Thursday, 28 February 2013

A Nation of Fat Ducks

Toby Benham

Feeding bread to ducks is the equivalent of giving them junk food. Scientists have warned that one of Britain’s favourite pastimes is making ducks fat. Feeding bread to ducks is a source of carbohydrate with little other nutritional value. Although this is ok in moderation, ducks can face copious amounts of bread thrown at them at certain times of year. They tend to seek out this easy food source meaning that ducklings lose the training to forage for food. This leaves them hungry when they are not hand fed. Other problems include becoming more susceptible to predation as too much starch leads to the animal becoming bloated and lethargic – a prime target. They can also suffer from diseases originating from mouldy bread or the increase in faeces associated with over eating. Suggestions on what ducks should instead be fed include: corn, barley, grain and duck feed pellets. So, next time you decide to go to feed the ducks, leave the stale bread at home and grab a handful of grain instead!

Wednesday, 20 February 2013

Weird and Wonderful: Tachyglossus - The Real Easter Bunny

Ione Bingley

Rumor has it that a bouncing bunny bestows his tasty eggs upon hoards of hungry young humans. Call me a cynic, but where is this reputed Lenten rabbit getting his endless supply of eggs? Surely Thumper must be Big Bird in disguise, everyone knows mammals never lay eggs…or do they?!

This time friends we are heading out for a jaunt down under, under down under, to the Australian undergrowth, where a certain prickly customer snuffles out his creepy crawly quarry. This spiny insectivore may look to the untrained eye like our familiar British bonfire-lover, but we must remember, looks aren't everything. I have the pleasure of introducing you to the Echidna (eh-kid-na), and though she doesn't like to show her face, preferring you to ponder her spiny rear-end, I promise she is most fascinating indeed.

The echidna is larger than the European hedgehog and if you’re lucky enough to glimpse its cigar-like snout you will see it’s actually rather different in structure. With no hinge and a lower jaw that is reduced to a couple of bumps the echidna is already rather peculiar, and this is before mentioning its penis that has 4 openings! Like any other member of the Mammalia class, the echidna is warm blooded, suckles its young and has fur, albeit hardened into spines. However, unlike any other mammals, apart from their sole compatriot of the Monotreme contingent, the duck-billed platypus, Mrs Echidna lays eggs! 

The echidna is not some kind of bird-mammal Frankenmonster. It may actually elucidate the evolutionary link between the mammal-like reptiles (therapsids) and our furry friends of today, including Homo sap himself. The echidna lays eggs, has reptile like shoulder bones, a venomous spur, doesn't pant or sweat and, though warm-blooded, has a body temperature of 31-33°C, the lowest functioning temperature of any of our Mammalian brothers; could the echidna be warming up from a reptilian state?

Winter is the time for lonely hearts in the land of the echidna with up to 11 males following one female in a love train seeking her affection. One egg is laid every 3 years and the baby echidna hatches, after 10 days of eggdom, a mere 0.3g with closed nostrils. It is so altricial that gas exchange occurs directly across the skin surface. Unlike kangaroos and wombats, there is no pouch for the babies to hide in; they have to cling on for dear life with their tiny front feet with the mothers’ belly skin forming a ‘pseudopouch’ for support. 120 miniscule pores exude milk for the teeny echidnas hat becomes progressively thicker and more nutritious. After 5 or 6 days the nostrils open and after 35 days the babes are covered in peach-like fuzz. By 50 days it’s ‘on your own two feet chid’ and the mother digs a nursery burrow up to 2m long returning for only 2 hours every 5 days. The ‘puggles’ as they are affectionately known at this teenage stage, are able to consume up to 30% of their body weight in one feed, blowing up like a balloon. That milk must be real nutritious stuff because after seven months they’re off, the adventurous young’uns, travelling up to 40km.      

It’s no wonder we’ve never seen the famed Easter Bunny, we’ve been looking in all the wrong places. Why do you think he always hides his eggs in the undergrowth? Check out the video below.

Monday, 18 February 2013

Why do we die?

Owen Gethings

They say that there are two certainties in life, death and taxes. As I am not an economist I do not feel qualified to comment about the state of the taxation system. As a biologist, however, I feel I am more than qualified to explain the notion of death. As a living organism we abide by several rules: we are born, we grow, we make mistakes, we reproduce and inevitably, we die. But why do we die? Organisms grow old, wither and die because we are no longer needed. There is no divine utterance regarding the meaning of life that once spoken will change the course of humanity forever. From a purely biological stand point, we are here to reproduce, and once we do, we die. This is the logic of the selfish-gene theory, coined by Richard Dawkins to explain the purpose of staying healthy, increasing longevity and maximising reproductive potential.

Different organisms go about this in different ways. If you are a salmon, an oyster or a dragonfly then this process is over very quickly. You reproduce, lay your eggs somewhere safe and hope for the best. If you are a dolphin, a whale or an elephant this process is not so simple. You must reproduce, raise your offspring, provide them with food and guide them safely to sexual maturity and inevitably reproduction. As humans, we tend to play a much larger role in our offspring’s life. As grandparents, we often play a large part in the lives of our grandchildren, meaning it is beneficial for us to stay around longer.

Eventually however, our bodies can no longer carry on the way they used to. We begin to age, we ache, we lose our memory, and we lose our hearing and vision. Our once faithful heart that has been pounding away for years begins to deteriorate and fail, and eventually we die. The main reason we die is not known, but it is believed to be a combination of oxidative stress, gene regulation and cellular degradation.

Cellular degradation
Each time a cell divides via mitosis, the DNA is unravelled and information contained within this DNA is copied. At the end of each strand of DNA are the telomeres. The telomeres prevent DNA from spiralling or fusing with other strands. Think of them as book ends on your bookshelf. Each time the DNA is copied, the telomeres are shortened until finally the DNA can no longer be copied and apoptosis (programmed cell death) takes over and kills the cell before it can mutate and cause a problem. This process is known as the hayflick limit, and dictates the amount of times a cell can reproduce before it dies. In humans the hayflick limit is approximately 40-60 times. This process does not occur in cancer cells, due to an enzyme called telomerase, which inhibits the shortening of the telomeres so the cell doesn't die.

Oxidative stress
During cellular respiration, reactive oxygen species (ROS) are formed as a by product of aerobic respiration. The mitochondria produce a large amount of these molecules during oxidative phosphorylation via the electron transport chain. These ROS molecules include superoxide anion, hydroxyl radical and hydrogen peroxide (H2O2). These molecules have the potential to directly damage DNA, protein and lipid reserves and as such, are implicated in the aging process. Metabolic rate has been linked with longevity. Naked mole rats, for example can alter their metabolic rate in response to nutrient availability. When food is scarce, they slow down their metabolism. It is also interesting that unlike other mammalian species, the naked mole rate does not maintain homeostasis in the normal mammalian fashion. The naked mole rate is a thermoconformer as opposed to a thermoregulator, meaning it maintains its body temperature according to ambient temperature. As a result it can live 10 times longer than other rodent species. If we compare a mouse, whose average lifespan is ~4 years, with a Galapagos tortoise, whose average lifespan is ~190 years we begin to notice a pattern emerging. The mouse is a very active species, whose heartbeat is much faster than that of the tortoise, implying that mice have a much greater demand for energy than the tortoise so therefore have a higher rate of metabolism to meet those energy demands.

Gene regulation
The idea that we have genes that control when we die has long been hypothesised and in 1993 gained strength. A study was carried on the nematode Caenorhabditis elegans and its response to oxidative damage. The team found a specific gene; DAF-2, that once mutated increased the longevity and increased resistance to oxidative stress. The worm’s average lifespan is ~2 weeks, however those worms that had mutations in DAF-2 lived twice as long as those worms that did not.

Although we do not know the exact reason why different species age and die at varying rates, we do know that a combination of gene function, oxidative stress and cell degradation are the most probable causes.

Sunday, 17 February 2013

Synapse science news #14

Too busy to keep track of all the science news during the week? Don’t fear Synapse is here. Check out this week's news.

Earth’s close call – This week the small Near Earth asteroid, 2012 DA14, passed by Earth. Read more

Deadly coronavirus in UK – Multiple people being treated in intensive care. More information

Drilling on Mars – Curiosity rover takes historic drill sample, although it was only 6cm deep! Read more.

Sea slug has disposable penis - Japanese researchers observed this bizarre mating behaviour in a species called Chromodoris reticulate. Find out more

Mosh-pit behaviour – Science behind collective behaviour is being investigated using  mosh-pits. More information.

Downtime for the LHC – The large hadron collider is being turned off for a 2 year upgrade and maintenance period. Read more.

Drive you round the bend – Self driving car technology is being developed in the UK. More information

Treatment on the ocean floor?  Researchers are beginning an £8m project to discover new antibiotics at the bottom of the ocean. Read more.

Katherine MacInnes and Saraansh Dave

Friday, 15 February 2013

Earth’s close call

Owen Gethings

As far as close shaves go, this Friday the 15th the Earth will be sailing pretty close to the wind. The small Near Earth asteroid, 2012 DA14 is currently hurtling towards us at 25,791mph (or 11.53km/second) and will pass Earth at a distance of 17,200 miles. That doesn’t seem very close but let me put that into perspective. The asteroid will pass within the ring of geosynchronous communication and weather satellites currently orbiting at 22,200 miles above the equator. Although NASA’s NEO program, that currently monitors around 9697 Near Earth Objects, with 961 of these being larger than 1km, say the asteroid will not hit us, it does give researchers an opportunity to study the large object. The asteroid will be visible through binoculars, albeit a very faint spec of light crossing the sky. The asteroid will be visible in the constellation leo, travelling towards the plough at around 7:30pm UK time.

The trajectory of DA14

Tuesday, 12 February 2013

Weird and Wonderful: Louisiana pancake batfish

Tom Stubbs

The Louisiana pancake batfish (Halieutichthys intermedius) is a strange-looking fish with a massive head, round flat body and limb-like pectoral fins. These pectoral fins are used to ‘walk’ along the sea floor. The pancake batfish attracts prey with a fleshy ‘lure’ on its snout. This bottom-dwelling fish species was only discovered in 2010 and it is restricted to the northern Gulf of Mexico. Happy Pancake Day!

Sunday, 10 February 2013

Synapse science news #13

Hi-tech specs - Hi-tech spectacles could help cure blindness - no more problems with telling green and red apart! This new invention, by an american research institute, could allow colour blind people to see the full spectrum of colour. Read more.

Alzheimer's figures might triple by 2050 - A new study based on increasing ageing population predicts that the number of people with Alzheimer's disease will triple. More information.

Elephants on the brink - 11,000 elephants have been killed in the last 8 years. In Gabon since 2004 thousands of elephants have been killed for their ivory in a situation called "out of control."  Find out more.

Magnetic salmon - Sockeye salmon use a magnetic field to get home. A new study in Current Biology states they use the memory of the magnetic field when they first entered the sea to find their way home. Read more

Mary Melville

Tuesday, 5 February 2013

The AI Lab: Brain-Computer Interfaces - The Future of Collaborative Mind-Control Systems Shaping Up

Alfred Omachar

One of the most challenging advances in human-machine interfaces is the use of a brain-computer interface (BCI) to communicate a user's intention to a computer by passing the classical hand input interfaces such as keyboard, mouse and touch-pad. 

However, recent research in BCI has shown impressive capability for controlling mobile robots, virtual avatars and even humanoid robots. For example, one study demonstrated the ability to control a humanoid robot with a BCI, where users (humans) were able to select an object in the robot's environment – seen through the robot's cameras – and put it in a desired area in the environment -  seen through an overhead camera. Similarly, BCIs have also managed to help people with disabilities to control, for example, a wheelchair, robotic prosthesis or computer cursor.

So how do BCIs work (in a nutshell)?

A BCI system records the brain's electrical activity using electroencephalography (EEG) signals. The signals can be taken invasively or non-invasively either from inside the brain or from the scalp. Non-invasive BCI takes signals that are present at micro-volt levels on the scalp and then amplifies them using an EEG. These signals are then digitised so that they can be used by the computer. Machine learning algorithms are then used to construct software that learn to recognise the patterns generated by a user as he/she thinks of a certain concept, for example, “up”  or “down”. 

A promising Future for Collaborative BCIs

Now researchers are discovering that they even get better results in some tasks by combining the signals from multiple BCI users. For instance, a team at the University of Essex managed to develop a simulator in which pairs of BCI users had to steer a craft towards the centre of a planet by thinking about one of eight directions that they could fly in. Brain signals representing the users' chosen direction were merged in real time and the spacecraft followed that path.

According to the results of this study, it turns out that two-brain navigation performed better compared to single brain navigation. Simulation flights were 67% accurate when controlled by a single user but were 90% on target when controlled by two users. In addition, random noise in the combined EEG signals were significantly reduced and the dual brain navigation could also compensate for a lapse in attention by any one of the two users. In fact, NASA's Jet Propulsion lab in Pasadena, California, has been observing this study while itself investigating the potential of BCIs controlling, for example, planetary rovers, among other space applications. However, for now the idea of planetary rover remote control still remains speculative as most pioneers in the field of BCI are in their research stage.