Author Archives: KatrinaLim

Diamonds In the Sky

As you may have already realized, living in Vancouver means it’s gloomy, cold, and wet 10 out of the 12 months each year. As a Vancouverite, an umbrella is an essential item to take with you when leaving your house.  But imagine, one day you’re walking down the street and a giant, sparkling diamond falls from the sky and lands right before you. How is this possible? Is it… raining diamonds?!

This is quite impossible on planet Earth, however, it may be the case for our gas giants, Jupiter, Saturn, and ice giants, Uranus and Neptune. Study shows that the atmosphere of these distant planets are filled with methane gas, a gas molecule with the molecular formula CH4, and have the ideal conditions for diamond formation. However, the proportions of methane gas in Jupiter’s and Saturn’s atmosphere is significantly lower than Uranus’s and Neptune’s atmosphere.

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Saturn Source: Flickr

Despite this difference in methane availability, spacecraft Cassini has reported sightings of lightning storms in the upper atmospheric region of Saturn. The presence of lightning can break up methane gas into soot (the carbon source for diamonds); similar storms are apparent on Jupiter.  As soot sinks deeper into the atmosphere, pressure also increases. The increase in pressure converts soot into graphite. Once graphite is made, it continues to fall deeper and deeper towards the planet’s core; with increasing temperature and pressure, diamonds are formed!

However, as the solid diamonds fall closer to the core of Jupiter and Saturn, the temperature also increases dramatically to approximately 12 000⁰K. This temperature is well above the melting point of diamonds, approximately 3800⁰K, thus creating a sea of diamond liquid. Albeit, the temperature on Uranus and Neptune is much cooler in comparison. As a result, diamonds formed in these planets stay in their solid state.

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Diamond in its solid state Source: Flickr

The possible size of these diamonds formed also vary. Just like rain, when the diamonds fall deeper into the atmosphere, they are capable of growth. When falling, some of the precious gems can grow so large that they can be classified as “diamond-bergs” (the size of an iceberg!).

Before you get all excited and wowed by this, I must say that is indeed not a fact. Unfortunately, this is only a theory from NASA and their scientists from observing the conditions and properties of these planets. We can only infer since we are restricted with the ability to travel to either Jupiter, Saturn, Uranus or Neptune to formally further investigate this research topic. Perhaps one day, technology will be advanced enough for us to send robots, or maybe even humans farther than Mars and investigate extraterrestrial phenomena and their precious secrets held within.

A video of how diamonds are formed on Earth:

-Katrina Lim

Resources:

  1. National Geographic. Diamonds stud the atmospheres of Saturn and Jupiter. http://news.nationalgeographic.com/news/2013/10/131009-diamonds-saturn-jupiter-planet-science-space/ (accessed Nov. 5th 2016)
  2. Cassini: unlocking Saturn’s secrets. http://www.nasa.gov/mission_pages/cassini/whycassini/planet.html (accessed Nov 5th 2016)

Autism versus Vaccines

Earlier this year, a huge controversy regarding the correlation of autism and vaccination resurfaced and caught the attention of many concerned parents over the internet. This matter sparked a large interest in the general public and caused many debates on whether if autism and vaccination is actually correlated.

This controversy first appeared in 1998, when Andrew Wakefield published a fraudulent paper on the MMR (mumps, measles, and rubella) vaccine and autism. His initial research proposed that the MMR vaccine caused inflammation in the guts of patients, which allowed a certain unproven protein to be so called, ‘leaked’ across the inflamed intestines and travel through the body to the developing brain, causing autism.

When I first heard about this controversy, I was enraged by the potential harm caused by the ignorance and misinformation sown through the general public. As a science student at UBC, I have considered it a personal goal to spread the truth. Despite what Khan Academy has explained in the attached video above, let us look into this matter scientifically, shall we?

First let’s dissect the causation of Autism.

To be honest, the exact cause of autism is unknown. However, research has shown that there are several possible factors, including genetics. Scientists have discovered that in some cases of autistic children, their chromosomes differed from the karyotype, the visual representation of all the chromosomes present in an organism, of a healthy, normal individual’s. It was often found that mutations arose in their set of chromosomes, causing changes in the DNA sequence that would affect the appropriate proteins later produced for proper physical and mental development.

Normal Human Karyotype (Male)   Credit: Flickr Commons

Now, let’s look at the function of vaccines. When vaccines are introduced to the body, it does in fact contain a small portion of the disease. However, it is in its deactivated or weakened form, thus unable to cause any virulent harm to the host. The purpose of vaccines is to introduce potential harmful foreign proteins to the body so our immune system is able to recognize these viruses or bacteria. In return, when our immune system is exposed to the fully activated version of the disease, the body is able to make antibodies fast enough before the host actually falls ill.

Between the function of vaccines and how autism may be caused, I find it absurd that some people believe vaccinating their children can potentially expose them to the risk of autism. By that logic, they are suggesting that deactivated or weakened versions of bacteria or viruses are able to change DNA sequences in cells.

I stand by the fact that vaccines do not cause autism in children. I truly hope parents who are against vaccinating their children for this very reason have looked into this topic in depth, and hopefully have changed their minds and have come to the correct conclusion. After all, why risk your child’s health and safety for something you’ve read on Facebook that has been proven false by many research studies?

– Katrina Lim

Resources:

Child Autism Parent Café. http://www.child-autism-parent-cafe.com/autism-and-genes.html (accessed Oct 10, 2016)

Zorica, H.I. et al. Numerical and structural chromosomal changes in a case of autism. [online] 2007. (accessed Oct 10, 2016) http://www.rombio.eu/vol12nr.3/manuscript_8_Hertzog%20BT%20nr.3.htm

Gillber, C.J. Chromosomal Disorder and Autism. Springer Link. [Online] doi:10.1023/A:1026004505764. 1998. 28: 415 http://link.springer.com/article/10.1023/A:1026004505764 (accessed Oct 10, 2016)

The Defense Mechanism of Plants

Close your eyes and imagine your sun soaked skin embracing the warmth Vancouver has finally blessed you with, the gentle cool breeze dancing through your hair, and your feet standing on top of a luscious, emerald lawn. Go ahead, take a deep breath, the smell of freshly cut grass. The scent of summer.

Why is the scent of freshly cut lawns so pleasant? The answer is pheromones. Plants are able to communicate with each other by sending out pheromones—chemical messengers. Plant cells synthesize these chemical compounds and then release them into the environment to elicit a response in the times of distress.

One of the key chemicals that elicits the defense response in plants is Jasmonic Acid. This organic compound activates the production of other genes for defense.

Methyl Jasmonic Acid is a derivative of jasmonic acid; its role is to regulate the developmental process and defense responses of plants when stress is detected. Part of the defence mechanism is releasing pheromones into the air warning plants around them that danger is near. These pheromones released are organic volatile substances known as Green Leaf Volatile (GLV). They have aldehydes, alcohols, and ester functional groups, which produces that fragrant aroma that people so often associate with summer.

Volatile Organic Compounds       Credit: Materic, D. et al. phys.org

Methyl Jasmonic acid is synthesized through the octadecanoid pathway. The picture below shows a detailed reaction pathway to this compound.

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Biosynthesis of Methyl Jasmonic Acid        Credit: Cheong, J.J. and Choi, Y.D. , Trends in Genetics

Although these volatiles may come from the same or entirely different species, the presence of these chemicals increase defence compounds. When cell membrane receptors detect these volatile chemicals, it activates self-defence by producing toxins, such as proteinase inhibitor. Furthermore, some of these pheromones produced by plants are able to attract insects to help defend themselves. For example, some plants release a certain type of pheromones to attract wasps. These wasps lay their eggs in caterpillars and when these eggs are hatched, the larvae eat the caterpillar from inside out.

I find this defense mechanism of plants absolutely fascinating. Plants are able to defend themselves in certain ways humans and animals cannot. While animals have physical features such as sharp talons or claws, speed, enhanced senses, and humans have martial arts and the sympathetic nervous system that elicits the fight-or-flight response as a form to defense mechanisms, plants defend themselves with the power of chemistry!

So the next time you’re out on a stroll enjoying that summer evening and you hear the roar of your neighbour’s lawnmower, you now know that the fragrant cut grass scent that follows is actually their distress signal. While releasing a series of organic molecules into the air to warn their plant friends and neighbours, it serves as an aromatic treat for us humans.

This video provides a more general explanation of this topic:

Resources:

Reece, J.B. et al. Fundamental of Physiology, 2nd ed.; Pearson: Canada, 2014; pp 237-238.

Cheong, J.J.; Choi, Y.D. Methyl jasmonate as a vital substance in plants. TRENDS in Genetics. [Online] 2013, 7. 409-412. http://www.cell.com/trends/genetics/pdf/S0168-9525(03)00138-0.pdf (accessed Sept 23, 2016)

Phys.org. De-mystifying the Study of Volatile Organic Plant Compounds. http://phys.org/news/2016-01-de-mystifying-volatile-compounds.html (accessed: Sept 24, 2016)