Science Spin 69

ISSUE

69

March/April 2015

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SCIENCE

SPIN www.sciencespin.com

IRELAND’S SCIENCE NATURE AND DISCOVERY MAGAZINE

Deciphering the Universe how Irish scientists contributed to an extrodinary achievement

Glass Cancer

what causes toughened glass to shatter?

Inside a Jet Engine

Award Winning Du Noyer Competition Photography

Barking Mad

why do some trees cast off their bark?

Contents

IRELAND’S SCIENCE NATURE AND DISCOVERY MAGAZINE

Cover: Weathered summit of Hen Mountain in the western Mournes. Photo by Brian McCready, Co. Down

Editors Tom Kennedy tom@sciencespin.com Thomas Kennedy editor@sciencespin.com Production & Design Thomas Kennedy elusivedge.com Commercial Manager Alan Doherty alan@sciencespin.com Production Support Marie-Claire Cleary marieclaire@sciencespin.com

Award winning Du Noyer Photographs p19

How it works: Inside a Jet Engine p37

Weird and wonderful animals Nosing around p35

Regulars

3

Upfront Brief Science Snippets

13

Science & Technology Innovation latest Irish science advancements

14

Ask a Scientist Q&A with our panel of pro’s

27

Science and technology careers Science & industry profiles

31

Family Science

33

Young Scientists

35

Weird & Wonderful Animals Sive finlay

Christina Campbell Student projects from the BTYSE

Editorial Support Con O’Rourke

Features

Printed By Turner Group, Longford

9

Limestone Paddy Gaffikin whats so special about irelands most common rock?

Subscribe From www.spinstore.eu

11

Glass Chemistry Tom Kennedy Irish expertise in solving production problems

15

Philae Landing Marie-Catherine Mousseau how Irish scientists contributed to an extrodinary achievement

19

Geo Images Du Noyer Winners award winning photographs from the annual Du Noyer competition.

24

Dating Easter Margaret Franklin how are the easter dates calculated and why?

25

Barking Mad Julia Galbenu why do some trees cast off their bark?

37

Inside a Jet Engine Jacob O’Neal a look inside the workings of an incredible engine

Science Spin Ltd. 5 Serpentine Rd, Ballsbridge, Dublin 4 www.sciencespin.com PUBLISHED BY Albertine Kennedy Publishing Cloonlara, Swinford, Co Mayo

Publication of Science SPIN has been made possible with the help of our sponsors.

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Research pays off

Beneficial bugs

IN 2005 Professor Mark Davies and Dr Tara Dalton set up Stokes Bio Ltd as a spin out from their University of Limerick research on microfluidic polymerase chain reaction (PCR) technology. After raising over $4 million in venture capital the company was sold to Life Technology Corp for $44 million. The return from this transaction helped the University of Limerick to establish the Nexus Innovation Centre. A number of UL PhD students also gained by taking up employment with Life Technology.

FURTHER evidence to show how much we depend on our gut microbes comes from the Karolinska Instituet in Sweden. It was found that the blood-brain barrier fails to develop properly in ‘germ-free’ mice. This barrier is essential in protecting the brain.

In recognition for his work on innovation that has an impact on society, Prof Mark Davies has become a Fellow of the National Academh of Inventors, a body representing over 150 research organistions.

As we reported in previous issues of Science Spin, reseachers at APC and UCC have produced evidence to show just how important our gut bugs in maintaining good general health.

The elderly, for example, age faster on a restricted diet.

The discovery was made by comparing mce born in a normal ‘dirty’ environment with those born in a sterile environment. If, however, germ-free mice were exposed to the faeces of normal mice, the condition of the blood-brain improved.

Jupiter’s pockmarked moon

CALLISTO, Jupiter’s second largest moon, is thought to be the

most cratered object in the Solar System. The moon, bearing the scars of numerous collisions, was recorded in colour by the Galileo pacecraft.

Callisto, made up of rock and ice, orbits about 880,000 km from Jupiter, and at this distance it is not affected much by the planets gravity. Because of this the four billion year old surface terrain, apart from the relentless bombardment, has remained intact since the early development of the Solar System.

Image, NASA/JPL/DRL

Gut population and diabetes TYPE 1 diabetes is thought to be associated with a change in our gut flora. Studies at the Alimentary Pharmabiotic Centre in Cork have shown that two types of potentially harmful gut bacteria are at an elevated level in diabetic rats. The authors of this study, led by Prof Catherine Stanton from Teagasc Moorepark, noted that Actinobacteria and Proteobacteria, are normally present in very low levels, and they suggest that the onset of diabetes results on a decrease in gut microbial diversity. At the same time, porentially disease causing bacteria increase. This type of change has previously been associated with diarrhoea and inflammatory bowel disease.

Diabetes is on the rise, and, according to the researchers, Type 1 diabetes is more likely to arise in children delivered by C-section, a practice that has become more common in Ireland. Such babies are born with an impoverished gut population.

Studies at APC and elsewhere indicate that re-establishing microbial diversity helps to prevent the onset of type-1 diabetes. Stanton’s group are currently looking at how incorporation of beneficial micro-organisms (probiotics) in our diet can rebalance our gut population to avoid diabetic-associated damage.

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Motor neuron disease BY analysing the genes of 363 people with Motor Neuron Disease a team of researchers from the University of Massachusetts and Trinity College Dublin have identified a coding fault in nerve building. Most of those with MND have this mutation that disrupts transport of materials during nerve building.

By identifying this mutation in a particular gene, known as TUBA4A, researchers can now focus on this as a possible target for treatment.

Malted barley IN Ireland there are more than 600 barley growers and a big proportion of this crop goes into making Guinness. Over 300 tonnes of barley a day are bought by Guinness.

To encourage high standards, an Irish Malting Barley Excdllence Award is presented to producers each year. The 2014 award, organised by the malting company, Boormalt and Diageo, went to Ivan Holden from Bagnalstown, Co Carlow.

Damaged parchment document from Yarburgh Muniments Lancashire Deeds YM. D. Lancs 13, 14th January 1576/7 (By permission of The Borthwick Institute for Archives)

Parchment dna PARCHMENTS from the 17th and 18th century were made from animal skins and many of these survive in archives.

Because of advances in DNA extraction, these documents can now yield information about the type of animals they came from, and how they compare to their modern equivalents.

In a collaborative project between the University of York and Trinity College Dublin, DNA samples from old parchements are being examined.

The malting process, which involves drying of germinating barley, is carried out at Boortmalt’s plant in Athy. The sugars produced by malting are acted on by yeast in brewing to produce the distinctive frothy topped stout.

Paul Armstrong from Diageo noted that the Irish drinks industry spends â‚Ź400 million in farm produced raw materials each year, and with increased production capacity at the Dublin brewery, he said we can expect a substantial boost in exports. The new brewhouse is producing 300,000 pints every two hours, he said.

Tests have shown that there were regional variation in the breed of sheep and because of this the parchements can yield valuable information about changes in breeding of stock over time..

Tongue of the ocean SEEN from above, this bank of limtestone lying north of Cuba, has been sculpted into a series of wavy patterns. Invisible on the surface, the underwater pattern has been revealed

by Landsat 8 satellite observations that can penetrate the shallow waters.

The shallows drop off into 4000 metre depths, but during the last Ice Age the area, now known as the apx 130 km long Tongue of the Ocean, was above sea level, and thus exposed to erosion. As ice retreated, melting water created numerous channels which now lie below the sea.

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Salty seas While we are more familiar with the beneficial impact of the Gulf Stream, the circulation of salty water, as this chart shows, is quite different. Since 2009 ESA’s SMOS satellite has been monitoring salinity in the upper layers of the world’s oceans.

Various factors have come into play to produce this overall pattern, such as evaporation, precipitation and run-off of fresh water from rivers.

Marine megafauna

Breast cancer

Just how big is a whale or a jellyfish? As Craig McClain, assustant director of the National Evolutionary Synthesis Centre in North Carolina, USA, noticed, descriptions of size are not always accurate. To get a better idea of megafauna sizes, a team of graduates and undergraduates reviewed what is known about 25 marine species, including whales, sharks, leatherback turtles, squids and clams. One of their conclusions is that bigger is not always better, and the exceptionally large specimens could be compared to the tallet recorded human, 2.72 metre tall Robert Wadlow. Far from average in height, Robert had health problems and a shortened lifespan.

One in eight women are likely to develop breast cancer during their lifetime, and while existing treatments are quite good, no effective therapy exists for some forms of the disease. In addition, it is thought that between 10 to 20 per cent of early-stage patients receive an un-necessarily high dose of chemotherapy.

Craug McClain said the study, published in the journal Peer J will help clarify the diversity of measurements quoted in academic papers, databases and textbooks. Many of these measurements are wrong, he said.

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In a five year project, being funded under the EU Framework programme Prof William Gallagher from UCD is co-ordinating the work of researchers around Europe on investigating novel treatments for more difficult types of cancer, and also to develop better targeting so that chemotheraphy can be reduced. The project, known as RATHER, embraces a number of focused studies such as one on the influence of diet.

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Jurassic insects from Rhône valley Limestone of the same type as those in Bavaria that yielded the emblematic Archaeopteryx also occur in the Ain and Rhône departments in France. However, until now most of the fossils from these French Jurassic deposits have been of marine origin.

Scientists from Museum National d’Histoire Naturelle working with amateur naturalists report in the journal Peer J that they have now discovered fossil insects, including a 6 mm long water strider in an outcrop at Orbagnoux. Scientists are excited by this discovery because the fossils are so well preserved and they are representative of the sort of life that existed on land surrounded by late Jurassic lagoons.

Marine Institute

Bone repairs

Foras na Mara

On developing a swelling in her jaw the outlook for a twoyear old thoroughbred filly was poor. Unable to chew because of a cyst, the filly might have had to be put down. However, after a novel procedure of tissue repair, the filly, Annagh Haven, has made a successful return to racing.

The bone repair treatment was developed by a team of researchers at the Royal College of Surgeons in Ireland, led

by Prof Fergal O’Brien. Working within the materials science group, AMBER, the researchers used collagen and hydroxyapatite, naturally occurring components of bone, to build a 3D scaffold. Bone cells and blood vessels begin adverting to this scaffold allowing the natural repair process to proceed.

Our Ocean - A Shared Resource Ár n-Aigéan - Acmhainn Comhroinnte Ireland’s National Agency for Marine Research and Innovation An Ghníomhaireacht Náisiúnta um Thaighde Mara agus Nuálaíochta

www.marine.ie Issue-69

Dr Florent David from UCD’s Veterinary Hospital carried out the procedure, removing the cyst and implanting sheets of scaffold.

As a result of this success, a spin-out company has been established to market the technology, and in the next phase of development approval is being sought for use in treating humans with large bone defects.

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Finding the Beagle In December 2003 the Beagle 2 Mars lander was released from ESA’s Mars Express. Six days later it was due to land and start transmitting back to Earth, but nothing happened.

Since then scientists have wondered what went wrong. Now, thanks to a painstaking search of images recorded by the Mars obiter, the landing craft has been found. Spotting the Beagle was a challenge as it’s size, two metres across when fully deployed, was just within the limits of camera resolution.

It appears that the lander came down within the target area, but not all of the solar panels opened, so it was not able to generate enough power to deploy the radio antenna and start transmitting data to Earth. This also meant that it could not receive commands, so the craft is, in effect, a write-off. According to ESA, there is no possibility of reviving Beagle-2.

The Beagle was the UK’s first mission to another planet, and although it could not complete its task, the success in landing is a significant achievement and the experience will help in the next phase of exploration. ESA has a new Mars lander due for launch in 2016 and 2018.

Workshops for Science Teachers

Inquiry and its Assessment in Science 2 n d & 3 r d June 2015 Dublin City University

For All Science Teachers:

The CASTeL research team, at Dublin City University, invites you to participate in a summer school on Inquiry and its Assessment in Science which will be hosted at DCU, Glasnevin, Dublin 9 over 2 days in June 2015.

Date

Time

2nd June

9:30 am – 4:00pm

3rd June

9:30 am – 4:00pm

Session Focus

Inquiry – what it is and what it is not!

What questions can lead to inquiry?

Implementing inquiry Developing students’ thinking through inquiry Assessing skills developed through inquiry

The summer school will provide strategies for addressing the issues raised above and will include copies of teaching resources developed as part of two EU-funded projects in Inquiry Based Science Education (SAILS and ESTABLISH).

Topics addressed are suitable for Junior Cycle and can be extended to relate to Senior Cycle. 

Register by emailing castel@dcu.ie

This summer school is provided free to participants through the support of the SAILS project which has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289085.

Accommodation is available on request.

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Solar storms

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For some years, astrophysicists at Trinity College Dublin have been studying solar activities, and now they have been joined by colleagues in Greece, Italy, France, Switzerland and the UK in developing a solar storm forecasting service for Europe. The FLARECAST project, backed with a â‚Ź2.5 million EC grant, aims to improve our understanding of why and when enormous flare-ups occur on the Sun. These flare-ups can cause disruption of radio and navigation communications systems, and the more severe solar storms can damage electronics in space and can cause power distribution systems to fail.

The Flare Likelihood and Region Eruption Forecasting (FLARECAST) consortium includes the Academy of Athens in Greece, the Universita degli Studi di Genova and Consiglio Nazionale delle Recerche in Italy, the Centre National de la Recherche Scientifique and the Universite Paris-Sud in France, the Fachhochschule Nordwestschweiz in Switzerland, and the Met Office in the UK.

Sewage discharge

In 44 locations reports the Environmental Protection Agency raw sewage is being discharged without any treatment into the sea or rivers. Of the larger sewage treatment plants, 38 do not meet the standards set out in a EU Directive 20 years ago and half of the infrastructural requirements required for EPA licencing in 2013 were not completed.

According to the EPA the inadequacy of water treatment plants at locations such as Youghal, Killybegs, Galway and Dublin reflects a legacy of under-investment.

Mexico sinking Large sections of Mexico city are sinking at up to 2.5 cm per month. Satellite radar scan observations collected between October and December 2014 show widespread subsidence, believed to be caused by extraction of ground water.

Image: European Space Agency.

THE MOST ABUNDANT IRISH ROCK

LIMESTONE ne

oolitic limesto

These rocks, these bones, these fossil ferns and shells, Shall yet be touched with beauty, and reveal The secrets of the book of earth to man.

Alfred Noyes (1880-1959).

General description

The colour of limestone rock in Ireland is quite variable – white, grey, red and even black. All limestones contain calcite, which is composed of calcium carbonate (CaCO3), but can contain impurities such as clays, which could give them a red colour, and ancient organic matter, which can produce a black colour. Limestones are easily scratched with a steel penknife and can contain fossils.

How do limestones form?

These sedimentary rocks form in shallow tropical seas – although, less

commonly, they can also form in fresh water. Limestones of marine origin form most of the exposed rock in Ireland and so the regions occupied by these rocks today were covered by the sea in the geological past. One of the ways by which limestones form is by precipitation from water containing dissolved calcium carbonate. Exceptionally, the solubility of calcium carbonate decreases with the increasing temperature of the water. Or, to put it another way, hot water will not ‘hold’ calcium carbonate as well as cold water and so it precipitates out of it. As a consequence of this special property, limestones are only deposited from warm water. Limestones can also form organically – for example from fragmented calcareous parts of marine creatures. Crinoidal limestones, that is ones that originated as a calcareous sand, composed of the debris of ancient marine invertebrate animals called crinoids, occur, for example, in quarries near Carlow, Kilkenny and Ballinasloe (Co. Galway). Some buildings and monuments in Dublin are constructed from the Ballinasloe Limestone. Feltrim Hill, near Swords, Co. Dublin and Knockmore Cliff, near Derrygonnelly, Co. Fermanagh, are composed of reef-limestone of Carboniferous age, in which fossils are present. Despite the name ‘reef’, these structures were not built by organisms

(a cross-sect ion of ) crinoidal lim estone. (like the polyps of coral reefs), but were formed by masses of muddy lime, building up in a mound against a net-like collection of creatures like bryozoans, in an area on the sea floor, free from currents or waves. An analogy would be wind-blown sand piling up against clumps of grasses in a sheltered area of a beach. Reef-limestones can usually be recognised because they have no bedding planes. Another type of limestone, called oolitic limestone, is composed of very small spherical ‘particles’ (called ooids), each containing a nucleus of a tiny shell fragment or sand grain, around which calcium carbonate was deposited. This variety occurs in a number of places, among which are: quarries at Lisduff, Co. Limerick; Borris-in-Ossory, Co. Laois; Edenderry, Co. Offaly and near Ballina, Co. Mayo.

commercial uses of limestone

This rock has a diversity of uses, among them being: (1) agricultural – as an additive to soil to facilitate the growing of crops such as brassicas; (2) pharmaceutical – limestone can be used as a source of calcium carbonate, utilised as a component of items from certain vitamin pills to some

Limestone walls in the Burren, Co Clare.

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toothpastes; (3) cement manufacture; (4) for ‘whiting’ used to mark out football pitches, tennis courts etc. – this is obtained from Chalk (a very pure type of limestone) and (5) as a building stone. As regards the latter, note that stone masons often ascribe the name ‘marble’ to any limestone that takes a good polish.

Localities in Ireland where limestones can be seen: • Co. Armagh. Age: around 330 million years old (Carboniferous).

(1) Acheson Quarry, about 2km south west of Killylea, on Cavanapole Rd. and (2) Quarry at Annacramph, about 5km NNE of Armagh city.

• Co. Clare. Age: around 330 million years old (Carboniferous).

The Burren region.

• Co. Dublin. Age: around 450 million years old (Ordovician) and around 330 million years old (Carboniferous).

(1) Portrane, 18km north of Dublin (Ordovician); (2) Malahide, about 14km NNE of Dublin city (Carboniferous); (3) Rush, about 24km NNE of Dublin city (Carboniferous) and (4) Loughshinny, about 4km north of Rush (Carboniferous). All the limestones occur at beaches.

• Co. Donegal. Age: around 330 million years old (Carboniferous).

St. John’s Point, 25km WSW of Donegal town (at beach).

• Co. Fermanagh. Age: around 330 million years old (Carboniferous).

(1) Carrickreagh Quarries (a series of quarries), about 13km from Enniskillen, on the L.H.S. of the Enniskillen-Belleek Road and (2) Marble Arch Caves, Florencecourt, 16km south of Derrygonnelly.

(Conducted tours are provided at certain times.)

A Carrickreagh Quarry, Co. Fermanagh.

• Co. Kildare. Age: around 450 million years old (Ordovician).

Chair Hill, Kildare.

• Co. Waterford. Age: around 450 million years old (Ordovician).

Garrow Strand, Caher, Tramore.

NOTE: Before entering a working quarry, permission MUST be obtained from the site manager and safety clothing MUST be worn.

A small limestone boulder, of Early Jurassic age, found in the dark bluish-grey clay in Co. Antrim.

A concluding note

View of Knockmore Cliff, Co. Fermanagh. It is composed of reef-limestone.

As Alfred Noyes (probably best-known for his famous narrative poem The Highwayman) succinctly pointed out, rocks can uncover a lot about our geological history. Limestone rock is no exception to this. Additionally, of all the many rock-types existing in Ireland, limestone must, arguably, be the most versatile, in terms of its usefulness to human beings today. And we should consider ourselves blest that the geology of Ireland has resulted in its plenitude.

NiS

Patrick, wants glass to do different things, and new products go onto the market so quickly that problems, such as those created by nickel sulphide inclusions, are hard to anticipate.

The researchers at CIMERA have become experts in this field, from solving glass-making problems to creating new products, such as a coating that increases light transmission in solar panels. With this new coating, said Patrick, six to seven per cent more light will reach the solar cells, and as he pointed out, this means boosting performance without having to improve the cells themselves.

SPOTTING THE SPECK Buildings around the world are being clad in glass from Ireland, and Tom Kennedy reports on how researchers in Limerick are helping manufacturers to meet the demand for high-performance products

I

nstead of being surrounded by concrete walls, offices are often encased in glass. Tall blocks are clad almost entirely by massive sheets of tempered glass. Glass is tough and durable, but if something goes wrong, said Dr Patrick Murray from Limerick Institute of Technology, it is difficult to replace, especially if defects are found ten or more stories up.

Soon after the international boom in building glad-clad office blocks took off, a mysterious problem began to appear. Glass panels, for no apparent reason would shatter, and in some cases enormous sums had to be spent on repairs and replacements. The cause was not always apparent, and in some, but not all cases, it was found that tight, inflexible fitting was to blame. However, when panel failure in a late 1950s office block in Melbourne, Australia, was investigated in 1960, particles of nickel sulphide were found to have caused the toughened glass to shatter.

Nickel sulphide had been identified as a problem back in the 1940s, but until the results of the Melbourne study were published, the problem of what became known as “glass cancer” was not widely recognised. When panels fail it can be hard to determine the cause, but in another wellknown case, nickel sulphide caused 30 glass panels to fail 21 months after installation at the Des Moines Central Library Building in Ohio, USA. Each panel is reported to have cost $8,000 to replace.

As Dr Patrick Murray explained during an Institute of Chemistry of Ireland meeting, not many people would think that such problems have any connection to Ireland, but glass is a big industry here. “Believe it or not,” he said, “Ireland processes the majority of Europe’s glass for large scale commercial buildings.” There are large plants in Tipperary, Galway and Portlaoise. Carey’s in Nenagh, established in 1965, said Patrick, is Europe’s largest European glass processor.

The Irish plants are not primary producers of glass, but they buy the raw stock from big producers such as Pilkington’s, and as Patrick explained, they are not limited to one supplier, so are in a strong purchasing position.

Patrick is Senior Scientific Researcher with the CIMERA group at Limerick Institute of Technology. Although Patrick said he enjoys the freedom of basic research, the CIMERA group is mainly focused on applying results and problem solving. Although the group is actively engaged on a number of diverse projects, a large part of their work is done in collaboration with the glass industry.

The industry is based on adding value to glass, and as Patrick said, this can be done in many different ways. There are antimicrobial coatings, self-cleaning treatments, glass that blocks UV, glass that lets UV through, glass to stop infra-red, and the pressure to come up with new properties is high. Everybody, said

In problem solving, nickel sulphide represents quite a challenge, said Patrick, because the inclusions are so hard to detect.

The problem arises from contamination during manufacture, and it only becomes a problem when glass is being toughened by undergoing a process known as tempering.

By heating the glass and suddenly lowering the temperature, the glass becomes much tougher, and if broken it splits into small fragments rather than shattering into dangerous shards. For these reasons tempered glass is used in car windows and large officeblock panels.

On heating, the tiny, unseen particles of nickel sulphide change shape. Normally, when glass cools the particles of nickel sulphide revert to the low temperature shape, but when cooling is rapid, they do not have time to adapt. Thus, in tempered glass, the nickel sulphide particles remain trapped in the hot phase. However, they eventually manage to change shape, and in doing so take up two to three per cent more space. The resulting pressure builds up until the glass cannot take the strain.

The particles causing failure are so small that they can be hard to find, and as Patrick explained, when the CHIMERA team examined a panel, a variety of analytical techniques had to be called into play before one was eventually found.

Knowing how a problem arises means that something can be done to eliminate it, but other research is aimed at creating new opportunities for the future. There are a lot of things that can be done with glass, said Patrick, but unless new techniques can be scaled up, they are not much use to industry.

Also, cost is an issue, so in one project the team is looking at vapour deposition using standard off-the-shelf equipment. In another project, researchers found an alternative way to improve transmission of light by controlled etching with acid, and this technique has been licenced out to two Irish manufacturers.

There is also a huge stream of waste glass, said Patrick, and one of CIMERA’s aims is to make better use of this as a resource to create new products.

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Family History

W

A Neanderthal toe-bone recovered from the Denisova Cave. Genetic analysis indicated that the 50,000 year old bone belonged to a woman with closely related parents. Credit: University of California, Berkeley.

hat would our ancestors have thought as they came over a hill and suddenly encountered a group of strange looking people? The differences we see today are a lot less than they would have been as modern humans began to emerge. We can only speculate how different the various hominoids were from each other 100,000 years ago, but we now know that there was convergence as well as divergence. Perhaps the delicate modern miss fell for the muscular charms of a Neanderthal hulk, but in spite of being classed as an extinct sub-species, their mingled genes lived on. It has been estimated that Neanderthals made a genetic contribution of between 1.5 and 2.1 per cent to all those who left our African Garden of Eden.

Neanderthals were not alone in the mix of groups that co-existed, and the genetic analysis of a 500,000 year old toe bone provides evidence that there was interbreeding of at least four different human “types”.

Among them were the recently recognized Denisovans, and like the Neanderthals, they became extinct, but not before leaving some genes behind.

In Australian aborigines, New Guineans and some Pacific Islanders about six per cent of the genome has been inherited from the Denisovans. In mainland Asians and Han Chinese, the Denisovan contribution has been diluted to just 0.2 per cent.

Tom Kennedy

Rasmus Nielsen from the University of California, Berkeley had observed that Tibetans have a genetic advantage when it comes to living at high altitude. When Nielsen’s research group compared the genome of Tibetans to that of a Denisovan bone fragment, they discovered an almost complete match. Both had a gene known as EPAS1. As Nielsen observed the only way Tibetans could have acquired this genetic advantage was through interbreeding. When the line that led to modern humans dispersed from Africa, he suggested, they picked up useful traits from those who had already adapted to their surroundings.

It is remarkable that the evidence to support these conclusions managed to survive. A 40,000 year old finger bone from a young woman was discovered in a Siberian cave during 2008. The cave, located in the Altai Mountains, yielded a rich harvest of human remains including a Neanderthal toe bone at a lower level that was 10,000 to 20,000 years older.

Although the fragment was small, researcher Svante Pääbo developed a technique that made it possible to recover DNA and produce a genome that could be compared to modern humans.

The genetic analysis of the toe-bone also produced interesting results. The bone came from a highly-inbred woman, the parents might have been half-siblings, supporting the view that inbreeding in small populations may have been more common in the distant past.

According to Montgomery Slatkin from the Univerity of California, Berkeley, interbreeding was probably infrequent, it may even have been rare, or it might have occurred over a prolonged period.

Humans had established themselves in Europe and Asia about 36,000 years ago, but interbreeding with Neanderthals is believed to have begun 54,000 years ago, earlier than had been previously thought.

Interbreeding could have had advantages, and modern humans managed to acquire some useful traits from their long lost relatives.

A family tree for four groups of early humans living in Eurasia about 50,000 years ago showing the level of interbreeding between them.

Chart, University of California, Berkeley.

Excavation in progress at the Denisova Cave in the Altai Mountains of Southern Siberia. A finger bone from the cave enabled scientists to produce a Denisovan genome. Neanderthal remains were found at a lower level, showing that the cave must have been occupied over a long period of time. Credit: Bence Viola, Max Planck Institute.

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Science Technology Innovation SONIC SORTING A SYSTEM, using sound waves to isolate and manipulate single cells has been found to work well by researchers at the Regenerative medicine Institute in Galway. the system was developed by Poly-Pico, a University of Limerick spinout company. the company, based in Galway, uses sound energy to dispense very low volume fluids, such as proteins, antibodies, DNA and other materials.

Manipulation of living cells is a challenge because they are easily damaged and up to now procedures were time consuming and costly. Frank Barry, scientific director of RemeDI said that after using the Poly-Pico instrument to deliver stem cells to different surfaces they remained viable and continued to grow well.

The ability to deliver cells this way, he added, opens up opportunities to do more in tissue engineering. www.polypico.com

BIOFUEL BOOST THE OIL produced from biomass generally delivers less power than conventional fuels. to boost this performance researchers at the University of Twente in the Netherlands have developed a production process that promises to deliver much better results. By heating the oil in nitrogen to 500ºC and using a sodium carbonate on alumina catalyst, the researchers report that performance can be as good as conventional diesel.

As the researchers explained, oil from biomass feedstock is usually has a high water content and is acidic. the catalyst, developed

by Professors Lefferts and Seshan was used successfully to produce 4,500 barrels a day in a pilot plant operated by a renewable energy company KIOR in texas, USA.

BARNACLE GLUE ONCE BARNACLES stick onto a surface they remain firmly glued in position. Adnesive manufacturers have often wondered how to make a glue that sticks so well. Researchers at the Universituy of Newcastle have found that the larvae of barnacles first secrete an oily droplet that clears away the water before producing a powerful phoshoprotein advesive. Dr Nick Aldred reporting on this research said that previously, scientists thought that barnacles produced the glue by combining two components, in much the same way as synthetic glues are mixed just before setting. However, that did not explain why the glue manages to stick so well to wet surfaces. By using advanced imaging techniques the researchers were able to observe that adhesion isactually a two-part process, and each process is separate.

Dr Aldred remarked that manufacturers can learn from this clever natural solution. Bio-inspired adnesives could, for example, be very useful in medical applications. Understanding how the barnacles attach themselves could also solve a big problem for ship owners who regularly have to clear hulls of accumulated marine life.

BIOPLASTICS CULTIVATED SEAWEEDS have the potential to replace imported food crops in the production of biodegradable plastics. According to the Cork based Daithi Omurchu marine Research Station, most of the polylactic acid used to produce biodegradable plastics in europe is produced from crops, such as corn, wheat, sugar beet and cane. the Irish marine station is leading a project involving partners from Portugal, Netherlands, France, estonia and France, to promote cultivation of seaweeds as a feedstock for biodegradable plastics.

Cultivated seaweeds can be used to produce a variety of food and industrial products, and if done in association with other forms of aquaculture, the nitrogen and phosphorus that otherwise escape out into the environment, are captured as nutrients. Furthermore, once the lactic acid precursor of polylactic acid is extracted, the seaweed residues can be used as animal feed or as a source of food supplements.

REDUCING AIRCRAFT NOISE WHEN PLANES are coming into land the noise level, apart from getting closer to residents below, goes up. According to engineers at TCD, noise from the landing gear can exceed that generated by the engines The Department of mechanical and manufacturing engineering at TCD is involved in coordinating a europeanwide project to develop less intrusive aircrafts. the TCD focus is on the landing gear and as Dr Gareth J Bennett explained, the overall aim is to develop a more efficient and environmentally friendly short-haul aircraft. As he commented, the existing planes used for relatively short hops around europe, use too much fuel and they are too noisy. Reducing noise, he said would also give european manufacturers, such as Airbus and Alenia Aermacchi a competitive advantage on the world market.

PHARMACEUTICALS THE PHARMACEUTICAL manufacturing technology Centre, based in Limerick is the latest addition to the fifteen industry-led centres of expertise. 24 industry partners and five higher education institutes are working together through this centre. www.pmtc.ie

MADE IN IRELAND INTEL HAS been presented with a ‘made in Ireland’ award for the recently developed Galileo Board by the Irish/American technology Leadership Group. the microchip is the first Intel product to developed completely in Ireland. the low-power consuming chip is likely to boost the production of wearable devices.

Issue 69 Science SPIN Magazine Page 13

Ask a scientist

More than 25 experts from a wide range of fields including biology, physics, chemistry and astronomy are ready to answer your questions. If there is something that puzzles you, let the panel know. Email questions, with your name and contact to question@sciencespin.com

What shape do raindrops have?

Joseph Cashell explains:

Conventionally, people imagine raindrops having a pear shape.

However this is not the case. The shape of a raindrop is very much dependent on it's size. Small raindrops have a spherical shape, but as they get larger, an indentation begins to form at the bottom of the sphere giving the raindrop a shape that is best described as the top bun of a hamburger. The largest raindrops will actually break apart leaving a thin film of water between them like a parachute before eventually completely separating to form the other shapes mentioned. * Joseph Cashell, Tyndall National Institute. www.tyndall.ie

How much information stays up on the Internet and does it ever go away?

Joseph Cashell explains:

The Internet isn't really some sort of magical digital place that doesn't exist in the physical world. it's actually quite physical. The Internet is just a massive network of computers, in fact as it contains nearly every computer in the world. All the information that you get from the Internet has to be stored somewhere and it's mostly stored on servers which are effectively hard drives that remain connected. So when you go on Facebook for example, your computer is accessing Facebook's servers wherever they are in the world and downloading their website so you can view it on your computer. So, to answer the question, because all the information on the internet is stored on servers all over the world, it's quite hard to estimate the size of the internet but best guesses put it around 5 billion gigabytes and to answer the second question, it can go away. If a website is taken down, perhaps because the business that owns it has gone bust, the servers go offline and therefore the information ceases to exist on the Internet. * Joseph Cashell, Tyndall National Institute. www.tyndall.ie

Is there a limit to what we can know?

Terry Moseley explains that there are three ways of looking at this:

1. Is there a limit to the amount of knowledge that humanity, collectively, can accumulate in any given period of time, or indefinitely if we assume that we can exist until the universe comes to an end, if it ever does? I would say that there is no reason why there would be an upper limit to the knowledge we can accumulate in terms of our human capacity, or the limits of what we can store digitally, on in whatever form may replace that.

2. Can we ever learn every possible fact that could possibly be known about every single thing in the universe? The answer to that is obviously NO, simply because we cannot know what is happening now in all the other parts of the universe that we cannot observe in sufficient detail. Nor can we turn back time, and find out everything that has happened in the whole history of the Earth, let alone the Solar System, not to mention the Galaxy or the rest of the Universe!

3. Quantum Uncertainty, or the Heisenberg Uncertainty Principle: This dictates that we can never know such things as the simultaneous position and velocity/direction of a subatomic particle. That's not beacuse of any defects in our measurement ability - it is a fundamental property of matter and energy at the quantum level. * Terry Moseley is author of Reach for the Stars, is a Fellow of the Royal Astronomical Society and has been President of the Irish Astronomical Association on three separate occasions.

Is it true that hot water freezes faster than cold, and if so why?

Margaret Franklin explains:

Yes, this phenomenon is known, but it does not always happen. For example, if the colder water is only a few degrees above freezing, while the hot water is a few degrees below boiling point, then the colder water will freeze first.

Let’s assume we have two identical containers, each containing the same amount of water, but at different temperatures when they are put into the freezer.

If both containers are open, then it is likely that the hot water will freeze first. This is because evaporation will occur at a faster rate from the warmer water. It is well known that evaporation produces a cooing effect. In addition, there is less liquid left in the container, so it will freeze sooner.

To eliminate the effect of evaporation, the containers should be sealed. Even without evaporation, it can happen that the water that was initially at the higher temperature can freeze first. One possible explanation may be due to the hydrogen bonding that occurs between neighbouring water molecules as the liquid cools. It has been suggested that Hydrogen bonding causes the other bonds in the water molecules to relax & give up energy, causing a cooling.

A simpler explanation was recently offered by Dr. Tom McCormack, of the UCD Physics Department. He explained that the hotter water, as soon as it is put in the freezer, will quickly melt any frost and ice in contact with its container in the freezer compartment. This cools the hot liquid rapidly because the melting of ice draws heat from it.

This is known as latent heat of fusion. The colder water will not give rise to much melting and so takes longer to cool and freeze. *Margaret Franklin is Vice President of The Institute of Chemistry of Ireland. e-mail: mfranklin@eircom.net

Why can’t Internet service providers stop spam, and where does spam come from anyhow?

Joseph Cashell explains:

There's a saying in IT that the problem exists somewhere between the chair and the keyboard and that is generally the case with spam. When you receive spam, it's because at some point you gave your email to a website giving it permission to send you spam.

Alternatively, in some cases, someone gave permission to a website to send emails to all their contacts spreading the spam further. Some email services will try and warn you that you are probably signing up for spam but in the end the decision generally rests with the user. * Joseph Cashell, Tyndall National Institute. www.tyndall.ie

Issue 69 Science SPIN Magazine Page 14

Deciphering the Universe with Rosetta

Marie-Catherine Mousseau

It’s 9.00am on November 12 2014; my phone rings and a familiar voice resonates at the other end. “we’ve made it!”

“Are you in Dublin?” I asked, a bit surprised to hear my friend who has been working abroad for a few years. “No I’m calling from Germany”, he said . “We’ve made it, the lander separated exactly according to plan!” he continued excitedly. I finally got it; today was the day. Seven years after I first interviewed Edward on the work he was doing in Dublin at the time with his company ‘Captec’– what he referred to as the ‘Rosetta mission (whose name came from the Rosetta stone, which helped deciphering the hieroglyphs) (see Science Spin 21?). Nobody really heard or cared at the time about the Rosetta spacecraft and its lander, Philae, which were supposed to carry out a long journey into space towards an unlikely rendezvous with a mysterious comet so many years ahead.

“C’est vrai?” I answered tongue in cheek, as I actually knew it was true. I had heard it in the news the day before. After 10 years, 5 months and 4 days, the moment had finally arrived; the day when the spacecraft and its lander were going to make history. And Edward Bach, who was involved in a key part of that mission – the timely separation of the lander from its spacecraft–, had been following all the stages.

“Where is the lander now?” I asked. “It should land on the comet sometimes around 4pm Irish time”, Ed replied. But for now what kept him excited was that the delicate separation process they had come up with, which was quite original, had worked. “How did it work?” I asked, though I reckon he had probably told me already a few times while he was working on it.

He took on a serious tone: “The separation was by means of a spring release which was held in place by a thick wax coating” he explained.” When the coating was heated until it melted, separation occurred”. The idea, and what was original about it, is that it was not an ‘explosion type’ separation, which once initiated would be impossible to stop. “Our system means that the process was also reversible simply by removing the heat before the wax had melted”, Ed said. Ensuring some level of control probably sounded like good idea in a mission so far away from earth that it takes 30 minutes for any signals to travel from there at the speed of light.

Edward told me that he took part in the ‘software’ part, including the analyses and verifications of the flight software requirements, code and design, as well as its validation with simulations of the spacecraft and its environment. “I participated in both activities, with my role in the validation more as analyst and technical manager and my role in the verification more as engineer”, he explained.

He was helped by some of his colleagues as the small team also included one analyst (also project manager), one developer, and two testers.

While Captec were involved in the flight software for the lander, another Irish company, Space Technology Ireland Ltd (STIL), was responsible for its hardware. Ed explained: “STIL participated in the flight hardware by building the computer on which the Captec software executed; they also provided a clean room for assembly and test”. Altogether hardware and software supported communications between the spacecraft and the lander.

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Below: An artist’s impression of the Rosetta cometary probe. The Rosetta spacecraft was launched in March 2004 and it arrived eleven years later at the comet, 67P Churyumov-Gerasimenko

The landing It took another 7 hours of careful approach before Philae successfully made it to the surface of the four-kilometer-wide comet 67P/Churyumov-Gerasimenko, a little bit after 16.00 GMT. As we have all heard since, Philae failed to anchor to the surface of the comet as its harpoons did not fire. The one-meter edge high-tech cube, which weighs 100 kilograms on Earth, only weighs a few grams on the comet given its small gravitational field. The lander thus rebounded very slowly, once, twice, moving away from the landing site that has been carefully chosen to optimize sunlight. At the original landing site Philae was expected to receive around 6.5 hours of illumination per 12.4 hour comet day; at its new location, it receives just 1.3 hours.

The mission

Never mind, Philae was still able to achieve its mission. About 56 hours of continuous scientific measurements of chemical, physical and mineralogical properties of the comet core and its surface were performed in the hope of achieving a greater understanding of the comet's origins and properties, and hence the evolution of the Solar System.

Comets are of special interest to scientists as they are believed to be the witness of the formation of our solar system. But aren’t all its planets as well? As Ed explained to me. there is a difference. Compared to planets like early earth which were bombarded with asteroids, comets are very stable environments. Their characteristics have not changed much since 4.5 billion years ago when the solar system was formed. And it is possible also that such stability was what made the emergence of life possible. “So we are looking for traces of water that could exist at particular spots on the surface, or in the core, and within those, traces of organic molecules”, said Edward.

Preliminary results have already been published; but data from Philae are still being analysed. And according to Ed, until their publication, the forefront findings of this pioneer expedition are likely to be kept top secret (see box on next page for details of scientific goal and preliminary findings).

Right: The comet viewed from a distance of apx 3 km during descent of the Philae lander. Image: ESA

Continue.. ›››› Issue 69 Science SPIN Magazine Page 16

›››› Continued..

A large fracture running across the neck between the two comet lobes

What’s next?

On the 15th of November 2014, Philae entered in a sleeping mode. However, the official end of the mission is not expected till the end of December 2015, as the Rosetta-escorted comet continues its journey towards the sun. So what is next?

“All of the science originally planned for the lander was completed”, Ed insisted, “so now we are really talking about a prolongation of its mission”. He continued, talking about the future of the mission: “It really depends on how much power they can generate, e.g. by repositioning the lander so its solar panels are more regularly sunlit—this will determine what can be done with the lander.”

So now we have to wait it is closer to the sun to be warmed up and brought back to life. Philae needs about 17 Watts to wake up and say “hello”. In fact it is not expected to warm up before the end of March, and it’s not before May or June that it will be able to transmit to Rosetta. It will then take Edward Bach was involved in a key part of the mission. even longer until it is fully charged and ready to do science again.

“They are now talking about August for reengaging with the lander, which I suppose would also give some time to study its situation in more detail”, said Ed. The observation of the comet's activity as it approaches the Sun and its interaction with the environment is one of the scientific objectives to come.

This is also one of the most challenging. “The lander is obviously quite vulnerable to jets, radiation or comet breakup or surface disturbance. All of these will be expected as the comet approaches the sun. The orbiter is less vulnerable but if it has to stay very far from the comet to avoid radiation, jets or even pieces of comet, there will be a point where it will not be able to observe much”.

So the suspense is not finished yet. And it may even continue for quite a while. As Ed noted, “Dec 2015 is the official end of mission but it might be extendable for another few months”.

Thus, Philae and its mothership may well have a few more cutting edge science to teach us before the end of the year, and beyond.

However, the biggest achievement of Rosetta may be less scientific than human. What impressed Ed most is, as he put it, “the successful international cooperation and the ability to operate for a long time, especially after undergoing deep space hibernation for several years, under widely differing conditions.”

“The Rosetta mission was definitely more interesting and challenging than a space telescope or planetary mission like Mars Express”, he concluded.

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Preliminary results of scientific analysis of Comet 67P/Churyumov-Gerasimenko *

•

Remarkably heterogeneous body with a varied surface exhibiting structures similar to 'goose bumps', which the re searchers have yet to explain o Roughly 70 percent of the comet’s surface has been mapped o 19 regions found, given Egyptian god names o five distinctive types that predominate on the surface: dust-shrouded areas, brittle material, large-scale

depressions, smooth terrains and exposed, consolidated structures

•

Among the darkest objects in the Solar System – its surface reflects a mere six percent of the incident solar radiation. o may be due to the dark materials such as iron sulphides, dark-coloured silicates and carbon-rich

compounds deposited across the comet's surface

water

•

•

Most likely, there is little or no frozen water directly on the surface of the comet's nucleus, as it was probably stripped during its journey through the solar system (by sublimation) However, there is, undoubtedly, frozen water inside the comet

Organic compounds

• •

Long chain hydrocarbons, organic compounds precursors to amino acids, have been detected These compounds can only form through complex reactions at low temperatures under conditions (i.e. ultraviolet or cosmic radiation) which are only found in the outer reaches of the Solar System, beyond the orbit of Neptune. o The comet may thus allow the planetary researchers to look back into the early life of the Solar System

•

This is one of the most interesting discoveries, which would not have been possible via ground-based observations.

Marie-Catherine Mousseau has a PhD in neuroscience from Pierre et Marie Curie University, Paris, and has an MSc in Science Communications from DCU/Queen’s. Marie-Catherine has worked as an editor of a medical periodical and is a regular contributor to Science Spin

Reference: DLR (German Aerospace Center, which coordinated the lander development** ) http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10454/662_read-12642/year-2015/#/gal-

lery/18315, latest results as per January 22 2015 * Preliminary results from seven of the 11 instruments on the Rosetta orbiter have been published in a special edition of the journal Science **The lander was developed and built by an international consortium involving the French Space Agency (CNES), the Italian space Agency (ASI) and MPS under the coordination of the German Aerospace Center (DLR).

Above: A mosaic of four images captured by Rosetta’s camera showing the two-lobed comet.

Left: A 45 metre wide and 25 metre high boulder is the largest among others lying upon the dusty surface of the comet’s larger lobe.

Right: One of the numerous pits on the comet surface viewed from a disrtance of 7.7 km. It is thought that gas vents into space from these pits carrying dust from the comet.

Read our pre launch feature on the rosetta here: http://sciencespin.com/articles/21-featured/67-meet-the-spaced-out-mathematician

Issue 69 Science SPIN Magazine Page 18

Award Winning Photography from the annual Du Noyer Competition

A rocky outcrop overhanging Cloonaghlin Lough in Kerry.

Photo by James Bannon, Co. Dublin. 3rd prize

The competition, organised by the Geological Survey of Ireland with the Irish Geological Association celebrates the geologist George Victor Du Noyer, 1817-1869. Apart from being a field geologist Du Noyer was a talented artist. During his career Du Noyer produced many fine watercolours, sketches and woodcuts.

The ‘Road to Nowhere’ is a former road cut off in both directions by lava flows on the eastern side of Kilauea in Hawaii. It sits as an ‘island’ in a sea of lava. Photo by Meg Earls, Co. Down

The weathered summit of Hen Mountain in the western Mournes. Photo by Brian McCready, Co. Down

First prize in the Irish category goes to Brian McCready - Rock Pools, weathered granite panholes on the summit of Slieve Binnian in the Mourne Mountains. Brian has won this competition for an unprecedented second year running!

A close up of part of the cyclothem and is a contact between an older siltstone and younger top set sandstone. Most of the sandstones in this area are beige in colour but this is a red colour. it illustrates the changes in the deposition all environments from the lower energy silts ones to the higher energy sandstones and the pupils would compare and contrast this to a beach sandstone from Ballycastle beach. Photo by Karen Parks, Belfast

Little Skellig Island, Co. Kerry. Great Skellig Island and Little Skellig are both highly exposed islands or sea stacks mainly composed of Old Red Sandstone and some slate, while veins of white quartzite can be seen between the bedding planes in the photo. In addition, white guano from the largest gannet colony in Ireland of over 26,000 pairs can be seen covering the highest peaks of the island. Photo by Shazia Waheed, Co. Cork. 2nd prize

Sedimentary layers of various ochre colours disrupted by microfaulting in the Roussillon ochre quarry, France. Photo by Anthony Cooper, Leicestershire. Winner of the Foreign Category

Issue 69 Science SPIN Magazine Page 21

The Burren, Co. Clare. The Burren is a region covered by a sheet of porous limestone, bare stone walls with rich patches of green wherever there is soil. Photo by Sean Tomkins, Galway Sea cave at Rinroe Beach. This image shows a sea cave eroded into the cliff that rises from the beach and the rising Moon.

North Coast of Co Mayo, Rinroe Beach near Carrowtighe. Photo

by Malcolm McPherson, Co. Mayo

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Taken at Ballybunion, Co. Kerry. Shallow caves in the cliffs to the right of ‘Ladies Beach’. Photo by Tara Rogers, Co. Limerick

Roque de Agondo, the largest volcanic chimney on the island of La Gomera, which is the second smallest of the Canary Islands. The islands developed as a result of a long period of successive volcanic eruptions. Volcanic chimneys developed when basalt and ash was spewed upwards and subsequently settled in layers. The layers were then burned by hot lava. The large size of the chimney can be ascertained when it is compared with the car in the bottom left hand corner. Photo by Michael Gavin, Co. Dublin

Taken from a boat in the middle of Santorini caldera in April, 2014. Showing Lateritized basalt flows in the caldera wall near Oia. Photo by David Chew, Dublin

Issue 69 Science SPIN Magazine Page 23

The

date of

Easter Margaret Franklin

Easter Sunday falls on April 5th this year. It is a moveable feast whose date is determined by an astronomical method, based on a combination of solar and lunar cycles. The determination of its date depends on rather complicated computations, involving relative movements of the Earth, Sun and Moon and has at times given rise to controversy. This arose partly because of the difficulty in carrying out the calculations in an age before computers and modern scientific instruments were available; partly because of the different calendar systems adopted by different cultures.

In the early years of the Christian church, the date of Easter was linked to the Jewish Passover, with Easter on the Sunday following the Passover.

The Jews used a calendar based on the cycles of the moon and celebrated Passover on the 14th day of the month of Nisan. The month began with a new moon, so that there was always a full moon at Passover, 14 days later. So the Christian Easter was celebrated on the Sunday following this Pascal moon.

In 325, the great Constantine, Emperor of the Holy Roman Empire, called a Council of bishops at Nicaea, the first ecumenical council ever held.

Its main purpose was to combat heresy and achieve agreement on matters of faith, resulting in the formulation of the famous Nicene Creed. In addition, the Council decided to discontinue the use of the Jewish lunar calendar for the purpose of determining the date of Easter and instead to adopt the Julian calendar, which had been introduced by Julius Caesar in 44 B.C. and was in use throughout the Empire. This calendar was based on the solar, rather than the lunar cycles and the length of the year was measured starting with the March equinox. This is the date on which the sun’s rays fall directly on the equator and day and night are of equal duration all over the earth. It is the Vernal, or Spring equinox in the northern hemisphere and the Autumnal equinox in the southern hemisphere.

Another equinox occurs six months later, in September, when the positions are reversed and it is Autumn in the northern hemisphere and Spring south of the equator. However, even at the time of the Council of Nicea, it was known that the equinox does not occur on exactly the same date in March every year, due to various factors, including the slight ‘wobble’ of the earth on its axis. This discovery of the ‘precession of the equinoxes’ is usually attributed to the Greek astronomer and mathematician Hipparchus, almost 200 years before the Christian era, but it may have been known even earlier, as Aristarchus of Samos was aware of the difference between the length of the siderial and tropical year. The siderial year measures the sun’s motion in relation to the stars; the tropical year is based on the turning or revolution of the earth.

For convenience, it was decided to use the date of March 21st as the nominal date (even though in fact the equinox occurs more often on March 20th) and the date of Easter is reckoned as the first Sunday following the Paschal Full Moon, which is the first full moon after March 21st. It must be remembered that in those ancient times, instruments for making astronomical measurement were rather crude. The astrolabe was not invented until the 10th century and the world had to wait for Galileo before the telescope was used to observe the heavens. Nevertheless it is amazing how accurate their predictions actually were. In the north of England, the Venerable Bede (born ca. 672) devoted much study to the motions of the heavenly bodies and he published a text known as the Computo, which was used to calculate the date of Easter. He also gave the world the first ‘digital computer’! This was obviously not an electronic device, but it provided a method, using the fingers (digits) of both hands, for carrying out quite advanced computations.

The Julian calendar continued in use for well over a thousand years, but it had a major flaw. It was based on the assumption that the earth takes 365 and a quarter days to carry out one complete revolution in its annual journey around the sun (or, in the thinking of the time, which regarded the earth as the centre of the solar system, it took 365.25 days for the sun to complete its journey!) Whichever way the relative motions of earth and sun are viewed, the fact that we don’t have an even number of days in a year creates an inconvenience for the calendar system. To compensate for this, an extra day was added to the month of February every four years, which we know as the leap years. However, this actually over-compensated, because the length of the year is not quite 365.25 days, but is more precisely calculated as 365.2422 days. So, as the centuries went by, the discrepancy between the date of the equinox and the date of Easter became greater and greater, with the equinox gradually drifting to earlier dates in March, even occurring as early as March 10th by the late 16th century.

Eventually, in the year 1582, Pope Gregory the Great decided to take things in hand. He decreed that ten days in the calendar would be suppressed in October of that year. And so it was done. People went to bed on the night of October 4th, 1582 and when they got up the following morning, hey presto, it was October 15th! There are rumours that some people grumbled at having their lives shortened by ten days! Most countries in the western world adopted this Gregorian calendar, which is the one we now use. It had the effect of bringing the astronomical full moon and the Paschal Full Moon into accord. It solved the problem for the moment, but perhaps in another millennium or so, a similar exercise would have been needed to reconcile the calendar. So it was decided not to count the centennial years as leap years, unless the first two digits are evenly divisible by four. Thus, the year 1900 was not a leap year, but the year 2000 was, while 2100 will not be a leap year. However, the Eastern and Orthodox Churches continue to use the Julian calendar for the calculation of the date of Easter, so they usually celebrate Easter on a different date.

According to the Gregorian calendar, Easter can fall on one of 35 possible dates, between March 22nd and April 25th. This year, it falls on April 5th, but in 2014 it was on April 20th, five days before the latest date possible. The last time Easter fell on the latest possible date was in 1943 and it will not fall on that date again until 2038. It last fell on the earliest possible date, March 22nd, in 1818 and it will not do so again until 2285. So it appears that a very early Easter is more rare than a very late one! Easter fell on April 24th in 2011, just one day before the latest possible date.

That year, there was a full moon on the night of March 19th, just before the equinox. The next full moon did not occur until the early hours of April 18th, which was a Monday, just narrowly missing the Sunday, giving the following Sunday, April 24th, as the date of Easter 2011. Easter is always celebrated on a Sunday and it all depends on how the days of the week fall in relation to the lunar cycle and the equinox. It turns out that April 19th is the most common date for Easter Sunday, while the cycle of Easter dates repeats after 5,700,000 years.

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Why Do Some Barks Peel?

A simple question that many trees squabble over the real answer for…

Ever since I was little I would go around peeling off the smooth, pastel-coloured bark from the birch trees that surrounded my house. Every time, I would excitedly give the bark back to my mum, exclaiming how easily it came off and how beautiful it looked.

Since then little has changed, except my curiosity to what exactly was going on.

Despite bark being a nontechnical term, we can define it as the part of a tree which overlays the wood. Specifically, bark consists of two main tissues. The secondary phloem, is the inner tissue, this part is alive and important in transporting organic molecules around the tree. An important feature of the secondary phloem is that it contains bands of fibre which prevent the splitting of the bark. The periderm is the secondary outer layer but again this consists of many layers; generally there is an inner layer which restricts water and nutrient movement from the outer layer, thus causing it to die.

This dead outer layer prevents gas exchange, therefore lenticels are present. These are loose areas of cells allowing gas exchange to occur. Bark has a huge number of functions, it reduces water loss, provides protection from insects, birds and disease; so why would some trees go through the effort of constructing this vital protective layer just to go ahead and loose it?

The flaking bark of an old sycamore.

Photograph: Roger Griffith

The shredding bark is a distinctive feature of the Australian gum tree forests, such as these Eucalyptus trees in Victoria.

Exfoliating Trees?

The process of particular trees shedding their bark is known as exfoliating, and us girls are fully aware that exfoliating has major advantages. So what are the advantages of exfoliating for a tree, if there are any? What seems to be such a simple question to begin with becomes, like most Biology, incredibly complex as we delve deeper in.

The generic answer that most rangers will go for when posed with the question from some bright eyed tourists or locals, is simply that the tree grows faster than the bark and so causes the bark to rupture. The mind can flow back to a similar image of an insect undergoing ecdysis to illustrate the idea. Simply, the tree grows too big for its shoes and needs to replace them. Trees grow from the inside meaning the outer layers must expand, and outer bark being dead means it can’t expand and so must be shed to make room for new more elastic bark, which can expand with the growing tree.

Yet this answer seems to fall through when we are confronted with slow growing trees which equally undergo exfoliation. The Shagbark Hickory, is a common tree in Eastern United States and Southeast Canada. This tree is incredibly slow growing, only normally reaching half its potential size, and usually accompanied with a shroud of cheat sheets to increase growing speed to the enthusiastic gardener- and yet it peels.

So perhaps there are evolutionary adaptions to why trees peel, rather then it being a default to an imbalance between growth rates. For if natural selection has taught us nothing it’s that things are the way they are for a reason.

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By looking at River Birch, we are confronted with a tree with plenty of water supplies and so reducing water loss becomes a distant priority in the trees mind. Exfoliation occurring in this species exposes the thin inner bark layer which can undergo gas exchange. Therefore exfoliation allows a higher amount of gas exchange and transpiration to occur. This would increase the trees metabolic rate as carbon dioxide and water no longer become such limiting factors as they were before. And so in this case exfoliating seems to allow River Birch to grow faster, and so more successfully.

While this could be a selective advantage which caused River Birch to undergo exfoliating, it does not provide us with an answer for all trees.

Many other trees that exfoliate do not live in water-abundant habitats and also have thick bark. Another theory suggests that exfoliating may have a protective function to the tree. The shedding prevents a build-up of parasites, fungi, mosses and lichens, whilst the thick cracked bark is much less attractive to herbivores then smooth bark which grows with the tree. This therefore gives us a highly probable evolutionary adaptation for thick bark shedding.

Linking in to the prior idea there may be a third reason why some trees exfoliate. Birches are able to photosynthesis through there bark. Therefore the peeling of bark may allow the removal of a lichen light-blocking layer to expose the live inner bark. This way the tree can take advantage of sunny winter days to create carbohydrates even with no leaves yet available.

Birch growing in Co Mayo, a common tree on peaty soil and boglands, has a distinctive peeling bark.

Though the true answer of exfoliating lays a little foggy, we must take into account that species diversity correlates just as much with bark diversity.

Therefore whilst one answer is simpler and easier to satisfy the curious mind, in reality the answer must be taken into account with regard to each individual tree. In addition it must be understood that a combination of reasons for exfoliating are more likely to be true then a singular one. Birch may shed to not only get rid of parasites and potentially harmful organisms but also because this shedding allows an increase of its metabolic rate from increasing gas exchange, transpiration and light absorption. Overall we are left with a much higher photosynthetic rate despite the tree having no leaves. With regards to other trees, whilst convergent evolution is very much true it’s essential that each individual species should be taken as a case on their own to determine the evolutionary reasons for why that tree undergoes exfoliation.

Julia Galbenu is a student of biological sciences at Oxford University. In addition to her studies, Julia writes about biology.

Plane trees, such as this one in Dublin, are commonly planted in cities where their shedding bark is believed to help them thrive in polluted streets.

Issue 69 Science SPIN Magazine Page 26

CAREER PROFILES

Aisling Connolly, Maths PhD Student What are the main tasks, responsibilities and skills required?

Supported by

I have always loved to ask questions and solve puzzles, figuring things out is a hobby of mine, so it seemed like a natural progression to continue through school and university so that I wouldn’t have to give up my hobbies.

The way I see it my job is to ask the questions that no one else will ask and to find answers to these questions.

I spend my time reading a lot of scientific papers to try to figure out what questions have been asked, and learning about the solutions that were used to answer these questions.

I write a lot of code that models and simulates the real world.

This is like experimenting with the ideas that I come up with to see how viable my answers to these big questions are. I also do some teaching, which can be a lot of fun too.

I work in computer science so useful skills in this area are good mathematical and computer skills, a deep curiosity to understand the world a little bit better, and patience!

Describe a typical day?

I spend a lot of my time reading, coding, thinking, teaching and solving!

What’s cool?

For me, the coolest thing is being able to hang out in a university all the time!

Not only are you surrounded by some bright and interesting people, there are so many other perks. From clubs and societies to academic things, everything is so open and you can just join in anytime. There is something to satisfy any interest I may have from day to day.

What’s not so cool? What are the main challenges?

As I said, for this job you need to have patience.

The work is hard and because it is original, there is not necessarily a ‘rule-book’ to follow so sometimes it can be a bit frustrating when your work or ideas or experiments don’t work out as you would hope. This is all part of the learning process though and is super exciting when you finally get things to work!

Who or what has most influenced your career direction?

I found that I was lucky in school and in university and had some inspirational teachers.

What subjects did you take in school and did they influence your career path?

In school I did Maths, Economics, Geography, Physics. I think all subjects in school help towards a career in a university.

Maths was the one that influenced me most. It was the one subject that I was best at and I got a satisfaction from solving problems.

My advice would be to choose your favourite subject, this makes it a lot easier to work hard at it.

What is your education to date?

After secondary school I did an Arts degree in N.U.I. Galway in the areas of Maths and Economics, then moved to UCD to do a Masters in Simulation Science – This is where I learned to model and simulate real world problems.

For my Masters, I wrote my thesis in the Power Tower with Paddy Power! I was building models that would predict information about soccer matches. After this, I came back to UCD and started into the PhD. What advice would you give to someone considering this job?

I think somebody who actually enjoys school and learning things would do well in my job. You need to be very patient and self-disciplined in order to get good work done.

What kinds of work experience would provide a good background for this position?

All school activities will give you an idea, but so will an involvement in any type of project like Coder Dojo, BT Young Scientist, Competitions and debating.

Issue 69 Science SPIN Magazine Page 27

Elizabeth Collins, Senior Quality Director, Global External Supply for Mallinckrodt Pharmaceuticals What are the main tasks, responsibilities and skills required?

I am responsible for the quality of all my company’s products manufactured externally at contract manufacturing sites around the world.

Describe a typical day?

I have teams in both Dublin and the USA, therefore mornings are when I have meetings with the Dublin Quality and wider teams based in Europe. From lunch time onwards, my calendar gets very busy with teleconferences with colleagues in the USA. In fact, most of my meetings are done over the phone. In addition to the day to day activities associated with my job, I deal with complaints or significant quality issues associated with the products I am responsible for. I am also involved in a wide variety of other activities such as due diligence, which is where we do research and analysis of a company or organization of companies we are looking to do business with or acquire, and then I work on integrating those we do acquire. As this is a relatively new group, I am also working with our Operations Vice President to develop the group’s strategy and mission.

What’s cool?

What are the things you like best about the job?

I enjoy the travel that my job involves. I get to travel a lot to the USA and Canada, and also within Europe. I enjoy the variety of my day and the activities I get involved in. I like understanding the very different medicinal products I am responsible for, and I feel proud of the real impact my role has on people’s lives. In addition, having the opportunity to be involved in projects that have significant impact for my company and its future is very exciting.

What’s not so cool? What are the main challenges?

The things you don't boast about! Necessary aspects of the job you least like.

Although I enjoy travel and the opportunity it brings to see new place and meet different people, sometimes it can be too frequent and impacts on my personal life. The nature of a global role is that the afternoon / evening can be very busy and sometimes I need to take meetings late in the evening while I am much more of a morning person.

Who or what has most influenced your career direction?

I always liked science and maths but nobody in my immediate family had ever done anything like this. I decided to do a science degree as I didn’t know leaving secondary school what I specifically wanted to do. Chemistry appealed to me most as I could see the real life implications for it. Once I completed my PhD, I

started out in R&D / Process Development but quickly figured out that I really preferred working closer to the customer or patient. As a result, I became involved in the support of production and then moved into the Quality arena.

Does your job allow you to have a lifestyle you are happy with?

I have always prioritized my family and when

my children were young, I did not actively pursue career progression. However, in that time, I did continue to develop skills, including six sigma certification, a diploma in management and a Qualified Person (QP) Qualification, which I believe allowed me to get the role I currently have when the opportunity arose.

My current role has some time flexibility associated with it as some meetings can be taken from home in the evenings for example. Our company is also in an exciting phase of development right now which is providing great opportunities for personal development and growth.

What subjects did you take in school and did they influence your career path?

I always loved science and maths, so I took all the science subjects (Chemistry, Biology and Physics) for my Leaving Cert.

What is your education to date?

• Secondary School: Mount St Michaels, Rosscarbery, Co.

Cork • UCC: BSc (Hons); PhD (Organic Chemistry) • National College of Ireland : Diploma in Management • Trinity College Dublin: Postgraduate Diploma in Phar maceutical Manufacturing Technology (QP qualification) What aspects of your education have proven most important for your job?

Working for a PhD allowed me to develop strong problem-solving skills which have proven critical throughout my career. The QP qualification has also been very important for my career as it provided a broad overview of pharmaceutical manufacturing.

What advice would you give to someone considering this job?

• • • • • •

An interest in science Ambition A desire to succeed The ability to adapt Problem solving skills Ability to relate cross culturally

What kinds of work experience would provide a good background for this position?

Any experience in a pharmaceutical company would be relevant

Issue 69 Science SPIN Magazine Page 28

The

Canaries Eruption Following an eruption of El Hierro on the Canary Islands in 2011 rocks from the depths were brought up to the surface. As geologists, Dr Fiona Meade and Dr Frances Deegan remarked, these rocks are quite unusual in that they contain well preserved fossils of microscopically small marine organisms. In spite of being violently thrust up, the fossils from the oceanic sedimentary rocks that underlie the island have survived.

Drs Meade and Deegan were part of a team of scientists from the universities of Uppsala in Sweden, Las Palmas de Gran Canaria in Spain, and Lisbon in Portugal that studied these fossils in order to cast new light on the origin of the Canary Islands. Known as the “floating rocks” from the way they came up to the ocean surface, the fossils they contain are helping to resolve competing models on how the islands formed. One model proposes that a fracture on the ocean floor controls the location of volcanic activity, while an alternative view is that a hot plume of magma is feeding island growth from below. A fixed magma plume would result in the underlying sediments becoming progressively younger in the direction of the westernmost island, El Hierro, while the fracture model would have given a random distribution of island ages.

Using these fossils, researchers under Prof Valentin Troll from Uppsala University report in the journal, Scientific Reports, that the original sediments, predating island building, become younger towards the west, thus agreeing with the view that the Canary Islands originated from a mantle plume.

Right: Diagram of the sub-surface structure of El Hierro island at the time of the 2011 eruption. Magma travelling from the mantle to the surface picked up pre-volcanic sediments, some of which contain fossils. Image source: Carracedo et al. 2012, Geology Today 28, 53-58

Left: (a) View of the white “floating rocks” on the sea surface off the coast of El Hierro in 2011. (b) View of a white “floating rock” covered with black lava. Image source: Carracedo et al. 2012, Geology Today 28, 53-58.

Below: Close-up view of a white “floating rock” with sedimentary relicts highlighted with red circles.

Issue 69 Science SPIN Magazine Page 29

Mapping rocks from below

Many of the observations recorded in the field notebooks are in the form of diagrams and drawings. Words alone cannot always convey the same amount of information as a sketch.

TCD geology students, Eoin Carbett and Garry O’Sullivan, with their Cunningham Award winning mapping project.

Before Eoin Corbett and Garry O’Sullivan set

geologists valuable information about otherwise inaccessible deep processes. Eoin and Garry were quite surprised to see just how well these ancient features had been preserved.

out to map the geology of Syros, an island 144 km north of Athens they had read all about the colourful blueschist rocks, but they had never actually seen them before. As Garry said, there is a big difference between learning about these rocks and encountering them in the field.

Working from their farmhouse base the mappers spent six and a half weeks covering about 16 km2. As they progressed through the landscape they noted any features of interest, and from this record of observations they produced their Cunningham Award winning map.

Going out into the field and mapping what they find is an important rite-of-passage for geology students, and as Eoin and Garry remarked, they wanted to go to somewhere off the beaten track where the chances of finding something interesting would be high.

Every year, in commemoration of Mark Cunningham, former assistant director of the Geological Survey of Ireland, awards are presented for the best two undergraduate student maps. For 2014, Eoin and Garry were joined by UCC student, Hugh O’Keeffe in winning the award.

While Eoin and Garry were away in

As their supervisor at TCD, David Chew, suggested, Eoin and Garry would find plenty to interest them by going out into an ancient subduction zone. This is where one of the Earth’s plates pushes up against another, a process that has been going on for millions of years as Africa collides with Europe.

Greece, Hugh had worked closer to home by mapping the Carboniferous sediments of the Clare Basin.

Taking notes, explained Eoin and Garry, is an essential part of the exercise, but how this is done is important. “If you look at the notebooks,” said Eoin, “most of the information is in drawings and diagrams.

It’s how you express your thoughts.”

Garry’s family are from Ballyvaughan in the Burren, and Eoin also spent his childhood scrambling among the rocks of Co Clare. Both were aware and interested in rocks from an early age, so after starting with general science at TCD they focused on geology. “The teaching staff there,” said Eoin “are excellent,” and he plans to continue studying there for his PhD. While many students go on into industry, Eoin, like Garry, would prefer to stay on the academic side of geology. At present, Eoin is working at TCD on the Geological Survey of Ireland’s rock collection, and Garry has started his PhD on apatite, a calcium phosphate mineral, important for teeth and bones, but also occurring in volcanoes.

Eoin and Garry decided that Syros, the one time home of Pythagoras, would be a good choice, particularly the northern end which, as they explained, had come up again after been pushed deep down. At one stage, said Eoin, the rocks we see now at the surface might have been 70 or 80 km below where they were subjected to heat and high pressure.

Both are keen to continue learning, and they said that having to go out into the field was a great experience because no matter what they decide to do in the future they have learned the value of relying on original observations.

Blue schists, garnets and other rarer minerals formed deep below, were not just carried up, but have been well preserved, giving

Issue 69

Folded glaucophane schist from Syros with its distinctive blue sheen. Photograph, Graeme Churchard.

Science SPIN Magazine

Page 30

Family Although I often hear it said that spring begins on the first day of February, for me spring starts at the beginning of March. Although a few flowers peep up earlier in the year, March is a month for Daffodils and April a month for Tulips.

Daffodils and Tulips both grow from bulbs. Bulbs are defined as a plant that stores its complete life cycle in an underground storage structure.

There are other signs of spring. The days are noticeably longer and there is more heat from the sun than there has been during the winter months As well as signs of new life in the plant kingdom, there are also signs in the animal kingdom.

At the beginning of March there are approx. 11 hours of daylight in Ireland.

By the end of April there are approximately 14 hours of daylight.

The following are the times for sunrise and sunset in Dublin March 1: Sun rise 07:14. Sunset. 18:02.

Giving 10 hours and 48 minutes of daylight April 30: Sunrise is at 5:54. Sunset 20.52 Giving 13 hours and 58 minutes of daylight.

So 3 hours and 10 minutes more daylight!

Frogs are visible, spawning in ponds on sunny days. clumps of frogspawn are visible in ponds. Frogspawn is made up of thousands of single eggs each containing a tiny black dot surrounded by jelly. It is the tiny black dot that will develop into a tadpole. Only about 1 egg out of every 600 laid by the female frog will become an adult frog. Others are eaten by other pond inhabitants fish, newts, water beetles, etc and birds.

Spring is also a busy time for birds. They are involved in finding a mate, build-

ing a nest, laying and hatching eggs and feeding their young.

Before starting to build they must find a safe location.

Then they go about the task of collecting items such as moss, twigs, dried grass, feathers and animal hair and carefully build their nest.

Many people put nesting boxes in their gardens to encourage the birds to nest.

Issue 69 Science SPIN Magazine Page 31

Science

Thanks to Ian McKay for the photos Christine Campbell christine@anyone4science.com

With the wide availability of webcams many people are able to watch life in a bird's nest. Although very interesting to watch, this is not for the faint hearted. Life for birds is often very hard and although mostly some eggs from a clutch hatch and grow to maturity many don't. It can be very difficult standing by watching nature take its course.

Female birds, reptiles, amphibians and fish lay eggs. The eggs of reptiles and birds have hard shells which prevent the egg drying out. Their young grow inside the egg until they are ready to hatch.

For thousands of years people have eaten eggs as they are very nutritious.

According to the Guinness World Records, the smallest egg laid by any bird is that of the vervain hummingbird (Mellisuga minima) of Jamaica and two nearby islets. Two specimens measuring less than 10 mm in length weighed 0.365 g) and 0.375 g.

The ostrich lays the largest eggs on land and the whale shark lays the largest eggs in the world.

For more egg facts visit www.incredibleegg.org & www.thinkegg.com There are so many fun and interesting experiments that you can do with eggs. These are two of my favourites.

Removing the egg’s outer shell

•

You will need: • An egg • A jar with a screw cap lid. I usually use a glass jam jar. The opening must be big enough for the egg to fit in. Be careful if you are using a glass jar -broken glass is dangerous• 250mls vinegar • Adult supervision What to do: • Inspect the egg to make sure it isn’t cracked.

• Carefully put the egg into the jar making sure it doesn’t get cracked. My tip is to put the jar on its side and place the egg just inside and then very slowly stand the jar back up.

• Pour in the vinegar – use enough to completely cover the egg.

• Put the lid onto the jar. I find that this speeds up the dissolution process.

• Wait patiently.

• You should see bubbles appear on the egg shell. These bubbles will rise up through the vinegar.

• Open the jar every few hours to release the pressure.

After a day or two, carefully remove the egg. The outer shell should have reacted and be gone leaving just the membrane. You will be able to see the yolk through the membrane. The egg will feel rubbery. It will be very fragile so be careful not to burst it.

You could also do some experimenting to see which other liquids dissolve egg shells. Try milk, coke cola, lemonade, orange juice, cooking oil.

Which ones work? Do some work faster?

What is going on here?

The egg shell is made from calcium carbonate. The vinegar reacts with the calcium carbonate producing carbon dioxide, which we see bubbling, water and a soluble acetate.

What to do: alking on eggs • Open the egg boxes and place them on the floor behind the chair or beside the counter.

Eggs are fragile. If you drop them • Use the tissue to secure the eggs if necessary. they break. We also know that dome • Holding on to the back of the chair or the counter, position your shapes are strong. Is it possible to first foot on top of the eggs in one of the boxes. Make sure your stand on eggs without breaking foot covers as many eggs as possible. them?

• Continue to hold onto the chair or counter leaning on it so it takes some of your weight. Put the other foot onto the other box You will need: of eggs, taking care to put your foot in the middle covering as • 2 boxes of eggs with 10 or 12 many eggs as possible. eggs in each. Use raw eggs • Now you are ready to let go of the chair or counter and let the • A chair or a kitchen counter eggs take your weight!

• A person – I like to do this in my stocking feet so I can feel the eggs and spread my weight What is going on here? evenly The dome is a very strong shape. Also because you are spreading your • Some tissue – sometimes I use weight over 20 or 24 eggs each egg only feels about 1/20th of your tissue to stop the eggs moving in weight so each one is not really being pressed very hard. the eggbox.

• Adult supervision

W

BT Young Scientist and Technology Competition

Primary Science

It is never too soon to begin learning about science, and primary school pupils are more than keen to undertake projects. With the support of the RDS, primary schools projects have become a big part of the BT Young Scientist and Technology exhibition. Participation provide a great opportunity for entire classes to become involved in projects, such as this one where pupils from St Machulla’s National School in Tulla, Co Clare investigated soil.

At the RDS Primary Science Fair were Brian Torpey, Daniel O’Sullivan, Laoise Carey, Victor Murphy, Caelyn Donlon and Aoife Halpin.

At their stand at the RDS, the pupils explained that they took soil samples from three different fields and with the help of a visiting scientist, they performed a series of tests to determine the chemical and physical differences. As they remarked, they were trying to find out if there is more to soil than just dirt. Under the microscope they found that there were big differences in the shape of particles, some round, others angular. They also determined that the pH varies, some soils alkaline and others acidic. Animals, they noted, are important as they contribute the nutrients that plants need to grow.

Lucy Kennedy with her project advising farmers to make better use of their slurry.

BT Young Scientist and Technology Competition

Nettle Farming

Adam Toner, Jamie Brannigan and Adam Connolly at the BTYSE with their project on phosphates recovery.

No one likes to get stung by nettles, but instead of clearing them away, some farmers are glad to see them grow because they can capture and return valuable nutrients to the land.

Adam Connolly, Jamie Brannigan and Adam Toner, became interested in nettles when their biology teacher at St Coleman’s College, Co Down, mentioned that phosphates are in short supply, yet they are being

discarded in waste water. Phosphates, explained the students are one of the main components of amino acids, they are essential for life, and to make up for widespread deficiency in soils, farmers have to make heavy use of fertilizers.

On investigating the ability of nettles to capture nutrients, the students found that they are so good at mopping up phosphates that they could be used more widely for recovery. Compared to no-cost nettles, the usual approach to phosphate recovery is quite expensive and relatively high-tech. In waste water plants, coagulants are used to produce a phosphate rich precipitate. Apart from capturing phosphates, this is done to prevent eutrophication downstream.

On the farm, said the students, waste water that would otherwise continue to wash away the phosphates, could be used on the nettles. Thus, instead of the run-off causing enrichment problems elsewhere, the nutrients would remain where they are needed, and the nettles could be harvested and used as a fertilizer.

The three students said they are keen to promote the idea of nettles as a farm-crop on the side, and they noted that the harvest could have additional cash value. Nettles, they said, can be sold to pharmaceutical companies and the seeds are used to make medicines to treat prostate disorders.

Too Much of a Good Thing

Tractors drawing slurry-spreading tankers across fields are a familiar sight in the Irish countryside. It is usually assumed that the return of nutrients will be of benefit to the soil, but as transition year students, Bronagh Morrissey, Lucy Kennedy, and Flavia Alverez found, this is not always so. As Lucy explained, slurry is a valuable resource, but soil will only benefit if it is spread in moderation.

Coming from a farming background, the students, from Presentation Secondary School in Thurles, had noticed that when the application of slurry was high, fields became waterlogged. To find out what was happening, the students decided to investigate. When they examined samples of soil they discovered that following heavy application of slurry, an impermeable layer was formed and this acted as a barrier against drainage. They also found that a heavy application of slurry had a negative effect on the worm population.

After one particularly heavy application, said Lucy, she noticed that worms began to come up to the surface and die.

Does this mean that spreading slurry is bad?

Not so, explained Lucy. The problems arise because

farmers do not always spread the slurry over enough land. While silage might be brought back from outfarms, slurry is often not brought back to them for spreading. As a result, fields closer to home receive too much, while the out-farms receive too little.

The students looked at three fields from three family farms and compared their worm populations.

They dug up seven by ten inch soil samples and counted the worms and from this estimated the total number per acre. As expected, fields receiving a heavy application of slurry, perhaps 2,000 gallons per acre a year, had the lowest worm population. However, fields receiving a more modest 1,200 gallons a year had a much higher worm population, higher than fields that received no slurry at all. As Lucy concluded, moderation is best, and while too much is harmful, fields receiving no slurry at all become exhausted and go into decline.

“Value your slurry,” advises Lucy, “it’s a resource with plenty of minerals and vitamins,” but use it wisely. A moderate application, she added, is best and it keeps the worms happy because they have something to chew on.

Issue 69 Science SPIN Magazine Page 34

Weird and Wonderful Animals Sive Finlay introduces us to the nosiest of moles

- We use our senses to discover the world. As humans, we usually rely on eyesight while the other senses kick in to fill the gaps. Yet many animals don’t live in a visually-dominated world. Some creatures feel instead of see the world around them, and they don’t just use their hands. -

Issue 69 Science SPIN Magazine Page 35

T

Sive Finlay is a zoology graduate currently working as a postgraduate scholar with the Macroecology and Macroevolution group at Trinity College Dublin

he star-nosed mole (Condylura cristata) is a champion feeler. Native to eastern North America, these hamster-sized creatures do have eyes but they are much reduced so they are effectively blind. Instead, the moles rely on their uniquely weird star noses to find their way around.

Star-nosed moles live in underground (sometimes underwater) tunnels in wetland areas. They eat small invertebrates, aquatic insects and even small amphibians and fish. Their noses are key tools for finding their dinners.

The moles’ noses are made of 22 separate appendages that resemble small wormy protrusions (sometimes described as looking like sneezed-up intestines!) Each appendage is covered in thousands of tiny, highly sensitive Eimer’s organs which allow the animals to gather information about their environments at super-fast speeds.

The moles use their wormy noses to feel their way to a tasty dinner. The sensitive organs on each appendage provide a rapid response touch system that detects potential prey in the moles’ dark, underground world.

Incredibly, star-nosed moles can detect and identify a prey item, move it to their mouth, consume it and start looking for more food in just 0.12 seconds: five times faster than the speediest of humans. This unique ability has placed star-nosed moles in the Guinness Book of Records as the fastest forager in the animal kingdom.

Even though each item of food may not be very nutritious, the short food handling time allows star-nosed moles to gain the maximum benefits in the shortest possible time.

The sensitive noses also come in handy underwater. Most land animals cannot use their sense of smell underwater because we need air to transport the smelly molecules. Star-nosed moles often forage underwater and, with their poor eyesight, they need a way to find their food. The solution: become a bubble sniffer!

Kenneth Catania from Vanderbilt University in Tennessee used high speed video photography to figure out how star-nosed moles sniff underwater. He discovered that the moles blow lots of small bubbles while they’re swimming and then quickly sniff them back up into their nose. If the bubbles encounter something smelly, then that scent will reach the moles when they sniff the air bubbles back up again.

Other species of mole also have sensitive Eimer’s organs but they have not developed the tentacle-like nose appendages. The reason may lie in the star-nosed moles’ habitat. They live in wetland areas and generally consume soft-bodied insects.

This environment is far less abrasive than the drier soils that other mole species inhabit so perhaps the moist environment allowed the starry appendages to evolve.

Whether it’s high-speed prey detection or sniffing underwater, it’s clear that star-nosed moles are truly weird and wonderful creatures.

Top Left: Specimen of the star nosed mole at the Muséum de Toulouse. Bottom Left: Star nosed mole from the US NPS. Right: Star nosed mole habitat range from the IUCN Issue 69 Science SPIN Magazine Page 36

Jacob O’Neal

A designer based in Portland Oregon obsessed with solid, hiqh-quality research and design presentation.

www.animagraffs.com

Subscription form Issue 69 Science SPIN Magazine Page 37

What is STEM? Science, Technology, Engineering and Maths

Ren ewable Energy En gineer

You could help protect the environment

Games and App Developer

European app economy is worth over€ 10 billion and employs 800,000 people

Why study STEM subjects?

Studying subjects like Physics, Chemistry, Maths, Biology, Technology and Engineering can lead to working in exciting jobs like...

Sport Science

Improve human health and athlete performance

Create new products for use in the medical field

Design new materials and processes

Benefits

Irish STEM Industry Facts 80 Jobs

Global opportunities come with STEM qualifications especially if you have language skills

Starting Salaries 31K

9 of the top 10 global pharma-companies are in Ireland

Medical Device Developer

Food and Beverage Manufacturer

Engineers

Pha rmaceutical Chemist

Science & Tech

24K

86,000 People

announced per employed in week in ICT physics-based Jobs

The top 10

Lab technicians are needed in biopharma, multinational tech companies food and medical devices industry are in Ireland

STEM graduates needed

STEM employers are struggling to fill positions!

So if you’re interested in what STEM has to offer, then visit:

www.SmartFutures.ie Sources: National Skills News Bulletin 2013 CPL Recruitment – Dublin IOP in Ireland Annual Report 2013 http://www.hea.ie/sites/default/files/ict_action_plan.pdf http://www.idaireland.com/business-in-ireland/life-sciences-pharmaceuti/ http://www.steps.ie/students/16-18/faq-s.aspx#How_much_do_engineers_earn_ http://www.digitaltimes.ie/mobile-app/european-app-economy-worth-over-e10-billion/

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