Number of the Week
The percentage of modern endurance runners who land heel-first. Scientists in Harvard compared long-distance runners in Kenya and in the US and found that more then two thirds of runners who ran barefoot did so on the balls of their feet. Running on tiptoes may explain how our ancestors ran long distances without the benefit of hi-tech running shoes.
The full letter to Nature is available here.
Friday, January 29, 2010
Number of the Week
Thursday, January 28, 2010
The humpback whale, nicknamed Hook, breaches off of Hook Head, Co. Wexford. Image copyright of Padraig Whooley, Irish Whale and Dolphin Group (IWDG)
Sometimes we're really spoiled when it comes to enjoying nature up close and personal. In the early part of this week, newspapers and RTE television news reports were full of images of humpback whales launching themselves majestically through the air off Hook Head in Co. Wexford.
The humpback was first seen off Wexford in early January and on the 22nd, a team of researchers from the Irish Whale and Dolphin Group (IWDG), Galway-Mayo Institute of Technology (GMIT), Bord Iascaigh Mhara (BIM) and a camera crew from Crossing the Line Films chartered the MV Rebecca C to view and film the animals.
Padraig Whooley, IWDG's Sighting Co-ordinator reports that this is a new humpback to Irish waters. He's sure of this because of analysis carried out on photographs of the whale's tail. Each whale has a slightly different one - a bit like a human fingerprint, which allows scientists to track them around the world. Just as long as they can get a good look at their tail.
This new animal brings the number of humpback's officially sighted in Irish waters to eleven. Many of these are regular visitors and return every year and despite the seemingly small numbers, the IWDG believe there is a slow but steady recovery going on in the Irish humpback population.
On Saturday last, as if to celebrate this good news, the humpback put on a spectacular 45-minute show where it breached the surface of the water on eleven occasions. All of this activity was documented in high definition by Ross Bartley from Crossing the Line films and the footage will form part of a new series of "Wild Journeys" due to start on RTE television later in the Spring. I for one am really looking forward to seeing that.
The humpback whale (Megaptera novaeanfliae) is one of the baleen whales. This means it filters its food directly from the water. Rather than having teeth with which to eat, the humpbacks are equipped with a baleen filtration system. This is made up of stiff plates which grow down from the gums of the upper jaw and extend in rows down both sides of the mouth. Baleen is made out of keratin- the same protein that our hair and fingernails are made from.
It is estimated that an adult humpback will eat up to 4% of its body weight per day. To do this, the whale gulps crustaceans and schooling fish in to its mouth and uses the filtration system to separate the food from the water.
In some cases, humpbacks will use a "bubble net" to capture food. The animal dives down beneath its prey then swims in a spiral upwards blowing bubbles from its blowholes as it does so. These bubbles form a sort of tubular net in which prey are trapped and pushed to the surface where the whale eventually gobbles them up.
Humpbacks have even been known to bubble net collectively. So, while one animal is blowing bubbles, another might be diving deeper to 'herd' prey into the net while more animals may be driving prey into the net by singing at them.
This whale song or vocalisation is particularly prevalent in humpbacks who may sing for 24 hours non-stop.
Scientists seem to be in dispute as to why baleen whales, and particularly humpbacks put on such amazing aerial acrobatics shows. One theory is that it is all an effort to attract a mate. Presumably the higher the whale can jump or the bigger the splash the whale can make, the fitter the animal is and all the better to mate with. In fact, breaching seems to increase when the animals are in groups, so this does suggest some sort of social function.
There is also some evidence that slapping the water with such force serves to stun and disorientate prey. This may be true, but it would hardly explain such elaborate displays seen off the Wexford coast.
Another theory gaining ground is that the animals are trying to dislodge parasites which attach themselves to their sides.
The IWDG website records 157 sightings of humpback whales in Irish waters going back to 1984. Despite a tiny handful sighted off the north coast and elsewhere, the vast majority of sightings have been recorded in an area stretching from Dingle to Hook Head. That means that in Cork, we have a front row seat for what Padraig Whooley describes as the "greatest wildlife show on earth".
Friday, January 22, 2010
Number of the Week
The commercial value of the pollination activity of bees in the United States. A team of scientists working in France have shown that bees fed on pollen from a single flowering plant had a less healthy immune system than bees fed on pollen from a variety of plants. The scientists have proposed a link between a fall in plant biodiversity and a decline in bee populations worldwide.
The full research article is published here.
Tuesday, January 19, 2010
Here at Communicate Science, there is nothing we like better than a night at the movies. So, stuffed to the metaphorical gills with popcorn and ice cream, I recently settled down in front of James Cameron's epic Avatar.
It's a good film (it should be since it cost a reported $300 million to make and another $150 to market) but I know you didn't come here for a film review. One of the startling images of the film is the use of special effects to create bioluminescent plant and animal life on the alien planet Pandora (I think, strictly speaking, it's a moon, but that's not important).
As the cast of characters move through the lush forest, the plant life is glowing around them. As they brush against leaves and fronds, the plants glow stronger as if influenced by the contact.
Whereas bioluminescence (that's the ability of living organisms to generate light) isn't as common or spectacular as illustrated in the film, it is evident in nature.It's estimated that up to 90% of deep sea creatures exhibit some form of bioluminescence.
During the (all too brief) Summer we had in 2009, I was lucky enough to take a night-time kayaking trip in the waters surrounding Castletownshend in West Cork. The whole aim of the trip was to look for bioluminescent algae which are at their brightest during late summer. As we paddled through the water and the night got darker, I was amazed to catch flecks of silver spilling from the paddle and lapping at the side of the boat. In places, these flecks became almost like a thick soup of silver sparks. It was as if a child had emptied a jar of glitter into the water, except on a massive scale.
Once we ceased moving, the algae too switched off, and we returned to darkness. But, by trailing your hand through the water again, I could set off a beautiful cascade of stars to rise to the surface of the black water.
You can try this out for yourself by taking a trip with Atlantic Kayaking. So what were the algae up to? There are three basic reasons for organisms to produce their own light: to locate food, to attract a mate or to defend itself against attack.
Unfortunately, no plant or animal produces its own light on land. So, James Cameron was certainly in the land of make believe there. However, it's reported that he was influenced by marine life that bioluminesce when designing his forest scenes.
Anglerfish are an example of deep water fish which utilise bioluminescence to attract food. At the bottom of deep, dark oceans, the ugly looking creature waves about a brightly lit lure at the end of an extended 'fishing rod' attached to the front of its head.
Once the preyfish has spotted this tasty bait (often disguised as a small fish itself) it moves closer to investigate. This is generally the last thing it does, as out of the darkness, the anglerfish's mouth opens and the prey is gobbled up in an instant.
In fact, the anglerfish is a tad unusual because it doesn't make its own light. It actually has some light producing bacteria inside the lure to do the job for it.
Back on land, scientists have now identified almost 70 species of fungi that are bioluminescent. Quite why they glow seems to be a bit of a mystery. In some cases, just the cap of a mushroom glows, suggesting that it may have something to do with the dispersal of spores. Alternatively, some scientists suggest that the glowing may just be a byproduct of normal metabolic function of the fungi and serve no purpose. I'm inclined to be suspicious of this theory - these things do usually have some sort of evolutionary advantage.
In West Cork, and in many other parts of the world, the bioluminescent single-celled algae which create such wonderful displays are called dinoflagellates. The light show in this species has been described as a sort of 'burglar alarm' designed to light up the water around a potential threat (or kayak). This is a shout for help.
The dinoflagellates are working on the theory that the best chance of avoiding getting eaten themselves is to attract something bigger to eat their enemy. Hence the big light show.
What's happening at the cellular level is that a chemical known as a luciferin is converted to oxyluciferin by the enzyme luciferase. This basic reaction involves the release of energy in the form of light.
As we've seen, at the organism level, this phenomenon can be used for a variety of purposes. The result is often quiet beautiful. Almost as spectacular as the movies.
Monday, January 18, 2010
For a number of years now, the Science Public Lecture Series at University College Cork has been organised by that college's Public Awareness of Science Office headed up by the well known academic and columnist William Reville.
This year is no different, with the lecture series having kicked off on the 6th of January. The lectures are an exciting opportunity to listen to experts speak on a variety of important scientific topics with lectures designed for a public audience.
Topics range from the Big Bang Theory to 'The God Delusion'. Admission is free and lectures are open to everyone!
6th January~ Mr. Noel Brett~ The Problem with Mathematics
13th January~ Ms. Claire Feeley~ The Cinema as Laboratory
20th January~ Prof. J. Ray Bates~ The Greenhouse Effect and Global Warming
27th January ~ Prof. Paul McSweeney~ From Molecules to Milk
3rd February~ Dr. Edmond Byrne~ Change or Collapse? Transforming Society and the New Engineer
10th February~ Dr. Dylan Evans~ Risk Intelligence- How expert gamblers can teach us all to make better decisions
17th February~ Dr. Sharon Murphy~ Ethics, Technological Interventions and End-of-Life Choices
24th February~ Dr. Fatima Gunning~ What Lies Beneath? How photonics can save the internet from the bandwidth crunch
3rd March~ Dr. Cormac O'Raifeartaigh~ The Big Bang, the Large Hadron Collider and the God Particle
10th March~ Joe Egan ~A Theological Critique of 'The God Delusion'
All of the lectures take place in Boole 4 lecture theatre in the Boole Lecture Theatre Complex on the UCC campus at 8pm.
Further information: http://understandingscience.ucc.ie
Wednesday, January 13, 2010
Number of the Week
The magnitude (on the Richter Scale) of the earthquake that hit the Caribbean state of Haiti on Tuesday. The quake struck about 10 miles south-west of the capital Port-au-Prince and was followed by two aftershocks of 5.9 and 5.5 magnitude. The US Geological Survey said the earthquake occurred in the boundary region separating the Caribbean plate and the North America plate.
Saturday, January 9, 2010
I hope you're wrapped up warm when reading this.
As if the awful flooding of November wasn't enough, we've now been hit with a cold spell to beat all cold spells. Since well before Christmas, Ireland along with many other Northern Hemisphere conuntries have been shivering at often sub-zero temperatures.
The boys and girls at Met Eireann tell us that last month was the coldest December for almost 30 years. Having started off the month mild and wet, the second half of December was characterised by much colder conditions with severe frosts and snow falls in places.
Temperatures were down by around 2 degrees celsius on average everywhere making it the coldest December since 1981. Average temperatures at Cork Airport were down 2.4 degrees. It was the coldest of any month, in fact, since 1986 in some areas.
It wasn't all bad news though. What we missed out on in terms of warmth, we made up for in the fact that it was a relatively dry month and the sunniest December since 2001.
As I write though, a severe weather warning is in place for the next few days. Snowfall of between 5 and 10 cm are forecast for Munster and Leinster during Sunday and Monday.
While its undoubtedly causing hardship - dwindling grit and rock salt stocks will surely lead to more dangerous roads and footpaths- we can thank out lucky stars that we're positively balmy when compared to the inhabitants of the Vostok Research Station in Antarctica.
That's because Vostok currently holds the dubious honour of being the coldest place on the planet. On the 21 July 1983 the station thermometer recorded a bone-chilling -89.2 degrees celsius.
The Russian scientific research station is located close to the South Pole and typically contains 25 scientists in "Summer" when temperatures reach a high of -28 degrees. During their winter, about 13 scientists brave the elements at the station.
Back in the Northern Hemisphere, Ireland isn't the only country experiencing a particularly cold spell. Parts of North America, Asia and our neighbours in Europe are all experiencing heavy snowfall and plummetting temperatures. But what's to blame?
Apparently, its all the result of a phenomenon called Arctic oscillation, where opposing atmospheric pressure patterns surrounding the North Pole shift back and forth and disrupts standard weather patterns in the Northern Hemisphere.
Since the 1960's, there has generally been relatively low pressure over the pole and this has been surrounded by a ring of high pressure, keeping the cold air where it should be - on top of the world.
This year however, the opposite has been true- high pressure over the pole and lower pressure surrounding it, has meant that cold air from the Arctic has moved down over many countries in the Northern Hemisphere - Ireland being one of them.
Nobody really understands what drives these changes in air pressure. John Wallace, Professor of Atmospheric Sciences at the University of Washington thinks of it as a "random thing".
"I don't think we understand any reasons why it goes one way one year and the other way another year" Wallace told the New York Times. One thing scientists seem certain about, is that the phenomenon has nothing to do with global warming.
Wednesday, January 6, 2010
Number of the Week
Fabrice bellard, a French computer scientist used a conventional desktop computer (costing around €2,000) to calculate the mathematical constant 'Pi' to nearly 2.7 trillion digits. That's around 123 billion more than the previous record set in 1995 using multi-million euro supercomputers. It took a total of 131 days for the computer to complete the calculation and check the result.
Saturday, January 2, 2010
Life, but not as we know it.
It's just a little bit of science!
I'm a plant scientist, so expect lots of plant-related posts but also lots on science in general and science communication.
All content, unless otherwise stated, is copyright of Communicate Science and should not be used without prior consent.
Opinions expressed on this blog represent my own views and not those of my employer. Any comments on posts represent the opinions of visitors.
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This is me
- Eoin Lettice
- I'm passionate about the need to enthuse, inform and engage everyone in society about science. I'm a full-time researcher and lecturer and a part-time blogger. I'm interested in all things to do with science. In particular, education and communication of science - especially biology. This blog represents my personal views.
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