Science Sunday #22
Posted by Don McLenaghen on November 13, 2011
– and on the seventh day we learn.
Each week I hope to give a synopsis of the interesting science stories I have heard on my plethora of science podcasts I listen to each week plus anything I pick up scanning the inter-web. We are going to try something different this week. I listen to over 30 podcasts and read over 1000 articles a week; limiting stories here to 5 +/- items seemed limited. So, less text and more stories…feedback welcome. This week’s top stories:
This week’s top stories:
Attention and Awareness Uncoupled –
A number of behavioural observations have recently led scientists to postulate that attention and awareness are fundamentally different processes and not necessarily connected. In the study now published in the journal Science, scientists of the Max Planck Institute for Biological Cybernetics in cooperation with Japanese colleagues provide the first experimental evidence that the primary visual cortex, the entrance stage to cortical visual processing, is modulated only by attention and not by awareness. This finding supports the hypothesis that attention and awareness differentially affect nerve cells.
Aliens don’t need a moon like ours –
In 1993, Jacques Laskar of the Paris Observatory in France and colleagues showed that the moon helps stabilise the tilt of Earth’s rotation axis against perturbations by Jupiter’s gravity. The researchers calculated that without the moon, Jupiter’s influence would make the current tilt of some 23 degrees wander chaotically between 0 and 85 degrees. That could cause huge climate swings, making it hard for life to survive, especially large, land-based organisms like us.
The result was taken by many to imply that complex life is rare in the universe, since Earth’s large moon is thought to have coalesced from the debris of a freak collision between a Mars-sized planet and Earth. Less than 10 per cent of Earth-sized planets are expected to experience such a trauma, making large moons a rarity.
“The astrobiology community has taken it to mean there will be these really wild variations, and we wanted to test that,” says Jack Lissauer of NASA’s Ames Research Center in Moffett Field, California. But a study now suggests moonless planets have been dismissed unfairly. “There could be a lot more habitable worlds out there,” says Lissauer, who led the research.
He and his colleagues simulated a moonless Earth over 4 billion years, about the age of the Earth today. They found that our planet’s tilt varied between only 10 and 50 degrees, a much smaller range than implied by the earlier study. There were also long stretches of up to 500 million years when the tilt was particularly stable, keeping between 17 and 32 degrees
EEG finds consciousness in people in vegetative state –
Signs of consciousness have been detected in three people previously thought to be in a vegetative state, with the help of a cheap, portable device that can be used at the bedside.
“There’s a man here who technically meets all the internationally agreed criteria for being in a vegetative state, yet he can generate 200 responses [to direct commands] with his brain,” says Adrian Owen of the University of Western Ontario. “Clearly this guy is not in a true vegetative state. He’s probably as conscious as you or I are.”
In 2005, Owen’s team, used functional MRI to show consciousness in a person who was in a persistent vegetative state, also known as wakeful unconsciousness – where the body still functions but the mind is unresponsive – for the first time. However, fMRI is costly and time-consuming, so his team set about searching for simple and cost-effective solutions for making bedside diagnoses of PVS. Now, they have devised a test that uses the relatively inexpensive and widely available electroencephalogram (EEG).
Universe gets three new elements –
New additions to the periodic table are artificial elements forged in laboratories that are so unstable they exist for just fractions of a second. Officially naming them, however, can take years.
The names for elements 110, 111 and 112 – darmstadtium, roentgenium and copernicium, respectively – had already been approved by the International Union of Pure and Applied Chemistry (IUPAC). You may even own a periodic table containing these names. It wasn’t until Friday, however, that physicists attending the annual meeting of the International Union of Pure and Applied Physics (IUPAP) in London rubber-stamped these choices and the accompanying symbols: Ds, Rg and Cn. This completes the final stage of the official element naming process – for now.
In the near future, there’s much more in store for any keen element watchers. As well as a slew of element claims awaiting entry to the periodic table, numbers 114 and 116, which were officially added in July, are expected to garner suggested names soon.
Brain Parasite are controlling your mind –
Findings from the University of Leeds research group are the first to demonstrate that a parasite found in the brain of mammals can affect dopamine levels.
Whilst the work has been carried out with rodents, lead investigator Dr Glenn McConkey of the University’s Faculty of Biological Sciences, believes that the findings could ultimately shed new light on treating human neurological disorders that are dopamine-related such as schizophrenia, attention deficit hyperactivity disorder, and Parkinson’s disease.
This research may explain how these parasites, remarkably, manipulate rodents’ behaviour for their own advantage. Infected mice and rats lose their innate fear of cats, increasing the chances of being caught and eaten, which enables the parasite to return to its main host to complete its life cycle.
Easily ‘Re-Programmable Cells’ Could Be Key in Creation of New Life Forms –
The success of the project to create a ‘re-programmable cell’ could revolutionise synthetic biology and would pave the way for scientists to create completely new and useful forms of life using a relatively hassle-free approach.
Professor Natalio Krasnogor of the University’s School of Computer Science, who leads the Interdisciplinary Computing and Complex Systems Research Group, said: “We are looking at creating a cell’s equivalent to a computer operating system in such a way that a given group of cells could be seamlessly re-programmed to perform any function without needing to modifying its hardware.”
Prehistoric Hitchhiker –
Scientists at the University of Manchester colleagues in Berlin believe have produced amazing three-dimensional images of a prehistoric mite as it hitched a ride on the back of a 50-million-year-old spider.
At just 176 micrometres long and barely visible to the naked eye, the mite — trapped inside Baltic amber (fossil tree resin) — is believed to be the smallest arthropod fossil ever to be scanned using X-ray computed tomography (CT) scanning techniques.
The study, published in the Royal Society journal Biology Letters, also sets a minimum age of almost 50 million years for the evolution among these mites of phoretic, or hitchhiking, behaviour using another animal species.
Weird World of Water Gets a Little Weirder –
Strange, stranger, strangest! To the weird nature of one of the simplest chemical compounds — the stuff so familiar that even non-scientists know its chemical formula — add another odd twist. Scientists are reporting that good old H2O, when chilled below the freezing point, can shift into a new type of liquid.
Pradeep Kumar and H. Eugene Stanley explain that water is one weird substance, exhibiting more than 80 unusual properties, by one count, including some that scientists still struggle to understand. For example, water can exist in all three states of matter (solid, liquid,gas) at the same time. And the forces at its surface enable insects to walk on water and water to rise up from the roots into the leaves of trees and other plants.
In another strange turn, scientists have proposed that water can go from being one type of liquid into another in a so-called “liquid-liquid” phase transition, but it is impossible to test this with today’s laboratory equipment because these things happen so fast. That’s why Kumar and Stanley used computer simulations to check it out.
They found that when they chilled liquid water in their simulation, its propensity to conduct heat decreases, as expected for an ordinary liquid. But, when they lowered the temperature to about 54 degrees below zero Fahrenheit, the liquid water started to conduct heat even better in the simulation. Their studies suggest that below this temperature, liquid water undergoes sharp but continuous structural changes whereas the local structure of liquid becomes extremely ordered — very much like ice. These structural changes in liquid water lead to increase of heat conduction at lower temperatures.
Smaller bellies do not represent bigger brains –
The so-called expensive-tissue hypothesis, which suggests a trade-off between the size of the brain and the size of the digestive tract, has been challenged by researchers at the University of Zurich. They have shown that brains in mammals have grown over the course of evolution without the digestive organs having to become smaller. The researchers have further demonstrated that the potential to store fat often goes hand in hand with relatively small brains — except in humans, who owe their increased energy intake and correspondingly large brain to communal child care, better diet and their ability to walk upright.
Brain tissue is a major consumer of energy in the body. If an animal species evolves a larger brain than its ancestors, the increased need for energy can be met by either obtaining additional sources of food or by a trade-off with other functions in the body. In humans, the brain is three times larger and thus requires a lot more energy than that of our closest relatives, the great apes. Until now, the generally accepted theory for this condition was that early humans were able to redirect energy to their brains thanks to a reduced digestive tract. Zurich primatologists, however, have now disproved this theory, demonstrating that mammals with relatively large brains actually tend to have a somewhat bigger digestive tract. Ana Navarrete, the first author on the study recently published in Nature, has studied hundreds of carcasses from zoos and museums.
Testing Morality –
Philosophers have tried for years to explain our sense of ethics, but now the BBC’s Lab UK is trying to understand why evolution may have a role to play in how our morality is shaped. They have developed an online morality test, an interactive questionnaire that puts users through various ethical scenarios, from a leader failing to defend their country from outside aggressors, to the selection of a candidate for a particular job because they are related to their employer. So what can this test teach us about the biological benefits of acting morally?
Universe’s pristine gas –
By peering into the distance with the biggest and best telescopes in the world, astronomers have managed to glimpse exploding stars, galaxies and other glowing cosmic beacons as they appeared just hundreds of millions of years after the big bang. They are so far away that their light is only now reaching Earth, even though it was emitted more than 13 billion years ago.
Astronomers have been able to identify those objects in the early universe because their bright glow has remained visible even after a long, universe-spanning journey. But spotting the raw materials from which the first cosmic structures formed—the gas produced as the infant universe expanded and cooled in the first few minutes after the big bang—has not been possible. That material is not itself luminous, and everywhere astronomers have looked they have found not the primordial light-element gases hydrogen, helium and lithium from the big bang but rather material polluted by heavier elements, which form only in stellar interiors and in cataclysms such as supernovae.