Micro Slavery


bacteria culture

This is the only way these modified organisms can live: in a dish in the lab

Bacteria can be both useful and lethal. In either case, scientists want total control over them to maximise their efficiency or prevent any diseases. However, it does sounds impossible: how can humans control a bacterium, which is a free living organism so small we can’t see it with our naked eye and is incapable of understanding our commands? But of course they have accomplished this, or otherwise I wouldn’t be writing an article on it.

Subjugating bacteria is done by a simple method. All living organisms require proteins made out of amino acids to live, and bacteria are no different. They use them to carry out many varied functions: they act as enzymes, hormones, connective tissue… so if you control how bacteria make proteins, you can basically dictate how they live their lives. Since proteins are coded by the DNA, scientists tweaked the genetic information so that bacteria didn’t code for proteins they way they would usually do. But changing the whole genome is a long, tiresome process; so instead, they targeted a specific set of genes which code for a specific set of proteins: those that are crucial for a bacterium to make other proteins. It is quite effective. If bacteria can’t make the proteins that guide DNA transcription and translation (the processes that produce proteins), then the bacteria are hindered and can’t work any further.

The modifications involved changing the bases in the DNA sequence so they didn’t code for the usual, natural amino acids. Instead, some new bases introduced coded for an artificial amino acid, created and only found in the lab, so proteins could only be made if this one artificial amino acid was present. This idea, although creative, was developed by two independent teams, one of which used a large, artificial amino acid and the other used three different artificial amino acids. Either way, if these bacteria wanted to survive, they would have to stay in the lab, the only place where they can obtain the amino acid necessary for creating proteins.

The main implications of this development are related to genetically modified organisms (GMOs). People fear that creating beings with features enhanced in the laboratory is dangerous, and if they somehow make it into the wild and grow there, they can harm other, more natural species, or reproduce with them, which would destroy the natural balance of natural selection. This technique solves both of those problems, since the new GMOs developed with dependency on this amino acid would only be able to live in the lab, and could be easily controlled and kept in small numbers.

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Light Sprints


light pulse

Small light pulses can now be modified so they slow down

Remember any physics lessons during your high school years? How it was always said the speed of a light was the most unchangeable constant of all? Well… keep reading. In a perfect example of how science changes to perfect itself, scientists at the University of Glasgow have carried out a very interesting set of experiments which ultimately showed that the speed of light can in fact change.

Now, we all know that when light enters a medium, such as water or glass, it slows down. Whereas the speed in a vacuum is said to be 299 792 458 m/s, it can go down to 225 056 264 m/s in water and even 124 018 189 m/s in diamond. This is due to the increased density through which the light has to pass through, so the light particles suffer more collisions which slow it down. But the news come from the idea that speed can also change in a vacuum, even if there is no change in medium and therefore in density.

However, there is a trick. This change in speed won’t happen spontaneously, it has to be slightly triggered. Although it is usually simplified as ‘straight’ or plane waves, where every point travels parallel to each other, light is a bit more complex than that. Two points in a ray of light can actually converge and join, bending their shape. When this effect happens, light speed is affected.

The experiment consisted of a source emitting only two photons. One of them was directed to flow through an optical fibre, so its journey was not interrupted and was as smooth as possible. The other one was passed through a series of apparatus which changed its structure for a short period of time and then restored it back to normal. The time it took each of the photons to arrive to the finish line was measured very precisely. No matter how many repeats the team conducted, the modified photons were always slightly slower and arrived after the untouched one.

The change is speed is not immense, and will have no effect on day-to-day calculations, but it could be have some importance on experiments which use short pulses of light. The fact this effect exists is already worth noting, as it is theoretically obvious but no one had proved it before.

Antibiotic Hero


Antibiotics are the real wonder drug. They were a revolution in the 20th century, capable of fighting the most powerful bacterial infections. Scientists understood their potential and worked tirelessly to create a wide variety of them to harness their power, but eventually they stopped. Since the 1980s, no new antibiotic has been discovered. Since we have a great amount of them, it wouldn’t be too big of an issue, if it weren’t for a growing problem: resistance.

Due to the threat antibiotics represent to bacteria, these organisms feel a high selection pressure to evolve and develop new ways to defend themselves from these drugs. And they have succeeded. Many strains of bacteria, especially for diseases like MRSA and TB, have become immune to many antibiotics and are proving really hard to fight. Due to the increase in antibiotic resistance, there has been a hunt for new antibiotics in the recent years, and it has finally paid off.

The most common way to obtain an antibiotic is from bacteria themselves. We are not the only ones who want to get rid of them; competing bacteria do too. So when these bacteria develop chemicals to destroy other bacteria, we need to extract them and use them to our advantage. But to extract the chemicals, bacteria need to be cultured in the lab, which can be difficult at time, since the most used bacteria for this process are found in the soil, which has conditions difficult to recreate in the lab. A new method created by researchers in Boston could solve this: it consists of creating a culture with three layers: two layers of soil on either side of a semi permeable membrane. These are perfect conditions for bacteria and have made it possible for thousands of them to grow and for a possible new antibiotic to be isolated.

teixobactin

Teixobactin could fight TB and other diseases which, over the years, have become immune to our medications

 It’s called teixobactin, and it targets proteins on the membrane of bacteria, eventually killing them. Because of its complicated mechanism, it is very hard for bacteria to develop resistance to its action. However, it is not impossible. Scientists predict that if used correctly (that is, without overprescribing), teixobactin could be effective for over 30 years, quite a long lifespan for an antibiotic. As it is completely new and bacteria have never been exposed to it, many say it could be the key to fight multidrug resistant bacteria, fighting superbugs and giving us and edge over the most fierce and dangerous infections. These hopeful results have yet to be confirmed in human trials, but the effectiveness of the new antibiotic seems to be as good as it sounds in animal tests.

 With this new method and this new antibiotic, the future of medicine could prosper, and bacterial infection could remain an enemy we can defeat.

2014 Science Highlights: Part 2


Continuing last week’s list of the most interesting scientific events of 2014, here I present 5 more discoveries that marked this year.

6. Curious Curiosity

moon earth curiosity

The picture Curiosity took in which the Moon and Earth can be seen together

2014 was Curiosity’s year. It was always present in the news, whether it was because of its 2 Earth years anniversary, its 1 Martian year anniversary, the popular selfie it took of itself or the breathtaking picture of the Moon and the Earth. But Curiosity is not only a great photographer; it’s a great researcher too. Since its arrival on Mars, it has provided us with a lot of information about the Red planet. It has made some curious discoveries on the methane gas concentrations in Mars’ atmosphere, and the deuterium to hydrogen ratio, to shed some light on the controversial history of water in Mars.

 7. ALS Fever

als icebucketchallenge

ALS got lots of attention from the insanely popular Ice Bucket Challenge

The Ice Bucket Challenge swept the world; almost everyone, from celebrities to normal citizens did it, and most donated some amount of money to the ALS Association. Overall, $115 million dollars were raised, and the money will now go into helping people with this condition and into research for a treatment and a cure. Although ALS is not a very common disease, it is a crippling one and can leave those affected with a very disabled life. Therefore, it is absolutely amazing to see the amount of support this charity received, and very hopeful how much effort was put into spreading awareness.

 8. The $1000 Genome

genome 1000

By making reading genomes cheaper, we are getting closer to personalized medicine

A machine that could effectively read a person’s whole genome for less than 1000 dollars was invented this year. This has been a very sought after discovery, and a milestone in the genetic field. Scientists have expected this for years, and it is such an important creation that even prizes were created for those who could accomplish this feat to motivate scientists into researching it. Now that we finally have it, it’s better than we imagined. The machine can actually sequence 5 sets of genomes per day. This could set off a revolution in genomics, and fasten the pace of discovery tremendously.

 9. Giant Dinosaur

giant dinosaur

A drawing of the largest creature ever; its size is roughly that of a seven-story biulding

Dinosaurs have always been known for their size, ferocity and majesty. A new species of dinosaur discovered in Patagonia has been calculated to measure 40m long and 20m high, with an estimated weight of 77 tonnes; that’s 77000 kg! Not only is this the largest dinosaur ever found, but it is also the largest animal to ever walk the Earth. What’s also great bout this discovery is that there were dozens of bones from this creature and allconserved in a great condition, so investigating these bones won’t be too difficult. Unfortunately, it still doesn’t have a name; it is such an important aspect that archeologists want time to think of a name that can represent the importance of this animal.

 10. Fake Life Flourishes

X and Y

Base X (left) and base Y (right), completely new bases which act like the natural ones

Synthetic biology grew greatly this year. On one hand, scientists were able to create a synthetic version of yeast’s chromosome, by substituting the original, natural genes by artificial ones created in the lab. But also, two new bases were proven effective this year. All animals use the usual 4 bases (A, G, C, T) in their genes to code for proteins. But new research has created a bacterium that uses two extra bases, named X and Y, which can code for new amino acids and extend the range of chemicals organisms can produce.

 

2014 was a great year for science; let’s hope 2015 has even more interesting and fascinating discoveries in store for us!