Why Is The Sky Blue?

Imagine sitting outside on the patio on a nice clear day. You look up towards the beautiful sky and see that it is…. As green as grass? As you look at the sky with confusion, your alarm clock rings, prompting you to wake up. The sky’s colour has always been something you never gave much thought to. After all, it’s just universally accepted that it’s blue. But after dreaming of such a weird sky… Have you stopped to wonder why the sky giving off the tint that it does?

A classic view of the sky (Source: https://www.flickr.com/photos/alex-r-/3599754765)

Doesn’t the Sky Just Reflect the Colour of the Ocean?

Actually no. Firstly, the sky is lit up by the sun, which emits white light. However, white light is not actually white in quality, but rather composed of all colours in the visible spectrum. In the day time, light from the illuminated sky reaches you at different distances depending on the position of the sun. When the sun is closest to us – directly overhead – it travels the shortest amount of distance, so it appears white. Light at any other point has travelled a longer distance, comparatively, through the atmosphere to reach our eyes. In its journey it has encountered gas particles in the atmosphere, which are smaller than the wavelengths of visible light. As it passes through the molecules the wavelengths are redirected, or scattered, in different directions. As one of the shortest wavelengths, blue light is scattered in high frequency by these small particles. The greater the distance travelled, the more the blue light is being scattered in comparison to the other colours. Thus, it reaches us the most and ends up being the colour that we see. Another example of this is at the horizon, where the sky may appear whiter because light there has travelled the greatest distance to reach us. Much of the blue light has been scattered away and the mixing of the other scattered colours is what we perceive.

The visible spectrum (Source: https://www.flickr.com/photos/entirelysubjective/6146868258)

Why Not Violet?

Hold on though… You may think, “isn’t violet light shorter than blue? Why don’t we see violet instead?”. You’re right, violet is shorter than blue. However, a lot of these violet wavelengths scatter higher up in the atmosphere and are absorbed as UV light.  Moreover, our eyes naturally contain three types of cones – red, green, and blue. The cones mainly detect these three types of light and as a result our eyes favour blue light over violet light, forcing us to see blue rather than violet.

The colour of the sky is an often overlooked topic that nobody thinks about, other than in the occasional pretty photos. However, we should consider ourselves very lucky because the exact composition of our atmosphere allows the sky to be blue. This is which is why in places such as the moon, which lacks an atmosphere, the sky is not blue at all.

A Quick Video Summary of Why The Sky is Blue

A podcast explaining why the sky is blue. (Source: https://www.vpr.org/post/why-sky-blue#stream/0)

Justin Wong

A Brief Analysis on the number of live births in Canada

Over the past decades, Canada has been converting from a high-fertility society to a low-fertility society continuously. While the number of kids in a family keeps decreasing, the moms are getting more and more aged.

The fertility rate in Canada has remarkably decreased over decades.
Source: Statistics Canada

 

Well, how much impact does this reduction have on the population in Canada? Let’s take a look at the data of live births in Canada over a recent dozen years.

With the development of Canadian society, birth rate, birth weight and their relations to genders are affected by a variety of factors, such as lifestyles, environment, financial conditions and some biological reasons.

The dataset ‘Live births, by birth weight and sex, Canada, provinces and territories’ contains number and percentage of live births sorted by birth weight, sex and areas in Canada through 2000 to 2014,  accessible via Open Government Portal, Government of Canada.

Source: https://www.parents.com/baby/care/newborn/new-mom-first-6-weeks/

According to a scatterplot of the overall trend of birth rate in Canada, 2000-2014, there is a consistent increase during the period of 2002 to 2008, and the number of birth increases rapidly from 2005 to 2009. Even though there are some fluctuations in these years, the overall trend is going up.

The amount of birth in Canada has soared over the 14 years.

From the further analyses conducted with the dataset, a more detailed idea of birth amount and birth weight in Canada in recent decade has arose. From 2000 to 2014, the overall amount of live births obviously increased by 4746.92 per year, but it fluctuated between 2000 to 2004 and 2008 to 2014. The period when the birth rate rapidly increased is from 2004 to 2007.

Fortunately, according to the above analysis, the number of live births in Canada over the period 2004 – 2007 was not influenced as badly as it looks at the first place. Even though factors that could negatively affect the population in Canada would always go with the development of the country, it can still be seen that the amount of newborn babies remains quite satisfactory from year to year.

 

Siqi Tao

If Focusing Was Just This Easy

We’ve all been there: either we’ve procrastinated by leaving all of our studying to the last day or, we’ve forgotten to do a paper until the night before. This is often where study drugs are introduced.

The Basic Facts

Adderall is a study drug, also known as a smart drug that is often prescribed to individuals with Attention Deficit Hyperactivity Disorder (ADHD). However, like many other prescription drugs, people have been using Adderall for purposes such as recreation and studying. As reported by the National Survey on Drug Use and Health, roughly 6.4 percent of college students have been found to use Adderall for recreational purposes. Particularly, most students think that Adderall will strengthen their ability to study. Although an Adderall prescription must be obtained from a doctor, people still have access to this drug from other sources.  A 2016 Recovery Brands survey showed more than 60% of individuals aged 18-28 get their hands on doctor-prescribed Adderall through family, classmates and street dealers.

How It Works

This drug works by increasing the amount of dopamine and norepinephrine in a user’s brain. Dopamine, also known as the pleasure centre of the brain, is responsible for our fight-or-flight response which controls focus, clarity and alertness. Norepinephrine helps to make all of these behaviours last longer. Combined, these two neurotransmitters allow the user to stay more focused, be more alert, pull all-nighters and be more efficient while studying.

The Big Picture

Nonetheless, the side effects of taking Adderall can be very detrimental to users. Some symptoms include irregular heartbeats, high blood pressure, nausea and loss of appetite. There has been a recent study showing correlation between this study drug and long term memory loss. Additionally, just like with any other drug, there is potential to become addicted to Adderall. According to the Drug Enforcement Administration’s Schedule II list of substances, Adderall is classified as a drug with a high potential for abuse that can lead to physical and psychological dependence.

Overall, study drugs may help you stay awake in order to cram information before an exam, but are the “benefits” worth the negative effects? Definitely no.

Basima Spindari

Genetic Genealogy: Using DNA for Police Investigations

Catching Culprits

The Golden State Killer terrorized California from 1974 to 1986. He killed at least 13 people and committed a series of rapes and burglaries during this twelve-year period, but was never caught. On April 24, 2018 however, Sacramento County Sheriff’s Department arrested Joseph James DeAngelo, who they believed was responsible for the crimes, before formally charging him. Genetic Genealogy was responsible for bringing him to justice and now crime solvers believe that more cold cases can be solved with this exciting method. While DNA profiling has been around since 1984, the genetic database was not large enough at the time to be as effective as it is today.  How it works is that genealogists upload DNA sequences from a crime scene to a large database consisting of genetic profiles from a mass of other individuals in order to find the relatives of an unknown suspect. Afterward, they narrow in on the possible perpetrator by constructing a family tree and pass on the information to law enforcement.

A Family Tree. Image from:                                            https://www.wikihow.com/Design-a-Family-Tree#/Image:Design-a-Family-Tree-Step-19.jpg

 

But First… what are SNPs?

Single Nucleotide Polymorphism (or SNPs) are markers in our entire DNA set. They signify that a portion of individuals will have one building block, called a nucleotide, at a specific position in a nucleotide sequence, but other people will have a different nucleotide (four different types) at that same position.  The two forms of SNPs are known as alleles.

https://digitalworldbiology.com/citation

This segment of a DNA strand has one SNP that does not match. Image from Molecule World: https://digitalworldbiology.com/archive/genetic-variation-i-what-snp

 

The Process

So how do genealogical DNA tests work? There are actually three major types of tests that can be conducted. Our focus is on the autosomal DNA test, which targets chromosomes 1-22 for analysis (the non-sexual somatic chromosomes). This testing method allows individuals to be matched within a database. An individual being tested may have a number of consecutive SNPs in common with a person already in a system’s database, in which case it can be inferred that they share a DNA segment within that section of their genomes. If this segment is longer than a threshold value set by a certain group, then the two subjects are treated as a match. Since half of the genetic information is inherited from each parent, the SNP of each individual decreases by approximately half each generation, but genealogical DNA tests generally account for about 700,000 SNPs. With this in mind, it is not expected that even somewhat distant family members will fail to match (as was the case in DeAngelo’s situation).

Video about how DeAngelo was caught. Video from CBC News: The National.

 

The Limitations

While this method is very effective, it does pose some limitations as well. DNA that is contaminated, degraded, or too small in amount can leave room for doubt when attempting to make a match. Also, due to privacy issues, many DNA-testing firms will not provide law enforcement any access to their database without consent from the user of the data or by a court order.

Genetic Genealogy is an effective way of solving cold and even active criminal cases. While some restrictions exist, the vast database now available can be a great resource for law enforcement.

– Hani Ghaffari

Is Taking Popular Supplements a Waste of Money?

How many dietary supplements do you take every day? According to Statistics Canada, about half of the Canadians take at least one supplement a day.  There are so many supplement products in the market today and consumers are overwhelmed with all the choices available. Are these supplements really necessary for maintaining good health? A recent review article published in the Journal of American College of Cardiology suggests otherwise.

How Supplements are made

Most supplements are synthetically made in laboratories and very few are made from naturally derived ingredients. In terms of chemistry, there is no difference found between the synthetically derived and naturally derived supplements. Most of the commercial vitamins found are made synthetically due to cost and efficiency.

Wide selection of vitamin supplements found in drugstores (source: Wikipedia)

Research on popular supplements

A team of researchers from St Michael’s Hospital and the University of Toronto claims that taking vitamin and mineral supplements have no significant effect on one’s health. The team reviewed 179 studies with single randomized trials that were published from January 2012 to October 2017. According to their review, the most common supplements taken were multivitamins, vitamin D, calcium and vitamin C. Their findings on these four common supplements reveal that there is little to no evidence in preventing cardiovascular diseases or early death. However, among all the dietary supplements that were reviewed, vitamin B9 (folic acid), and other B-vitamins such as B6 and B12 with folic acid were found to decrease the risk of stroke by 20%. On the other hand, the team was able to conclude that vitamin B3 (niacin) and antioxidants have rather a negative effect on our body, which may even lead to early death regardless of the cause.

What should we do?

Dr. David Jenkins, the lead author of the study reassures people that there is no harm in taking most of the popular supplements, however, he also adds that people should know that there are no significant benefits in taking them. He recommends that people should rely on eating a healthy and balanced diet to get their vitamins and minerals. According to his research, fruits, nuts, and whole wheat pasta were some of the foods that people should consider adding to their grocery list.

Here is a video from TED-Ed providing background information on the vitamins that were mentioned in the review. (Source: YouTube)

Tina Kwon

Let Dark Chocolate Keep Your Blood Vessel Healthy

Have you ever heard having approximately 1-2 ounces of dark chocolate every day is good for our health? Several studies announced that dark chocolate helps to keep our blood vessels healthy. But, do you have any ideas of what makes dark chocolate be beneficial?  Compared to white or milk chocolate, dark chocolate is made of higher contents of cocoa solid in the range of 50 to 90% where the cocoa is known for a rich source of flavonol, a type of flavonoids.

Dark chocolate bars source: https://www.eatthis.com/best-dark-chocolate-bars/

 

What does flavonoid do to our body?

First of all, flavonoid is a plant nutrient that reduces cardiovascular diseases and can be found in many fruits and vegetables. A type of flavonoids, called flavonol, is found in cocoa and also it is the key source for the benefits of dark chocolate. One of its main function is antioxidants effects. An antioxidant is known for a protector of our body from any harmful damages caused by free radicals and their oxidation. For example, flavonoids lower the amounts of LDL cholesterol, also known as bad cholesterol, in our body since oxidized LDL cholesterol reacts with free radical and cause heart diseases. Another function of flavonoid is that this chemical is used to stimulate cells in inner blood vessels called endothelium. By stimulating the cells, nitric oxide can be produced and used to improve blood flow since nitric oxide can dilate arteries.

The following video explains further details about flavonoid and its function.

 

Research study on the effects of dark chocolate

A study on flavonoid-rich dark chocolate was done at the University of California. 21 healthy adult subjects were randomly assigned to high-flavonoid or low-flavonoid chocolate for 2 weeks. As a result, The group of intake high-flavonoid chocolate has significant mean changes of 1.3 ± 0.7% in dilation of the brachial artery, the major blood vessel in the upper arm. This study concludes that flavonoid improves endothelium functions and blood flow.

 

As dark chocolate contains flavonoids more and more, its impacts on our health, especially on cardiovascular health is significant. However, dark chocolate still contains fats and sugars that possibly lead to diabetes or weight increases. 30 to 60g of dark chocolate per day is recommended.

 

 

Ellen Lee

 

 

 

 

 

 

 

 

The Science of Aging: Can we live FOREVER?

Qin Shi Huang, the first emperor of China who built the great wall of china desperately sought the elixir of immortality later in his life. As he grew older, he was terrified by the fear of death and was obsessed with the fabled elixir of youth. Unfortunately, he failed to find the elixir and died by mercury poisoning believing that mercury has the power of reversing the aging process. Now, more than 2000 years have passed since he died. The progress of science has made remarkable changes in our mode of living. Can scientists find the legendary elixir? If it cannot be found in nature, can we create the magical elixir ourselves?

The fabled elixir of life lets us live forever (Source: Innovation Toronto, click the image to visit the website)

What is aging?

We know intuitively what aging means, but what does it mean in the scientific term and how can we define ‘aging’? Scientists define aging as the intrinsic physiological process that declines body function and causes an increase in death rate. The mechanisms of aging are still not fully understood due to its complexity but scientists have recently made advances in this area. First, scientists have hypothesized the reasons why we age. In 1990, there was an effort to categorize 300 theories of aging by Zhores Medvedev and one of the main reasons is that cells can’t divide forever.

 

The Hayflick limit

In a laboratory in Philadephia, a young scientist Leonard Hayflick found out that our cells have a finite number of times – 40 to 60 times – to undergo cell division before they die and stop functioning. Once we run out of healthy and functioning cells in organs, we die. This means that we all have a biological clock that tells us when to die from the moment we are born. Why does this occur? Scientists believe that shortening of the telomeres accounts for this phenomenon. Telomeres protect DNA by acting as caps which prevent the chromosomes from deterioration. Telomeres are at the end of the chromosomes. As cells undergo cell division, telomere length gets shorter and shorter. When the cells run out of telomeres, DNA strands become susceptible to damage and this leads to cell death.

The Hayflick limit of a normal human cell. Cells can no longer divide at some point. (Source: The Bio Regulator Company, click the image to visit the website)

Not everything dies by aging

Does this mean that every living thing will die by aging? Not really. For example, cancer cells are biologically immortal under ideal conditions – which is not very good news for us. How about in living organisms? It turns out that some animals and plants are biologically immortal and do not die by aging. Hydra – a small, fresh-water invertebrate – is one of the organisms that does not age. In 1998, Martinez found out that Hydras do not exhibit evidence of aging. More recently scientists working at a biotech company founded by Google have discovered that naked mole rats defy the definition of aging; their death rates do not increase with age. So, by the same physiological mechanisms which hydras and naked mole rats use, can we live longer?

Hydra, an aquatic animal, is biologically immortal. (Source: Wiktionary, click the image to visit the website)

 

 

Anti-aging drugs?

Unfortunately, we are neither hydra nor naked rat mole. Physiological systems of the human body are much more complicated. So, we can not exploit their physiological mechanisms. What if we can extend our telomeres and let cells divide more times? Wouldn’t we be able to live longer? The answer is a half yes. Telomerase is an enzyme that can fix and extend telomeres at the end of DNA strands. It is like a small machine that resets our biological clock. Telomerase can be found in some types of cells in our bodies – especially stem cell. It seems like a no brainer. Let’s get some telomerase and put it in a pill. Well, the problem is that’s what cancer cells do. That’s why cancer cells are biologically immortal. So, unless you want to get cancer, don’t put that extra telomerase in your body. According to Elizabeth Blackburn, nudging up telomerase could decrease aging effects, but it could also increase the risks of certain and rather nasty cancers. She mentioned that there are many websites marketing drugs saying that they can extend telomere, but the problem is those drugs could nudge up the risks of cancers. Here is a major dilemma, cancer or aging?

(Video – Ted: The science of cells that never get old  by Elizabeth Blackburn)

Conclusion

So, there is no clear solution to aging yet. However, a journey of finding the elixir of immortality continues. Scientists keep on pouring tremendous efforts to understand aging and how to resolve the riddle of the true antiaging drug. Instead of making the drug, there could be other ways to approach the immortality. Netcome, a neuroscience startup that seeks to back up the human brain on the computer server. Biolife4D, a biotech company in Illinois, United States is trying to build human organs with stem cell technology and 3D bioprinting technology. Maybe in the near future, we will figure out an answer to the immortality.

Uploading the human brain to the computer. (Source: Live Science, click the image to visit the website)

Still worry about your procrastination? Maybe it’s not your fault!

Have you ever submitted an essay the minute before it was due, heart pounding and fingers flying across the keyboard?  Have you ever try to focus on your work but you can’t hold yourself to take a look of your cell phone, play with your pencils or even just lay on the bed doing nothing. After hours or days struggling, you give up and finish your work roughly and you say alright, my procrastination is killing me.

“procrastination”的图片搜索结果

credit: https://goo.gl/images/Z9ZFEf

What if I tell you it’s not your fault and not even “procrastination” ‘s fault. Scientist already identified that two parts of brain may explain why people procrastinate so much. Generally, people with poor action control will result in procrastination.  However, a study done in few month shows that people with poor control over their actions have a larger amygdala. The amygdala can warns people about their negative effects actions. What’s more, the study found out that people with poor action control, were also suffering from  less pronounced connection between the amygdala and the dorsal anterior cingulate cortex (ACC).

In this video, Science in YouTube will explain how the ACC play the role in emotion.

https://youtu.be/3F4HS6Eo5q8

credit: https://youtu.be/3F4HS6Eo5q8

The video can help you to have a clear idea about how ACC work to procrastinator and  non-procrastinator brains .You can also  view the physiological differences in procrastinator brains vs. non-procrastinator brains by the pictures below.“procrastinator vs. non-prostinator brains”的图片搜索结果

 

 

“procrastinator vs. non-prostinator brains”的图片搜索结果

credit:

https://goo.gl/images/dEQzHm

https://goo.gl/images/RfE1t7

Research study on ACC and procrastination

The scientists — bio psychologists at Ruhr-Universität Bochum in Germany studied how ACC different effects people. Scientist scanned 264 people’s brain through magnetic resonance imaging (MRI). And then  looked at the volume of specific regions in the brain. After that they figured how the regions connect to each other. The participants were asked to fill in a survey about their ability to control their actions and how if they procrastination in daily life. Most of them were university students with no neurological disorders. The result of the study is that ” people can’t control their actions successfully if the connection between the amygdala and the dorsal ACC is impaired.”

If you are still regret about wasting time and feel guilty about  procrastination. Don’t be so said, it’s not all your fault! Your given body somehow makes you can’t focus on the work and delay. Scientifically make plans will be more helpful than blaming yourself!

Drinking too Much Water Can Kill You

Growing up, we have been told numerous times to drink at least four-to-six cups of water a day to stay hydrated. Water is an essential part of life, but what if I told you that drinking too much water can kill you? There are many studies that explain how over-hydration, especially when you are finishing a workout or have kidney issues may increase the risk of water intoxication. Water intoxication, also known as hyponatremia can be hazardous to your health and in a few cases lethal.

image

Drinking 3 Litres of water a day keeps you well hydrated.                Credit: Chris Bishop http://teded.tumblr.com/post/142459697422/10-facts-about-water-your-body

How Can Over-hydration Kill You?

In this video, Science Insider a YouTube channel that primarily creates educational videos, explains how dangerous and harmful over-hydration can be.

Drinking faster than your kidney can process disrupts the balance of Sodium and water in the cells resulting in the cell swelling up and expanding.  The video continues explaining how the continuous swelling of cells, especially brain cells  leads to dizziness and brain damage.

Research Study on Water Intoxication

A study from Queen Mary University of London, explained that water consumption is indeed beneficial to the human body in healthy amounts. However, Exercise-associated hyponatremia (EAH) also known as water intoxication in marathon runners are more prevalent.

The study collected surveys on 298 participants who were all runners in the 2014 London Marathon, surprisingly only 48% of participants had knowledge about the effects of water intoxication and how much water should be consumed during the run. As study shows that 13% of marathon runners show mild symptoms of water intoxication. The saying “drink to thirst,” is known to be the most effective guideline to prevent water intoxication compared to “drink to max.” There isn’t enough proof  that establishes when mild symptoms of water intoxication becomes symptomatic. But what is known is that hydration strategies is vital to the safety of participants that are involved in high physical activity.

image

Know your limit and stay within it!                                            Credit: Chris Bishop http://teded.tumblr.com/post/142459697422/10-facts-about-water-your-body

 

The effects of over-hydration is lethal and should not be taken lightly! We’re all guilty of gulping down a few drinks or even consuming excess amounts of water after a workout, however we should definitely take a few sips back and think about how much water we really need.

 

Cindy San

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