a whole different species!

But now, a team of German, American and South-African scientists have discovered that giraffes can be split into nine subspecies, but into four actual species. The scientists have split the old giraffe species into Northern Giraffes, Southern Giraffes, Masai Giraffes and Reticulated Giraffes. This doesn’t mean, however, that two giraffes from different species can’t have fertile offspring. They still can, but to the scientists’ surprise, they don’t interbreed that often in the wild. This is quite odd since giraffes can move big distances and could easily reach other groups of giraffes. And since different giraffe species don’t interbreed, this means that the four different species of giraffes are still getting more diverse. To define the different species, the team of scientists analysed the DNA of different giraffes and compared the results. They found out that some giraffes’ DNA differ even more from each other than a brown bear’s and a polar bear’s do. Those bears belong to two different species, so those two giraffes most likely belong to different species as well. After a detailed study of the DNA of a large group of giraffes in Africa, they discovered a total of four different species of giraffes. And this discovery has some important consequences for animal protection.

Last chance to see; West African Giraffes

Save the giraffes!

The original giraffe species was already somewhat endangered; there are only 100,000 left, where there used to be 150,000 thirty years ago. This means that giraffes aren’t as endangered as rhinos or elephants. But since giraffes can be split into four species, three of those four species are seriously threatened with extinction. Only the Southern Giraffes seem relatively safe, while the Northern Giraffes, of which there are only 4500 left, and the West African Giraffes, of which there are only 400 left are classified as endangered. This new discovery now asks for better protection of and more attention to giraffes, otherwise one or more of these newly discovered species may be gone for good soon.

Click here to read more about biology.

Sources:

http://giraffeconservation.org/giraffe-subspecies/

http://www.cell.com/current-biology/fulltext/S0960-9822(16)30787-4

http://www.sciencemag.org/news/2016/09/surprise-there-are-four-species-giraffe-not-one

https://www.theguardian.com/environment/2016/sep/08/researchers-discover-there-are-not-one-but-four-species-of-giraffe

https://upload.wikimedia.org/wikipedia/commons/9/99/Al_Ain_Zoo_Giraffe.JPG

http://thegracefulgiraffe.weebly.com/uploads/4/5/9/9/45997813/8357383_orig.jpg

Dawn on almost three dwarf-planets

In 2007, space probe Dawn was launched. And now, nine years later the probe has reached its final destination; Ceres. It has already discovered some strange, exciting things.

Is it salt or water?
When Dawn started orbiting Ceres in 2015, it found strange, white spots on the dwarf-planet’s surface. Unfortunately, Ceres’ cameras couldn’t take pictures that were detailed enough for us to see what those white spots were. The NASA scientists that control the space probe then managed to get Dawn into a lower orbit around dwarf-planet Ceres. In this lower orbit, Dawn can observe the white spots more closely. Scientists discovered that the white spots are all the bottoms of craters. This made them think that the spots are either made of salt or ice. The space probe couldn't get close enough to the dwarf-planet to find out which one it is. If the white spots are ice, this means that the dwarf-planet has at least one requirement for life; water. However it’s unlikely that we’ll find aliens there, since the big rock is way too cold. And on top of that, the dwarf-planet doesn’t have an atmosphere. But Ceres isn’t the only dwarf planet space probe Dawn visited.

Two for one!
Space probe Dawn already orbited another dwarf planet called Vesta between in 2011 and 2012. This makes Dawn the only space probe that has orbited a celestial body, studied it and travelled further to orbit and study a second celestial object. The two Voyager space probes also studied multiple celestial bodies; the gas giants of our solar system, but they never orbited them. On Vesta there were dark spots that sparked the interest of scientists. Fortunately, Dawn could zoom in enough onto those dark spots to tell what they are; craters. Craters may not sound as interesting as water and possible - though highly unlikely - alien life. Those craters can tells us something else though; we can discover a lot about what happened during Vesta’s life, and what it was like in our solar system billions of years ago. Dwarf-planets are a bit like time-capsules in this way.

Philae on its comet

Orbiting forever
If we want to learn more about the history of our solar system, the main thing we have to do is study asteroids better. This is also the reason that space probe Rosetta and comet lander Philae were launched. Those probes closely studied comet 67P/Churyumov-Gerasimenko, and even discovered the building blocks of life there. Space probe Dawn, however, isn’t going to orbit another asteroid. NASA scientists had proposed plans about sending Dawn to another asteroid, but this was cancelled. The scientists leading Dawn’s mission think that staying in orbit around Vesta can give us way more scientific data than a quick visit to another asteroid. So it was decided that Dawn will stay in Vesta’s orbit forever, and gather data until at least 2017.

Click here to read more about astronomy.

Sources:

https://nl.wikipedia.org/wiki/Ceres_(dwergplaneet)

https://nl.wikipedia.org/wiki/Dawn_(ruimtesonde)

http://science.sciencemag.org/content/353/6303/1008

http://sci-hub.bz/10.1126/science.aaf4219

http://www.planetary.org/blogs/emily-lakdawalla/2014/10091306-what-did-dawn-learn-at-vesta.html

https://en.wikipedia.org/wiki/4_Vesta#Observations_from_Dawn

https://en.wikipedia.org/wiki/Dawn_(spacecraft)#Cancellation_and_Reinstatement

https://www.newscientist.nl/nieuws/komeetlander-philae-is-gevonden/

http://arstechnica.co.uk/science/2016/04/nasa-dawn-asteroid-probe-after-ceres/

https://www.scientias.nl/wp-content/uploads/2015/04/dawn-954x477.jpg

http://blogs-images.forbes.com/bridaineparnell/files/2015/06/Philae_touchdown-1940x1092.jpg

Tasmanian devils got rid of their cancer

Since 1996, the population of tasmanian devils have been decimated by a contagious cancer. Recently, it has been discovered that the tasmanian devils have developed a resistance to this cancer.

Devil Facial Tumour Disease

The contagious cancer affects tasmanian devils and gives them facial tumours. These tumours begin as lumps around the mouth area and can spread to the rest of the body. They can affect the devils by preventing them from eating, giving them infections or causing their organs to fail. All of these usually lead to the death of the animal within about 6 months.

Tasmanian Devil with tumors

Lots of biting

The disease spreads when the devils bite each other. Since the disease is spread this way, it is easily propagated through a colony since they bite each other very frequently. A lot of Tasmanian devils’ social interactions are based on biting, for example when they fight.  As well as this, the tasmanian devils are thought to have a very low genetic diversity which lowers their chances of resistance to disease. This means that the devils aren’t very different from each other, so if the cancer can harm one Tasmanian devil, it can harm the other devils too. This gave the disease a very easy way to make it around nearly all the colonies.

Fighting Tasmanian Devils

Immune

But now, because of an accidental change in the Tasmanian Devils’ DNA, their genetic code, they’re now immune to the contagious cancer. They can’t get the disease anymore. And the best thing is, when they begin to reproduce, the next generation of tasmanian devils will have the immunity as well. Over time, maybe all Tasmanian Devils will have be immune and the cancer will go extinct.

That’s odd...

Scientists discovered this by comparing the genome of the immune tasmanian devils with that of a past tasmanian devil which existed before the tumor had begun. They realized that there was a difference in the actual genetic makeup of the tasmanian devils. This genetic change happened in seven different genes. Five of those are related to immune response against cancer in other mammals such as ourselves. But, the most amazing part of this discovery is that this immune response has happened very quickly. This entire immunity was evolved over just about five generations, which is around twenty years. This evolution can be compared to rabbits when a disease called myxomatosis began to affect Australia. The only difference is that the rabbits took much longer to become immune.

Looking into the future

This exciting new discovery could affect the future of cancer treatment. With the new technological advances which are being made in the realm of genetics, we might soon be able to use this discovery as a cure for cancer. This could be possible since these genetics are similar in other mammals.

Click here to read more about Biology

Sources:

http://www.pnas.org/content/108/30/12348
http://www.nature.com/ncomms/2016/160830/ncomms12684/full/ncomms12684.html
https://www.sciencemag.org/news/2016/08/tasmanian-devils-are-rapidly-evolving-resistance-contagious-cancer
https://en.wikipedia.org/wiki/Devil_facial_tumour_disease
http://www.upi.com/Health_News/2015/12/30/Second-form-of-contagious-cancer-found-in-Tasmanian-devils/4961451508112/
Di Giallonardo, F. & Holmes, E. C. Viral biocontrol: grand experiments in disease emergence and evolution. Trends Microbiol. 23, 83–90 (2015)
Epstein, B. et al. Rapid evolutionary response to a transmissible cancer in Tasmanian devils. Nat. Commun. 7:12684 doi: 10.1038/ncomms12684 (2016)
http://animals.nationalgeographic.com/animals/mammals/tasmanian-devil/

Dragonfly 44: the darkest galaxy yet

Astronomers have found a really small galaxy, which has one weird trait. It spins a lot faster than it should. Pieter van Dokkum and his team think dark matter is the explanation.

A dark dragon

The yellow smudge in the middle is Dragonfly 44

The galaxy measures around 60 000 light-years across, and is about 300 million light years away. It weighs almost the same as the Milky Way, but has nowhere near the amount of stars. Dragonfly 44 consist of about two billion stars, while our galaxy has over two-hundred billion stars. What is really strange is that the Milky Way and Dragonfly 44 appear to have roughly the same mass; both the Milky Way and Dragonfly weigh about as much as a trillion suns. This means 99 percent of the Dragonfly galaxy must consist of matter we can’t observe. A team of American and Canadian scientists think that a lot of dark matter is hiding in Dragonfly 44. It was discovered last year in the Coma galaxy cluster along with other similar galaxies, which the team combined and named Ultra Diffuse Galaxies (UDGs). Dragonfly 44 is the largest out of all of them.

What dark matter would look like if we could see it

We can’t see it, so it’s dark
What exactly is dark matter? Well, the truth is that we don’t really know. What we do know is that more than a quarter of the mass of the whole universe is dark matter. Overall, dark matter leaves scientists completely puzzled. The reason that it’s such a mystery is that dark matter doesn’t interact with light. That’s why it’s called dark matter - we can’t see it. We can only say it exists at all through the effects it has on its surroundings. One way we notice dark matter is in galaxies that appear to have more mass than their amount of stars can explain. An extreme case is Dragonfly 44, but our own galaxy also has quite a big mass-star misalignment. Scientists think that around 90 percent of all the matter in our galaxy is dark matter. This also means that everything you can see, your house; your food; the sun; and everything else is just a tenth of all the matter in our galaxy.

You’re spinning too fast!
If the hypothesis that Dragonfly 44 is made almost completely out of dark matter, it would explain some mysterious things about the galaxy. First of all, it spins way faster than it should. The general rule is the bigger the mass, the faster a galaxy spins. This is because more mass creates more gravitational force, which speeds up the spinning of the galaxy. If all the mass of Dragonfly 44 consisted of normal matter, stars that we can actually see, the galaxy would never reach such a fast spin. On top of that, even if it would, the galaxy would most likely tear itself apart. If the mass is low, the gravitational forces would be too weak to keep such a fast spinning galaxy together if there weren’t any dark matter around. Scientists also consider this discovery to be particularly interesting since galaxies that are almost completely made of dark matter have already been predicted by some theories, and this new discovery only helps those theories to become even more likely. 

Click here to read more about astronomy.

Sources:
http://arxiv.org/pdf/1606.06291v2.pdf
http://www.sciencemag.org/news/2016/07/dark-matter-search-comes-empty
http://www.sciencemag.org/news/2016/08/dim-nearby-galaxy-nearly-100-dark-matter
https://nl.wikipedia.org/wiki/Melkweg_(sterrenstelsel)
http://cdn.sci-news.com/images/enlarge3/image_4135e-Dragonfly-44.jpg
https://i.ytimg.com/vi/PznhzHOtr_Y/maxresdefault.jpg