Dry Feet Are More Than Just A Big Comfort Factor


Dry feet are more than just a big comfort factor if you want to run up walls as some creatures have a penchant for doing (not including Spiderman of course).

Smooth Feet
Geckos have a strategy of using soft, smooth feet. Their pads deform to give intimate contact over the whole area of their feet. When two materials are within tens of nanometers of each other, London- van der Waals forces become quite significant so they want to stick together and friction is high.
For a Gecko this is great, it can stick to a wall without sliding down and can peel off a foot to place it higher up. Very smooth surfaces like glass are best for vertical running. Stark et al from U Akron wanted to know how much a Gekko gecko could carry up a sheet of glass and what would happen in the rain (1, 2). Their pet gecko was fitted out with a body harness that was then hitched up to an electric motor and the force to drag it off the glass was measured. A gecko can hold on with loads up to 20 times its own weight.
What happens in a rainforest? The glass was misted and the gecko came perilously close to slipping. Put a liquid between to surfaces and the London-van der Walls forces are ameliorated, but also liquids shear easily – hence the slip. But geckos have very hydrophobic feet so when they place them, the water is repelled and their pads can get some close contact in patches so it’s not total disaster.
It may be close, but not total until you stand your gecko in water for an hour and a half to give it thoroughly wetted feet. At that point it can barely hold on, certainly it couldn’t carry a friend.

Hairy Feet
In a related piece the BBC draw attention to Hosoda et al who have an interest in green dock beetles (3). They observe that their beetles have hairy feet, which are oily and hydrophobic. When they walk on a wet surface, the water is displaced to trap an air bubble and the surface tension holds their feet to the leaf, wall or whatever they decide to climb.

Just don’t start spraying soap solution about or the geckos and beetles will be taking out court orders.

  1. http://jeb.biologists.org/content/215/17/i.1.full
  2. http://jeb.biologists.org/content/215/17/3080.abstract
  3. http://www.bbc.co.uk/nature/19149870



Better Pay Promises Gives Better Performance Makes Shirkers Workers


Promises of better pay gives better performance even for jobs that aren’t eligible for the higher rate. At least that’s the story that some social psychologists from the Netherlands have for us. We’d better keep this information out of the hands of the Business Schools or we’ll be seeing even more jam tomorrow, but not today, than we have at present.

The Utrechies who did this study were Zedelius et al and their paper is in the Public Library of Science this week (1). They bribed 91 undergraduates with promises of big bucks if they listened to tones in one ear or the other and pressed a button to say if it was on the right or left. Speed and accuracy was the way to rewards, but only every other tone was eligible for a reward.

Everywhere speed on the line was of the essence. The reward value of the task was flashed briefly – it could be a 1-cent job or a 50-cent job. Then a brief tone was played and there was a short time to press a right or left button to indicate which ear it was played in. This was then repeated, but only this second tone counted for payment of a job well done. If the button press was wrong or it was pressed to late, there was no payout.

Results, results are all that matter, of course. And there was a trade off between speedy button pressing and thinking time to ensure accuracy, but remember too much thinking would result in time out and nothing to take home to feed the kids.

Well, bigger promises improved performance. The participants were geared up and concentrating. As a result they performed better with the non-scoring intermediate task as well as the one that would deliver a 50-cent payout. They relaxed and became shirkers not workers for a 1-cent job.

At 1 cent a time there’s not a lot of trickling down going on. They would have sore thumbs before they earned one beer.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042547


Moral or Amoral – Are We Born One Or The Other?


Moral or amoral – are we born one or the other? This seems a strange question at first sight, but maybe people have been assuming one or the other for years. Ask a psychologist and they will rush off and design an experiment and check out a handy group of infants who are just a few months old.

Scarf et al from U Otago have carried out some experiments to check if the results of Hamlin et al were correct (1, 2). The earlier work with very young infants concluded that a moral compass was built in as a biological adaption. The infants watched toys climbing a hill and in some cases they bumped into another toy that helped them get to the top. In other events, the colliding toy hindered the climb. The observation was that the infants wanted the helper toy as a playmate.

Scarf et al re-did the experiments with rather more laconic toys (no bouncing with excitement when reaching the summit) and threw into the mix a neutral toy that minded its own business. What was the result this time? The 10-month old infants wanted the neutral toy as a playmate. They didn’t like collisions.

So it seems that there was no moral reasoning involved, but they were averse to confrontational collisions whatever the outcome and were opting for the uncomplicated peaceful life without unnecessary complications.

Interesting how many of us have retained this trait as we grow up as a way of avoiding trouble.  We stay as simple creatures that prefer to leave the wrestling with huge moral choices to characters in the movies.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042698
  2. J.K Hamlin, K Wynn, and P. Bloom, Nature, 450, 557, (2007).



Romance Is Not Without Its Pitfalls


Romance is not without its pitfalls. A rebuff can be hard, but a welcome signal is not always good news either. It may entail giving your all for the sake of passing on your genes. Things are pretty tough if you’re a honeybee drone, but things could be worse. You could be a praying mantis, a scorpion or one of those spiders whose mate likes to relax afterwards, not with a cigarette, but with a warm snack.

There are several theories out there as to why some female spiders decide to munch on their suitors. It has been suggested that it’s the female’s way of judging his fitness for the job. Some say it’s just because they can as they’re aggressive beasties and some say that it just how the express themselves when they approve.

Where there’s a theory, there’s scientists rushing to test it and in this case, Berning et al from U Pittsburgh have been out and about checking with denizens of the inner city, namely the clan Agelenopsi pennsylvanica (1, 2). This is a funnel web spider and they got on their good side by tossing them crickets. Once a rapport was established and they knew their ‘girls’, the researchers set up a dating program.

The ‘guys’ were willing and able, but some of them paid the ultimate price for a momentary dalliance and ended up staying for dinner with their cannibal mate.

A great deal of data was gathered and pored over to check out those extant theories. They didn’t appear to stack up. Size wasn’t important, that is male or female body size so the egg situation was examined. There were no correlations with number of eggs in a case, the size or the mass of individual eggs.

Aggressive and hungry females were more likely to indulge in cannibalistic practices, but the big correlation turned out to be the mass of the egg case that she produced and the number of hatchlings that came from it. So in Pittsburg, if you are a member of the A pennsylvanica persuasion, eating your mate is good for your kids.

  1. http://www.sciencedirect.com/science/article/pii/S0003347212002916
  2. http://www.bbc.co.uk/nature/19072196



Smartphones In The Mountains Will Soon Be Ubiquitous


Smartphones in the mountains will soon be ubiquitous. Right now, wandering around Switzerland’s alpine meadows is very pleasant at this time of the year with the sun shining and the cowbells chiming in the distance. The good news is that musical ringtones will not be drowning out these traditional sounds. The sheep there also enjoy the sweet grass and the clear pure water running down from the melting glaciers.

However, the music in the mountains is no longer just from cowbells and tumbling streams. The howling of wolves is joining the chorus. Not a welcome sound if you’re a sheep. The BBC reports that the Bernese Oberland is having more frightened sheep than a few years ago in the shadow of the Matterhorn and the Eiger (1).

In some parts of Europe, the farmers have big dogs to defend their flocks, but this apparently is not a practical proposition here, mainly on the grounds of cost. Not to fear, a new solution is rushing to the rescue.

The sheep will be fitted with collars. Not for bell, though. They are for carrying each sheep’s personal smartphone. They won’t be making and receiving regular calls (hence the absence of ringtones). Instead they will use them for texting the shepherd in the event of a wolf emergency.

They don’t have thumbs, but that wasn’t an obstacle to Jean-Marc Landry from the group Kora. He set up heart rate monitors to trigger the “SAVE OUR SHEEP” text when the pulse rate hit a frightened by hungry wolf threshold.

A placid sheep enjoying the sunshine, just chilling out and chewing the cud, has a heart rate ~ 70bps, but with red slavering jaws coming ever closer however hard escape is attempted can drive it up to ~200bps, so there is plenty of scope to set a threshold which won’t entail too many sheep crying wolf.

  1. http://www.bbc.co.uk/news/technology-19147403



Humans Like To Theorize And Our Jealous Nature Is No Exception


Humans like to theorize about almost anything, but human nature comes pretty high on the list. We like to sit around, drink, discuss the state of the world, but sexual relationships and jealousy will grab most people’s attention.

Those with an eye to evolution will theorize that men are more jealous than women in regard to their mates in order to safeguard their genetic future. There’s nothing they like better than stamping their image across the species. There are critics who argue that if more careful measures are used in assessing both imagined and real infidelities, these differences between men and women vanish.

The game is not so simple, though, and back in 2010 Levy and Kelly threw in an additional theory,­ the theory of attachment (1). They started from the position of men being more jealous of sexual infidelity than women, while women were more jealous of emotional infidelity than men. Combing through the data they found that a significant percentage of men were more upset with emotional infidelity. This is where attachment theory comes into play and participants who felt secure in their relationships felt more jealous at emotional cheating.

Now Sagarin et al in Evolution and Human Behavior have waded in with a meta-study covering 40 manuscripts of different studies. Men popped back to the top of the list for jealousy and distress (2). Being hurt and emotionally upset showed a weaker difference between men and women.

So short of a poll conducted on Twitter, we can ease off on the theory and order another round of beer –­ men are more jealous beings and get distressed when cheated on. Women do too of course, but we men are rather delicate volatile creatures.

  1. http://pss.sagepub.com/content/21/2/168
  2. http://www.ehbonline.org/article/S1090-5138(12)00024-4/abstract



We Are Creatures Of Habit, Just Like Pavlov’s Dogs.


We are creatures of habit, just like Pavlov’s dogs. Normally we don’t like nasty surprises and will make an effort to avoid them. If we get a signal we respond once we’ve learned that the signal means bad news.

As we know by now, dopamine is associated with our reward, feel good system, and serotonin is involved with our mood regulation and anti-depressant feeling. So it seems natural to look at these whilst our Pavlovian responses are been tested. Attar et al at U of Hamburg-Eppendorf got stuck into scaring the pants of 58 young 20-something guys and checking their responses in terms of serotonin limited responses (1).

Chili peppers have Capsaicin, which is responsible for that excitement at the restaurant when you’ve chosen the wrong dish. This was extracted and painted on the left arm of the human lab rats. The sensitized area had a one-inch square fast response heating/cooling unit strapped to it.

The guys focused hard on a computer screen as a visual signal preceded some gratuitous pain infliction by heating the sensitized area. Young guys are fast learners and the quickly learned to clench and hold their breath when a dreaded triangle appeared on the screen. Prof. Pavlov would have been proud of their responses.

Of course, this is not the end of the story. We’re not playing with dogs. With people we can stuff them into the big magnet and see what their brain is playing at and we can play games with their diet. Remember, broadly, we are what we eat and our experimental participants were fed on high or low amino acid diets to play games with their tryptophan load, which in turn ups or downs their serotonin level.

With depleted serotonin levels, the subjects were slow learners Pavlovian-wise. This is a result in conflict with other studies. I guess more painful procedures are required to get to the bottom of this.

In the meantime, be careful for what you sign up for if you don’t want to have a panic attack every time a triangular shape appears on your computer screen.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042397