Weekly Roundup 102

Over a week ago now I was just glancing at some of the titles of paper published in Nature when this one caught my eye. It’s a paper about how the feeding territories of the ayu fish change based on population. I’m not really going to be discussing that paper, it just triggered my memory back to the experiments of John Calhoun and his paper Population Density and Social Pathology which can be thankfully read due to the work of the National Centre for Biotechnology Information. This second paper is basically letting a population of rats grow in a contained area and watching how their behaviour changes eventually leading to self destruction. Of course, Calhoun then went on to predict a similar future for humanity as we began living more congested lives within cities, competing for scarcer resources.

I suppose my only real view on this is that it’s just ridiculous. I mean, people make jokes about social sciences all the time and it’s this kind of result that doesn’t help. There is no way to properly simulate the conditions to convincingly imitate the human condition within the rats. Rats can’t entertain themselves, I’m half convinced their erratic and harmful behaviour was more the result of boredom than anything else, but this is simply my view. Calhoun had his own view, so did the sensationalist newspapers that wrote about it and if you read the study you might come to your own conclusion.

Until tomorrow, goodnight.


Studying The Frictional Force Provided By Soft Porous Substances

When you think about it, the friction between the blood cells, plasma and the inside of the arteries can’t be very big. Even a small increase in the frictional coefficient between these surfaces would increase the amount of work you heart has to do to a ridiculous level. For a long time the existence of the endothelial glycocalyx layer, a layer of molecules bound to the walls of the blood vessels (made of endothelial cells), has been known about. These molecules are mostly the protein glycocalyx and form a layer about  a micrometre thick. Only when direct comparisons were drawn between experiments in simulated blood vessels and actual ones was the importance of this layer for vascular biology understood.

Continue reading Studying The Frictional Force Provided By Soft Porous Substances

Study Into Salts Affect On Nutrient Absorbtion

Trees and plants gather nutrients from the soil through absorption into their roots. But there are those unfortunate plants that live in such desolate conditions that there are very little nutrients to absorb. Any that do get caught need to be held onto and used as efficiently as possible. This is where the action of resorption comes from. When a leaf starts senescing (just the technical term for ageing) the plant can pull back and retranslocate the nutrients from the failing leaf in order that they don’t get lost when the leaf inevitably falls off. The global average is to be able to pull back and recycle a bit over 60% of the nitrogen (N) and phosphorus (P) in each leaf. All plants do this to some degree but it was theorised that in nutrient scarce environments the plants will rely on the process a lot more. Interestingly, one study showed an increased resorption in desert shrubs than nondesert shrubs, while another has shown that there is no difference.

Continue reading Study Into Salts Affect On Nutrient Absorbtion

Creating Dynamic Cognitive Model

My ability to use computer programs is incredibly limited. I can often make them do roughly what I want (and always what I tell them) but the most infuriating part for me was when I’d (thought I’d) copied a piece of code perfectly from a different program, but it wasn’t working in its new context. I think this is no doubt a universal feeling, failed imitation leads to frustration. Now for the brain. Everyone knows that the brain can be described as a computer, running algorithms and producing thoughts. But this a purely external view, it doesn’t take into account what the brain is actually like. The other main model of the brain is the neural network. This matches the physical structure of the brain, a series many units which work together in a highly dynamic pattern. But no neural network we’ve ever been able to model has been able to produce any higher level cognitive function.

Continue reading Creating Dynamic Cognitive Model

Examining New Evolution Ideas In Osteichthyes

As a child I, like many children, was a very big fan of dinosaurs. I would like to think that my obsession was perhaps a bit more technical than the average and so I can distinctly remember memorising (or at least attempting to) large phylogenies (those trees of species) often extending long before and long after the reign of the dinosaurs. Today’s paper is about the relation between species, although it isn’t giant lizards, but bony fish, which are the target of the study.

Continue reading Examining New Evolution Ideas In Osteichthyes

Monitoring Motor Cortex Activity When Object Is Imagined And Not

There are many aspects of humans that makes our species unique among animals. Our intelligence is clear but from that stems our language and empathy. We also have acute mechanical abilities, our standing upright and our incredible stamina are also unique aspects of being human. But most of all, of course, is our opposable thumbs. They grant us the ability to perform such delicate manipulation that so many tasks, such as the typing I’m doing right now, become simple when really it’s a whole more complicated than we ever really think about. It is unsurprising, therefore, that people who have suffered spinal cord damage report that restoration of arm and hand functions is what they desire most. Important for spinal damage, and even more so for amputation, the brain-computer interface so that the control of a robotic replacement can be optimised is essential.

Continue reading Monitoring Motor Cortex Activity When Object Is Imagined And Not

Reaching A Conclusion On Conduction Anomalies At Subduction Points

When two tectonic plates run into each other, the normal results is that one goes up and the other is forced down. The plate that moves under the other, the subducting plate, dissolves as the intense pressure and friction melt it and it is also melts as it comes into contact with the mantle. The types of rock melting are very relevant in this process. Obviously the denser the rock, the more likely it will exist in the subducting plate. A simple way to make a mineral more dense is to enclose water within it’s structure to make it a hydrous mineral. Just to be clear, these aren’t the same rocks but waterlogged, the water molecules are inherently linked into the crystal structure of a hydrous molecule as compared to an anhydrous molecule.

Continue reading Reaching A Conclusion On Conduction Anomalies At Subduction Points