A propagation of behaviours between individuals is known as “social contagion”. This is just a fancy term that includes a range of things from information spread between users of the media to flocking behaviour in birds. However, while measuring the rate and direction of information spread is reasonably straightforward, how various forms of contagious behaviour are initiated and what social interactions act as clues for the spread of particular behaviour in nature is not well understood. Over the years many different hypotheses have been proposed to explain the workings of social contagion in different animals; from suggestion of communication via telepathy in flocking birds to, a more reasonable sounding, changes in water pressure caused by sudden movements in schooling fish. One strategy of studying social contagion in animals is to create models of networks between individuals in the group, where each individual is connected to another one by one or more strings of information that can act as social clues to help to decide what behaviour to adopt.
Considering it is Easter I though it would be very appropriate to write something on an egg-related topic and, as a personal bonus, to mix some viruses in as well ☺ .
I suppose most of us are used to seeing eggs that have either white or brown shells. However, those are just the types that are sold in supermarkets, but people who grow different types of chickens will note that sometimes the eggshells can be blue or green as well. Were do all these colours come from? Eggshell colours are determined by the pigments that are secreted when eggs develop in uterus of a hen. Pigment protoporphyrin, for example, is derived from blood haemoglobin and contributes to brown eggshell coloration. By contrast, blue eggs predominantly have billiverdin pigment in their shells. Billiverdin is a component of bile salts and acts as an antioxidant, which is why it has been proposed that blue egg coloration could act as a signal of female genetic fitness (figure 1).
We spend almost 30 years of our lives asleep, however, we still have limited understanding about the function of sleep. Scientists and philosophers have been trying to understand why animals need sleep for more than 2000 years. In his book “On Sleep and Sleeplessness”, Aristotle wrote:
“With regard to sleep and waking, we must consider what they are: whether they are peculiar to soul or to body, or common to both; and if common, to what part of soul or body they appertain: further, from what cause it arises that they are attributes of animals, and whether all animals share in them both, or some partake of the one only, others of the other only, or some partake of neither and some of both”
As we are heading towards the high season of flu I though it would be interesting to remember how the vaccines against influenza virus (the causative agent of flu) are actually made.
Human microbiome is definitely one of the trending topics in biological science right now (admittedly, I also have been caught up in this trend and blogged about microbiome before). Each week new research announces it discovered a new role of the microbiome (last week there was a nice paper studying a link between alcohol dependency and gut microbiome) and many researcher now consider the microbiome to be another organ in our body, the functions of which we are only beginning to understand. And here is another great story about the gut microbiome but this time, maybe somewhat unexpectedly, it involves the jet lag. Continue reading
Recently I was river tracing here in Taiwan. It’s basically hiking but in the water, you just jump into some kind of a stream and go upstream, it is very fun, especially when rocks are slippery because then you always feel like a very bad ballerina. After several hours spent in the water, our fingers became very wrinkly, you know, as they always do after a long bath, a swim or any prolonged water activity. And during the lunch brake people started discussing why does that happen, why do fingers get wrinkly in the water? Most of us started to mumble something about osmosis, i.e. water entering or leaving the skin. Yes, it’s very smart of us to say ‘osmosis’ and pretend that we know something about it but really this was just another case of what episode #293 of This American Life called ‘Modern Jackass’: situations in which people act as if they are knowledgeable about something but they actually have no clue. As Nancy Updike put it, “The thing about Modern Jackass is, it’s usually not something about which you know nothing. It’s something about which you know a little bit, enough to sort of get yourself into trouble.” And to be honest osmosis doesn’t really make sense if you think about it, I mean shouldn’t then all of our body turn wrinkly in water not just the fingers, and at least I haven’t notice any particular differences about wrinkling in fresh and salt water, but clearly the osmotic pressure in the two must be quite different (it’s easy for me to speak post factum).
For many people microbes are associated with infections, diseases and in general mainly negative things but some microbes actually do more good than bad for us. We often take for granted that without microbes we would not have many things that we eat and use everyday and, as a matter of fact, humans would not even survive without these little creatures :)
I’m no expert on dinosaurs whatsoever, however, as many science geeks I find them extremely fascinating.
Hope this will spark your interest as well.
Even though we have started to appreciate the importance of human microbiome relatively recently, it is no longer a question’ if the microbiome is important?’ but rather ‘how the microbiome affects us?’. I define human microbiome as the total diversity of microbes in and on human body, however, this definition is definitely simplified version and for those interested in the subtleties of its use can go and read some of the debate in here.
Some people report that in fear-related situations time seems to slowdown. That is to say, for example, during a car crash the event takes much longer from the point of a person experiencing the crash than the observer. But how and why the brain creates this slow motion experience is not completely understood. Recently, on the World Science Festival panel called ‘The Deceptive Watchman: Mind, Brain, and Time’ David Eagleman mentioned his study on the subject, which both intrigued and amused me, so let me tell you why.
In his study Eagleman asked if in a fear situation time slows down because of increased temporal resolution of an experienced event (as when in slow-motion videos a better movement discrimination is seen because of increased number of frames in it). In other words, are people in life-threatening situations somehow able to increase their visual recording of an event, which leads to a more detailed recall and consequent slow motion-like experience?
Here comes the amusing part. To answer the question one obviously needs to place a person in a fear-inducing environment and what is better a way of doing it than a 31m freefall. The participants in this study were dropped from a huge tower in an amusement park and asked to preform a task while free falling (apparently no incentives where given, so I have a suspicion that the study is biased towards fear-junkies ☺ ).