The circle of life

MufasaEverything you see exists together in a delicate balance. As king, you need to understand that balance and respect all the creatures, from the crawling ant to the leaping antelope.
SimbaBut, Dad, don’t we eat the antelope?
MufasaYes, Simba, but let me explain. When we die, our bodies become the grass, and the antelope eat the grass. And so we are all connected in the great Circle of Life.

(Hey, who else is nostalgically hyped for the Lion King?)

The circle of life. Simple really. (Arrows point from the one that does the eating.)

Obviously, actual ecosystems don’t work that way. In Mufasa’s circle, if one of the nodes disappears due to a mysterious antelope-plague, all of life would break down. But more likely, the lion would eat a zebra instead. And if there is no grass, the herbivore will eat some leaves of a tree. (Okay, I know that Scar then went ahead to mismanage everything and life did basically die, but there’s also the part where the little plant breaks through showing that life happens anyway.)

Ecosystems are intricate webs where everything is connected to everything. If one thing falls away, the balance probably shift, but it wouldn’t be a full blown mass extinction. Even if all bees disappear, we’d end up being okay.

We don’t fully understand the intricacies of the ecosystem. We’ve tried, for example through the Biosphere 2 project (planet Earth was considered number 1). This artificial earth was built in the late ’80s in the middle of the desert in Arizona. The “bubble in the desert” was intended as a testing facility, creating a “closed system” where nothing would come in or go out, recreating different natural biomes on a smaller scale to test if a small little earth with human interference would be sustainable.

One of the goals of this facility was to see how we would build human habitats in space, and whether such closed ecological could be maintained. Remember how in the Martian, Watney had to do crazy science to be able to grow potatoes (which is “kind of really possible”, apparently)?

Biosphere 2 looks really cool and futuristic but is essentially a failed experiment.

We wanted to recreate a complete ecosystem and failed. Biosphere 2 is on the list of the 100 worst ideas of the 20th century. We obviously do not understand complete ecosystems enough to create an artificial one. It should be noted, though, that the crew members, who spent the full 2 years in the the sphere, call the experiment a success.

I am currently watching The Expanse, and in one of the episodes they talk about the Cascade. This describes how one element in a closed system breaking down (in this case an agricultural biosphere on one of Jupiter’s moons) leads to the whole system will fail in a cascade of events we cannot predict. Cut out the lions at the top of the food chain, and the antelopes will overgraze the grass and everything will die.

We can try to recreate a tiny world, completely isolated from everything else, but do we really know enough to make it work? It’s not a circle of life, life’s an intricate mumble jumble of wiggly squiggly connections and wow I just sound like the doctor talking about time.

Writing this post just took me on a weird tip through time and space. This post is a mess… (Tardis Blue Space by Koko Priyanto)

Inspiration for this post was an article in ARCADE 37.1 by Nicole DeNamur: Recognizing our environmental arrogance: what an artificial earth taught me about failure


Note: apologies for the relative radio-silence. I am currently working on a few writing projects and job applications, leaving blog writing on the down-low. Apparently my brain and typing fingers can only handle so much?

Twinsies

The twin paradox states the following:

There are two identical twins. One of them travels through space in a high-speed rocket. When they return home, the Earth-bound twin has aged more. This is a result of special relativity. Very briefly, this is due to time slowing down as higher speeds are reached, and why Matthew McConaughey returned to Earth only to find his 90-something year old daughter on her dying bed.

This thought experiment has long been exactly that, a though experiment. But recently, we actually were able to learn what happens to twins when one is in space (granted, not in a high-speed rocket, but on the ISS) for almost a year, while the other twin stays on Earth.

Real Space Twinsies

On March 27 2015, astronaut Scott Kelly arrived at the International Space Station (ISS), while his brother, astronaut Mark Kelly, remained on Earth. (One can have a discussion on who was the luckier of the two.) They did the same activities, ate the same things, and followed the same schedule*, the only difference being that Scott was 400 km from the Earth’s surface, travelling at a speed of 7.66 km/s, while Mark was 0 km from the Earth surface, travelling at a speed of merely 460 m/second, as we all are.

340 days later, March 1 2016, Scott returned to Earth. For the full duration of his time on the ISS, as well as after his return, numerous samples were collected and tests were conducted to monitor his health and compare the physiological and biological changes that happened as a consequence of spacelife. Using his twin brother, a perfect genetic duplicate, as a control.

twins patch
The Twin Study, a massive undertaking involving lots of collaboration and fancy badge design.

The effects of space

There are many “unusual” aspects about living in space, compared to living on Earth, including the odd noises of the ISS, the isolation (Scott was in contact with a mere 12 people during those 340 days), the ultra-controlled environment, a disruption of the normal body clock (imagine perpetually being jet-lagged because of constant switching of time zones), living in micro gravity and the excess of radiation.

An ultra-combined effort, i.e. a major collaboration between a lot of different labs that looked at all possible aspects of physiological and biological function, the effects of 340 days in space (in this specific set of twins) was published last month. There are a lot of changes that occur to the human body in space, some more severe than others.

An immense effort and a lot of numbers went into creating, collecting and comparing samples from the twins. Credit: NASA

There are some changes that don’t really matter much, like changes in the gastrointestinal microbiome and changes in biomass, which were affected during Scott’s time in space, but rapidly returned to normal after he returned. Not much to worry about.

Mid-level risks included known effects of living in microgravity such changes in bone density (you don’t really need to use your skeletal muscles while floating around) and changes in how the heart pumps around blood (you don’t need to fight gravity to pump blood to the head). NASA already knows this and therefore has a rigorous rehabilitation program for returning astronauts to re-acclimatize to Earth’s gravity.

However, it’s the high-risk findings that we all have to worry about, which a mostly due to prolonged floating and prolonged radiation exposure. Due to changes in air pressure as well as that thing I mentioned about blood pumping, a lot of astronauts experience ocular issues after their return, a risk that only increases with increased dwell time off-Earth. This can severely compromise vision. There is also evidence of some cognitive decline. Both those aspects are worrying in the light of long term space travel, we would hope that space-explorers can see and think clearly while carrying out dangerous tasks in dangerous conditions. And that’s without considering a final severe risk…

Who’s the oldest twin?

In addition, the radiation that Scott experienced on ISS is pretty much equivalent to 50 years of normal exposure on Earth. This causes significant genomic instability and DNA damage, and consequentially an increased risk of developing cancer.

One example of this genomic instability has to do with telomeres**. Telomeres are bits of DNA that cap the end of chromosomes. Every time a cell divides, and in the process duplicates its whole DNA library, the telomeres get shorter. When they get too short, the cell can no longer divide. This is something that happens naturally during aging: shortening of telomeres phases out cells until they can no longer divide. Eventually, this leads to cell death.

1 year of space had an odd effect on Scott’s telomeres. Some of them grew longer, while others showed shortening. However, the lengthened telomere returned to normal after Scott’s landing on Earth, while the shortening persisted. So even though Scott was the space twin in our paradox, he seems to have ended up aging faster than Mark…

At a glance, the different effects of one year in space on a human body. Well, it probably takes more than a glance to read this.

A lot happens to a body in space

Overall, the results are pretty surprising, prolonged living in space had more of an effect on the human body than researchers expected. And there is probably a lot more to learn, even just with the data collected from Scott and Mark.

On one hand, the twin study showed how resilient and robust the human body is. 91.3% of Scott’s gene expression levels returned to his baseline level within six months of landing, and some of the changes that occurred to his DNA and microbiome were no different than what occurs in high-stress situations on Earth. That’s amazing, the human body has not evolved to survive in space, but it seems to do pretty well considering how outlandish the conditions are!

On the other hand, the prolonged exposure to microgravity and high radiation does have severe effects on the human health, leading to increased risk for compromised vision, cardiovascular disease, and cancer development. Even with the rigorous preparation and rehabilitation programs astronauts go through before and after spaceflight, some of these effects will be impossible to avoid.

The massive study, combining the effort of 84 researchers in 12 different universities is a feat of collaboration (though nothing compared to the black hole telescope, if I’m honest) and it’s definitely a first that the genomes of space vs. Earth could be compared with a true genetic control. This compiled study, and the many pieces of research that are expected to be published in the next year with the results from the individual studies, provide crucial insight on the effects of space in the long term. If we think that it takes approximately 1 year for a return journey to Mars, this research is valuable for the health of future astronauts and mankind’s ambition to explore further into space.


Want to know more? Watch NASA’s video on the three key findings, or read more in the Science paper or the NASA website (links below).


Sources:

Markus Löbrich and Penny A. Jeggo. Hazards of human spaceflight. Science 364 (6436) p. 127-128. 2019. DOI: 10.1126/science.aaw7086

Francine E. Garrett-Bakelman, et al. The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight.
Science 364 (6436) eaau8650. 2019. DOI: 10.1126/science.aau8650

Twin study on the NASA website: https://www.nasa.gov/twins-study

Cover image: The International Space Station crosses the terminator above the Gulf of Guinea, image credit NASA


*I remember reading this somewhere, but I cannot find the source anymore. It is thus possible that Mark just went about his normal life. Regardless, it is amazing that NASA had the opportunity to do this experiment with a perfect genetic control.

** Fun fact, my spelling check does not know the word “telomeres” and suggests that I mean “omelettes”. Well, I guess they both get super scrambled up in space? (Eeeeh for an inaccurate joke, sorry).

One printed heart, please

It goes without saying that 3D printing is cool*. The ability to think up any three dimensional structure, design it in a 3D design software and have it materialize blows my mind. Granted, I’m making it sound like it’s a very easy and fast process and I know that’s often not the case, but I also know that for a lot of engineering and physics laboratories, the ability to relatively quickly print a model or prototype for anything is extremely useful. In addition, it’s an amazing educational resource. You can print model organs, molecular structures, planets, … and have something physical to show or throw around during a science demo.

Just to name a few reasons why 3D printing is cool.

What is possible even cooler is the potential of printing tissues and organs. And now, for the first time according to a group of researchers in Tel Aviv, it has happened: a complete 3D heart was printed.

They started with some cells isolated from a sheet of fatty tissue from a human patient. These cells were reprogrammed to what’s called pluripotent stem cells. Pluripotent stem cells have the potential to give rise to many different cell types , depending on the biochemical cues they get – for example by changing the formulation of the culture media, which contains nutrients, hormones and other components to “feed” the cells.

In this case, the cells were driven towards being heart muscle cells and blood vessel cells. By mixing these cells with a personalized hydrogel, consisting of collagen (remember, from the reindeer eyes?) and glycoproteins (proteins have a sugar molecule connected to it), the researchers created a “bioink”, a material that could be used to print cardiac tissue in the same way a 3D printer prints 3D structures using a plastic “ink”.

3D printing a mini-heart (image credit AFP or licensors)

While the 3D printed heart – currently around the size of a rabbit’s heart – cannot beat yet, the possibility to be able to print custom organs, starting from a patient’s own cells and therefore eliminating an immune response, is of major importance for medical applications. To enable heart function, the heart cells would have to be taught how to contract in an organized manner, and create a beating heart.

Beating has already been achieved in heart organoids. Organoids are little mini-organs grown in a petri dish, that mimic the organization and function of an organ in a living organism. The difference between 3D printed organs and organoids, is that organoids are allowed to form their own structure and cell types, driven by the media cocktail they are given, while 3D printing positions already differentiated cells in a 3D scaffold. Heart organoids, starting from one or a few reprogrammed cells, grow into structured groups of cells that spontaneously start beating.

Beating heart organoids (gif from Popular Mechanics US)

These organoids, however, don’t really mimic the structure of the heart unless you “force” structure by growing these mini-hearts in a mold, basically geometrically confining the cells to form a predefined structure.

A model of a pumping heart was developed last year, creating an in vitro biomimetic system that could help with drug discovery and studying cardiac diseases. While it doesn’t look as much as a heart as the 3D printed one developed by the Israeli research group, it’s still pretty amazing to watch this little blob of tissue beating under electrical stimulation:


In any case, I hope to see a combined version of all of the above: a 3D printed, functional heart. Nevertheless, this first (though debatable if they actually were the first) 3D printed heart is pretty awesome and has a lot of potential applications in medicine and clinical research. Not to mention that it looks pretty cool:

3D confocal image of the printed heart (Advanced Science, scale bar = 1mm)

Sources used:

Noor N., Shapira A., Edri R., Gal I., Wertheim L., Dvir T. 3D Printing of Personalized Thick and Perfusable Cardiac Patches and HeartsAdv. Sci. (2019), 1900344. https://doi.org/10.1002/advs.201900344

Ma Z., Wang J., Loskill P., Heubsch N., Koo S., Svedlund F.L., Marks N.C., Hua E.W., Grigoropoulos C.P., Conklin B.R., Healy K.E. Self-organizing human cardiac microchambers mediated by geometric confinement. Nat. Comm. 6 (2015), 7413. https://doi.org/10.1038/ncomms8413

Li R.A., Keung A., Cashman T.J., Backeris P.C., Johnson B.V., Bardot E.S., Wong
A.O.T., Chan P.K.W., Chan C.W.Y, Costa K.D. Bioengineering an electro-mechanically functional miniature ventricular heart chamber from human pluripotent stem cells. Biomaterials 163 (2018), 116-127. https://doi.org/10.1016/j.biomaterials.2018.02.024


*Sudden realization that most (if not all) of this blog is me saying “Hey, did you hear about this science thing, it’s really cool!!”

Behind blue eyes

Occasionally, a colleague passes by my desk and says something along the lines of “Hey, did you know that *insert fun – usually science-related – fact here*?”

The other day, this exact thing happened:

“Hey, did you know that reindeer’s eyes turn blue in the winter?”

The question was prompted by the magnificent drawing of an octomoose (name pending) on the white board in our office. How the octomoose came about, is not that interesting a story, but I would want to share with you that we held a poll to determine the name of the 8-tentacled creature. My vote was for moctopus. I did not win (6 vs 3 votes).

Behold the mighty octomoose. Name votes currently stand at 3 for “moctopus”, 6 for “octomoose”.


So now that winter has come to an end, let’s talk about those weird reindeer eyes.

Discerningly, the first suggestions google search gave me when I typed in “reindeer eyes” was “reindeer eyes recipes”, which is just creepy; though actually clicking through reassured me that it was about chocolates and cookies (phew).

The struggle did not end there. The next page I found had a photo of a “summer reindeer eye” vs a “winter reindeer eye”:

Credit: Alexandre Buisse. From this website.

Jackpot? Nope. The photo was photoshopped (quite obviously). Sigh. This is turning out to be a lesson in fact checking.

In the original, the reindeer has brown eyes. Never trust photos you find on the internet, I guess .

However, I was not chasing a myth. It’s still true that reindeer’s eyes change color from gold in the summer to blue in the winter. Proof of this is in a scientific paper (hurray for backtracking to the source) which features some very creepy photos of reindeer eyeballs:

Reindeer eyes collected from reindeer killed in the winter (left) and in the summer (right). Credit: Glen Jeffery

The explanation to why this happens seems to lie in the reflective layer that sits behind the retina: the Tapetum lucidum. A lot of mammals have this layer; you might have noticed it when shining a light in your cat’s eyes (and survived to tell the tale). This extra layer helps animals see when it’s all twilight-y. It reflects light that passes through the retina, causing the light to pass through the retina twice, giving the light-detecting cells of the retina a second chance to detect any photos. When you see that yellow glow in your cat’s eyes, it’s the light reflecting right back at you off their Tapetum lucidum.

The Tapetum lucidum sits right behind the retina and causes creepy glowy yellow eyes in most mammels. Image from medwrite.biz.

The next bit of eye knowledge you need to understand the changing reindeer eye color is the fact that pupils widen and shrink depending on how much light is available. Dilated pupils allow more light to enter the eye, and hence more photons can be detected by the light-sensing cells in the retina.

Dilated pupils, a sign of darkness. Or physical attraction. Or drug use. But for the sake of this post it’s a sign on darkness; let’s just go with that.

In the arctic winter – basically 3 months of darkness – the reindeer’s pupils are continuously dilated. The constant effort to keep the irises open, constricts the small vessels that usually drain fluid out of the eyes. This in turn causes a pressure buildup within the eye, which compresses the Tapetum lucidum.

The Tapetum lucidum is mostly made up of a protein called collagen. This fibrous protein is a hydrogel, an ordered mesh of fibers that absorb and retain fluid. However, when this mesh is compressed, the fluid is squeezed out (like when you squeeze a sponge) and the orderly rows of collagen fibers become more tightly packed. The type of light that is reflected by the Tapetum depends on the spacing between these fibers. When they are “normally” spaced, like in the summer, longer wavelength light (yellow) is reflected, giving the Tapetum a golden color. When tighter packed, blue wavelengths (which are shorter) are reflected, giving the reindeer blue eyes.

In short, in the months of darkness, reindeer’s pupils are permanently dilated, leading to swollen eye, leading to compression of the collagen fibers, changing the color that is reflected by the Tapetum.

Or, in a drawing, if you will.

Research is still ongoing, because even though the mechanism behind eye-color-change has been explained, the effect on eye function is still unclear. Perhaps this change in eye color changes the sensitivity of the eyes. And why do other arctic animals, who also live through months of perpetual darkness, not have this cool change in eye color?

However, one thing is for sure, Rudolph’s red nose cannot be explained by science. Yet.

And in the mean time, octomoose remains on our office white board.

Sources:

Screwing; the right way*

For some obscure, unknown, mysterious reason, most things in nature are right-handed. I don’t mean that most people prefer writing, eating and doing other activities that require some dexterity with their right hand – although the word dexterity does seem needlessly biased towards the approximately 90% of the population that is right-handed. No, I am talking about right-handed helices.

A helix is an object having a three-dimensional shape like that of a wire wound uniformly in a single layer around a cylinder or cone, as in a corkscrew or spiral staircase**. What makes a helix right-handed, depends on whether the structure twists clockwise when you are looking at the structure from the top, and looking at the direction of the twist moving away from you.

Always use toys to explain concepts.

Another way of looking at it is by using the right-hand-rule – I am not sure this is its official (or even unofficial) name, but if you are like me and need to make an “L” with your hands to figure out which way is left, hand-based rules come in handy. Point your right thumb up and twist your hand upwards in the direction your other fingers are pointing, et voila: right-handed helix.

Pictures make more sense than words. This picture is worth 23 words.

Apparently, nature has decided that twisting right is the right way to twist. Proof for this is the structure of many macromolecules. For example, DNA, which is a double helix, is a right-handed double helix. The interactions that cause the structure to twist, happen to favor right-handed twisting. I should mention that left-handed DNA does exist, but it is are very rare and/or produced experimentally. Helical protein structures, such as alpha-helices, are also typically right-handed, and so is actin, a type of cytoskeletal filament.

Even on larger scales, nature prefers what turns right. Snail shells coil to the right. Most of the time. In fact, the rare case of a snail with a left-coiled shell resulted in a love triangle fit for Hollywood***.

Us humans, ever the inventors, have copied nature’s propensity to right-handedness in our hardware. Most screws have right-handed threads, leading to the handy mnemonic Righty Tighty, Lefty Loosey****. This is because most people are right-handed (about 90%, did you know?) and it’s just easier to screw that way*.

Left-handed screws do exist though, for special applications. No, not for exclusive use by lefties, but for situations where a right-handed screw would loosen over time, or cause extra stresses to occur in a system. For example, left bicycle pedals have a reverse (i.e. left-handed) thread because otherwise, the pedal would start unscrewing while cycling. Certain parts in airplanes have reverse threads, and so do types of machinery with rotary blades.

A right-handed thread runs clockwise, and a left-handed thread runs anti-clockwise. Turning a threaded rod upside-down does not reverse the direction of its threads.
The right way to screw… *****

To conclude, screwing right isn’t always the right way to screw. More importantly, I sincerely apologize for making you read whatever just happened to my brain. I must have a screw loose.

____________________________________________

* Phrasing!

** Definition taken directly from the Google results to “what is a heliz” because I am unable to type four words correctly.

*** I was going to say “fit for Disney,” but I feel like love triangles are not sappy enough. While we’re on the topic of rare animals finding their true mate, a story about a rare frog finding love hit the news this week.

**** I obviously am not able to remember things without help.

***** Are we still doing phrasing?

____________________________________________

Sources and/or further reading:

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The inspiration for this post came from a number of conversations; including with T. about airplane parts, S. about the lonely snail, and A. about left-handedness (I think, might have dreamt that one). Also potentially inspired by a certain famous person saying something about “And then they turn left, it’s always left.” (It’s not.)

Baking vs cell biology

Recently, I have learned that baking sourdough bread is very similar to maintaining cell culture. Lately, the conversations I’ve been having with my dad remind me very much of the conversations I used to have when I was still actively maintaining a cell line in the lab.

This inspired me to take out my drawing notebook and fail at sketching this concept:

IMG_20180913_095325 (1).jpg

If you would like to start up your own sourdough bread culture, basically, you just take some flour (50 g, apparently rye works pretty well) and add the same amount of water and leave this on your kitchen counter. For a week or so, mix in a tablespoon of flour and a tablespoon of water. Over time, this mixture will become alive with a culture of bacteria (the good kind) and yeast (the good kind) that you can then use to bake bread. Basically, if you take out some of this starter mixture for your bread, and supplement whatever you took out with new flour+water, you can keep this “culture” going in the fridge and bake bread until infinity. (For details, the internet has lots of examples of how to start up your own sourdough and subsequent bread recipes, for example, this one)

A little bit like culturing cells in the incubator until infinity.

And if you mess up (like accidentally use all your starter), you can either start over or take some out of the freezer (if you’ve frozen some down at some point, obviously). For cells, you’d take some out of the -80C.

So you see, similarities are endless!

Whatever you do, don’t talk about your cells/yeast like it’s a pet. It weirds people out (trust me).

_____________________________

Notes:

* The calculation bit is about things that are actually pretty simple but somehow are complicated to explain.

Also, I should note that my dad isn’t really that bald, I just can’t draw hair (sorry!). Also, you’re supposed to tie up your hair when working with cell culture.

This is why I usually don’t draw stuff, people.

The devil’s in the details

One of the “hallmarks” of cancer is the ability of cancer cells to spread to other parts of the body, settle themselves in this new environment and give rise to a new tumor. This process of spreading is known as metastasis and is something that typically aggressive cancers are known to do. In almost all cancers, cells can only spread within one organism. Almost all. There are a few – so far 4 that we know of – types of cancer that can spread to another body. In other words, there are types of cancer that are contagious, or transmissible, and that’s kind of creepy.

A transmissible cancer is a cancer where the cells themselves can spread to another organism and cause tumor growth in that organism. This is not the case for virus-born cancer. For example, in the Human Pappiloma Virus (HPV) is a virus that can be sexually transmitted and some types of the virus can cause a whole range of different cancers.  In other words, the virus is transmitted and the virus gives rise to cancer development.

But in the case of transmissible cancers, it is the cancer cells that spread to another organism. Most types of transmissible cancers are sexually transmitted; these types are found in snails and dogs. There is one type of transmissible cancer that is a bit of the odd one out: devil facial tumor disease or DFTD. Sounds kind of satanic, no?

DFTD is a very aggressive non-viral transmissible cancer that affects Tasmanian devils, you know, that Looney Tunes character that creates little tornadoes when it moves…

taz_whirling_tornado_baby_t_shirt-rc0e658ac580545ad8b692cf76c2e97ca_j2nhu_307
Why you so aggressive, Taz?

Okay, not really.

DFTD is a mouth cancer that looks really bad (don’t google it, or do, whatever, I’m not your boss) and is spread because Taz devils bite each other a lot. I guess, it kind of is an STI because they also bite each other during mating.

And because Taz devils are pretty isolated (they all live on the one island), and the cancer is very aggressive (spreads easily and is very lethal), and Taz devils are pretty aggressive animals (they bite each other a lot), it is a bit of a problem. DFTD has been observed since 1996 and has now spread to most parts of the island. It is feared that DFTD may cause the extinction of Taz devils.

Last year, I went to a talk by Elizabeth Murchison, who studies transmissible cancers, and it turns out that DFTD is actually quite interesting. In her talk, she explained that her team used genome reconstruction to track the origin and evolution of DFTD, and this led to the discovery that there are two independent types of DFTD (if I remember correctly, one of the cancers originated in a female Tax devil while the other originated in a male and that’s how they knew it had to be two separate types of DFTD).

Why would I care? Well, first of all, it is a unique situation to have a transmissible cancer that is isolated to one island, which – scientifically – is a unique opportunity to study how cancer evolves and spreads. Moreover, it is pretty strange that there are two types of a rare cancer (transmissible cancers are very uncommon) that have originated within one species. The two types of cancer started in similar tissue types, and have similar mutation patterns, which implies that Taz devils may be particularly susceptible to transmissible cancers.

But then the question is: why now? Taz devils have been around for ages, why have they now, within what seems to be only decades, developed two different diseases that are very similar to each other and that may lead to their extinction? Is it due to human influence, or perhaps climate change*? Has this happened to other species before, but we just didn’t know because we weren’t around or we didn’t know about cancers yet?

And, can we save the Taz devil? There are efforts to set up Taz devil sanctuaries on smaller islands off the coast of Tasmania to avoid these cancers spreading to the whole population. But if this type of cancer can spontaneously originate, how do we avoid this happening a third time?

Unfortunately, I haven’t made it to Tasmania yet (did I mention I traveled to the other side of the world recently), but I did see a Taz devil in the zoo. Can we save Taz, so he may roam around and make weird tornado thingies?

IMG_20180406_110826
Tazzie spotted in Taronga Zoo (Sydney)… Okay, they’re kind of cute in a giant rodent-looking type of way.


* Okay, technically speaking that means that it is still indirectly due to human influence.

Science of the mozzies

It’s that time of year: it’s been nice and warm and dry and sunny for weeks now, and the result of continuously exposing lots of bare skin and being slightly sweaty means I am completely covered by mosquito bites. For example, this morning, when I went for a run – yes, see how I just casually worked into the conversation that I’m a jogger, next thing I’ll tell you that I vape and am a vegetarian and do CrossFit and love IPA, #hipster (only half of that is true) – I felt like I had to do  more effort beating of the mosquitoes than actually doing the running. Though that may say more about my running skills.

In any case, like I do every single year, I wondered: why are there even mosquitoes? They are annoying, they spread disease, they bite, and they are annoying. No-one likes mosquitoes, except for maybe those few crazy mosquito-scientists. And I also wondered: Why me? There are so many other human specimens around that have perfectly tasty blood (I’m just guessing here, obviously I don’t actually know for sure), why do mosquitoes seem to favor mine?

mosquitoes-meme

Okay, first things first, as with everything out there, including the annoying and gross, mosquitoes have their place in the ecosystem. If they were to be completely wiped out, all the animals that feed on mosquitoes and mosquito larvae would suffer. This includes other insects, small fish, and amphibians. Move a bit more up the food change (game fish, raptorial birds, etc.) will also decline in numbers. So not good. Ecology is an intertwined network that we better not touch.

Wait, I just realized this means that we’re on the bottom of this food chain?
Damn, my human pride cannot handle this!

Anyway, in addition, mosquito control programs so far have been very destructive. Draining swamps, using pesticides and DDT, etc. is just not really good for the environment. In other words, we’re stuck with each other. *Sigh*

If we have to bear the itching, which is actually an allergic reaction to the anticoagulants in mosquito saliva, maybe we can find a way to avoid getting bitten. Well, apart from spraying really smelly annoying sticky insect spray. I have days when I smell like sunscreen, sweat and insect repellant and I really apologize to everyone for that.

Maybe we can find out why some people get bitten more than others? There has been quite some research on that topic, and as it turns out, it depends on the type of mosquito (there are hundreds of mosquito species), genetics, blood type, sweatiness, and eating habits. So, unfortunately, there is no straightforward answer…

It does seem that mosquitoes are slightly more attracted to:

  • sweat, which explains why I seem especially tasty after my run;
  • sweaty feet (there was a famous study involving Limburger cheese), isn’t that just a lovely thought;
  • pregnancy, so I’m not worried in that regard but I mean, com’on mosquitoes, like being pregnant in the summer doesn’t have enough down sides;
  • beer consumption, it turns out that alcohol is a strong attractant,  which is a major shame because I really think the summer is so much nicer sitting on a terrace with a nice pint;
  • and finally, I’ve heard it said that eating bananas makes your blood nice and sweet, but I can’t find any evidence on this.

Unfortunately, this all depends on the type of mosquito. Moreover, there seems to be no evidence that there is something you can eat to avoid being bitten. I mean, they are bloodsucking but not exactly vampires (you can stop eating all that garlic, Karen, seriously, you reek).

So it seems that we have to stick to spraying really smelly annoying sticky insect spray.

I’ll leave you with a final fun fact: the oldest fossilized mosquitoes are 100 million years old! Quite recently, a 46-million-year-old blood-engorged mosquito was found in Montana, which actually led to a publication that directly mentions the 1993 film Jurassic Park. #OMG (I’m easily pleased).


Sources:

http://theconversation.com/health-check-why-mosquitoes-seem-to-bite-some-people-more-36425

https://io9.gizmodo.com/what-if-every-mosquito-on-earth-went-extinct-tomorrow-1646840383

https://www.annualreviews.org/doi/abs/10.1146/annurev-ento-120811-153618

 

Hug a micro-bear

Water bears. Moss piglets. Those are just two examples of “cutesy” names for tardigrades (literally “slow stepper”; because they look like they do everything in slow motion), some of the most amazing animals in existence (IMO). These little animals, averaging 0.5 mm when fully grown, are almost cute with their short, plump little bodies, eight legs and looking a bit like a tiny Michelin guy.

Ugh, I’m so fabulous! (scanning electron microscope image of  SEM image of Hypsibius dujardini)

Water bears are water-dwelling tiny animals that mostly live in mosses and lichens (top tip – get yourself a pet tardigrade by soaking some moss in water), but basically can be found anywhere (#GlobalCitizen).

And I mean everywhere. Some tardigrades live on the highest mountaintops. Others in the deepest trenches in the sea. They have been found in rainforests as well as in Antarctic regions. This is because tardigrades are so awesome. While they are not exactly extremophiles (organisms adapted to survive extreme conditions such as extreme temperature and pressure), they are able to survive extreme conditions for a certain length of time. Expose them for too long, and they will die, unfortunately. But expose them to extreme conditions, including very high or low temperatures, incredibly high or low pressure, air deprivation, dehydration or starvation for (depending on the system) a lot longer than what humans would survive, and they will bounce back! Some tardigrades have gone without water for more than 30 years, just to rehydrate and get back to living.

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Happy Space Tardigrade

I mean, tardigrades can survive space! Tardigrades have been exposed to open space and solar radiation combined for 10 days and have lived to tell the tale. This makes them the first known animal to survive in space.
Just to give you a few more examples of the extreme conditions tardigrades have survived in:
    • Tardigrades have survived extreme temperatures, such as a few minutes at 420 K (151 °C) or 1 K (-272 °C) at the other extreme. Put one in -20 °C and it could survive for 30 years.
    • As well as surviving the extremely low pressure of a vacuum, they can withstand very high pressures such as 1200 times the atmospheric pressure (or even 6000 times for some species).
    • The longest that living tardigrades have been shown to survive in a dry state is nearly 10 years.
    • Tardigrades can survive 1000 times more radiation than other animals.R8CozXH
Basically, they could survive global extinctions. In fact, they are one of the few groups that have survived Earth’s five mass extinctions.
So after the end of the world, whether human-inflicted or natural, we can at least count on these amazing little creatures to survive the apocalypse. Maybe they will even evolve to giant, sentient, space-travelling (no spaceship required) giant water-bears.
Actually, giant water bears would be terrifying. Let’s not think about that.
_______________________________________

Source:
Most (read: all) of this was found on wikipedia, the ultimate internet information hub that we all love to hate. I found the images at some point while browsing imgur, they’ve been on my phone waiting to be used for ages. I can’t find their original source.

Not just your usual conference (100 years, Part VIII)

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Spotted in the Bell Pettigrew Museum of Natural History (St. Andrews)

Last weekend, I attended the Centenary conference commemorating the 100-year anniversary of the publication of On Growth And Form by D’Arcy Wentworth Thompson. You might have heard me mention this book and its centenary at some point?

It was not just your usual conference. While most conferences centre around a certain field or topic, this one explored the influence of D’Arcy and his book on many different fields It was the most interesting mix of people and topics at any meeting I’ve been at, it succeeded in bringing scientists, mathematicians, computer scientists, historians, artists, architects, musicians and knitters in the same room.

Also, the sessions were not organised topically, but pretty much random, which meant that even if you were just interested in a few talks (on paper), you ended up hearing the wide variety of topics that have something to do with D’Arcy. Personally, I thought this was a very clever choice of the organisers (kudos to them), and I enjoyed hearing about art, architecture, history, and yes, knitting, instead of boring ol’ science for a change.

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I also feel like I made some type of personal achievement. I was accepted to give a talk on the Physics of Cancer, which you might remember as the topic of my two FameLab contributions. For each of these, I had written a little song. So, in a crazy phase of over-confidence, I decided to incorporate these songs into my talk. And, why not, I also incorporated Star Wars references, weird cartoon cell drawings and pretty dodgy doodles I had drawn myself.

The response was amazing. I’ve given talks at conferences before but never have I received such positive feedback. Not only because they found the songs entertaining (I can assure you no-one fell asleep during my presentation) but I was also complimented on the clarity and accessibility of my talk (the very mixed audience, remember) and my optimistic approach to a “heavy” topic. If possible, I will from now on take this approach for every talk.

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Finally, I have a new favourite D’Arcy quote (it’s quite convenient to have three days full of inspirational quotes to muse about):

“(…) things are interesting only in so far as they relate to themselves to other things; only then you can put two and two together and tell stories about them.”

Closely followed by this one, actually:

“Facts are pointless unless they illustrate greater principles.”


(The comics snippets and the second quote are from the graphic novel “Transformations“.)