Category Archives: Issues in Science

Solar Powered Sea Slug: Power of Photosynthesis!

We have learned that photosynthesis is an inherent characteristic of plants reserved for their survival by collection of sunlight as a means to their survival, but what would you say when there is an animal living on photosynthesis? Prepare to get your socks knocked off by what is about to come because this is an introduction to the sea slug literally living off the solar power.

Sea-Slug, Elysia chlorotica From Pedro Jorge Peu (pinterest)

Sea-Slug, Elysia chlorotica
From Pedro Jorge Peu (pinterest)

Photosynthesis is a process that generates sugar by absorbing the sunlight. More specifically, chloroplasts which are the food producers of the cell converts light energy of the sun into sugars that can be used by cells. It is a process thought to be reserved for the Kingdom of Plantae, eukaryotic, and multicellular organisms. Imagine a solar panel powering electricity to charge our cell phones; plants absorb their energy in a similar way too.

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Photosynthesis From Flickr Commons

Kingdom of Animalia on the other hand, derives from the Latin word Animalis literally meaning “having breath”, they are eukaryotic, multicellular, and do not survive relying on photosynthesis. However, in 2010, CBC news reported that in the case of the brilliant emerald green coloured sea slug Elysia chlorotica, it is not the case.

The photosynthesizing sea slug lives by the incorporation of chloroplasts within the cells which allows it to capture energy directly from sunlight as most plants do, through the process of photosynthesis. What was thought to be exclusive to plants is not the case due to the discovery of organisms such as E. Chlorotica. Generally speaking, it will have algae for its food supply, but if they are not readily available, these slugs will survive and function for up to nine or even ten months by the sugars produced through photosynthesis performed by their own chloroplasts.

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[Credit to FORA.tv]

In a study, it was found and proven that these slugs definitely have a way to support the survival of their chloroplasts. After the eight month period of its survival without readily available food source, “the majority of the chloroplasts within the slugs appeared to have remained intact and also maintaining their fine structure.” They do this by not spending their precious energy on activities involving finding food but staying intact synthesizing their own chloroplasts; ability acquired from yellow-green alga (Vaucheria Litorea). The studies are on-going for this slug as scientists are researching for its potential genes that could support chloroplast survival and photosynthesis.

Even after all this, they are still not truly photosynthetic organisms. Last year, Gregor Christa and his researchers reported that as E. Chlorotica can survive in dark environment which is why they still belong to the Kingdom Animalia. Animal or plant, it may be up to how the reader may decide. I decide on classifying this beauty as an animal true to its purpose; survival.

Grace Kim

Can we predict the future?

back to the future II dash board

October 21, 2015 by Mike Licht from Flickr Commons

In celebration of the  “future day”, Oct 21, 2015, from Back to the Future II, many media have listed things about what the movie has predicted right, and they actually found quite a few. This might not be that surprising to you, since they were often based off some advanced technologies at that time. However, all fantasy aside, from a scientific perspective, as technology advances and more data is accumulated from our everyday life, can we actually predict the future?

Predicting the future has been a very attractive scientific topic from all times. We have already been trying to predict weathers by monitoring clouds and winds, stocks by monitoring the market performance and related information, and even politics. Every year, we also use data of influenza cases and circulating viruses around the world to make vaccines predications for the flu season. Just like the movie, we managed to predict correctly for quite a few times, but since it’s not a movie, when the prediction is not correct, sometimes the consequences could be heart-breaking. What can we learn from these?

To predict the future, the first thing we need to know is that not all false predications are tolerated equally. For example, if a forecasted rainy day turns out to be sunny, people probably won’t complain; however, for a hurricane like Patricia, the “strongest landfalling pacific hurricane on record“, missing the prediction of its arrival would be very devastating. Thus, for a better prediction, we often need to consider the costs of false positive/negative results.

Secondly, we learned that we may not be very good at predicting what is going to happen in the next 30 years, but we could get pretty good for the near future. You may have noticed that the weather forecast for tomorrow is much more accurate than the forecast for next week. This is because we have more relevant data for tomorrow’s weather prediction. It might seem intuitive, but having more data is crucial for all kinds of predictions. As Kenneth Cukier would probably say , the more, the merrier, based on his TED talk here.
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[by youtube channel TED]

Thirdly, based on what I have learned from my machine learning class (it studies algorithms that “learn” from existing data), averaging predications from multiple qualified good models makes the prediction more trustworthy. Taking global warming for example, despite the fact that different prediction models don’t agree on the level of global warming 85 years from now, they do agree on the trend if we average them all together especially in the near future.

Global Warming Projections by Pflatau from Wikipedia

Global Warming Projections by Pflatau from Wikipedia

Finally, we should always be cautious about future prediction. Just like in the movie, our predication model is only good if we don’t act on it based on our prediction; once we intervene, the prediction would no longer be valid. As most movies would tell you that you have already entered a parallel universe.

Earth From Google Image

Earth From Google Image

by Sainan Liu

The Promising Near Future of Blood Transfusions

rbc

Rendering of red blood cells. Source: Flickr Creative Commons – Nocturnal lust

Have you ever donated blood? Canadian Blood Services is always looking for more blood, because they need lots of it. For example, here’s a table of the required donations per single procedure.

Required amount of blood donors per case. Source: Canadian Blood Services – Who does my donation help?

As you can see, a single car crash can require blood from up to 50 donors. Such events can cause a shortage of blood. In fact, just last year, Canadian Blood Services issued an appeal for more blood donations, as blood supplies hit an all-time low, especially for type O universal donors.

What are universal donors? Donors of blood type O can donate to every other blood type, because they have no antigens (molecules that can cause severe and harmful responses by immune system on the recipient of the transfusion). The video below explains the concept of blood types and why some people can flexibly donate to all others blood types. Credit for this video goes to user nafis A on Youtube.

The problem with blood donations is that we can’t simply take many donations and stop worrying about blood reserves. This is because, just like milk, blood is perishable. Blood Centers Organization states that red blood can only be stored for 42 days before going bad. This creates a need for a continuous supply of blood donations to account for any emergencies.

On the bright side, the future of blood supplies look promising due to a recent publication by a research group at the University of British Columbia (UBC) at the Centre for Blood Research. They discovered a method to genetically enhance an enzyme which removes the antigens from blood. To do this, they used a genetic manipulation method called directed evolution.

David Withers’ Research Group at the Centre for Blood Research. Source: UBC Centre for High-Throughput Biology

This process introduces step-wise mutations in the DNA that encodes the enzyme. They use a multi-pronged approach by introducing many random mutations to the gene, and select the best performing mutants and do this for multiple rounds. The researchers at UBC claim that after five rounds of directed evolution, the enzyme which removes antigens from red blood cells is 170 times faster than the original enzyme. The original enzyme, although functional, was never fast enough to be a feasible way of removing antigens from blood. This genetically enhanced enzyme, however, can be used practically in the medical setting.

This discovery could potentially eliminate the shortage of antigen-specific blood by converting all donated blood to donor types! I think this has great potential for saving lives. From what I know about Biology, once the DNA of this hyper-enzyme has been sequenced, it can be easily generated from protein farms – where bacteria produce large quantities of the protein which can be purified and extracted for clinical use. I think it’s amazing to hear that my university is at the frontier of such impactful discoveries!

Blog by Justin Yoon

Commented on the following blogs:

Electronic cigarettes by Brian Cheng

Bioethics dilemma by Paul Yi

Imposter syndrome by Luxi Xu

DNA TAKE ON A NEW ‘SUPERCOILED’ SHAPE

The iconic double helix of DNA that James Watson and Francis Crick first published in 1953 was not the end of DNA structure as new Study revealed.The double helix of DNA was just a tiny fraction of a real genome.It consists of 12 DNA base-pairs that later formed building blocks of DNA known as helical ladder.

DNA structure is made up of almost 3 millions base-pairs that must fit into nucleus of a cell which is just 10 micrometers across, thus DNA must really have to coil to fit into nucleus.

To get the bigger picture according to the new research,the researchers recreated DNA molecules in the lab. The researchers forced DNA strands to coil and recoil it at the same for several turns using short circular snippets of DNA that is made up of many base-pairs.
The researchers the discovered a panoply of a breathtaking new shape of DNA.YouTube Preview Image
Supercomputer simulations show how the dynamic motion of the supercoiled DNA causes its shape to change constantly to form a myriad of structures.

Most of which have different shape of DNA like handcuffs or sewing needles.Others through their coiling shape look like rods.
Supercoiled DNA strands

Photo credit: LIVESCIENCE/Thana Sutthibutpong

To make this ‘supercoiled’ DNA strands visible in the human body,researchers inserted an enzyme called human topoisomerase II alpha into the body to show how this ‘supercoiled’ DNA look like in the body.
The enzyme relaxed DNA twisted DNA in human body.This new discovery of ‘SUpercoiled’ DNA was reported today (oct 12) in the Journal Nature Communications posted by livescience that the structural shape of DNA created in the lab resembled the strands of DNA found in the cell nucleus.

The DNA samples were then froze and used a special form of microscopy to capture the first-ever images.
According to James Watson and Francis Crick, DNA helix is formed when complementary base-pairs like adenine and guanine are bound together which is now being contradicted by the new simulation of DNA in the new study that these base-pairs peel apart when the helix is unraveled.

The new discovered has shown us the complexity of the structure of DNA.It is now beyond double helix and it is so interesting to see how ‘supercoiled’ is DNA.

KUOL BIONG

Tragic Island Threatening Our Marine Life

Have you heard about a huge floating island of plastic? You may not believe it, but there it is in the central North Pacific Ocean, called the Great Garbage PatchThe size of the garbage patch is enormous estimated about twice the size of Texas! Charles Moore, the scientist who first discovered the garbage patch, mentioned that the garbage island will even likely double in size in the next ten years. The Great Garbage Patch has become a discourse of environmental debate for its adverse effects on marine life.

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Source: Flickr Commons

Though there are various types and sizes of debris, the majority of the marine debris consists of plastics. Algalita Marine Research Foundationan organization that studies sampling the marine debris to determine the density of plastic debris in the pacific garbage patch, analyzed the increasing ratio of plastic to zoo plankton by weight. This means that the concentration of plastic debris is increasing, contaminating the largest biome on Earth. Increasing accumulation of plastic debris leads to the biological loss by entanglement and ingestion. Every year, over 100000 ocean animals become trapped in marine debris and unfortunately, many of them die. In addition, many marine organisms ingest plastic debris, mistaking them as their food source, being poisoned and starved.

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Author: Chris Jordan Source: Wikimedia Commons

The chemical toxicity in plastics is another factor that deteriorates marine ecosystem. Plastic debris not only contains organic contaminants, but it also contains persistent organic pollutants such as pesticides and petroleum hydrocarbons, which are resistant to environmental degradation: they will remain in the water, aggravating and propelling the speed of contamination of marine life. Also, the high concentration of contaminants causes lethal threats to marine ecosystem as they accumulate in their body through ingestion. Contaminants, such as phthalates and Bisphenol A (BPA), adversely affect reproduction in many marine animal groups, disrupting the development of amphibians and inducing genetic abnormality. BPA acts as a feminizing agent that produces an estrogenic effect in fish. It also affects the processes of sex hormones and disrupts growth, insulin signaling, bone development and brain development. Furthermore, bioaccumulation of chemicals can occur; persistent organic pollutant can accumulate in the fatty tissues of organisms and higher the trophic level, the greater potentially the negative effect on birth or mortality of marine animals.

From the serious damages caused by the garbage patch, people have to be aware that we have caused the destruction of marine life. The environment constantly lets us know through diseases or disasters that it needs care, and people must pick up on the cues and change their behavior in order to save the world from a dark future!

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YouTube video courtesy of: National Geographic

By InHye(Lisa) Kim

I commented on :

Adrian Li’s post on Vitamin C. Miracle Cure or Wannabe Dud or Neither?

Grace Kim’s post on Almost there! Universal blood for all.

Julia He’s post on My Grandma Can Become Stronger by Eating Apples and Tomatoes.

Video

Is in vitro meat the future meat source?

 

Cell Culture, Author: Umberto Salvagnin, Source: Flickr Commons

Cell Culture, Author: Umberto Salvagnin, Source: Flickr Commons

While “Humans no longer raise animals for food” is still a science fantasy in TV shows like Star Trek, growing meat from a Petri dish as one solution to achieve this goal is no longer a far-fetched dream.

Around 2000, Morris Benjaminson, has successfully produced fish fillet from goldfish skeletal muscle in the lab, and deep-fried their result. “It looked and smelled pretty much the same as any fish you could buy at the supermarket,” says Benjaminson (Scientific American).

Two years ago,  two people tasted the in vitro beef muscle prepared as a burger patty at a news conference in London for the first time.

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[by youtube channel Maastricht University Cultured Beef]

They both agreed that the texture was quite close to meat. “I know there is no fat in it so I didn’t really know how juicy it would be, but there is quite some intense taste,” said one taster.

We seem be able to see lab-grown meat in production fairly soon. However, would in vitro meat be our future meat source even if they taste no different from natural meat?

I think there are some obvious advantages. First of all, in vitro meat allows us to control its nutrition content, hence it can be much healthier than farmed animals. Secondly, reducing animal farming can significantly reduce animal cruelty, the burden on land use, and animal waste. Last but not least, from a environmental point of view, in vitro meat can even reduce green gas emissions. For example, cattle farming is infamous for their Methane emissions (Food and Agriculture Organization of the United Nations), and Methane has a global warming potential 72 times more than carbon dioxide over a 20-year-period based on a 2007 report by  Intergovernmental Panel on Climate Change (IPCC).

Name: Confined animal feeding operation, Author: SlimVirgin, Source: en.wikipedia

Name: Confined animal feeding operation, Author: SlimVirgin, Source: en.wikipedia

However, people do argue that there might be some disadvantages that we should look out for. For example,  Science Friday  has pointed out a few down-sides such as reduction on animal by-product, and the $300,000 price tag for a beef burger patty. However, I think these are trivial problems given that animal by-products have already been largely replaced by artificial materials, and the scientists were quite confident about cutting the price down. The most interesting point is that they mentioned that it is just like industrial revolution, artificially producing natural product is always going to cost more energy, which is not necessarily a good thing for the environment. I agree that it does seem like more energy cost is inevitable, but energy related environmental damage is something that we have already been working on for years, and it is up to us to prevent it from very beginning.

All in all, I think with a combined effort with other solutions that we have already been working on such as animal farming regulation, and a global effort on reducing green house gas emission, there is definitely a place for in vitro meat to benefit us to some extend in the future.

By Sainan Liu