Category Archives: Fun!

A Lovely Indecision

There’s hardly anything as conflicting as tastes, especially subconscious tastes that vary on a monthly cycle and alternate with circumstance. In honour of Valentine’s Day, we shall explore the theme of indecision in female mate selection, featuring the wonders of the pill.

To begin, attraction in females shifts between when she’s ovulating and not.

While in the fertile throws of follicle phase, females generally prefer a male with manly features and high testosterone levels, as well as a dissimilar Major Histocompatibility Complex (MHC). MHCs are linked to immunity, so humans naturally seek to diversify for maximum heterozygosity and variation. A fun fact, while fertile, girls in relationships are also known to develop a taste for dominant smelling men.

YouTube Preview Image (A little More on MHC)

Most of the time though, women are not in fertile mode, and in these circumstances tend to fall back on men who have a similar MHC to themselves. They also favour men who are less masculine and more nurturing and supportive, especially if they live in a healthy environment.

Based on these natural cycles, we can see how there might be some conflict of interest depending on what day it is.

"I don't know what I want!" Image:ehow.com

Sometimes, one doesn’t even need cycles to complicate things. While single, girls have an increased preference for MHC similar men, but then have dissimilar MHC preference when they’re already with someone. If that’s not enough, these changing preferences of MHC make a huge impact as scent is much more emphasized in importance with women rather than men. Occasionally, scent can even be at odds in importance with visuals though it varies on the population and culture.

That said, a person’s heterozygosity of their MHC can be sensed through the inspection of facial features. While females favour as much heterozygosity as possible, they seem to be attracted to those with similar MHC as well.

So, visuals conflict with olfactory cues? Awesome.

Now what about the pill? Surely this fabulous contraption of contraception must simplify things no? Well, sort of.

The Pill adds some consistency, whereby everyday is non-fertile day. It’s more or less a fake pregnancy that replaces the possibility of a real one, and this causes women to go into “find a nurturing, similar man phase.” It’s without any surprise then that women on the pill have a marked preference for MHC similar men that totally overrides any ambition for seeking a dissimilar partner.

Consistency? Fabulous! What’s the catch?

Women who find their man on the pill tend to have less sexual attraction to their partners as well as decreasing sexual satisfaction over time. They become very jealous at a rate proportional to estradiol intake, and also have an increased desire to cheat, meanwhile having much more severe “affective responses” to partner infidelity, and having an increased frequency of “mate retention behaviour.” And you put on a few :3

But don’t worry, there are some positives. Those that meet their partner on the pill have more satisfaction with their partner in non-sexual ways, have happier relationships with more emotional satisfaction, and have relationships that last 2 years longer on average.

So really no matter what, it’s a mess of matter of preference. Just have a preference for the mess that you prefer.

"Use Both Instead!" Image:ehow.com

Black Stripes White Body or White Stripes Black Body

Zebras are the cute animals living on grasslands. Have you been wondering if they have black stripes with white body or white striples with black body? And, what are the stripes for anyway?

Revealing the mystery, zebras have black body and white stripes. According to Wendy Zukerman, the zebras are completely black in their early embryo stages, while the white stripes appear later on.

Also, Lisa Smith has reported that the black color is the pigment activation and the white color is the inhibition, meaning that the color of fur is orginally black while the white fur simply lacks the pigment.

Although scientists are not sure why zebras have the alternating stripes, there are some theories

Having a higher albedo, the alternating pattern of fur can deflect up to seventy percent of heat during daytime. Since a lot of zebras live in high temperature enviroment, the fur can reduce a lot of heat from the sun.

Moreover, one theory says that the alternating pattern can act as a camouflage to confuse the predators. The Stripes can form some kind of illusions to intimidate the predators like lions or hyenas. The illusion is especially effective when the zebras are in a great number, so the pattern may make them look like a giant creasure.

While there is little evidence for camouflage, a new finding Justin Marshall points out is that the pattern can get rid of horseflies becasue it “provides an unattractive surfaces” for horseflies to land on. In africa, there are a lot of horseflies, so a pattern that prevents horseflies would result in less disease and healthier zebras.

A short video about horsefly theroy.

YouTube Preview Image

So the black zebras with white furs stills have their alternating pattern remained mystery. More studies are need to to support the theories such as camouflage and horsefly.

 Source

Buzzle.com.

How Stuff Works.

New Scientists.

 

It’s A Bird…It’s A Reptile…It’s A Mammal…It’s A Monotreme???

In my head, I am thinking of an animal which lays eggs, has venom and dives in lakes & ponds to catch prey. Oh, it also has fur and mammary glands. If you are a little confused right now, do not worry, you are not alone. When European settlers in Australia first brought back pelts and drawings of this curious creature to England, scientists thought it was a hoax!

Rest assured that this animal is real. I am talking about the platypus, Ornithorhynchus anatinus. Native to the eastern and southern coasts of Australia, this semi-aquatic mammal builds its burrows deep into the banks of the bodies of freshwater in which it spends about 15% of its time. About half a metre long, the platypus has one of the highest fur densities of any animal with up to 90,000 hairs per cm2 (sea otters take the top spot with over 150,000/cm2!).

Platypus on display. Picture by TwoWings.

The three extant (i.e., still living) mammalian groups are the eutherians (e.g., humans), marsupials (e.g., kangaroos), and monotremes. Platypuses, along with echidnas are the only living members of the monotreme order. This group diverged from the last common mammalian ancestor about 166 million years ago, thus explaining the bizarre origins of this seemingly paradoxical egg-laying mammal.

As mentioned earlier, platypuses (or platypodes) forage for aquatic invertebrates on the bottom of lakes and streams. When it dives under water it closes its eyes, plugs its ears and does not use olfaction to detect its prey. You might think that it has run out of ways to find food, but that is definitely not the case here!

Platypus underwater. Image from LearnAnimals.com

The skin on the bill of the platypus is highly specialized, containing at least two cutaneous receptors which aid in the location of prey. There are over 45,000 push-rod mechanoreceptors spread almost uniformly over the four surfaces of the bill. These receptors give the bill skin a sense of touch which is almost as sensitive as that on the tips of human fingers. More interestingly, platypus bill skin has over 38,000 sensory mucous gland electroreceptors. That’s right, electroreceptors!

These electroreceptors are so well-tuned that they can detect electrical signals from the muscle contractions of their invertebrate prey in the water. These electroreceptors are arranged in rostro-caudal stripes along the top and bottom bill surfaces (i.e., from tip to base of bill). It is thought that this striping pattern helps the platypus to pinpoint the exact location of its prey. By feeling the environment with the mechanoreceptors and detecting prey with the electroreceptors the platypus is very good at finding food without the use of sight, sound or taste.

When the platypus comes out of the water it is able to close these electroreceptor glands to prevent desiccation of mucous glands which are crucial to the function of these receptors. Platypuses are one of the few electroreceptive animals which have no specialized sensory cell to receive the incoming electrical stimulus. Instead, the electrical stimuli from prey are conducted through mucous and low resistance cells in an epidermal invagination to a bare nerve terminal.

As you can see, the electroreceptive ability of the platypus enables it to find food, therefore is crucial to the survival of this very bizarre animal.

YouTube Preview Image

 

Sources:

Grant, T.; Dawson, T. J. Physiol. Zool. 1978, 315-332.

Grant, T.; Temple-Smith, P. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences 1998, 353, 1081-1091.

Klamt, M.; Thompson, R.; Davis, J. Global Change Biol. 2011, 17, 3011-3018.

Manger, P. R.; Pettigrew, J. D. Philosophical Transactions: Biological Sciences 1995, 359-381.

Manger, P.; Pettigrew, J. Brain Behavior and Evolution 1996, 48, 27-54.

Warren, W. C., et al Nature 2008, 453, 175-U1.

Platypus Parts. YouTube video. Accessed 12 February 2012.

Doing It The Old Fashioned Way

It’s a nightmare scenario to modern science students: facing a physics midterm with a dead calculator. We have all used these miniature computers so extensively in learning math that most of us don’t trust ourselves to do it any other way.

We are all aware that there must have been some stygian era before these wonderful devices came into existence. Calculations must all have been carried out manually. This is not the case. Before there were digital computers, there were analog computers.

The first known analog computer was manufactured around 100 BC. This device, known as the Antikythera mechanism, was used by ancient Greek astronomers to predict the movement of celestial bodies.

A fragment of the Antikythera mechanism. Source: computus.org

Analog computers reached their most advanced forms in the 1950s, when they were used in to aim the weapons of naval vessels. This may seem counter-intuitive; artillery problems are used to teach some of the simplest concepts in first-year physics, surely this could be done by hand. Bear in mind, these simple artillery problems have only two dimensions and involve stationary targets and stationary firing platforms all operating in a frictionless vacuum.

The real world is so much more complex than these problems that fire-control computers accepted as many as 25 variables. For comparison, the simplest kinematics problems have 5 variables. A mathematician could do the same calculation in minutes, at best, and only then for one selected instant. Fire-control required continuous output under constantly changing conditions.

While the history of these devices is interesting, how do they work? To illustrate the basic principle, we’ll construct a very simple analog computer.

For illustrative purposes, our goal will be simple, to divide by two. We will call our known, or input, variable y and our unknown, or output, x. The function calculated is:

 y=2x

To start we have two wheels, which could just as easily be gears, designated A and B.

Public domain

Wheel A has a diameter of 1, wheel B has a diameter of 2. Since circumference is the diameter multiplied by pi, if the outside edge of A were flattened out, it would be half the length of the similarly flattened edge of B. When A turns once, it will roll along half the edge of B, driving a half revolution of B.

Public domain

The revolutions of A represent the input and the revolutions of B represent the output. Six turns of A will produce three turns of B, just as 6/2=3.

To make input and the reading of output easier, we can label the inputs and outputs on the wheels. For simplicity, only a few outputs are labelled, but high resolution can be achieved with the same principle.

Public domain

Here, we see that the input and, consequently, the output, are zero. Rotating A 90 degrees, rotates B 45, so that the input of 2, gives an output of 1.

Public domain

Analog computers have many more complex mechanisms, but the guiding principle is the same; displacement or rotation of components used to model variable values.

This 6 part training film outlines this and many more mechanisms used in mechanical computers.

YouTube Preview Image

References

(1) The Antikythera Mechanism Project The Antikythera Mechanism Project. http://www.antikythera-mechanism.gr/ (accessed 02/12, 2012).

(2) Navy Dept. Bureau of Ordnance In Basic Fire Control Mechanisms; Ford Instrument Co. Inc.: Long Island City, NY, 1944; , pp 425.

SCIE 300 Scientific Investigation Project: The value of good taste

Rachel Lee, Bryant Rathbone, Colin Todd

PowerPoint slides (link)

References

(1) Brentari, E.; Levaggi, E. Food Quality and Preference 2011, 22, 725-732.

(2) Brochet, F.; Dubourdieu, D. Brain and Language 2001, 77, 187-196.

(3) Gawel, R. Journal of Sensory Studies 1997, 12, 267-284.

(4) Goldstein, R.; Almenberg, J.; Dreber, A.; Emerson, J. W.; Herschkowitsch, A.; Katz, J. Journal of Wine Economics 2008, 3, 1-9.

(5) Harris, L. C.; Cai, K. Y. Journal of Market-Focused Management 2002, 5, 171.

(6) Hughson, A.; Ashman, H.; De La Huerga, V.; Moskowitz, H. JOURNAL OF SENSORY STUDIES 2004, 19, 85-105.

(7) Kumar, N.; Scheer, L.; Kotler, P. European Management Journal 2000, 18, 129.

(8) Laoro, M.; Delahunty, C.; Cox, D. Food Research International , 44, 3235.

(9) LaTour, K. A.; LaTour M.S.; Feinstein A.H. Cornell Hospitality Quarterly 2011, 52, 445.

(10) Lawless, H. Journal of Food Science 1984, 49, 120-123.

(11) Lehrer, J. The Subjectivity of Wine. http://scienceblogs.com/cortex/2007/11/the_subjectivity_of_wine.php (accessed 01/17, 2012).

(12) MacQueen, K. MacLeans 2011, .

(13) Mckinnon, M. The Globe and Mail 2011, .

(14) Morrot, G.; Brochet, F.; Dubourdieu, D. Brain and Language 2001, 79, 309-320.

(15) Solomon, G. American Journal of Psychology 1990, 105, 495-517.

 

 

Psychology in Magic: Cognition and Misdirection

Hello SCIE 300 students and readers of science, this is Bruce Wayne, multimillionaire industrialist and hobbyist magician.

I enjoy magic. I enjoy the study and the practicing of it. But what I enjoy the most about magic is the science behind it. The history behind the techniques and the methodology behind what creates “magic” for people.

Image by Asrar Makrani

To understand magic, we must first break magic down to “What is magic?”

In the real world where there are no dragons or wizards, magic can be broken up into two parts: the method (how the trick works) and the effect (what the spectator sees).

For magic to be successful, the audience must see the effect clearly without being aware of the method.

So why does magic work?  Why does it fool so much of the population?

The answer is because of how the human mind works. The human mind likes to make a lot of assumptions of the real world, which for most people is learned at a young age through experience. For example, object permanence, the assumption that an object continues to exist even when it is no longer visible. Try it. Put a sock in your drawer and close it. Look away for five seconds and open your drawer. The sock should still be there. Of course, we would already know that because we learned that from experience growing up. We learned at a young age that even if mom covered her face with her hands, she would still be there.

Now these assumptions are often correct. However, magicians use methods to take advantage these assumptions to create a result that is rather inconsistent to what is supposed to happen. In the video below, a coin is placed into a hand and seemingly disappears.

YouTube Preview Image

 

The magician’s most well-used tool is misdirection, used to divert attention away from the method. In a general term, misdirection is the control of the audience’s attention and perception. Magicians have known for centuries now that out of the information that enters the eyes, only a small amount of it enters attentional awareness. This limitation of attention allows the magician to operate in an covert manner while looking ordinary.

Image by Blog De Magia

The most known form of misdirection is physical misdirection. The control of attention using the body. There are certain actions that automatically capture attention, such as speaking, using hand gestures, rolling up the sleeves. The objective is to create high areas of interest to capture the audience’s attention so that the method may be carried out in a low area of interest. One’s own gaze is a powerful tool as well as there has been recent work that show eye gaze can lead to automatic shift of attention.

So now that you know why magic works, I am confident to say that you are now a professional magician. Armed with the knowledge of human cognition and misdirection to fool the eyes, you are ready to perform. Good luck and may you look handsome doing it.

 

Super Action Iron Man Time: Fiction becoming reality

Hello SCIE 300 bloggers and interested readers of Science.

My name is Bruce Wayne, winged crusader of the nigh—American billionaire, playboy, industrialist, and philanthropist. Let me just say that I am very excited that I can finally refer myself as Bruce Wayne from this day forward. Very cool.

 

Jumping right into the blog, remember the movie “Iron Man” in 2008? It is my favourite movie of 2008. It has action, special effects, Gwyneth Paltrow, terrorists, futuristic robot suits and explosions. Lots of big explosions. Very satisfying.

 

Fast forward to last Friday to when I am re-watching “Iron Man” and thinking to myself about the things I could do with a nuclear reaction-powered, plasma-blasting suit of battle armour in Camaro red with gold highlights. If only I had an Iron Man suit. How hard could it be to build one?

Tony Stark building the Iron Man suit

Image from thisischris.com

Of course I knew that it would be highly unlikely to build an exact working replica of what I saw in that film (reality can be disheartening). But after researching and googling (yes that is a word) different sources around the web, I was actually very surprised to see the amount of researching and development that has already gone into this field of research. To begin, the closest iteration of the “Iron Man” suit currently is what is called a human exoskeleton suit, which is essentially a wearable robot. The first exoskeleton suit was also built in the 1960’s by the US military. Nicknamed Hardiman it could amplify the user’s strength so that to emulate super-strength. However this suit was deemed a failure due to the fact that it could not be operated safely with a person inside of the suit because of its dangerously violent movements.

Hardiman with user inside

Image from David Szondy

 

Since Hardiman, a number of different companies and universities have produced their own version of the exoskeleton suit. Take for instance HAL (Hybrid Assistive Limb). Created by Yoshiyuki Sankai of the University of Tsukuba, HAL is an exoskeleton suit capable of enhancing a user’s arm and leg strength by tenfold similar to Hardiman. Instead of being designed for military use however, it was designed for the more civilian function in mind. It is able to be used in rehabilitating disabled patients to move such as those with spinal cord injury. HAL can be also used in jobs that are physically demanding, for example construction work. The suit can be used in rescue missions as well where heavy lifting is required, but having heavy machinery is not practical such as working on a building with weak structural support.

Cyberdine's HAL

Image from Cyberdine

 

And remember automotive company Honda’s Asimo? Now you too can walk and possibly dance like him with Honda’s Exoskeleton Legs which is a partial exoskeleton built only along the hips and legs. The design of the suit, particularly the saddle-like seat, allows for the transfer of the user’s weight to the exoskeleton to relieve the joints in the legs. It runs approximately for 3 hours; but that is only if the suit is not moving faster than about 4.5 kilometres an hour.

Video from youtube user: wiredautopia

 

 

There are a number of design issues and limitations that come with the current models of suits such as finding suitable power source. The source powering the exoskeleton must be able to sustain the suit for longer periods of time without overheating and must be small enough fit within the exoskeleton. Currently longest running time is only a few hours, which is why present-day research models are usually designed to be powered by an external power source. Another notable challenge the issue of joint flexibility. Several joints in the human body are termed “ball and socket joints” which are essentially joints that are capable of moving in several directions such as the hip or shoulder. For an exoskeleton to perfectly mimic those movements has proved to be quite difficult because of the nature of how exoskeletons fitted onto the user.

 

There are a lot of good that this area of research can bring. Aside from the idea of creating an “Iron Man” suit, this technology could essentially make life easier to live for those who are disabled or are elderly and those who work in areas heavy-lifting is prevalent, or perhaps those who want to enter the world of professional exoskeleton arm wrestling. Or possibly become Robocop?

Robocop doing his thing

Image from Kate Raynes-Goldie

 

 

If you want to read further here are some resources that you can check out:

 

 

Oh I forgot I was Bruce Wayne, so I probably have an Iron Man suit hiding somewhere in the bat ca-.