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!

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.

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.

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

Earth’s close call

Owen Gethings

As far as close shaves go, this Friday the 15^th 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

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!

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

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.

Synapse science news #12

Dung beetle's guide to the galaxy - Could dung beetles really be guided by the galaxy.  More here.

Can Stress chemically silence genes which are passed on to offspring? - Scientists have recently found evidence to suggest this is true. Read here for more.

First world problems? - Will scientists solve the problem of chocolate melting on your biscuits? More information here.

"Fascinating" - The Star Trek Tracker Beam has been invented in miniature. Read more here.

Polymer Carpets

Hannah Bruce Macdonald

It seems as though every new development nowadays is on the nano-scale, and this is no exception. Professors from the University of Munich and the University of Dresden have improved a method for the synthesis of polymer carpets.

A Polymer Carpet

Polymer carpets are made by grafting styrene polymers onto copper supported graphene and these scientists have discovered that the carpet density and thickness depends on the hydrogenation of the graphene. Graphene is an incredible material, due to its versatility, but what makes it so useful as a support for making polymer carpets is how stable it is to mechanical and chemical influences. The team working on these carpets say that the ‘Polymer carpets exhibit remarkable and unprecedented properties combining extreme thinness, mechanical and chemical stability, robustness, flexibility, and (chemical) sensitivity’. The chemical sensitivity mentioned by the team may sound like a flaw, but this actually means that the nature of the carpet (effectively its thickness, fluffiness or tangled-ness) can be fine-tuned with changes in conditions like the solvent quality, wetting and pH.

Natural (left) and artificial (right) nacre

Polymer carpets are one of those materials that seem to be good at everything. They are similar to biological membranes, such as the outside layer of cells, but have the significant advantage of stability and the ability to withstand considerable pressure. This feature means they have been applied to use in water purification and desalination. Any developments in these fields are of huge importance globally and more research and discoveries in this field could make these polymer carpets a viable solution to the cleanliness of drinking water.

Another unsuspected use of these is in the synthesis of artificial nacre. If, like me, you don’t know what nacre is, it is mother of pearl, the shiny inside coating of some seashells and the outer surface of pearls. Pearls have had many uses over the years, but these tend to be mostly decorative, in jewellery or furniture, but are beginning to be applied in more areas. The pearl is originally made as a surface to protect the molluscs’ soft material from damage through bombardment and protection from parasites. Nacre is now being used as a novel material in medical surgery, as it has been shown to stimulate the growth of cartilage when injected into bones. The ability to make a Nacre alternative in the labs could prove to be advantageous, over having to source it from the sea.

Any improvements in the understanding of the mechanism or the synthesis of polymer carpets is useful, and allows a large step to be taken towards applications such as these, however the greatest use of these diverse materials could yet to be discovered.

Best title ever?

Surely this is the best title on an academic paper you have seen in a long time! The article, published in PLOS Neglected Tropical Diseases, investigates the prevalence of parasitic worms in stool samples. This paper has serious implications for people living in tropical regions and it is written in good humour, check it out here. It also features some stunning figures that must have taken hours to produce.......

Figure 1 from Krauth et al.

Weird and Wonderful: The Hooker's Lips plant

Meet Psychotria elata, also known as the ‘hooker’s lips’, ‘hot Lips’ and even ‘Mick Jagger’s lips’ plant. This is not fake, it is a genine plant that can be found in the understory of tropical forests in places such as Costa Rica and Colombia. The vibrant colourful red flowers attract pollinators, including hummingbirds and butterflies. P. Elata acts as a host plant for the golden silkmoth (Xlophanes adalia).

Relics amongst us

Tom Stubbs

Meet the organisms that have outlived the Egyptian pyramids, the Roman Empire and all humanity.

As humans we are familiar with lifespans on a decadal timescale. Human life expectancies vary globally from 32 to 83 years and the oldest person ever officially recorded was a whopping 122 years old. It is amazing to think animals such as the giant tortoise can live past the age of one hundred, such as the legendary Lonesome George. Nevertheless, these lifespans are truly eclipsed by representatives from the plant kingdom.

Methuselah

The oldest individual living organism on Earth is a bristlecone pine, aptly named Methuselah, from the Hebrew Bible. This individual, hidden away in the ‘Forest of Ancients’ in the Inyo National Forest of California, is an incredible 4,800 years old. To put that into perspective, the tree must have sprouted around 2800 BC! It was already a centenarian before the first Egyptian pyramids and the Mayan civilization would not appear for 800 years. It has existed through wars and the rise and falls of civilisations, yet it still sits there humbly in the mountains of California. Bristlecone Pines are not particularly large, reaching around 50 feet, and they grow very slowly, taking around 700 years to grow 3 feet! At first glance the plant appears rather drab, but so would you if you had outlasted every other single organism on the planet.

Believe it or not, Methuselah is not the oldest recorded individual tree, there is a member of the same species that was older. This was Prometheus, which might have been 5,000 years old. Unfortunately Prometheus was felled by an enthusiastic graduate student in 1964! There is a chance that Methuselah may over take its rival and continue to live past our great-great grandchildren. Who knows, scientists might be blogging about a 6,000 years old tree in the very distant future.

Sarv-e-Abarkooh

Bristlecone pines are not the only primeval trees living amongst us. There is the giant 82 feet high cypress named Zoroastrian Sarv (or Sarv-e-Abarkooh). This individual evergreen is between 4,000 and 4,500 years old, around the same as Stonehenge! It can be found in Abarkooh, Iran.

So why do some trees live so long? Their compartmentalised vascular system helps considerably, allowing sections of the tree to deteriorate while the individual survives. They also have the ability to synthesise defensive compounds to protect against parasites and bacteria. An underlying physiological mechanism prevents genetic mutations from accumulating in their cells to the same extent as other organisms. Longevity is naturally selected as it increases the organism’s reproductive opportunities.

We have trees that have existed for thousands of years, how would you feel if I told you there are plants that may have lived for tens and hundreds of thousands of years, surely not? The exceptional trees described above are all individual units, with a single stem and root system. There are a group of plants which have evolved a clonal mode of life. This involves using many genetically identical clones stems that to the untrained eye, appear to be individual trees, but beneath the surface they are all connected in a massive network of roots. This allows these plants to defy time. The loss of a single unit stem or ‘tree’ does not mean the death of the overall organism and clonal colonies can live for incredibly long periods.

Part of the 'Pando' colony

Perhaps the most famous ancient clonal colony is ‘Pando’, a colony of Quaking Aspen in Utah. This colony is 80,000 years old, so compared to this Methuselah looks like a spring chicken! An age of 80,000 years is difficult to comprehend, but during this time our ancestors were all confined to Africa. Unbelievably some reputable estimates believe the colony could be as old as 1 million years. If so Pando would be 800,000 years older than the earliest human. Also known as the ‘The Trembling Giant’ Pando is made up of 47,000 stems that are clones of a single male aspen, when a stem dies it is simply replenished. Together this colossus weighs 6,000,000 kg making Pando the heaviest living organism on earth.

Old Tjikko

If you consider Pando a cheat for being made up of multiple stems then check out Old Tjikko. This ancient spruce tree from Sweden is 9,550 years old, twice the age of Methuselah. Unlike Pando this tree has only a single stem, so it looks like a normal tree. However, this stem is just one of many and is only 600 years old. It is a clone that is continuously replaced from an ancient root stock.

In February 2012 a new contender to the title of oldest colonial organism was announced. To find it we have to venture into the marine realm. Reports suggested a species of seagrass, Posidonia oceanica, along the Mediterranean coast is between 80,000 and 200,000 years old. It looks like a meadow but as with other clonal colonies, it is all one genetic individual. Ironically, this ancient seagrass now faces its greatest threat - humanity. Induced Mediterranean climate change is causing P. oceanica meadows to decline by around 5% each year. You will also remember that it was a freak human related accident that led to the felling of Prometheus and ‘The Senator’, previously the fifth oldest living tree, was burnt down by a woman in Florida in 2012! As a species we must be careful we do not destroy these wonderful relics.