Tuesday, May 31, 2011

Z-Day: Are You Prepared?

I was catching up on some NPR Wait Wait Don't Tell Me and heard about this story. The Centers for Disease Control and Prevention (CDC) has released a new emergency guide on their Preparedness and Response webpage and in their Public Health Matters Blog. The guide is called Social Media: Preparedness 101: Zombie Apocalypse. The idea here being that if you are prepared for a zombie apocalypse then you are prepared for any emergency. Genius.

Get A Kit, Make A Plan, Be Prepared. emergency.cdc.govAfter a brief history of zombies the entry goes into general safety for when zombies (or hurricanes, pandemics, etc.) rise up. First, have an emergency kit in the house containing water (1 gal per person per day), food (non-perishables), medications, tools and supplies (utility knife, duct tape, battery powered radio, etc.), sanitation and hygiene products (bleach, soap, towels, etc.), clothing and bedding, important documents (driver's license, passport, birth certificate, etc.), and first aid supplies. Although, with that last one, you're a goner if a zombie bites you, but if you, let's say, cut yourself while boarding up your house against zombies then you'll be all set. Next, you should have an emergency plan. Identify all of the types of emergencies possible, besides and/or including zombie attacks. Know where to go and who to call when the zombies start lumbering down your street. Pick a rendezvous point (one close, one far) and identify emergency contacts. Plan your evacuation route. Despite being mostly brain dead, zombies are rather clever and definitely relentless when going after prey (you) and so you should not only know where to go but multiple, safe ways to get there. And finally, the CDC ends their post with a plea (well, I'm calling it a plea) for you to trust them to track the outbreak of the zombie infection and provide assistance. That is if they are not all zombies themselves.

Now that we're prepared how do we go about realistically (yeah, someones modeled it!)getting rid of the zombie plague? Go back to the short but informative Mmm...Brains! post from April of last year to find out.

Read the entire entry here:
http://www.bt.cdc.gov/socialmedia/zombies_blog.asp and http://blogs.cdc.gov/publichealthmatters/2011/05/preparedness-101-zombie-apocalypse/
and grab your own buttons, badges and widgets here: http://emergency.cdc.gov/socialmedia/zombies.asp


Happy Guys Finish Last

James Dean
Finally, science has figured out the romantic pull of characters such as Heathcliff (Wuthering Heights), Edward Rochester (Jane Eyre), and even Edward Cullen (Twilight) and James Dean, among others. It's all in those brooding expressions.

A new study in the journal Emotion examines the relative attractiveness of various facial expressions. In general, showing a happy face is considered essential to friendly interactions (including sexual attraction) but few studies have actually looked at whether or not a happy expression is, in fact, attractive. Think about it. What kind of facial expression is attractive in the opposite sex? A smile, confidence, pride, appeasement, neutral? After all, you can tell a lot by a person's expressions; they are indicators of a person's dispositional qualities. Previous studies have shown that pride signals express a high social status and that shame, an appeasement display, signals low social status. Studies have also shown that happiness communicates friendliness, approachability, and some measure of trust. That makes sense, but is the attractive expression the same in men and women? Up till now the research suggests that women tend to seek partners who are reliable providers and that men seek partners that are young, healthy, and receptive. In terms of facial expression that would translate to women seeking pride and men seeking happiness. This paper discusses two studies used to test this.

Study 1: This first study tested the prediction that the effect of emotion expression on attractiveness would vary by gender. A total of 184 Canadian undergraduates were approached by an examiner (of the same gender) holding a photograph of an opposite sex target posing with an expression of happiness, pride, shame, or neutral. Using a 9-point scale, the participants were asked to view and judge the image based on how sexually attractive they found the person in the photo. Controlling for absolute gender differences (standardizing ratings within gender to equate male and female means), happiness was found to be more attractive in women than men, pride was more attractive in men than women, and of the lesser attractive expressions shame was found to be more attractive in men than in women.

Study 2: The first study used only one male and one female in their photos and so the participants could have been responding to the unique features of those individuals. This second study addresses that by including multiple people across photos, portraying each expression, that had been gathered from the Internet. This study was further broken down into groups of people: Sample A and Sample B and Sample C. Sample A were undergraduates who viewed and rated 80 photographs (20 of each expression: happiness, pride, shame, neutral). Then they completed a Socio-Sexual Orientation Scale that measured the individual differences in mating strategies. Basically, it tested whether the effect of an expression on how you viewed a target's attractiveness varied if you view the target as a potential short-term or long-term partner. Sample B consisted of adults recruited through social networking websites who were asked to view and rate the attractiveness of photos. This time, though, it was of 40 photos, 10 of each gender showing each expression. Sample C were undergraduates who viewed and rated the same set of photos viewed by Sample B. The results showed that male pride was the most attractive male expression and female happiness was more attractive than pride. Surprisingly, male happiness was rated as one of the least attractive expressions by most participants.

Overall, this research shows that men are made most attractive by displaying pride and least attractive by displaying happiness whereas women are most attractive displaying happiness and least attractive by displaying pride. The shame expression was found to actually increase the attractiveness of both men and women, at least compared to a neutral expression. So, well, why? Here's what the authors suggest --

Pride: In males, "the pride expression may convey heightened masculinity...and may signal a man's competence and ability to provide for a partner and offspring" while in females "the mate value of a high-status women is more ambiguous" as males "seek female partners who [are] best equipped to bear children, but not necessarily to support them." This is evolutionarily speaking, of course, as contemporary men did not rate pride expressions as unattractive, just less attractive than happiness.

Shame: In females this expression fell between happiness and pride. The assumption with a shame expression is that the individual is of low-status and "submission connotations increase its apparent femininity, and thus the attractiveness of shame-displaying women." That women who express shame are "signalling the respect for social norms and the awareness that she has violated them" (what I would probably call the I've Been a Bad Bad Girl Hypothesis), and what the authors say may indicate trustworthiness. In men the shame display was more attractive than happiness. That one is difficult to explain. The authors postulate that "shame's communication of trustworthiness and group commitment" is the reason behind it's attractiveness rating. Ya know, maybe it is that coy, slightly suggestive look that gets peoples' boosters going.

Happiness: This expression usually consisted of a nice big smile :-) In men, happiness was rated very low, perhaps because a happy expression gave the "appearance of femininity and low dominance" In women the expression is a "friendliness signal...taken to indicate sexual receptivity, [increasing a] woman's mate value." It is one of friendliness, trustworthiness, and approachability. All things that men like when on the prowl for the ladies. After all, a male signalling that he is sexually receptive...uh, duh.

So guys, adopt that brooding, prideful, no-smile policy when lookin' for your next girl. Of course, some romantic wind-swept moors would be to your advantage. Just...leave the vampire body glitter at home.

Here's the paper:
Jessica L. Tracy and Alec T. Beall (2011) Happy guys finish last: The impact of emotion expressions on sexual attraction. Emotion: published online 23 May. (DOI: 10.1037/a0022902)

I was first turned on (no pun intended) to this by an article I read online. Here are a few links to sites that have covered this paper:

Sunday, May 22, 2011

Fishy Codependency

Angler fish belong to the order Lophiiformes. They are deep sea fish named for their unique way of luring in their prey. They have a long filament that extends from the top of their head, near the eyes and mouth, that is movable (some even have tips that can light up!) and so can be wiggled to imitate prey. It acts as bait to bring in smaller creatures, like a fishing lure, and when the curious, hungry critter gets close the angler fish strikes. The topic of today's post, inspired by the comic below from The Oatmeal, is about angler fish reproduction. Some angler fish, particularly the Ceratiidae, have one of the most unusual matings systems you'll find in the animal kingdom.

This story is completely true.

(click on comics for a larger view)

(Comic via The Oatmeal)

Some additional internet sources on angler fish:

Sunday, May 15, 2011

Flexible Furniture

When I see a link for a website called FlexibleLove I want to make sure my computer's virus protection software is up-to-date and am wary about opening it at work. In this case, though, it is actually a pretty cool site. This is a company that sells expandable furniture...weird and cool all at the same time. The furniture has an accordion-like design with a honeycomb structure and is made from recycled paper, recycled wood paste, and it is produced using pre-existing manufacturing processes in order to reduce environmental impact. The name "FlexibleLove" is derived from "flexible love-seat" because it can expand to hold anywhere from one to sixteen people. Crazy!

Check it out: http://www.flexiblelove.com/

Saturday, May 14, 2011

Particle Business

I really hope that this is the orientation video at Fermilab.

Does This Fat Make Me Look Fat?

I'm going to see the new movie Bridesmaids this weekend, and that prompted me to type the word "bridesmaids" into Web of Science to see what popped up. Surprisingly, only one article came up that wasn't related to electronics, poetry, aristocratic history, or used the "always a bridesmaid never a bride" line as a clever segway. It is a study out of Australia that was published in Body Image in 2008, and it takes a look at pre-wedding body image concerns in both brides and bridesmaids.

If you've ever been a bride, know a bride, been a bridesmaid, or just plain been associated with a wedding at all then you know that it is all about the dress. All right, it is all about looking fabulous in a fabulous dress. The bride's appearance is an extremely important component of the wedding day. There is an entire industry built around the event. That industry includes all kinds of advice for women on how to look great for their big day, including popular articles on getting that perfect gorgeous body. Pre-wedding weight loss has become expected by dressmakers, bridal store assistants, and the bride's family and friends. On average brides loose approximately 9 pounds (4.1 kg) for their weddings. Some women are so pressured for the perfect wedding that their need for weight loss becomes extreme and maladaptive in terms of body image. There's even a term for it: bride-orexia. And it isn't only the bride that feels the pressure. Other members of the bridal party way also feel pressed to improve their appearance for the wedding day, namely bridesmaids.

This study surveyed 347 brides and 122 bridesmaids recruited from bridal expos in Adelaide, South Australia. They gave the participants a short questionnaire that asked them to identify whether they were a bride or bridesmaid, give the wedding date, and record body measurements (current height and weight for BMI calculations). They they were presented with a list of possible pre-wedding beauty practices based on popular bridal magazine content and asked to check off what they planned to do (or had done). Next they were asked whether they had an ideal wedding weight, whether they would be unhappy if they did not reach their ideal weight, and whether anyone had told them to lose weight for the wedding (and if so who). Next, the participant was asked to rate on a scale of 1 (not at all important) to 7 (extremely important) the importance of looking good on the wedding day. Finally, this question was immediately followed by an open-ended question inviting comments on why looking good on the wedding day was important, for which four major themes (photos/memories, big/important day, center of attention, looking/feeling beautiful) were identified and categorized.

It was found that brides and bridesmaids had similar current weight means and a BMI within the upper range of normal. Over 50% of the participants stated that they intended to exercise more, lose weight, and have their hair colored for the wedding. Around 40% intended to diet and tan their bodies for the big day. Brides were also significantly more likely to have their teeth whitened and join a gym than were bridesmaids. A total of 46% of the brides and 42% of bridesmaids had an ideal wedding weight but, of these, 45% of brides and 51% of bridesmaids said that they would be unhappy if they didn't reach their personal ideal weight. Though, note that women who gave an ideal weight tended to be heavier than women who did not.

Now let's pack on the pressure. Approximately 13% of brides reported that someone had told them to lose weight for the wedding, and, of those, 65% of brides had been told so by their families and 12% by their friends. The bride herself is not innocent here. Out of the 11% of bridesmaids that had been told to lose weight, 38% had been told to do so by the bride. Note here too that women who were told to lose weight for the wedding were significantly heavier than those who were not.

All of this is directly related to the importance of looking good on the wedding day. Brides rated the importance of looking good on the wedding day significantly higher than did bridesmaids. The most common reason for brides was because of the wedding photos followed by the overall importance of the event. Surprisingly, one of the less frequent responses was looking good for the groom. The bridesmaids responded that they mostly wanted to look good for the bride or to feel beautiful.

Admittedly, this isn't one of those huge groundbreaking studies. It's one of those that really just quantifies what we already know. We would all like to think that the bride (and her bridesmaids) will look beautiful for the groom and because of the happiness she is feeling on the day. Studies like this show that large numbers of brides put an extreme importance on their appearance for their weddings. This raises concerns about disordered eating and low body esteem as women suffer from dissatisfaction with their bodies and themselves. Add to that the pressure from others, particularly pressure for heavier women, and you've got a problem. Perhaps we need to rethink if there should be a perfect bridal body.

Read the article:
Prichard, Ivanka and Marika Tiggemann (2008) An examination of pre-wedding body image concers in brides and bridesmaids. Body Image: 5(4), 395-398. (DOI: 10.1016/j.bodyim.2008.05.001)

(image from sofiesfavors.com)

Airlifting Ants

Competition. A contest. An opposition. A rivalry for supremacy.

It may occur directly or indirectly between members of the same species or different species. Commonly you will see it over such resources as food, space, or mates. Usually something that is limited. Let’s focus on indirect competition. Here species clash over access but in such a way that one interferes with the other’s ability to utilize the resource. These interference interactions are common in social insects, and that is the topic of today’s post.

A recent article in Biology Letters reports such interference behavior in ants and wasps. Now, you might think indirect competition would be a common avenue of study as the evolutionary and ecological importance of exploitative competition has been well documented. Not so. It was only recently that behaviors such as ant avoidance when wasps catch prey, wasps robbing food from ants, and wasps guarding mutualists against ants has been published. Why even care? Don’t think of this topic as wasp vs. ant (although it is fun to envision such a showdown) but rather from the viewpoint of an invasive species biologist or manager. Understanding interactions between invasive wasps and native ants can inform us as to why a species (invasive or native) thrives or declines after an introduction.

This study takes a look at the social wasp Vespula vulgaris. This wasp is native to temperate regions of the Northern Hemisphere and is a major invasive species in New Zealand, particularly in beech (Nothofagus spp.) forests. Enter the limiting resource: honeydew. Mmmm. These beech forests have healthy populations of scale insects and scale insects produce large amounts of honeydew, which is rich in carbohydrates. The invading V. vulgaris consumes this honeydew as do a variety of native animals including ants (particularly Prolasius advenus). But honeydew isn’t the only resource of contention. Wasps and ants have also been observed scavenging on the same prey.

What peaked the scientists attention was the observation that wasps would pick up worker ants in their mandibles and then drop them some distance away from the food. The researchers hypothesized that this was an example of interference behavior and that by removing the ants the wasps were effectively decreasing the competition and freeing up more of the food for themselves. Sorta like shoving the weaker kid to the back of the cafeteria line. To test this they set up 48 bait stations containing canned tuna fish randomly among the leaf litter and filmed them. They counted and time-averaged the numbers of ants and wasps that visited the traps as well as the number of aggressive wasp-wasp interactions. Then they looked at each interaction between wasp and ants by looking at the film frame by frame, scoring them as one out of 12 behavioral categories. One of these categories included “ant-dropping” where a wasp would pick up an ant in its mandibles, fly backward, and drop it away from the resource.

They found that when few ants were present the wasps had more conflict among themselves, but if many ants were present it was more likely interference behaviors would predominate. They concluded that the ant-dropping behavior was not predatory as the wasps were never seen leaving the bait station with an ant and not returning, and the removed ants were not injured. They also ruled out a defensive response as most of the ants were not behaving aggressively towards the wasps. The results showed that even though a wasp weighs 212 times more than an ant, that the wasp more often hung back or moved away in the presence of a high abundance of ants. I feel it is important to mention that P. advenus belongs to the Formicidae, so named because of their ability to produce and spray formic acid along with their bite. You can see why the wasps limited their contact with the ants. They typically picked up an ant to remove it from the bait when it was feeding or walking around the food. In fact, ants were successfully moved away from the food 83.9% of the time, 47.3% of which those dropped ants did not return to the food. And if the ant did return the wasp preceded it in 75% of the cases.

As a competitive strategy, this behavior is pretty efficient, at least on an individual level. V. vulgaris lack nest-based food recruitment mechanisms and so individual workers must be independent and opportunistic. In strategies such as this you often find that individuals adopt behaviors that allow them to exploit a resource early and quickly. The results of this study support this. Ant-dropping is a short term advantage to individual wasps that allows them to garner additional food.

Here’s the paper:
Grangier, Julian and Philip J. Lester (2011) A novel interference behaviour: invasive wasps remove ants from resources and drop them from a height Biology Letters: published online 30 March. (DOI: 10.1098/rsbl.2011.0165)

and the link for the above video: http://vimeo.com/21599670

Story links:

(image from kuleuven.be/bio/ento/photo_gallery.htm)

Monday, May 9, 2011

Solder Blob

If you've ever built a power board, or the like, then you'll find this comic particularly great. It is the real circuit diagram.

(via xkcd)

Friday, May 6, 2011

What You Know About Math?

After the Space-Time is Epic story I felt the need to post a video about math. Enjoy!

Space-Time is Epic

When NASA posts a story about the results of an "epic space-time experiment" I just have to read it.

The story can be boiled down into four words: Einstein was right again.

Space-time is a mathematical model that combines space and time into a single continuum. If you look at the history in the formation of this model you'll find that it steps through the theories/rules of some well known mathematicians. The explanation of space-time didn't start with them all put together and hyphenated, it started with simple geometry and the Pythagorean Rule (you remember that from 8th grade geometry class right? a2 + b2 = c2). When that wasn't enough a Euclidean model for space was was used (he was the one that built the coordinate system). The Euclidean model explained space in terms of dimensions, with the universe consisting of three dimensions of space and one dimension of time. By Newton's time, people were getting pretty good at explaining space using a Euclidean distance function but it did not work when gravity becomes strong. Newtonian physics took the model a further but still had some problems including dealing with the speed of light and gravity. Then Einstein came up with the concept of special relativity. It explained observations like that the speed of light is constant everywhere and in every direction. Einstein's theory of gravity provided a geometric understanding of gravitation.

According to Einstein, space and time are woven together,  forming a four-dimensional fabric called space-time. The mass of a large object causes that fabric to curve or dimple. Think of it like a big rubber sheet that has a heavy ball set on top of it. That is how space-time curves around a planet or star. Now let's add gravity to the mix. Einstein explained gravity as the motion of objects following the curvaceous lines of the dimple. Think of it like a very large funnel that you spin a small ball around, starting at the edge it will slowly spin around to the bottom/center of the funnel. Alright, now lets make the object, the Earth, move. As the planet spins the dimple twists, pulling it around into a four dimensional swirl. That's the theory at least.

NASA went to test this theory with its Gravity Probe B (GP-B). The experiment is actually pretty simple. Put a spinning gyroscope into orbit around the Earth, with the axis pointed at a distant star as a reference point. If the gyroscope is free of external forces the axis should continue pointing at the star for forever. If it not free of external forces, if space is twisted, then the direction of the axis will drift over time. Note the direction of the dirft and you can measure the twists of space-time. The twisted space-time around the Earth should cause the axis of the gyroscope to drift about 0.041 arcseconds (1/3600 of a degree) over a year.

Admittedly, that is a pretty simple concept, but the actual conducting of the experiment is not so simple. GP-B has four gyroscopes. These gyroscopes are about the size of ping pong balls and contained the most perfect spheres ever created by humans. They are made of fused quartz and silicon that never vary from a perfect sphere by more than 40 atomic layers. And because the drift of the gyroscopes would be so small the instruments had to have a precision of 0.0005 arcseconds. Whoa. But we're not done yet. The satellite the gyroscopes were one needed to be drag free so that when it brushed against the outer layers of the atmosphere the gyroscopes would not be disturbed. The satellite also had to keep the Earth's magnetic field from penetrating the spacecraft. And then they created a device that measured the spin of the gyroscope without touching the gyro. Is your jaw on the floor yet because I know mine is.

After a year of taking data and five years of analysis the results are in: A geodetic precession of 6.600 plus or minus 0.017 arcseconds and a frame dragging effect of 0.039 plus or minus 0.007 arcseconds.

Uh. Ok. Well, let's break that down. Geodetic precession is the amount of wobble caused by the static mass of the Earth (the dimple in space-time) and the frame dragging effect is the amount of wobble caused by the spin of the Earth (the twist in space-time). These results are in precise accord with Einstein's predictions. It is evidence that the predictions in Einstein's theory are correct and that it can be applied to other objects in the universe.

Yep, Einstein was the man. Epic.

Here's the news report from NASA: http://science.nasa.gov/science-news/science-at-nasa/2011/04may_epic/

The Gravity Probe B mission homepage: http://einstein.stanford.edu/

Learn more at Spacetime 101: http://www.theory.caltech.edu/people/patricia/st101.html

And finally, here are a few more NASA stories on this topic you may find interesting:
A Pocket of Near Perfection - http://science.nasa.gov/science-news/science-at-nasa/2004/26apr_gpbtech
Was Einstein a SpaceAlien? - http://science.nasa.gov/science-news/science-at-nasa/2005/23mar_spacealien
In Search of Gravitomagnetism - http://science.nasa.gov/science-news/science-at-nasa/2004/19apr_gravitomagnetism

(images from the NASA story linked above)

Catching the Yawn

I'm yawing. Now you are picturing me yawning. Are you yawing yet?

Contagious yawing is well documented in humans. You probably don't need a scientific study to tell you that, just yawn in the presence of another person and watch them yawn right back. It isn't known exactly why people yawn. It has been suggested that yawning increases arousal and therefore reduces the probability of sleep. Or it could be some kind of social signal, one to synchronize a group's behavior, communicating drowsiness, social stress, or boredom. The contagiousness of yawning may simply be a fixed action pattern (an instinctive behavioral sequence produced by a neural network and consisting of a response to a releaser stimulus that triggers the sequence to run to completion) where the releaser is the yawn of another. It could also be the result of nonconscious mimicry, where we adopt postures, gestures, and mannerisms of others without really realizing it. Or perhaps it is a form of empathy, in this case understanding another's feelings by inferring their mental state.

Contagious yawning has been studied in non-human primates as well including chimpanzees (Pan troglodytes), stump-tailed macaques (Macaca arctoides), gelada baboons (Theropithecus gelada), and dogs (Canis familiaris). But, overall, little is known about the function and prevalence of contagious yawning in other animals. A new study in Current Zoology (note: formerly Acta Zoologica Sinica) looks at discriminating possible mechanisms controlling contagious yawning. They do this by picking a species that strikes out some of those possibilities for contagious yawning I listed above. Here they look at the red-footed tortoise (Geochelone carbonaria) because it is a species that is unlikely to show empathy, nonconscious mimicry, and social mimicry. This is mainly because these tortoises are solitary and so have no need for a sensitivity to social cues, but they are highly visual and so can observe the behaviors of other tortoises.

Before starting the study the researchers had to prep the tortoises. Seven tortoises were housed together in two groups for six months prior to the experiment so they could get used to living in a group. They picked one tortoise as a "demonstrator," and taught that tortoise to yawn. Now, how do you go about teaching a tortoise to yawn? Well, they used a training technique called successive approximation. Whenever the tortoise opened her mouth slightly in the presence of a red stimulus she was rewarded with food until the point where she performed a gape-like response that appeared highly similar to a naturally occurring tortoise yawn. Once the training was complete they broke their study down into three experiments:

Experiment 1:  Tested the response to of others to a single yawn. To do this they exposed them to three yawning conditions: (1) a single conditioned yawn, (2) a control with a non-yawning individual, and (3) a control with just the red stimulus. Then they measured the number of yawns. The results of this experiment showed that there was no difference in the responses across conditions. Three of the six tortoises tested did not respond to any of the conditions, but of the three that did respond two responded more in the conditioned yawn than the controls.

Experiment 2: Tested if contagious yawning would occur if the tortoise was presented with multiple yawns. To do this they exposed the tortoises to the experimental conditions from Experiment 1 with 2-3 yawns per trial. They they counted the number of responding yawns. The results of this experiment again showed no difference in response between conditions.

Experiment 3: Tested the possibility that the lack of yawning in the first two experiments was because the conditioned yawn did not appear as a yawn to the tortoises. To do this they presented the observing tortoises with video stimuli of real yawns, fake yawns, or an empty background. Again they counted the number of yawns in the observers. The results here? Nobody yawned.

The take-home message of this study are that the red-footed tortoise does not yawn in response to the yawns of other red-footed tortoises. This suggests that yawning, at least in this species, is not a fixed action pattern. It, therefore, may be a social cue or higher level mechanism controlling this behavior. Basically, these researchers were able to cross one contagious yawing hypothesis off their list.

All right. So why post about a study that ultimately showed nothing at all? First, because it was a study about tortoise yawning and that's neat, even if they didn't end up yawning. Second, it is a great example of a study of negative results. In science you don't always get those significant differences you expect when you start an experiment, and it is difficult to get such results published. Kudos to Current Zoology for publishing a study that had results such as these. And lastly, because I just had to know how you train a tortoise to yawn.

Read the study for yourself (note, this link is to the uncorrected proof):
Wilkinson, Anna, Natalie Sebanz, Isabella Mand, and Ludwig Huber (2011) No evidence of contagious yawning in the red footed tortoise Geochelone carbonaria. Current Zoology: published online (Link)

Also, a story in The Guardian: http://www.guardian.co.uk/education/2011/may/02/improbable-research-yawning-contagious-tortoise

(image from tortoisetrust.org)
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