See you soon for more exciting articles

Vampires, evil beings that fed on blood, have been particularly prevalent in in the 18th century. Although superstition may have originated from Western Europe, fear of vampires became wides spread and sent the whole of Europe into mass hysteria. A well-known defense against vampires is to chew garlic and have cloves of garlic around you at all times. Of course chewing garlic release a putrid smell that is almost impossible to get rid of. This is because upon chewing garlic a sulphur containing chemical called allicin is produced, and sulphur containing compounds (thiols) are well known to smell nasty. The smell is often associated with rotting eggs or rotting meat, and it this is exactly what people wanted as surrounding oneself with this smell is thought to offer protection against the evil vampires. The Romanians took this so far as to smear garlic on every nook and cranny (including their windows, doors, gates and even cows). Now the question begets, “Why is Garlic useful against vampires”; wouldn’t it be more logical propagate a myth where vampires are terrified something that smells good? If not, something that smells less vile.

One of the possible explanations for this odd belief is that garlic is known to have anti-bacterial qualities. Garlic was used to ward off various diseases such as the plague and it is believed to have many health benefits.  Infact, there have been many scientific studies (2)(3) showing the anti-bacterial properties of garlic. As vampires were associated with “evil”, a category that diseases and plagues belong to, one might assume that garlic might also ward off this evil.

Another possibility is that garlic is natural mosquito repellent. Since vampires are also blood sucking fiends, having an odour of garlic might repel them away also.

Vintage arsenic poison bottle

A rather interesting hypothesis by the French Occultist Robert Ambelain (4)(5) is that the burning of arsenic compounds started off this whole trend. This might sound a bit preposterous, but there is certain logic to the argument. During the time vampires lore is dominant; Arsenic, a potent poison, was believed to hold power over evil (arsenic was also used in many folk medicines). This ideology was strongly held by many alchemists in major cities like Prague and Moravia at that time. When alchemists were hired to ward of vampires, they would burn arsenic containing compounds to provide the illusion that they are warding off evil with powerful evil slaying odours. These arsenic containing compounds when burnt would provide a nasty odour that smells exactly like that of chopped garlic. The peasants would of course notice this and make the connection that chewing garlic would produce the same effect and would be cheaper than hiring and alchemist (hence contributing to its spread and popularity). One critique of this theory is that garlic burning was localized to a few countries in Europe whilst Vampire lore was much more widespread.

One interesting twist to the story is an experimental study done in 1994 by Sandvik H et al (6). Devoid of real life vampires, the group used blood sucking leeches to try to find out if a garlic smeared hand would repel the leeches. As it turns out, the garlic actually attracted the leeches and decreased the amount of time it took to attach itself to the hand. They therefore proposed that garlic might actually attract vampires. This might not be a conclusive theory, but it is sure enough an ironic result. Perhaps they should try an experiment with vampire bats next time.

Of course there are many other other explanations, if you have have any ideas please post them below:

1. Silver & Ursini, The Vampire Film, pp. 22–23.
   
2. Cavallito, C. J.; Bailey, J. H., Allicin, the Antibacterial Principle of Allium sativum. I. Isolation, Physical Properties and Antibacterial Action. Journal of the American Chemical Society 1944,66 (11), 1950-1951.
3. Farbman, K. S.; Barnett, E. D.; Bolduc, G. R.; Klein, J. O., Antibacterial Activity of Garlic and Onions: A Historical Perspective. The Pediatric Infectious Disease Journal 1993,12 (7), 613.
4. http://www.shroudeater.com/agarlic.htm
5. William R Cullen, Is Arsenic an Aphrodisiac?: The Sociochemistry of an Element, William R Cullen
6. Tidsskr Nor Laegeforen. 1994 Dec 10;114(30):3583-6.
   

What do you think is the origin of “The origins of Garlic vs Vampires” ? Post your ideas in the comments below!

Plastics take a huge amount of time to decompose

Massive plastic buildup

Biodegradable plastic are a potential solution to the massive waste problem facing the planet Earth today. As plastics are used extensively in product packaging, disposable utilities, plastic bags and water bottles, waste buildup is an enormous problem. This problem is made worse by the fact that normal plastic takes 10 to 500* years to decompose, hence the only real solution is to send it into land fills.

Biodegradable plastics

Biodegradable plastics are designed to decompose in composting and landfill environments. Microorganisms in the landfill/compost would then metabolize the molecular structure of plastic films to produce an humus-like material that is less harmful to the environment. This would in effect turn the plastic back into materials that go back into the Earth. In addition to this, a lot of biodegradable plastic bags are made from renewable resources such as corn or sugar cane. This greatly reduces our dependence on oil.

Not without criticism

The major criticism of biodegradable plastic is that it produces CO2 and Methane upon decomposition. These two gases are of course greenhouse gases that would accelerate global warming. The counter argument for this is that a lot of biodegradable bags are made from natural resources which absorb CO2, thus the net change in CO2 is zero (think of it as carbon offset).

Earth Day

Enjoy your Earth Day and celebrate the wonders of this beautiful planet has to offer! Now that you have an appreciation for biodegradable plastics, considering buying products made from them next time you are in the supermarket.

*There is a huge discrepancy in the estimate for how long it takes for plastic bags to decompose due to difficulties in estimating this number.

References

Wikipedia

How green are plastic bags?

Final exam time!

Exams are probably is probably the most dreaded aspect of academic life. Like an age old torturing device, every course would have one of these at the end to the demise of all the students taking it. The debate would always question “Why do we take exams” and “Do exams really hold any value other than rote learning”. The common answer would be that exams give an indication how much one has learnt in the course along with one’s mastery of the subject. Although this is true, it has been proposed that

exams actually greatly improve one’s memory according to the “Mediator Effectiveness Hypothesis”.

Time to work hard!

The idea is simple, during revision; one would use catch phrases, mnemonics or “mediators” to remember difficult concepts. An example of this would be ROY G BIV to remember the colours of the rainbow, “Red Orange Yellow Green Blue Indigo Violet”. For this mediator to be useful, one must be able to recall it during the exam. In addition to this, one would also have to “decode” this into its true meaning

ROY G BIV = Red Orange Yellow Green Blue Indigo Violet

The Mediator Effectiveness Hypothesis proposes that tests improve the mediator retrieval and decoding. The trial to validate this hypothesis was conducted by Mary A. Pyc and involved 118 participants who were asked to remember and distinguish 48 Swahiki-English translations. Participants were divided into groups that would do tests to restudy the material or groups that simply looked at the material to restudy it.

Results of trial showing greatly improved results for group that had test-restudy (Science Magazine)

The results show that the group what did a test restudy had a resounding success rate as opposed to the group that simply looked the material.

There are ofcourse limitations to this study, for example, subjects such as physics require the full understanding of a concept instead of simple memorization. In addition, the long term memorization of the material is not tested.

Overall explanation for why we have exams is provided; it’s so we can remember the material better (whether that material is useful or desirable is another issue). Maybe next time you have an exam or test, you will look at it in a new light (or do self re-tests to improve your memorisation).

Reference

Pyc, M. A.; Rawson, K. A., Why Testing Improves Memory: Mediator Effectiveness Hypothesis. Science 2010, 330 (6002), 335.

POLL: Are there still things you remember from exams you have taken in the past?

Some sample BPA free baby bottles

Too long didn’t read (tl;dr) version:

*Bisphenol A (BPA), a molecule produces effects similar to the hormone estrogen (xenoestrogen), is used in the manufacturing plastic bottles.
*Issue is a big deal because of media / political attention.
*Concerns are (possible effects): Attention-deficient hyperactivity disorder,  breast cancer, thyroid function
*Issue is up to debate because of the low quantities of material involved

What is Bisphenol A ?

Bisphenol A (BPA), a molecule produces effects similar to the hormone estrogen (xenoestrogen), is used in the manufacturing plastic bottles. This compound is used to make the strong, clear and shatter proof plastic known as polycarbonate plastic. These properties make it perfect for producing milk bottles, sports bottles and some food containers (with usage dating back to 1957, more than 50 years ago). Bisphenol A has been at the center of a lot of media attention due to recent scientific papers which make large claims against BPA. However, the problem is that not all the results are conclusive and not all the papers are in agreement with each other. This article will hopefully clarify the situation and more importantly give some room for discussion; a necessary and major part of scientific research.

Wikipedia actually contains quite some useful information on this issue. With all research one needs to keep a critical mind on whats being said. The wiki entry highlights the recent conflict and media exposure into the chemical, and of course, there is a lot of drama. One key point is that

“Bisphenol A is used primarily to make plastics, and products containing bisphenol A-based plastics have been in commerce for more than 50 years”. What that really says is that everyone we know has been exposed to this chemical. Second thing is, its not only used in baby milk bottles, “Bisphenol A has been known to be leached from the plastic lining of canned foods[119] and, to a lesser degree,[citation needed] polycarbonate plastics, especially those that are cleaned with harsh detergents or used to contain acidic or high-temperature liquids.”

This pretty much means we have all been exposed throughout our lives and including childhoods. So empirical evidence stands that the majority of humans who are exposed to this is fine. We are not going to turn into brain dead zombies just yet.

Chemical structure of Bisphenol A (BPA)

Next question is, why is it an issue? One common theme now is that we are discovering small quantities of chemicals in everything due to improvements in detection techniques. In terms of detection limits, the sensitivities of modern instruments are now orders of magnitude high than before. And ofcourse as scientists, we love new instruments and want to test it out on everything. Also we want to publish papers with bold statements. And as this diagram shows almost everything can be correlated : http://borkweb.com/story/global-warming-causes-pirate-population-decrease . This pretty much explains why we have so many “re-discoveries” making its way into the media.

However, these reports are not without merit. As our quality of life improves, we must eliminate all the small factors which might hinder this. Removing chemicals that look like hormones is a very good start, as hormones pretty much dominate our growth. This brings us back to bisphenol A, which mimics estrogen in our body, how large of a factor is this compound?  The answer to this question is not simple. This is mostly because concrete scientific data proving that Bisphenol-A adversely affects our health doesn’t exist, however, there might be a major effect from public fear of the compound. Public fear has been shown to large contributors to the actual damage something causes, mostly due to the placebo effect or public paranoia.

Are you concerned about Bisphenol A from your plastic bottles? Here is an open thread to discuss them!

Angler fish are deep sea dwelling fish that have a profoundly alien way of life

Original from Oatmeal

So is it factually correct?

Apparently some male angler fishes are absorbed into the female according to wikipedia

Some anglerfishes, like those of the Ceratioid group (Ceratiidae), employ an unusual mating method. Because individuals are presumably locally rare and encounters doubly so, finding a mate is problematic. When scientists first started capturing ceratioid anglerfish, they noticed that all of the specimens were females. These individuals were a few centimetres in size and almost all of them had what appeared to be parasites attached to them. It turned out that these “parasites” were highly reduced male ceratioids.

Fascinated by these terrifying creatures? Post your comments below!

Imagine a world where you can lose fat while EATING YUMMY, FATTY, GREASY, SMOKEY BACON. TONNES OF BACON!!! (No. Not really. Attempts to consume multiple tonnes of bacon may result in… unpleasant effects. You have been warned.)

Eggs, Milk, And… by DJBisparulz

In short:

about 70% fat, about 30% protein, <10% carbs, Your daily carb limit is about 30 grams (you can do more as you’re more experienced at balancing it out).  Of course, you still have to eat fewer cals than you burn. All bodily functions will be using fat for energy instead of carbs/protein. After dietary fat is used up you instantly start using bodily fat.

For CKD (Cyclical Keto Diet) on Sundays you can eat high carb, low fat, medium protein. Saturdays too if you work out enough. This is the Carb-Up phase where glycogen (derived from sugars/starches) is stored in your body for use durign the week.

TL; DR Version

Disclaimer: I am not a qualified nutritionist, and scishark is not responsible for any health problems/death/wild cheetah attacks/asteroid impacts resulting from your use of this information.

Daily protein should be at least 1g/lb of lean body mass (calculate with calculator thingy) eg. 100 lb lean bodymass should be eating 100g protein/day

So here’s example

Yummy avocado + chicken + BACON + with romaine lettuce + a few cherry tomatoes!  Dressing? How about balsamic vinegar + lots of olive oil + basil (FRESH!?) + rosemary + brown sugar (not too much, it be carbs after all) -> blend for a bit.

Maybe some chicken wings.

Want a snack? BACON!!!… or cheese; peanut butter + butter made into a ball is quite popular too.

What do I do for breakfast? Protein shake (quite yummy), then I drink a few table spoons of olive oil (not quite yummy). If you actually have taste buds and don’t want to  drink bloody olive oil, you are probably better off with peanut butter, cashews, cheese etc.  Health freaks prefer griding flax seeds for flax oil every morning, bottled flax oil has shitty Omega-3:Omega-6 ratio.

How about chocolate? Sure why not, just make sure you don’t eat >30g carbs/day… and every time you eat a piece of choco you throw in some cashews… hmmm bacon + chocolate? (Yes I am obsessed with bacon.)

Just do the math,  about 70% fat, about 30% protein, <10% carbs; with a minimum of 1g of protein per lb of lean body mass per day.

SCIENCE, YEYY SCIENCE!!!

Fatty acids are broken down in the liver, producing ketones bodies, which are used for energy. Excess ketones bodies are filtered by the kidneys and will be detectable with ketostix or alternatives. One type of ketone body is acetoacetic acid which is then broken down into acetone, which is also a ketone body. There is debate whether decades long ketogenic diets will harm the user, pro-keto side often cite inuit/eskimo diets which would’ve been purely ketogenic. Anti-keto side often argue that inuit/eskimos have genetic predisposition, and the fact that acetone is toxic.

During  carb up phase glycogen is stored for use during exercise. Each glycogen molecule bonds with one water molecule so initially you will lose about 10lb of bodyweight, simply from water loss. This is normal. Weekly fat loss of 2lb is quite common. Use calculator thingy, don’t trust BMI or simply the scale.  Some people gain weight through muscle while losing fat at a similar rate.

Cholesterol

FORGET CHOLESTEROL!… at least for now.

Food cholesterol (at least in eggs) does not affect blood cholesterol for 70% of the population, for the other 30% both “Good” and “Bad” cholesterol are elevated by the same amount, so you’re safe. More info here. HDL:LDL ratio is unaffected.

Also, it’s unlikely that you will want to maintain this diet for years and years.

Pictured: Not Science

Harry Potter in his invisibility cloak

The idea of becoming invisible could be described as one of humanity’s most sought after traits. This could be seen in films like Predator or Harry Potter where cloaking is one of the key plot elements. Most people would dismiss this as fiction and purely part of the imagination; how can something simply vanish in front of us? This brings us to the question: What is the science behind cloaking?

This disblief may soom come to an end as scientists are rapidly trying to make cloaking a reality through the use of transformation optics. The idea behind this is simple and could be summed up in the diagram below:

Diagram explaining how an object (shown in grey) can cloak. Nature

Here, the object directs the light beams smoothly around it and allows the beams to exit on the other end in the same direction. This creates the optical illusion that the object is not there as the eye assumes that light travels in straight lines and hence this must have come from the light source behind the object. This illusion is possible through the use of meta-materials, which are artificial materials that are composed of metal, circuit board, ceramic, teflon or fiber composite.

Metamaterial cloaking structure

The first microwave cloak

The science of cloaking started with the first demonstration of cloaking done in 2006. This experiment was unfortunately not done in the visible range of light; instead it was done  in the microwave range. This is the part of the electromagnetic spectrum (which includes visible light, radio waves and ultra violet) which the human eye cannot detect. Thus although we cannot actually see this achievement with our eyes, it provided the ground breaking proof of concept for cloaking devices. Another limitation of this cloak is that it is only invisible in two-dimensions(2D) and hence if you walk around the object, it would would be immediately visible.

Next generation of cloaking devices

Recent advances in cloaking have taken rapid leaps forward, including the blueprint for a new device that cloaks in all three dimensions and in infra-red range. This symbolizes the leaps science has made since the first experiment in 2006 as the objects now cloak in the the infra-red range, in other words we are one step closer making cloaks invisible to the human eye.

Blueprint for a 3D cloaking device. ScienceMag.

Challenges ahead

One of the limitations of these cloaking devices is the illusion is only effective in a narrow range of wavelengths. This means that the cloaked object would be only invisible if the observer could only see one color. However since humans can see a wide range of colors, the object would still  be visible. One could say that the principles for this science has been established, not its just a matter of fine tuning the details.

Article by Yuxuan Wei Gu

Further reading:

http://www.sciencemag.org/content/314/5801/977 – 2006 original paper on Cloaking

http://www.nature.com/nature/journal/v471/n7338/full/471292a.html – Nature review on cloaking

http://www.msnbc.msn.com/id/12961080/ns/technology_and_science-science/ – MSNBC news article

http://www.loa.espci.fr/cargese2009/Cargese2009_Pendry.pdf – Presentation on Cloaking materials

http://www.sciencemag.org/content/328/5976/337.full#ref-1 – Three-Dimensional Invisibililty Cloak at optical wavelengths.

Interesting video on cloaking

http://www.youtube.com/watch?v=Ja_fuZyHDuk

Found any interesting articles about the science behind cloaking? Post them below!

Go back in time through your DNA

Can the things we experience in life leave a mark on our DNA?  This idea has captured the imaginations of many and is incredibly popular in today’s media. For example, the entire premise of the Assassin’s Creed series is that memories leave a mark on and are passed down through DNA, allowing the ordinary Desmond Miles to relive the adventures of his Assassin ancestors.  And while we probably won’t be able to explore the memories of our ancestors in real life, there actually is a scientific basis behind the idea that our DNA can be modified after birth, holding important psychological and physiological consequences that would greatly impact our lives.

Before going on, here are some simple concepts:

DNA – “the building blocks of life”, DNA is like an instruction manual on how to build a human. It is in the form of long sequences which forms the famous double helix structure.
Gene – genes are particular sections of DNA that has instructions on how to make one particular protein. Much like a chapter in an instruction manual, they hold instructions on how to make one specific component.
DNA methylation – a chemical change to our DNA which changes the way it is read by our body. This doesn’t change the sequence, its more like a on/off switch for particular genes.
Proteins – the body’s machinery to perform certain tasks such as digest food or maintain our body. Proteins are the outcome of DNA.

Epigenetics – study of changes in gene expression that is not caused by changes in the gene sequence

Caring mother rat

Childhood experiences could effect us at a genetic level.

In the past decade, the age old question of nature versus nurtured has been answered by the solution by epigenetics, “can’t it be both”. It turns out that experiences in our childhood may alter our DNA through the process of DNA methylation (think of this as a switch that turns on and off certain genes). What this means is that nurture might also change nature; not only change emotionally, but we also change physically.

Scientifically, this subject has been called “behaviour epigentics” and is one of the hottest topics in this decade. The experiment that started this off was the examination of rats brought up in different environments. Some rat mothers would nurture their pups by licking and grooming them; whilst others would mostly ignore their pups. Rats that were raised by negligent mothers were found to be more sensitive to stress (so if you grew up in a nurturing environment you might cope with stress better). The response to stress was measured chemically via the detection of cortistone (a hormone - chemical messenger that is sent throughout the body). The scientists proposed that this is due to the reduced number of glucocorticoid receptors (a protein that is expressed in DNA) these rats had and this is in turn attributed to methylation in the DNA. Hence different upbringings that rats experience are correlated with in DNA expression.

How this epigenetic experiment relates to human beings has been a topic of great scientific debate. Important questions such as the long term effects of childhood abuse have been proposed and examined. Initial findings suggested an increased amount of DNA methylation. However, as with all things relating to humans, experimental evidence is much harder to obtain and hence it is much more difficult to provide a concrete answer.

Agouti mice that have the same genetic code but different genetic expressions. Image source unknown

Environmental consequences

Epigenetics effects could also be caused by major events for an example a major famine. One well know example is that children that have survived a famine have a increased risk for obesity. It was found that children who have been directly affected by a famine had less DNA methylation compared to same family siblings who were not directly starved. Epigenetics caused by environmental factors have also been used to explain why identical twins (who have the same DNA) might develop different diseases.

To conclude, one could picture our DNA as a book and this book can have different meanings depending on what pages you read. The methylation of DNA (epigenetics) controls what pages of our book is read and hence we might become different people even if we have the same DNA. If the experiments prove to be true, then one could hypothetically make a machine that would look at DNA, more specifically where it is methylated and find out a bit about our childhood upbringing or major events we have been through. Unfortunately, whether we could relive our ancestor’s memories might be a far stretch as DNA methylation doesn’t change our genetic sequence and hence isn’t very readily passed to the next generation.

References

http://www.sciencemag.org/content/329/5987/24.full – The Seductive Allure of Behavioral Epigenetics

http://tinyurl.com/4z73mw6 – DNA methylation and demethylation probed my small molecules

http://www.nature.com/neuro/journal/v13/n11/abs/nn.2666.html?lang=en – DNA methylation and memory formation

http://www.pnas.org/content/105/44/17046.abstract – Famine and DNA methylation

http://www.time.com/time/health/article/0,8599,1951968-3,00.html – Time news article on epigenetics

http://pubs.acs.org/cen/science/87/8714sci1.html – Genes and Epigenetics

Diagram sources: ACS, ScienceMag

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Article by Wei Yuxuan Gu in collaboration with Claire (introduction and editing)

Comments / Discussion:

Where do you stand on the debate of nature vs nature. Do you think events in your past greatly impacted you and caused  you to become a different person?

Post your thoughts in the comments

Fukushima Nuclear Power plant japan

The extent of the damage to the Nuclear Power plant in Fukushima Japan has been greatly obscured by the media and thus it is an issue where actual facts and scientific insight is hard to find. This article aims at keeping you up to date with constant updates and additional insight into the issue.

Reactors 1, 2, 3 seems to have sustained considerable damage

Reactor 4, which was under repair at the time of the earthquake seems to have suffered structural damage and was a concern last week due to speculation that the spent fuel rods could undergo critical mass.

UPDATE: Work to recover AC power for Unit 1 through 6 is in progress. External AC power has reached to Unit 2, 4, 5 and 6 and is now available in all the units. (You can keep up with the event on wikipedia - http://en.wikipedia.org/wiki/Timeline_of_the_Fukushima_nuclear_accidents)

The major fear of this event is a major meltdown similar to Chernobyl whereby nearby areas were severely (made worse by the radiation clouds that blew West to Europe). The fear in japan is mainly due to the uncertainty of what is happening inside the reactors (workers had to abandon the facility due to the large amounts of radiation detected which were well above safe limits).

Japan nuclear threat: The tsunami is the bigger tragedy – Another take on the radioactive situation

Summary of article

• A full body CT scan (which people can legally do) is “a [radiation] dose equivalent to being 1.5 miles from the centre of the Hiroshima explosion.”
• We are exposed to a large amount of natural radiation each day and this is no different from radiation that comes from nuclear reactors
• Fear is greatest harm that can come from this event

Whats up with the iodide?

According the a new UN report, “[contaminated milk caused by Chernobyl] led to a substantial fraction of the more than 6,000 thyroid cancers observed to date among people who were children or adolescents at the time of the accident (by 2005, 15 cases had proved fatal)“. This is due to radioactive iodine being absorbed by the thyroid gland as opposed to normal non-radioactive iodine. The solution to this is of course taking a large dose of iodide (from potassium iodide tablets) and which can compete with the radioactive iodide. However, do to the fact that potassium iodide is not retained in the body for long periods of time, this is only from up to 6 hours before to after the exposure. As of writing, extremely large amounts of radioactive iodine has not been released from the reactor and hence such precautions are not necessary.

Maybe we should stop stockpiling the tablesalt to get every last drop of potassium iodide.

Post disaster consequences

As the situation stabilizes, the world turns its attention to the consequences of the Japanese nuclear crisis. Reports are mostly focused on the above standard radioactivity levels found in plants and food in the area near the power plant. More recently however, it is discovered that radioactive water that was used to cool the plant may have leaked out.

April 5th : Seems like they have plugged the leak.

Update: There seem to have been reports that levels of radiation that are beyond normal limits are found in milk and vegetables grown in the area. This is expected because radioactive isotopes of elements behave almost identically to the normal isotopes, this it will get incorporated into the food chain. What is unclear is the amount of radioactivity since government standards are set to be extremely stringent.