MARSDEN FUND NEWSLETTER

No 22 december 2002

Contents

• Gap junctions: is location everything?
• Sea shells, bones and teeth ­ construction tips from nature
• News from Marsden Cottage
• Beating bullying for safer schools
• Marsden books Country of Writing
• Other Books
• Léon Foucault, pendulum man
• Conserving wetland culture
• Switching molecular lights on and off

Gap junctions: is location everything?

Image showing the characteristic hexagonal shape of the lens fibre cells and the distribution of gap junctions (dark areas).

While "location, location, location" is the well known adage of real estate, it appears that the function of multicellular tissues also depends on location ­ that of cell-to-cell channels called gap junctions.

Gap junctions allow adjacent cells in a variety of tissues to communicate with each other, for example, by providing a channel through which chemical signals can flow. In tissues without blood vessels, as in the lens of the eye, gap junctions provide vital nutrient supply routes.

With support from the Marsden Fund, two University of Auckland laboratories in the Department of Physiology are combining their expertise to investigate how the location and composition of gap junctions affects tissue function. Dr Paul Donaldson has a long-standing interest in the role gap junctions play in the maintenance of lens transparency. Professor Mark Canell and Dr Christian Soeller use state-of-the-art optical techniques to study tissue function.

Dr Marc Jacobs, the research fellow on the project, has mapped the way that gap junctions change in location and size throughout the lens of the eye. The cells of the lens are initially an orderly array of hexagonal cells, which allows light to pass through without scattering. As new cells are laid down on top of the old cells, the aging cells elongate and lose their nuclei. Dr Jacobs found that gap junctions, initially aligned on opposite sides of the cells, change their location during this aging process. In the older cells nearer the centre of the lens, the gap junctions are more evenly dispersed around the perimeter of the cell.

A reconstruction shows the gap junction "holes" between lens cells at the periphery of the lens. Experiments with two-photon microscopy have shown that fluorescent tracermolecules flow in the direction of the arrow.

For this mapping, the researchers exploit the unique advantages of a two-photon microscope. The sample is illuminated by laser light, which the gap junction absorbs only when two photons arrive simultaneously. The researchers can restrict the region over which this simultaneous absorption occurs by focusing the laser light to a point. This focal point is then moved throughout the lens, building a full three-dimensional image.

To see how the gap junctions allow molecules to move between cells, the researchers released fluorescent molecules at a point in the lens, then followed their diffusion into neighbouring cells. They found that the direction in which the fluorescent tracers flow depends on the position of the gap junctions ­ direct proof that gap junction location affects function.

The researchers are also looking at the molecular components that make up gap junctions ­ proteins called connexins. In the lens of the eye, only three types of connexin are used. The researchers have established a colony of mice in which one of these types of connexin is missing. The lenses of these mice are prone to cataracts, which suggests that when present, this type of connexin prevents cataract formation. A PhD student, Aran Sisley, will investigate the diffusion of fluorescent molecules in these mice's lenses. His investigation will examine whether the lack of this type of connexin alters the location and the permeability of gap junctions to small molecules ­ fundamental questions in gap junction research.

While the research is aimed at basic understanding, the multidisciplinary approach of the Auckland group will lead to insights on cell death, cataracts, and cancer.

Sea shells, bones and teeth ­ construction tips from nature

Figure 1 - Sea urchin spine. Total length, 0.3 mm

University of Otago researchers are taking construction tips from nature's own building materials ­ biominerals such as seashells, our skeletons and teeth. Their attempts to copy the structures so far have brought new insights into the proteins that control construction.

Chemist Dr Kathryn McGrath, along with Drs Mike Barker (Marine Science) and Sigurd Wilbanks (Biochemistry), are investigating a sea urchin endemic to New Zealand. While the structure of these sea urchins appears at first glance to be needle like, closer examination reveals a secondary and tertiary structure ­ a characteristic called hierarchy. In sea urchin spines (figure 1) it is the proteins that control this hierarchy.

The Otago team wants to know how proteins, which are incorporated in the structure of the calcium carbonate spines, influence the final form of the material. The group is looking also at how a much more simplified system works, by growing calcium carbonate in the presence of organic molecules that are small parts of the proteins from urchin spines.

The research team first tried changing the calcium levels in the sea urchin's environment. This, they found, does alter the urchin's skeletal development. But because calcium plays a large part in most of the urchin's developmental processes, the researchers have yet to ascertain if the effects are directly due to changes in the biomineralisation process itself.

Figure 2 Scale bar = 10 µm

The team also took a close look at the proteins and attempted to separate and identify each one. This was not easy, since the more than 40 proteins involved all have similar chemical properties.

The researchers found something particularly interesting when they separated the proteins from their exterior sugar attachments. When they grew calcium carbonate n the presence of the "naked" proteins and their separated sugars, they found that the structures most closely resembled growth under the entire protein when only the sugars were present. This is highly surprising, and contradicts the firmly held belief that it is the amino acids of the proteins that control the final form. Rather, it is the sugar groups that largely determine the structure.

Finally, the team has been looking at the effects that alcohols and carboxylic acids have on the growth of calcium carbonate, and the effect of adding chemicals that reduce surface tension. The researchers found that alcohol, while it did not interact with the growing inorganic crystal, made the solution more viscous and affected the type of growth. When the solution is thicker, building blocks move more slowly towards the growing material, which causes the growth of a crystal form called a hopper (figure 2).

Figure 3 Scale bar = 20 µm

The addition of carboxylic acids, such as vinegar, produced the first truly hierarchical growth in a model calcium carbonate system. While these crystals are not so dramatic as the hierarchical growth of a sea urchin spine, one appeared to be the world's smallest Mercedes Benz symbol, just 20 millionths of a metre across (figure 3).

Many scientists believe that biomaterials have an important role to play in the future of materials science. The possibility of synthetically producing hard tissue materials similar to paua shells or sea urchin skeletons has potential in applications as diverse as all-purpose building materials and thermally insulating glass. The Otago team's approach will further contribute to the significant advances that are expected in the near future.

News from Marsden Cottage

by Dr Don Smith, Manager, Research Funding

Applications for 2003

The deadline for preliminary proposals for the next funding round is 14 February 2003. We have kept a similar timetable to that used this year which gives people more time after the Christmas break to prepare their proposals. Information, application forms and guidelines for the preliminary proposals are available from research offices at institutions, from the Marsden Fund office, and are on the Royal Society website.

Other documents relating to the process such as information on full proposals, guidelines for panellists, referees and so on, are also on the website.

As well as standard proposals, the Fast-Start scheme started in 2001 will continue. There are some changes being introduced for both types of applications in 2003. These include a restriction at the preliminary proposal stage on the number of proposals in which a person may appear as a principal investigator, a request for additional information for proposals that have a specific interest for Maori, and the option of awarding four or five year funding for some standard proposals.

Marsden Fund Council

The current members of the Marsden Council are: Professor Diana Hill (Chair), Dr Garth Carnaby (Deputy Chair), Professor Robert Ballagh, Professor Sally Casswell, Professor Marston Conder, Dr Ian Ferguson, Mr Jonathan Mane-Wheoki, Professor Pat Sullivan, and Dr David Wratt. Dr Ferguson's term as a Councillor ends in April 2003. Information about each person can be found on the website.

Staff matters

Rachel Averill will have a break next year from her duties as a research assessor. She will be taking parental leave from the end of January. As well as needing to find a temporary replacement for Rachel, we intend expanding the assessment capability and will shortly be seeking applications for a new position.

Andrea Knox who is the Evaluation Officer for the Royal Society, recently travelled to the USA to attend the American Evaluation Association Conference in Washington DC. While there, she participated in workshops on quantitative methods and evaluation of research. She also visited the National Science Foundation to meet with people associated with programme management and evaluation.

Christmas greetings

The Marsden Fund staff wish you all a very good and satisfying year in research for 2003.

Beating bullying for safer schools

Almost half of our secondary students are not expecting ready help if they tell their teachers about bullying, according to a nationwide survey. Many were not sure whether their school had a policy on bullying or were convinced that any such policy would give support to victims. In contrast, more than 90% of teachers in the survey said they were ready to help, that their school had a policy on bullying, and that the policy meant something would happen when kids were bullied.

Researchers Professor Anne Smith and Dr Karen Nairn, from the Children's Issues Centre at the University of Otago, say these findings show that anti-bullying programmes that advocate telling teachers will only succeed if children are convinced of their effectiveness.

The Marsden-funded work, a questionnaire which canvassed 107 secondary schools, 439 staff and 821 students around the country, looked at the rights of children to recreation, health, safety and participation in decisions within the secondary school environment. Other aspects of the survey have been reported in Marsden Update previously (September 2001 and December 2000).

Some surprising results came from the part of the survey addressing bullying. For example, less than half of both the students and staff agreed with the statement, "teachers do not bully students". One male teacher at a co-ed school pointed out how difficult it can be to challenge bullying by teachers. His comments spoke of "a group of staff who are bullies to both staff and students. I believe some of their actions are abusive (verbally) but have been unable to change this. Our board thinks they are firm but fair and supports such behaviour."

The researchers believe there is a need to investigate further how teachers might bully students in subtle and not so subtle ways.

Interestingly, more staff than students thought that teachers bullying students, and verbal and physical bullying in general, occurred at their school. Whether students underestimate or staff overestimate bullying is an issue that requires further research. Somewhat contradictorily, however, students were more likely to identify specific types of bullying ­ such as name calling, passing rumours, or physical and racist abuse ­ as occurring very often or often.

The frequency of bullying of all types in New Zealand secondary schools is comparable with that in Britain. In both countries about 20% of students say they are bullied either sometimes or often.

Student suggestions from the survey for dealing with this bullying emphasized punishment, helping the bully, mediation and other talking strategies. Relatively few mentions were made of curriculum initiatives, despite this being a common strategy within schools.

Discovering which strategies work for diverse groups of young people is not easy. This survey found gender differences in the strategies favoured by students for combating bullying. Other researchers have also found that children from privileged backgrounds are often unable to manage conflict: Dr Nairn and Professor Smith aim to examine their data in light of this finding. Information from such surveys, incorporating the perceptions of both students and staff, is important in the ongoing debate about what keeps kids safe from bullying in schools.

 

For further information, contact Professor Anne Smith Children's Issues Centre University of Otago P. O. Box 56, Dunedin Tel: (03) 4795087 Email: anneb.smith@stonebow.otago.ac.nz Dr Karen Nairn School of Education University of Otago P. O. Box 56, Dunedin Tel: (03) 4798619 Email: karen.nairn@stonebow.otago.ac.nz

Marsden books Country of Writing

This print record is a dramatic way to demonstrate, two centuries later, the force of the encounter between European andnon-European peoples. Simply as an illustration of the tidal wave that overtook the local oral culture, travel books, emigration guides, shipboard newspapers, journals and logs are overwhelming in their quality and range.
Travel narratives alone accounted for almost a fifth of the nineteenth century book market.
Country of Writing , funded with a Marsden grant, surveys this particular genre of print history nineteenth century books about New Zealand that have travel as their essential condition for production. Author Dr Lydia Wevers, from the Stout Research Centre, tracks the varied interests, objectives and writing conventions that shaped these texts.
The nineteenth century had a prescribed formula for travel books, more scientific than today's typical guide. This formula was elucidated in books such as What to Observe (or The Traveller's Remembrancer ) by Royal Society Fellow, Colonel Julian Jackson.
But many travellers, such as William Colenso, also followed the style of the immensely popular travel books of the eighteenth century. Colenso, who came to New Zealand as a printer for the Church Missionary Society in 1834, modelled his writing on the travels he read of in his youth, especially the heroic story of solitary exploration in Mungo Park's Travels in Africa .
Colenso's descriptions of his travels make no mention of his missionary activities, focusing instead on his role as a botanist and explorer. When he lands on an East Coast beach in 1841, to visit country previously untravelled by Europeans, he is met by several natives by whom I was conducted to their village of miserable hovels among the sand hills. Yet in the account of this trip he sends back to William Hooker in Britain, there is no one present but himself, and he appears to spend the night on the beach.
The force of competition is evident in Colenso's botanical work; he quickly publishes his account of travels and sends to London a stream of specimen cases, book requests and impassioned letters querying the classifications and discoveries of other botanists.
Not all of Colenso's writing was so de-peopled. In a paper to the Hawke's Bay Philosophical Institute in the 1880s, he described one of the striking effects of colonisation in the Bay of Islands at that time. Maori, he claimed, had few natural materials with which to produce the colour blue, and so were quite taken with the blue shirts, caps, jackets and trousers of European dress.
Still, Colenso's recollections of the post-contact community of the Bay of Islands dressed in blue give a chromatic cohesion and misleading peaceful flavour to the scene of colonisation. Many of his efforts to preserve Maori knowledge occurred after war, land confiscation, dispossession and depopulation. These effects of European expansion are excluded from or diminished in most travel writing, which focuses instead on observation and the transmission of knowledge.

'William Colenso, botanist-printer.' Photolithograph of scraperboard illustration by George Woods, ca 1945. ATL E205Q017

Dr Wevers also examines the motivations of writers more generally. Some, she finds, wrote to claim a professional identity, others to demonstrate their knowledge, or some simply because the experience of travel was so fresh and exciting they wished to record it.

Still other books in nineteenth century New Zealand had clear agendas, such as the many works produced by people associated with the New Zealand Company. These books were part of the promotional strategy of the Company. Other manipulations included employing artists to paint the best possible views of settlements, in which they added extra shops along the shorefront. The books were aimed at providing information that would convince prospective colonists. Charles Heaphy's Narrative of a Residence in various parts of New Zealand (1842) and New Zealand Company naturalist Ernst Dieffenbach's Travels in New Zealand (1843) provide the reader with information on the history and prospects of various settlements, geography, geology and botany, climate, bird life and an anthropology and ethnography of Maori. Heaphy's Narrative has numerous books and plans of settlements listed in its advertising appendix.

After the New Zealand Wars, the nature of travel in New Zealand changed. Extra infrastructure and the advent of steamships meant travel was no longer as arduous nor as solitary as earlier. Must-see, iconic sites of New Zealand quickly were established the hot lakes, cold lakes and mountains. These, claimed as equal to the scenic wonders of the rest of the world, locked in place assumptions of New Zealand as a place pleasing to European taste.

With this tourist boom, travel books diverged down two paths. Some, such as Anthony Trollope's Australia and New Zealand , became professional money-making ventures. Others tended towards privately printed journals or collections of letters.

Country of Writing surveys and analyses the avalanche of books produced by these travellers. The book traces the way the printed word transmitted knowledge of the world to cosmopolitan readers and developed a culture in which literacy and mobility were inextricably linked.

Other Books

The Book of Iris, A Life of Robin Hyde is the long awaited biography of New Zealand journalist, poet, and novelist Robin Hyde. The book was completed last April by Hyde's son Derek Challis, and published by Auckland University Press.

Rere Atu Taku Manu! Discovering History, Language & Politics in the Maori Language Newspapers was launched this past October. Edited by Jenifer Curnow, Ngapare Hopa and Jane McRae, the book covers the Maori language newspapers since the 1840s. It is published by Auckland University Press.

Carved Histories: Rotorua Ngati Tarawhai Carving by Roger Neich, was published by Auckland University Press last December. The book covers the history of the Ngati Tarawhai carvers, one of the most prolific and influential schools of Maori carvers in New Zealand.

A Civilising Mission? Perceptions and Representations of the New Zealand Native Schools System, is a look at the history of native schooling in New Zealand. Edited by Judith Simon and Linda Tuhiwai Smith, the book was published in 2001 by Auckland University Press.

Te Tangi a te Matuhi contains writing and a compact disc of artworks and reminiscences about the complex world of Te Kooti. Edited by Wystan Curnow and Leigh Davis, the project is published by Jack Books.

Geometric Function Theory and Non-linear Analysis, by Tadeusz Iwaniec and Gaven Martin, was published in 2001 by Oxford University Press. On a subject that intersects many areas of modern mathematics, the 550 page book covers the foundations, recent developments, and new approaches for research.

HdO, Warfare in Inner Asian History (500-1800), edited by Nicola Di Cosmo, was published in the Netherlands, in 2002. It contains a series of essays on warfare in Asian history.

Old New Zealand and other Writings by FE Maning, published by Leicester University Press in 2001 and edited by Alex Calder, includes an introduction, editorial notes and unpublished letters that illuminate the work's historical, ethnographic and literary contexts.

Léon Foucault, pendulum man

Pendulum in the Panthéon, 1851

In 1851 the French physicist Léon Foucault demonstrated the rotation of the Earth with the slow veering swing of a giant, 67-metre-long pendulum. His display in the Panthon, in the heart of Paris's Latin Quarter, didn't change anyone's mind no one doubted by then that the Earth did turn.

But after two centuries of fruitless searches for subtle deviations in vertical cannon shots or weights dropped down mineshafts, this was the first direct evidence from the dynamics of motion. The experiment wasn't Foucault's only significant contribution to nineteenth century science, but it established his fame, then and now.

Foucault's other work includes the invention of the gyroscope, measurements of the speed of light, and the invention of the reflecting telescope in essentially its modern form.

Dr William Tobin, a senior lecturer in physics and astronomy at Canterbury University, recently completed a scientific and personal biography of Jean Bernard Lon Foucault (181968). The Marsden-supported work, written for the general reader, is currently available in French and will be published in English next year. The French publication was timed to coincide with a major exhibition on Foucault, which opened at the Paris Observatory in October.

The book also covers Foucault's contribution to photography, journalism, and his search for fortune through mechanical regulators.

Foucault, says Dr Tobin, astounds by the modernity of his views and his attachment to rationality.

Conserving wetland culture

Almost all of the wetlands on privately owned lands in Taranaki have been drained as a result, many of the Maori artefacts they contain will have been damaged by oxidation.

Kakau, a wooden handle to which a stone adze would have been attached. Found in 1960 near Urenui, north Taranaki, and donated by farmer Phillip Carr to the Taranaki Museum.

Maori had used the wetlands for nearly 800 years for food and storage of cultural materials; they now form a significant part of the archaeological landscape of New Zealand. But the prospect of deeper and more efficient drains threatens these wet sites and the cultural and ecological information they contain.

While Taranaki farmers have protected many archaeological sites on their farms, they are still draining wetlands. Current legislation offers little or no protection for these fragile ecosystems or the spiritual concerns of Maori.

A Marsden-funded project aimed at increasing knowledge on these wetlands developed from links between the University of Auckland's Wet Organics Conservation Laboratory, the Taranaki Museum (now Puke Ariki) and Ngati Mutunga, the local tribe. These groups have worked together over the years to preserve collected artefacts and store them at the Museum. These finds, however, served to highlight how little of the location, physical history, ortraditional significance of the wetlands was known.

Research collaboration between the University of Auckland, Landcare Research and Ngati Mutunga will provide information that will help councils, Maori, landowners and the general community make decisions during the resource management process.

Using archival sources and aerial photographs, the researchers mapped the century-old distribution of wetlands in north Taranaki and compared this with the location of archaeological sites, mostly fortified pa.

They also used carbon-14 dating and stratigraphic and pollen analysis of drain sections to discover the landscape history of the sites. That history shows a complex story of post-glacial sea level rise, storm events, and vegetation change from coastal lowland forest to

Pteridium fern. This latter change, produced by Maori firing and gardening about 300 years ago, is later than most Maori-induced vegetation changes in the North Island.

Ongoing research is looking at the effect oxidation from water-table changes has on archaeological values when swamps are drained. Researchers are also working with Ngati Mutunga informants to collate traditional information concerning the wetlands.

Foremost, the researchers hope that close collaboration between councils, Maori, landowners and scientists will lead towards a sustainable management solution for the wetlands of north Taranaki.

Switching molecular lights on and off

The team examines a fluorescent film made from a novel naphthalimide switch. Left to right: Brian Robinson, Jim Simpson, Bogdan Dana, Joy Morgan, and John McAdam.

As their contribution to a world wide drive to mimic familiar functions at the molecular level, University of Otago researchers have miniaturised a device familiar to all office workers the traditional fluorescent tube light. The researchers' new molecules could be useful in areas as diverse as electronics and neuroscience.

In fluorescent tubes, an electrical starter activates a gas to emit light. The Otago team worked to develop a molecular switch for fluorescent (or light emitting) molecules, where incoming light or an electrical signal stimulates the molecules to emit light of a different wavelength.

Led by Professor Brian Robinson, the Marsden-funded team constructed molecules with three main components: a light emitter, a switch to control the light's emission, and a spacer that allows the other two components to talk to each other.

For the switches the team chose organometallic molecules, which can gain or lose electrons. This, the researchers felt, gave the material flexibility, robustness and thermal stability. But the conventional wisdom was that such molecules also quench fluorescence, so the researchers needed to overcome this.

In the first attempt to tackle this, PhD student Joy Morgan combined molecular squares of a highly fluorescent flat organic molecule with an organometallic switch containing the metal element rhenium. In collaboration with Drs Keith Gordon and Henrik Kjaergaard, study of the spectra and theoretical calculations provided the first complete description of this molecule. To everyone's surprise it was completely insoluble. That put it out of the running, since the light-emitting assemblies need to be made from solution.

Professor Jim Simpson showed that the molecules stacked to form flat layers with strong bonds in-between. This molecule was believed to be the first example of a stacked structure where such bonding imparted complete insolubility.

A second attack on the problem took a fluorescent molecule that is well known in the dye industry, napthalimide, and combined it with an organometallic compound of iron. Studying these synthesised molecules in detail led the team to two concepts that helped them encourage molecular switching. The first was to incorporate an organic grouping into the molecule that left a gap, with no electron density, between the switch and the light emitter. That limited the direct energy transfer between them, preventing quenching. The second concept was to transfer the electrical stimulus through the space between the components of the molecule rather than along the bonds.

With these ideas the team assembled stable fluorescent molecules. By removing an electron from the iron compound they could turn the fluorescence off. Adding the electron again turned it back on. The combination of physical measurements, theoretical modelling, and synthesis paid off the researchers had achieved their Marsden aim.

In the course of their investigation, the team synthesised other series of compounds. One ranged from insoluble powders to beautiful orange oils and yellow-red solutions of aggregates. Serendipity also showed her hand an attempted synthesis that went wrong yielded a new series of organic dyes. These are so simple that the researchers are puzzled why they have not been made before. A patent application is being processed.

The researchers had early on realised that adding a switch to existing fluorescent molecules might generate novel fluorescent polymers. Marsden-funded PhD student Bogdan Dana worked on synthesising monomers, the precursors to these polymers. A wide range of these, several of which display fluorescence, are now under development.

The team, on a New Economy Research Fund contract, is now looking into using organometallic fluorescent molecules for electro-optical devices, such as light-emitting diodes, low band-gap conducting polymers, and new composite materials. Other ongoing work includes synthesising more complex switchable fluorescent compounds for neuroscience applications and, through a European collaboration, investigating non-linear optical systems.

Marsden Update is published quarterly by the Marsden Fund and is available free on request. Editor: Glenda Lewis Email: glenda.lewis@rsnz.org