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Easter 2011 Issue 21 Cambridge University science magazine www.bluesci.co.uk > 1 2 0 0 0 2 9 6 8 4 7 1 7 7 ISSN1748-6920 9

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Cell Lines . Chimeras . Chocolate Marie Curie . Freedom of Information . Magnetoreception ‘‘‘‘

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To access Cambridge Journals please visit: journals.cambridge.org Easter 2011 ‘‘‘‘ Issue 21 Contents You now have access to over Features Regulars 6 Between You and Me On the Cover 3 Louisa Lyon examines how distinct genomes can News 4 260 Cambridge co-exist in an individual Book Reviews 5 8 Mountains: Go with the Flow Behind the Science 22 Alex Copely explains how uid dynamics can Jessica Robinson uncovers some of the Journals help us understand geology pioneering female scientists 10 The Challenge of Chocolate Perspective 24 Rachel Berkowitz looks at the science that will Tim Middleton gives his perspective on allow us to make chocolate better access to data and the recent scandals

12 Birds’ Eye View Arts and Reviews 26 Thanks to an agreement with Ian Le Guillou  nds out about the ‘biological Stephanie Glaser discovers how shadows caught by compass’ of cows, crocodiles and migrating birds camera-less photography bring light to an image Cambridge University Library, 14 Superheroes, Fact or Fiction? History 28 all staff and students of the Mark Nicholson discovers how nature has Nicola Stead looks back at the turned fantasy into reality beginnings of cell culture University of Cambridge have 16 Technology 30 online access to over 260 FOCUS Anders Aufderhorst-Roberts examines the demands of the digital economy peer reviewed academic Small Channels, Big Ideas A Day in the Life of... 31 BlueSci explores micro uidic journals and over 180 Andy Shepherd talks to Richard Thompson technology and its dazzling about working at Caudex Medical array of applications journal archives published by Weird and Wonderful 32 Cambridge University Press.

About Us... Committee BlueSci was established in 2004 to provide a student forum for President: Tim Middleton ...... [email protected] science communication. As the longest running science magazine Managing Editor: Stephanie Glaser ...... [email protected] in Cambridge, BlueSci publishes the best science writing from Secretary: Jessica Robinson ...... [email protected] across the University each term. We combine high quality writing Treasurer: Wendy Mak ...... [email protected] with stunning images to provide fascinating yet accessible science Film Manager: Sita Dinanauth ...... fi [email protected] to everyone. But BlueSci does not stop there. At www.bluesci. Webmaster: Joshua Keeler ...... [email protected] co.uk, we have extra articles, regular news stories and science Advertising Manager: Richard Thomson ...... [email protected] To access Cambridge Journals please visit: fi lms to inform and entertain between print issues. Produced Events & Publicity Offi cer: Helen Gaffney .... [email protected] entirely by students of the University, the diversity of expertise and News Editor: Robert Jones ...... [email protected] journals.cambridge.org talent combine to produce a unique science experience. Web Editor: Jonathan Lawson ...... [email protected]

Contents 1 Issue 21: Easter 2011

Editor: Wing Ying Chow In Ink and on Paper Managing Editor: Stephanie Glaser Business Manager: Michael Derringer

Second Editors: Tom Bishop, Felicity Davies, Emma Hatton-Ellis, Tamara Litwin, Luke Maishman, a n o t h e r t e r m , another issue of BlueSci—as a Claire Mclaughlan, Imogen Ogilvie, magazine that has succeeded through 20 Cambridge Kirsten Purcell, Paul Simpson, terms there is certainly no doubt that we will be Raliza Stoyanova, Talya Underwood, carrying on—or is there? Georgie Ward Do not get me wrong, the BlueSci community is as Sub-Editors: Stephanie Boardman, Emma Hatton-Ellis, Muhammad Zaeem strong as ever. As you can see on the left, this issue has Khalid, Jonathan Lawson, Tim Middleton, been the culmination of over thirty people’s hard work. Lindsey Nield, Rose Spear, With the new series of [POPULAR Science] talks, we Richard Thomson will certainly keep growing. But in these austere times, can we justify continuing to print a colourful and News Editor: Robert Jones glossy magazine? News Team: Jonathan Lawson, I am very grateful to our sponsors who make it Imogen Ogilvie, Katy Wei possible to continue our magazine in ink and on paper. Book Reviews: Taylor Burns, I am sure they appreciate, as I now do, that printing a Talya Underwood magazine brings a set of challenges that one may not Focus Team: Helen Gaffney, face while publishing in electronic media. Deadlines Lindsey Nield, Wendy Mak, Vivek Thacker need to be set and met, otherwise the magazine cannot Weird & Wonderful: Tom Bishop, be printed in time for distribution at the start of each Mike Kenning, Georgie Ward term. Teamwork and creativity are needed to find images and lay out the design. Technical details such Pictures Team: Felicity Davies, Stephanie Glaser, Emma Hatton-Ellis, as picture resolution and colour management need to Muhammad Zaeem Khalid, Wendy Mak, be considered. The negotiation of advertisement and Tim Middleton, Jessica Robinson, sponsorship has to be preceded by networking and Nicola Stead, Richard Thomson, initiative. In all, learning opportunities that will enrich Talya Underwood the skills of every volunteer involved, transferable and Production Team: Stephanie Boardman, valuable in any career that they might head on to. Felicity Davies, Ian Fyfe, Stephanie Glaser, Tim Middleton, Kirsten Purcell, For me, it is a great pleasure to have the opportunity Mrinal Singh, Rose Spear, Nicola Stead, to work with so many perceptive and enthusiastic Talya Underwood individuals, who contribute each in their own way to Illustrators: Dominic McKenzie, Alex Hahn make BlueSci magazine a pleasure to read, in content, Cover Image: Jamie Gundry style and visual appeal. So what do we have in store for you this issue? Our ISSN 1748-6920 Focus section looks at microfluidic devices made of channels as wide as a human hair. Elsewhere in the issue, we look at other small things: the history of cell lines, the wings of insects, the molecular makeup of chocolate and the internal compass of cows. We also look at other big ideas: pioneering woman scientists, open data and freedom of information. Find yourself a nook and have a good read—and if Varsity Publications Ltd Old Examination Hall you feel inspired to get involved, do get in touch. Free School Lane Cambridge, CB2 3RF Tel: 01223 337575 www.varsity.co.uk [email protected]

BlueSci is published by Varsity Publications Ltd and printed by The Burlington Press. All copyright is the exclusive property of Varsity Publications Ltd. No part of Wing Ying Chow this publication may be reproduced, stored in a retrieval Issue 21 Editor system or transmitted in any form or by any means, without the prior permission of the publisher.

2 Editorial Easter 2011 A Prettier Shell than Ordinary Tom Ash looks into the story behind this issue’s cover image

COMBING BEACHES and collecting pretty shells and form the cornerstone of species defi nitions. is a common childhood hobby. For some the MacAndrew was also interested in collecting enjoyment continues into adulthood, maybe growth series, mounting specimens of each species even formalising it as a scientifi c interest. Robert at various stages of development on his signature MacAndrew, whose collection now forms the blue card, so increasing the value of his collection nucleus of the shell collection at the University as a reference tool.  e majority of the specimens, Museum of Zoology, was one of those. by necessity, are stored in great cabinets behind the As the owner of a shipping company, he took public face of the museum, but work is afoot to the ample opportunities his ships provided to open this great resource up to the public. collect mollusc shells from the North ---Atlantic, Recently, a project was undertaken at the Mediterranean and Gulf of Suez, gaining museum to produce an online catalogue of all their fellowship of the Royal Society for his work. bivalve molluscs. Bivalves have shells consisting of MacAndrew was one of the pioneers of deep two halves hinged along one edge by interlocking sea dredging, working closely with prominent teeth and fl exible ligaments.  e group includes naturalist Edward Forbes.  ey reported annually clams, oysters and mussels. During the last eleven to the British Association for the Advancement of months, Hilary Ketchum has catalogued every Science on the material that they recovered from one of the ten thousand bivalve molluscs in increasingly greater depths. the museum’s collection. Each of the 200 or so On the cover is Divaricella macandrewae, molluscan type specimens have been photographed from MacAndrew’s collection, showing beautiful by Jamie Gundry, examples of which we see on the intersecting ribbing that helps it to burrow.  is front cover and on this page.  e bivalve collection specimen was collected from the Gulf of Suez in is now fully recorded online, meaning that early 1869, before the opening of the Suez Canal researchers can view good quality images of type later that year. It forms part of a larger collection specimens from remote locations, reducing the of shells that provide a baseline from which to need to send material out on loan. A key strength gauge the extent of subsequent animal migrations is the ability to search by sampling sites, collectors between the Red Sea and Mediterranean via or dates of collection. the Suez Canal, which are called ‘Lessepsian’  is project, sponsored by a designated migrations after the engineer of the Canal. development fund of MLA, is another step  is is not the only example of molluscs aff ected to achieving the museum’s long term aim of by human activities. According to the 2010 statistics cataloguing all of its specimens online, giving the of the International Union for Conservation of whole world access to these rich scientifi c resources. Nature, 44% of the animal species that have been If you want to see examples of the shells yourself, recorded as becoming extinct since the year 1500 a new display has opened at the University have been molluscs. Several species of mollusc in Museum of Zoology, showing bivalves thematically the collection have already become extinct, due to displayed according to their lifestyles. habitat destruction and introduction of invasive species to their vulnerable habitats. Tom Ash is a PhD student in the Department of MacAndrew bequeathed his collection of mollusc Clinical Neurosciences shells to the University Museum of Zoology on his death in 1873. It now forms part of a wider collection of mollusc specimens assembled there, one of several collections of international signifi cance in the museum that have led to it receiving designated status by the Museums, Libraries and Archives Council (MLA). Most notable in the MacAndrew collection is the large number of type specimens.  ese are the original specimens of a species to be scientifi cally described, JAMIE GUNDRY

Easter 2011 On the Cover 3 News The Sun as we’ve never seen it before Human migration out of Africa

n a s a h a v e moved the twin i t i s widely accepted STEREO imaging probes that humans originated into position on opposite in Africa, and current sides of the Sun, revealing theory states that modern our star for the first time ARCHAEOLOGY WESSEX humans did not leave in all its 3D glory. The their original homeland telescopes on STEREO until 65,000 years ago, NASA are sensitive to four with the exception of a wavelengths of ultraviolet radiation, allowing them to few isolated populations. However, a team working in trace key aspects of solar activity, including solar flares, Jebel Faya in the United Arab Emirates have proposed tsunamis and magnetic filaments, which will greatly a much earlier dispersal into the Arabian Peninsula. advance not just theoretical solar physics research, but The team discovered tools which are at least also space weather forecasting. 95,000 years old, suggesting that modern humans Previously, active regions could suddenly emerge migrated across southern Arabia around 125,000 from the far side of the Sun, spitting flares of intense years ago when the area was more hospitable. electromagnetic radiation towards the Earth that can Some of the tools found at Jebel Faya show notable cause severe disruption to airlines, power supplies and similarity to those made by contemporary Homo satellite operations. With STEREO, active regions sapiens in Africa, leading the authors to suggest that of the Sun can now be tracked, so that scientists can modern humans have lived continuously in the area predict with accuracy when solar radiation is likely to until at least 40,000 years ago. However, this directly reach dangerously high levels. Solar storms on their contradicts genetic evidence stating that populations way towards other planets can also be tracked, which were constantly wiped out and replaced by the holds great importance for NASA missions elsewhere in changing climate during this period. Additionally, the solar system. the team found no human fossils and their dating Monitoring the entirety of the Sun’s surface could evidence was strongly inconsistent. also help to solve some of the many fundamental Whilst it seems likely that Jebel Faya was inhabited Check out puzzles underlying solar activity: researchers have by modern humans earlier than was previously www.bluesci.co.uk long suspected ‘global’ interactions between eruptions thought, the humans probably only stayed for a or @BlueSci on opposite sides of the Sun, and STEREO provides short period, and other human species may have also on Twitter observational data to test these theories. With higher occupied the area. Whilst this is a promising lead, more for regular resolution images on their way, it seems that the sky’s work is needed to reliably establish the role of Arabia in science news the limit for solar physics. k w early migration of H. sapiens out of Africa. j l and updates

New mosquito subgroup solves malaria mysteries?

m a l a r i a i s distinct, Goundry was found to have an important responsible for behavioural trait which surprised many scientists; around one rather than living primarily inside people’s homes, the million deaths new strain lives outside.

f ee qu T how aan in Africa alone This behaviour has potential implications for malaria S h if every year. The eradication programmes that have previously focused on disease is transmitted to humans from bites by Anopheles preventing mosquito bites in the home. The researchers mosquitoes that carry the Plasmodium parasite. working on Goundry have already found that the new An international team of scientists describing subgroup is more susceptible than other strains to populations of Anopheles gambiae in West Africa have picking up the Plasmodium parasite from infected blood. discovered a new subgroup of the mosquito that The next step is to ascertain whether they commonly bite may hold the key to a better control of malaria. The humans. If the newly discovered mosquitoes are found genetically distinct subgroup, called ‘Goundry’, was to be an important transmitter of malaria, eradication identified by comparing genetic markers and mutations programmes must shift their focus to include outdoor in mosquito genomes. As well as being genetically bite prevention too. i o

4 News Easter 2011 Book Reviews The Humans Who Went Extinct

AS OUR CLOSEST RELATIVES and surviving alongside us until 28,000 years ago, our fascination with the Neanderthals is understandable. How similar to us were they? How intelligent were they? Most importantly, why did they die out? Clive Finlayson addresses these fundamental questions head on in e Humans Who Went Extinct. He challenges the central dogma that humans drove Neanderthals to extinction. Instead Finlayson places greater emphasis on the role of serendipity in the Neanderthals’ demise, demonstrating the importance of rapidly fl uctuating environmental conditions during this key period of evolutionary history. e equally important question of why humans survived is also brought to our attention and the book charts the journey from our birth in Africa to our establishment across the wider world. e great strength of the book is that Finlayson avoids subscribing to traditional viewpoints that may hinder our understanding, providing a refreshing and perceptive overview of a topic fraught with controversies. e book leaves the reader with a sense of humility that our survival as the only species of the human lineage was strongly shaped by the environment, climate and chance. TU OUP, 2010, £9.99 Delusions of Gender

IS THERE A FEMALE BRAIN ? By its biased formulation, the question induces the various stereotypical schema that stain any attempt to answer it. We assume, from the very basis that men and women do exist, that male and female ‘brains’ must also exist. en, so very often, we, as scientists, work backwards: our culture has found its conclusion—that men and women are diff erent in most aspects—so we search for evidence to support this thesis, uncharacteristically turning the scientifi c process on its head. is is why we should be ever grateful for Cordelia Fine’s latest book. Fine makes a strong neuroscientifi c case for the cultural—rather than biological—dimension of gender. But Fine is not trying to convince you that gender is a purely cultural phenomenon. Rather, her conclusion is much humbler—and more palatable than the overextended conclusions of much gender research: the debate is still open, and that research on the ‘biological’ basis of gender is largely inadequate. At the very least, Fine has provided us with an engaging, literate and powerful argument Icon Books Ltd, 2010, £14.99 for thinking twice about gender ‘science’, bringing our brains back from Mars and Venus to a culturally complex Earth. TB

The Three Cultures

“IT IS TIME FOR THE MEMBERS of the three cultures to adopt a posture of greater humility.” Humble, says Jerome Kagan, because they are losing their appeal. e ‘three cultures’ of the natural sciences, social sciences and humanities are, Kagan claims, plagued by insularity and a lack of mutual respect. Now, it seems, all three cultures only share one characteristic: their claims and authority are only valid and substantive within their own specifi c communities. Accordingly, the infl uence of all three areas of study is receding in the public sphere, and whenever borders are crossed, it is usually marred by impotence and misunderstanding. eir primary concerns are scattered, they have no respect for the others’ sources of evidence, they are increasingly jargon-rich and dominated by hegemonic funding bodies. But, Kagan is clear, there is reason for hope. ough they each have their fl aws and limitations, including natural science, they all contribute to a shared understanding of the universe that would be impossible if one was not present. Narrow-mindedness, then, is the danger, and it was not so long ago that a healthy integration existed between the three cultures CUP, 2009, £14.99 —a paradigm that Kagan would like to reinvent. e book is certainly with some fl aws. For instance, barely 10% of the book is dedicated to the humanities, while the social sciences receive well over half of the attention. But the importance of the message remains: that the sum of the human pursuit for knowledge is greater than its parts. TB

Easter 2011 Book Reviews 5 DOMINIC McKENZIE Between You and Me Louisa Lyon examines how distinct genomes can co-exist in an individual

i n 1998, k a r e n k e e g a n , a 52-year old woman from dominate while in other tissues, including Karen’s Massachusetts, received some extraordinary news. Tests ovaries, both cell types co-existed side-by-side. One of revealed that she was not the mother of two of her three Karen’s sons had developed from an egg containing grown-up sons. While genetic tests had confirmed her Karen’s first set of DNA—the DNA also found in the husband as their biological father, the same tests had majority of her blood cells—while the other two sons failed to detect a match between Karen’s own DNA developed from egg cells containing Karen’s second and that of two of her children. When the tests were genome. Researchers believe that the most likely repeated, using new samples, the same results were explanation for this phenomenon is that Karen’s mother obtained ruling out the possibility of mislabelling may have conceived non-identical twins who, at an or cross-contamination in the lab. While it seemed early stage of pregnancy, fused to form a single embryo, possible that both sons had been swapped at birth, the otherwise known as a chimera. chances of this happening to the same woman on two In Greek mythology, the Chimera was a fire- separate occasions, years apart, are incredibly small. In breathing female monster with the body of a lioness, addition, Karen’s husband’s DNA had produced the the head of a goat, and the tail of a snake. In genetics, expected match. Although this unlikely-sounding story a chimera describes an individual in whom two or is indeed true, the explanation may appear as strange as more genetically distinct populations of cells, derived the finding itself. from different individuals, co-exist. While chimerism The breakthrough in solving the mystery came when is extremely rare, with only around 30 cases described researchers used a tissue other than blood to obtain to date, it is likely that many more instances of the a sample of Karen’s DNA. When genetic material condition go undetected, as there are usually no from a cheek swab was sequenced, the anticipated outward signs. match between Karen’s DNA and that of all three of Microchimerism, on the other hand, is far her sons duly emerged. Further studies revealed that, from rare. Microchimerism may be described as remarkably, Karen’s body comprised two distinct chimerism diluted: whereas chimeric individuals have populations of cells, each with its own unique genetic broadly similar numbers of cells derived from each code. In Karen’s blood, one cell-type had come to constituent individual, a microchimeric person will possess approximately 50 ‘foreign’ cells per million Chimera on an of their ‘own’ cells. The most common source of Apulian plate microchimerism is transfer of cells, across the placenta, from the MARIE-LAN NGUYEN MARIE-LAN NGUYEN from foetus to mother. Foetal cells can be detected in Louvre Museum the bloodstream of nearly all pregnant women by the third trimester and this cell exchange may actually help the mother’s immune system to tolerate the foetus. Interestingly, microchimeric cells do not appear to be fully eliminated after birth: stable populations of these cells have been detected in women many decades later. Notably, transfer across the placenta also occurs in the opposite direction—from mother to foetus—providing a mechanism through which infants may become microchimeric. The condition may also result from transfer of cells between twins as well as between unrelated individuals via organ transplants, bone- marrow transplants and blood transfusions.

6 Between you and me Easter 2011 Apart from producing occasional conundrums for geneticists, does chimerism—and indeed microchimerism—have any enduring consequences for health? The evidence for this is mixed, with both beneficial and harmful effects reported. In terms of harm, it has been suggested that microchimerism may increase the risk of developing a number of autoimmune diseases including scleroderma, rheumatoid arthritis and multiple sclerosis. A link was first proposed for scleroderma, a disease characterised by hardening of areas of skin or internal organs, after it was noted that the disease bore some resemblance to graft-versus-host disease. This is an autoimmune response that sometimes occurs following an organ transplant wherein the donated organ begins to attack the recipients’ tissues. One possibility, therefore, is that microchimeric cells may trigger an inappropriate scri bb letaylor and damaging immune response within their ‘host’. determine whether microchimerism is an autoimmune Cell transfer Many studies have reported an increased number of friend or foe. from foetus to microchimeric cells in scleroderma patients as well as in When it comes to cancer biology, microchimerism is mother is the those with other autoimmune diseases. However, not viewed in an altogether more favourable light. Women most common all autoimmune disease sufferers show microchimerism, who have previously been pregnant and who show source of and clearly not all microchimeric individuals develop microchimerism appear less likely to develop many microchimerism autoimmune disease. forms of cancer. They also show greater therapeutic The fact that both microchimerism and autoimmune response and better survival rates, as compared to disease are affected by pregnancy may offer a further women who have previously given birth but in whom clue. Most autoimmune diseases are markedly more microchimerism cannot be detected. The evidence common in women with clinical onset typically seems to be particularly strong in the case of breast occurring around the child-bearing years. And yet, cancer. In a mouse model of the disease, microchimeric paradoxically, some patients find that their symptoms cells were detected in large numbers at the tumour site. actually improve during pregnancy, but return shortly These cells did not express tumour-markers, however, after the birth. Studies into rheumatoid arthritis and did not behave like tumour cells; instead they suggest that the relationship between pregnancy appeared to be helping with cell repair. Microchimeric and autoimmune disease may depend upon human cell transfer, from foetus to mother, may be particularly leukocyte antigen (HLA) genes. HLA class II genes beneficial in this regard as some of the cells transferred exist in many different variants and are known to appear to be pluripotent stem cells with the potential play a key role in determining immune responses. If to develop into any of a number of different cell types. a mother and foetus possess relatively distinct HLA In a rat model of liver and kidney disease, for example, gene variants, arthritis symptoms are likely to improve microchimeric cells have been observed moving to the during pregnancy, while if mother and foetus have site of the two organs, transforming into hepatocytes more similar HLA types, symptoms tend to remain and renal tubular cells, respectively, and seemingly constant or to worsen. Outside of pregnancy, the degree engaging in repair of damaged tissue. of HLA compatibility between microchimeric cells and The precise mechanisms through which their host may likewise be one of the key factors that microchimeric cells exert their effects remain largely unknown. Indeed, it is often difficult to identify the role that microchimeric cells are playing. They may be Marmosets innocent bystanders, accomplices to automimmune have been diseases, or helpful agents in cell repair. Multiple factors shown to exhibit chimerism including HLA type, the origin of the microchimeric cells and the length of time since cell transfer may all influence which of these roles microchimeric cells adopt under any given set of circumstances. One thing that is clear is that many of us may have rather more in common than we previously thought. üller . M Louisa Lyon is a postdoctoral researcher in the

Joachim S Department of Experimental Psychology

Easter 2011 Between you and me 7 DOMINIC McKENZIE Mountains: Go with the Flow Alex Copley explains how fluid dynamics can help us understand geology

a t s c h o o l w e a r e t a u g h t the theory of plate differences between the chemical composition of the tectonics, originally developed during the 1960s. rocks forming the oceans and those underlying the We learn how the Earth’s surface is divided into continents. Consequently, there are differences in about 14 rigid plates that are slowly moving across the strengths of the rocks. The strong oceanic plates the surface of the planet. The theory has a simple break along narrow plate boundaries, such as at the elegance: only three parameters for each plate are mid-ocean ridges, and behave exactly as set out in required to describe all of the observed motions. the theory of plate tectonics. However, the most However, plate tectonic theory cannot explain the dramatic mountain ranges on Earth, such as the movement and formation of all regions of the Earth, Andes, the Himalayas, and the Tibetan Plateau, have and an exciting and vigorous area of research within grown where some of the weaker continental regions the Earth Sciences is trying to understand the have been squashed between converging plates. One regions where plate tectonic theory does not work. such example is southern Asia, where for the past The rocks that form the continents are extremely 50 million years India has been colliding with Asia diverse. They have been formed in a variety of at the geologically rapid rate of 4 centimetres per different ways and have ages of formation varying year. The Tibetan Plateau and the region extending from over three billion years ago to the present day. thousands of kilometres to the north is being In contrast, those underlying the oceans were all deformed by this plate convergence, resulting in the formed by volcanic activity, along the network of unfortunate occurrence of many earthquakes. Unlike undersea mountain ranges where plates are moving the stable interiors of tectonic plates, the entirety of apart. These different origins have led to significant this area is actively deforming. It is in regions such as the Tibetan Plateau that we have been required to As custard develop an alternative to the theory of plate tectonics cools, a layer of in order to understand what is happening. skin forms on The presence of earthquakes, which occur when top, which may sometimes tear: two blocks of brittle rock suddenly slip against earthquakes can each other, shows the Tibetan Plateau to be actively be understood in deforming. However, this only tells us about the same way what is happening in the uppermost layer of the Earth. The thickness of this brittle layer is tiny, equivalent to less than 0.2% of the Earth’s radius and less than 10% of the upper layers of the planet that participate in mountain building and plate tectonics. Deeper within the planet the temperatures are hotter, which means that defects in the crystal lattices of minerals are able to move with increasing ease (the diffusion and dislocation creep that will be familiar to many scientists from other disciplines). S JOHN DAVEY This movement of lattice defects causes the rocks

8 Mountains: Go with the Flow Easter 2011 Fluid dynamics tells us that in this situation the flow The mountains forms a very distinctive shape with a flat top and a ooze outwards steeply sloping front, as we see on the northern and under their own southwestern sides of Tibet. weight onto the The gentle slopes on the northeastern and lowlands, which southeastern sides of Tibet show that the story here are made of more rigid rock is clearly different. In these regions, there are no hard rocks being pushed under the edges of the mountains, as is the case in India, so the mountains spread out over hotter and weaker underlying material. Our custard is now spreading over the surface of a tank of olive oil, rather than a slice of toast. In this case fluid dynamics tells us that gentle slopes should form, as we see on the eastern edges of the mountain range. The notable exception is the location of the devastating magnitude 8 earthquake that occurred in the Sichuan province of China in 2008. Here we see steep slopes because the Sichuan Basin is a region of hard rock (much like India), with the mountains oozing out over it. The earthquake was a manifestation of this motion in the brittle upper layer of the Earth—the skin on the top of our custard. Treating the Tibetan Plateau as a pile of viscous fluid has shown that we can understand the shape alayan T r ails Rajash H i m alayan of the mountain range and the earthquakes within composed of these minerals to behave as viscous the region by applying our existing knowledge fluids, with a viscosity over 1020 times greater than of fluid dynamics. So the next time you’re eating honey. Mountain ranges can therefore be imagined Marmite on toast, take a moment to place a large as piles of very thick custard left out to cool. dollop in the middle of the slice and look at how it Earthquakes become the tearing of the cool skin on spreads out under its own weight; by doing this you the surface. Given this fluid-like behaviour of the are recreating southern Tibet and the Himalayan majority of the mountain ranges, we can use the rich mountains in miniature. body of fluid dynamics research to understand how This story, however, carries a sobering postscript: the ranges behave, and shed light on the forces that the same processes which are occurring in the cause the earthquakes. Himalayas are also occurring in the region of the Such research has recently been conducted on devastating Sichuan earthquake. This means it the Tibetan Plateau. The figure shows that the is only a matter of time until a similar or larger southwestern (Himalayan) and northern margins earthquake rocks the very densely populated Ganges of the Tibetan plateau are steeply sloping, whilst River Valley—an event which, as historical records the northeastern and southeastern sides have show, has happened many times in the past. much more gentle gradients. Because of their geological histories over the past few billion years, Alex Copley is a Research Fellow in Pembroke the rocks that form peninsular India and those in College and the Department of Earth Sciences the lowlands on the northern side of the Tibetan Plateau are very hard and inert. This is because in The Himalayan previous episodes of mountain building, the rocks and northern have been heated to extreme temperatures. Although margins of the Tibetan Plateau they have since cooled down, all of the volatile are steeply constituents, which serve to weaken the rocks as sloping, whilst a whole, have been melted out of them. In these the northeastern regions the convergence between the Indian and and southeastern Asian plates forces the rigid lowlands underneath sides have much the mountains. The mountains ooze outwards under more gentle their own weight, over-riding the lowlands like a gradients dollop of custard spreading under its own weight across a slice of toast, known as a ‘gravity current’. A lex copley

Easter 2011 Mountains: Go with the Flow 9 The Challenge of DOMI N IC McKE ZIE Chocolate Rachel Berkowitz looks at the science that will allow us to make chocolate better: healthier, cheaper and as tasty as before

w i t h i n c r e a s i n g p r e s s u r e to produce healthier foods Maillard reaction, which introduces a ‘cooked’ flavour. and soaring energy costs, companies such as Mars and British expatriates in the US and elsewhere pay top Nestlé are increasing their support for research into dollar for imported British chocolate so that they can the manufacture of healthier and cheaper chocolate. enjoy the tastes of home. British research councils are also in on the act: last The classic chocolate bar is adept at satisfying our autumn the Institute of Food Research (IFR), a UK exacting taste buds. Most of the flavour of chocolate research institute under the Biotechnical and Biological comes from sugar, which along with cocoa comprises a Sciences Research Council, announced its involvement particle suspension in a fatty fluid, usually cocoa butter. in new projects aimed at diet and health-related research To keep the mixture smooth, chocolate manufacturers worth a total of four million pounds. Researchers are add emulsifiers. Emulsifiers eliminate friction between collaborating with companies to make the most of what particles by sticking to non-fat particles and making it they know about the chemistry of chocolate—and easier for fats to coat them. consumer tastebuds—to create a new line of lower-fat, As you bite into a bar of milk chocolate, the chocolate cost-effective chocolate. melts in your mouth and reverts to a fluid state. The Making a low-fat chocolate bar that tastes and feels creamy texture spreads the taste across your tongue, right is not easy. “The big question is how chocolatiers but you might not realise that the melt reaches three can meet the growing demands of the market for a different types of flavour receptors in your mouth at lower-fat chocolate while keeping true to the classic different times. The timing is perfect, thanks to the taste and texture,” says Cambridge chemical engineer carefully engineered size distribution of particles which Joel Taylor. affects the friction in the mixture. British consumers are particularly picky. Chocolate Manufacturers are already making progress towards a crumb, the basis of the chocolate we know today, was healthier chocolate by adding oil substitutes and varying developed in Britain during the early twentieth century ingredients in the emulsion to reduce fat content. to increase the shelf-life of chocolate; and is the source However, chemical engineer Phil Cox and his team at of its unique flavour. It is made by combining dry the University of Birmingham went one step further in ingredients with water to form a paste. The paste is then 2009, producing chocolate using more water than oil dried and milled, lowering water content and preventing while still retaining the taste of conventional chocolate. moulds from growing. The drying process causes a Their cocoa butter emulsions, which are suspensions of reaction between proteins and sugars known as the two liquids that do not mix, contained up to 60% water. Most emulsions rely on the propensity of oil to remain a n The classic separate from other liquids and, as a result, are fattier. chocolate bar is The water-based emulsions remained stable during adept at satisfying storage and the cocoa butter melted around 33°C, the our exacting taste buds temperature which consumers find the most attractive according to Stephen Beckett, a former Nestlé chocolate researcher. Further research at Birmingham has led to me n R iz w Ay MUHAMMAD ZAEEM KHALID, the development of a protein structure filled with air that mimics the properties of fatty molecules in cocoa

10 Chocolate Easter 2011 butter, and can replace some of the fattening oils in a rheometer that applies a shear stress or strain over foods such as mayonnaise and salad dressings. time. The most commonly used rheological model However, these innovations have not been without for chocolate was originally developed to model the their own problems. Less fatty chocolates have a harder rheology of printing inks. However, after studying texture. In an attempt to counter this, biochemist Bettina chocolate over a wider range of shear stresses, Taylor and Wolf and students at the University of Nottingham fellow chemical engineer Alex Routh recommended tried adding limonene to low-fat chocolate. Limonene a different model. Their new, improved model better is a citrus fruit-derived oil-soluble substance that describes the properties of crumb chocolate rheology. compensates for the compromised softness and quality Routh argues: “if you can understand chocolate in reduced-fat chocolate. It decreases cocoa butter structure over time, maybe you can achieve [the same] viscosity by mixing within the cocoa butter’s structure structure using less energy, and perhaps eventually and diluting the fat. It also reduces the formation of fat bypass the conching process.” crystals in cocoa butter, decreasing the solid fat content However, as Taylor highlights “it is not just chocolate, and hardness of the chocolate. all food manufacturers face the same challenge” of Cost is always a concern, too. Taylor notes that “cocoa producing lower fat products while maintaining their butter is expensive, so substituting other fats in chocolate traditional taste. Therefore, the food industry has entered is important economically as well as for health reasons. a new period of research into health and nutrition. Hence you get combinations of milk fats and cocoa fats, Nutritionist Alison Lennox of the Human Nutrition which affect taste and texture.” Manufacturers make Research (HNR) centre in Cambridge notes that recent particles in the chocolate mixture as large as possible to years have seen food companies’ research teams increase reduce costs. Smaller particles have a higher surface area their interest in nutrition quality. Research at the HNR and require more fat to coat. On the other hand, larger has provided an understanding of specific nutrients particles make for less smooth, grittier chocolate, which and health implications, but Lennox needs to explain does not taste as good. Getting the size of the particles to those who support government initiatives “why you right is yet another challenge for researchers. cannot make a low-fat biscuit and still have it taste During the manufacture of chocolate, mixtures of right.” That is where the scientists are needed. different particle sizes clump together tightly leading Will food companies have trouble finding talented to thicker fluid and rougher textures. To avoid this, young minds to do the research? Not likely, if the manufacturers use energy-intensive techniques including Cambridge research group is anything to go by. “I have conching, a process of kneading and stirring at high always liked eating chocolate,” explained Taylor, “so temperature for many hours in a seashell-shaped vessel. researching the stuff seemed like a pretty good idea.” Taylor questions whether the conching process is as efficient as it could be. He studies the flow, or rheology, Rachel Berkowitz is a PhD student at the BP Institute of molten crumb chocolate using a machine called in the Department of Earth Sciences

Easter 2011 The Challenge of Chocolate 11 D OMINI C M cKE N Z I E

Bird’s Eye View Ian Le Guillou finds out about the ‘biological compass’ of cows, crocodiles and migrating birds

t h e a n c i e n t g r e e k s , like many people since, Over fifty animal species have been found to use were confounded and fascinated by the migration an internal magnetic compass so far, and several of birds. Homer recognised that cranes “flee different mechanisms have been proposed and the winter and the terrible rains and fly off to observed. The most established mechanism relies the world’s end”. Meanwhile, Aristotle wrongly on the presence of small crystals of magnetite, a asserted that each year summer redstarts would naturally magnetic mineral, in either the nose or the transform into robins come winter, as the two beak, surrounded by receptor nerves. Magnetite has species were never seen in Greece together. In been found in many animals, including humans, modern times, we have come to appreciate the vast where it can be used to sense the magnetic field distances covered by migratory animals and the of the Earth and create a magnetic field map for remarkable precision with which they make the migration. However, in experiments on birds where journey. How is this feat achieved? this magnetite receptor was deliberately disrupted It is known that animals use sounds, landmarks by anaesthetic or a strong magnetic pulse, the birds or even smells to guide and navigate their way could still orientate themselves along the magnetic across continents. But the most intriguing and least field. This suggests that there is an alternative understood navigation ability is magnetoreception: mechanism at work. Even more intriguingly, this the detection of the Earth’s magnetic field through alternative magnetoreception mechanism only works an internal, biological compass. Evidence for this when there is visible light, and did not appear to be capability was shown in a wide variety of animals, influenced by reversing the polarity of the field. from ants to crocodiles. In fact, wildlife rangers in In 1978, Klaus Schulten suggested a mechanism Florida resorted to taping magnets to the heads of for this type of magnetoreception, known as the crocodiles in order to prevent them finding their radical pair mechanism. This mechanism proposes Robins were one of the first way back after being relocated. Magnetoreception that there is a light-activated reaction in the bird’s species to be has even been suggested in the humble cow, eye that is affected by magnetism. By detecting the observed using after researchers using Google Earth accidentally rate of the reaction, birds can sense the strength and an internal discovered that cows tend to line up parallel to the direction of Earth’s magnetic field. The problem magnetic Earth’s magnetic field. with this idea is that the Earth’s magnetic field is compass Magnetoreception was first observed in captive incredibly weak, and so its influence on a normal robins in 1957. In autumn, when it was time for reaction is six orders of magnitude less than the v i d them to migrate from Frankfurt to Spain, they energies involved in a normal chemical reaction. ve j / Da a kept flying southwest in their cage. This happened How could it possibly have a detectable effect? even though the room was isolated from any The secret to detecting the magnetic field lies in Diamon dd external visual stimuli with which the robins could generating a pair of radicals, which are molecules orientate themselves. This led to the idea that with unpaired electrons that interact strongly with robins might use an internal magnetic compass to magnetic fields. Creating these radicals requires a migrate. Many studies have been conducted since, burst of energy, as provided when the molecules but controversy still rages over the exact underlying are exposed to light. Within a suitable molecule or mechanism of magnetoreception. protein, two radicals can form what is known as a

12 Bird’s Eye View Easter 2011 ‘spin-correlated pair’ that exist in two different states. Conversion between these two states is affected by

a magnetic field, and the rate of conversion can J e nny Flying be monitored through the concentration of the radicals. In this way, a weak magnetic field can become detectable by cells in an organism. The radical pair mechanism fits with the observations that cannot be reconciled with magnetite receptors. It is both dependent on the presence of light and unresponsive to the polarity of the field. Experimental evidence was lacking in 1978 when Schulten proposed the mechanism, so the idea received little attention for twenty years. In 2000, a research group from Illinois suggested that proteins known as cryptochromes may be behind this source of magnetoreception. With growing evidence of weak magnetic fields Birds use small Cryptochrome proteins are found in the eye of affecting biological processes, there is increasing crystals of robins, and absorb blue light to initiate a radical interest in how they might affect us. Numerous magnetite in reaction—the perfect candidate to generate studies have shown a significant correlation between their beaks to biologically detectable spin-correlated radical pairs. proximity to high-voltage power lines—which carry create magnetic This led to renewed interest in the area, including a low frequency magnetic field­­—and increased rates field maps for migration the development of a proof-of-principle artificial of childhood leukaemia. In 2001 the International magnetoreceptor system by a team of researchers Agency for Research on Cancer classified extremely at Oxford University. This was the first man-made low frequency magnetic fields as a possible chemical compass; the first artificial chemical carcinogen. Yet several attempts to demonstrate system sufficiently sensitive to detect the Earth’s magnetic field induced carcinogenesis or tumour weak magnetic field on the planet’s surface. promotion in cells have failed, so this issue is still The contribution of cryptochrome and the radical surrounded by uncertainty. pair mechanism to magnetoreception in animals is Perhaps in years to come our suspicions of still being investigated. Despite initial scepticism, magnetic fields transforming healthy cells into evidence from model systems and computational cancerous ones might be viewed just as fanciful as work has shown that this mechanism is feasible for Aristotle’s redstarts to robins hypothesis. While we detecting magnetism. Cryptochromes are primarily cannot be sure yet that power lines cause cancer, responsible for maintaining circadian rhythms further analysis of Google Earth has shown that in many animals, including humans. Like many they can certainly disrupt the ability of cows to proteins throughout evolution, cryptochromes have line up with the Earth’s magnetic field—tricking found a new role in a different part of the body. them into aligning with the magnetic field of the From their presence in the eye, it has even been power line instead. suggested that robins can sense the results of the radical reaction along the optic nerve, therefore the Ian Le Guillou is a PhD student in the Department direction of the magnetic field may be visible to of Biochemistry them in some sense. Due to magneto- Bill L iao reception, cows tend to line up parallel to the Earth’s magnetic field

Easter 2011 Bird’s Eye View 13 DOMINIC McKENZIE Superheroes, Fact or Fiction? Mark Nicholson discovers how nature has turned fantasy into reality

w h a t a b i l i t i e s spring to mind when someone says mechanisms to increase their lift beyond that predicted ‘superhero’? The ability to fly? Walking on walls? Or an by simple fluid mechanics. Firstly, their wings beat at a uncanny talent for surviving against the odds? Although sharp angle to horizontal, creating an effect known in Marvel Comics have been writing far-fetched tales aviation as stalling. In aircraft, this is disastrous, causing about characters with superhuman powers for decades, huge loss of lift due to separation of the air flow from evolution has turned fiction into reality and provided the wing and often causes the plane to crash. In insects us with living, breathing and indeed flying proof that however, the act of stalling creates a vortex (think it got there first. So how do animals effortlessly achieve miniature whirlwind) immediately above the leading these things that humans merely dream of? And can we edge of the wing, which provides a large lifting force, replicate them? almost as if the insect is being sucked upwards. Secondly, A huge number of species across the animal kingdom as their wings travel through the air, they rotate. This can fly, from buzzing midges to lumbering vultures. But rotation creates an additional down-current, which not all fliers are created equal. Most birds are only able helps to keep them aloft in a manner analogous to a to fly forwards, and are often relatively ungainly in the tennis ball with backspin. Finally, in addition to creating air, at least as compared to their smaller brethren: the the leading edge vortex, any wing beat will inevitably insects. Insects are often capable of flying backwards create smaller trailing edge vortices behind the wing. or hovering on the spot, more like a helicopter than These usually sap energy from the flier, but insects have an aeroplane, and possess a fine control over flight that adapted to sweep their wings back through the turbulent many birds lack. This allows them to land on your skin air, recapturing energy that would otherwise be lost. without detection, or even land on water. But how do All these mechanisms contribute to a system far more they accomplish their feats of aerial acrobatics? innovative than our brute-force methods of getting into It turns out that insect flight is a complex the air. One complex enough that we’re unlikely to be phenomenon that is still poorly understood. According replicating it any time soon. to some researchers, insects use at least three different So perhaps insect-like flight is out of our reach, but walking on walls is a different story. Many species Insect flight is possess the ability to hang around obnoxiously on far more agile our ceilings and walls. Their methods may vary, but than birds or i g nal s OakleyOr a couple of unifying themes emerge. Small insects, aeroplanes often flies, tend to take the rather obvious route of having sticky feet. They have tiny glands which slowly secrete an oily adhesive that literally glues them to the surface in question. Spiders have claws on their feet that hook into grooves too small for us to see (which, incidentally, is why they struggle to get out of very smooth containers such as baths and sinks). Yet clever as these two options are, the most ubiquitous and ingenious method is yet to come and proves that you don’t have to be an insect to have superhero qualities. This number is showcased by a friendly little creature: the gecko.

14 Superheroes, Fact or Fiction? Easter 2011 Gecko feet stick to surfaces using a well-known Insects can avoid freezing at temperatures piece of chemistry called van der Waals forces. These below zero by utilising the curious properties forces are attractive, though very small, and exhibited of ultra-pure water. The scientific principle by all atoms and molecules towards any other atoms dictates that although conventionally or molecules via generation of instantaneous dipoles. ‘pure’ water freezes at 0°C, water This effect is in part responsible for many everyday which is completely devoid of phenomena, from being able to fill our cars with any impurities remains liquid liquid petrol to the delightful experience of peeling down to around -40°C, defying chewing gum off our shoes. These forces vary inversely all conventional wisdom and with distance, therefore they are very weak when the entering a ‘supercooled’ state. It molecules are greater than a couple of nanometres appears that in ordinary water, apart. Most solid surfaces are too rough to see a ice crystals do not just form significant interaction on this scale, even those we spontaneously; they always think of as being extremely smooth and flat such nucleate around some impurity, such as a as glass. This is because only a tiny fraction of the speck of dirt. This impurity lowers the surface surfaces are ‘touching’ closely enough to experience area of the budding crystal, reducing its energy s caly a force. The exception to the rule lies with extremely and making it easier for it to form. In order for Furry pliable solids, like the aforementioned chewing crystals to nucleate without their specks of dirt, they Setea on a gum, which warp when sufficient force is applied require a much greater driving force—and so a much gecko’s feet and mould themselves to surfaces so closely that van lower temperature. Some insects stop feeding prior to maximise der Waals forces come into play, sometimes with the onset of freezing temperatures to avoid the food van der Waals interactions, unpleasant consequences. residues and mineral dust particles acting as nucleating allowing them to But humans can’t walk on walls just yet. The agents. Other insects avoid freezing by producing walk on walls problem with sticky pliable substances is that they antifreeze substances such as glycerol for their body tend to stretch and deform when force is applied, fluids. Imagine if you could do that too. and they still fail to have enough van der Waals Organisms using a cryogenic approach take the interactions to bond anything remotely heavy to opposite view—rather than removing all nucleating surfaces­—imagine trying to stick yourself to the agents, they make the effort to create highly efficient ceiling with Blu-Tack. nucleating proteins. Traditionally, intra-organism Once again, nature provides us with the answers. ice has been considered lethal as water expands on Rather than using a single flexible mass, evolution freezing, and so the growing ice tends to rupture has bestowed some animals with structures known cell membranes. However, this only happens if the as setae on their feet. Much like a microscopic ice forms within the cell. Instead, animals such as hairbrush, the setae form a mat of bristles each the wood frog (Rana sylvatica) and many insects a great deal smaller than the hairs on your head. nucleate ice in the intercellular space, which lowers Individually, they deform very easily to allow good the amount of liquid water in the cells, making it contact between the gecko’s foot and the ceiling, harder for the remainder to freeze into large and yet they are all relatively strong, so can be pulled damaging ice crystals. Ultimately, most of the water off intact and re-used millions of times. As a result, in the organism is locked into this extracellular ice, a gecko’s foot is sticky, though it has no glue or and so—when the temperature finally gets so cold claws; it just sticks. Now how about that for a that even the cells freeze—there is so little liquid superhero solution? water left that very few cells burst. Aerial acrobatics and parkour-gone-mad are all Although most of us regard insects as nuisances, very well; animals perform these feats every day. the science which has made this class the most Yet nature’s superheroic tendencies do not end populous on the planet, outweighing all other there. Throughout history, some organisms have species put together, is truly incredible. We should survived incredibly harsh conditions, enduring take the opportunity to learn from our miniature weather that would rapidly kill any human without cousins and other superheroic organisms, and the support of technology. A personal favourite our efforts in mimicking nature will continue of mine are the insects found near the poles, such to enhance our technology. I don’t expect to see as the goldenrod gall moth caterpillar, which can Superman whizz past my window any time soon— survive astonishingly low temperatures, remaining but perhaps Spider-Man isn’t quite so far-fetched. mobile and unfrozen at temperatures as low as Maybe it’s time to stock up on some skin-tight -50°C. Other animals and some plants do freeze, outfits and a cape. but in such a way that they enter a cryogenic state, and so survive to tell the tale some months later Mark Nicholson is a 3rd year undergraduate in the when the temperature increases. Department of Chemistry

Easter 2011 Superheroes, Fact or Fiction? 15 Small Channels, Big Ideas

22 Katpitza Lent 2010 FOCUS

BlueSci explores microfluidic technology and its dazzling array of applications Small Channels, i m a g i n e a c h e m i s t r y l a b the size of a postage stamp. Or a medical device that fits in your wallet with Big Ideas the promise of an instant health check. Perhaps you would like to scan the atmosphere for pathogens and analyse chemicals on Mars, Star Trek style? Thanks to the myriad of rapidly developing technologies that rely on microfluidics, all this is becoming possible. So, how does microfluidics work? Microfluidics is defined as the manipulation of systems in which tiny amounts of fluid flow through very narrow channels. Typically, the channels are as narrow as a human hair, less than 1 millimetre wide. The amount of fluid flowing through a device made with these narrow channels can be as little as several ‘attolitres’, which is 1/1000000000000000000th of a litre, smaller than the volume of the smallest viruses. Microfluidic devices are usually built systematically from a series of basic components, including an entrance for reagents and samples, some means of moving and mixing the fluids, and other components for producing output, such as detection or purification devices. First used as an analytical tool in chemistry, the relatively new technology offers many advantages over larger systems. Devices require a very small volume of reagents, a small amount of sample material, but are capable of delivering high resolution results at low cost and short analysis times. Yet simply scaling down a larger system into micrometre size would not yield a working microfluidic device. This is because the behaviour of fluids at a shrunken scale is very different to that in a larger device. In the narrow channels, fluid flow is turbulent free, so there is very little mixing. If you put coffee and milk down the same channel in your microfluidic device, instead of well-mixed white coffee towards the end of the channel, you will have black coffee and milk, still separated, and flowing side by side. Only when the coffee and milk exit the channel into a big coffee cup would they resume turbulent flow, producing your milky coffee in a few seconds. The smooth flow of fluids in microchannels means that whilst it is easy to keep two different chemicals lbert Fol c h A lbert

Lent 2010 Focus 17 Cate & d Cate Davi S e th f rad n

separate even when they are flowing side by side, it is also very hard to get them to mix. Stirring is not an option because the channels are too narrow. Designers of microfluidic devices have to find ingenious ways to introduce turbulent flow and force mixture, such as building sharp bends into the channels, or using microvalves or micropumps. The potential of microfluidics to facilitate the work of research scientists and medical professionals has led to rapid and exciting developments in the field. Personalised medicine, rapid disease identification, forensic evidence from tiny sample; these technologies may seem decades away from realisation, but the development of lab-on-a-chip devices has helped to bring them closer to reality. These applications depend on identifying genetic material, in particular the exact sequence that builds up a DNA strand. For example, to identify a bacterial cell unambiguously, you need to make a comparison between the DNA sequence of that cell and the sequence of a known bacterium. In many cases, the Professor Seth Fraden is visiting from Brandeis amount of genetic material available is small. In order University in Massachusetts. He specialises in to carry out tests, the DNA extracted from the cell soft condensed matter physics and is currently of interest needs to be ‘amplified’ by a process called spending four months collaborating with polymerase chain reaction (PCR). members of the Department of Chemistry In PCR, the original DNA sample passes through and Cavendish Laboratory in Cambridge. In three specific temperature stages for a large number of America, his group has developed a new protein cycles. First, a high temperature stage breaks apart the crystallisation technology using microfluidics, double helix of DNA in a ‘melting’ process, yielding culminating in a device called the Phase Chip. two single-strand molecules. The temperature is He talks to BlueSci writer Vivek Thacker about lowered in the next stage, where the building blocks his current work and future plans. of DNA adhere to the single chains in a sequence- What started your interest in microfluidics? specific manner. Finally, the temperature is kept low SF: My background is in biological materials, while the building blocks are linked into a strand looking at liquid crystals of viruses. Work on of DNA by an enzyme, yielding two copies of the microfluidics began in my last sabbatical—at the original double helix. Through repeating many such time I was very impressed with the technological cycles, this doubling process can exponentially amplify advances being made by Stephen Quake’s group at Caltech. He had developed a suite of Many of the microfluidic tools to synthesise small amounts artistic images in rt Fol c h A lb e rt of materials on a valve-based network, and he this article are kindly provided by showed that it was a very scalable technology. Albert Folch, I saw that as an advance to study my liquid Professor of Gr eg Cook se y & systems in a very efficient manner, and decided Bioengineering at to pick this up in my upcoming sabbatical. the University of Is it easy to scale up from a microfluidic Washington, system to a bulk system? also Art Editor of SF: No! Because the physics is different, you do the journal not want to have the intention of scaling up. But Lab on a Chip. the technology is scalable. Microfluidic valves The work of his lab has been are made photo-lithographically, like printing, showcased at so the effort to make a hundred is the same. It is BAIT: Bringing Art like semiconductor manufacturing—once you’ve into Technology learnt to make one transistor, you can make ten million of them on the same wafer.

18 Focus Easter2011 FOCUS rt Fol c h Alb e rt rt Fol c h Alb e rt rt Fol c h Alb e rt Gr eg Cooks e y &

the sample mass while conserving the sequence of the as opposed to the linear workflow used in larger Intricate DNA being investigated. DNA analysis machines. Thus microfluidic DNA channels can Traditional methods of PCR require large machines sequencing is much faster. be etched onto and large quantities of reagents, making this process Microfluidic PCR has obvious implications for a handheld expensive and time consuming. In addition, if the human genome sequencing. In the human genome chip, capable amount of sample is tiny, such is often the case in project, the whole DNA sequences of several of carrying out complex forensic investigation, then even after PCR the material individuals were ‘read’. The traditional methods chemical tasks, is still insufficient for analysis. Errors can also be available meant the process took many years and such as analysing introduced by amplifying contaminants, damaging several hundred thousand US dollars. With the ability blood samples admissibility of the DNA evidence in a court of law. to sequence DNA on a microfluidic chip, the process PCR can be speeded up using microfluidic should be faster and cheaper. principles, by performing each stage of the process Beyond looking at DNA in cells, microfluidic on one of three layers of a single chip. Fluid flow is principles can be applied to the detection of cells carefully controlled in the device, allowing mixture and chemicals in body fluids. An example is the only at desired places. The proximity of the layers also i-Stat device, allowing doctors to carry out bedside means reaction products are transferred in a fraction blood tests with almost instantaneous results using a of the time. handheld device. Only a few drops of blood are needed Since typical lab-on-a-chip devices only require to carry out a series of tests. The device allows many several billionths of a litre of reagents and samples, patients to be seen and tested at the same time, as their they have increased sensitivity, accurately amplifying blood is collected onto relatively cheap, single-use and identifying DNA sequences where larger systems microfluidic cassettes. This technology is already in use fail. As many channels and detection chambers can in some parts of the UK; NHS workers in Kent have sit on the same chip, analyses can be done in parallel, reported that it is especially useful for home visits.

Your Phase Chip carries out protein crystallisation. Is this something some labs focus on particularly? SF: Some labs do focus on making protein crystals, but their interest is not on the crystallisation process itself. They just want to use the crystals in diffraction experiments and obtain the structure of the proteins. If I am going to make a contribution to the field, the product has to leave my lab. If the chip costs $1000, then it will not leave my lab because it is not commercially viable. Since realising this, I have focussed on the question: can we make a device which retains the essential qualities but is 100 times cheaper? How do you propose to do that? SF: You can achieve protein crystallisation with discrete components. Before we had one integrated device that did everything, but now you can make one optimised device for each step. To really tackle the protein crystallisation problem, since the crystals we produce are so small, we have to develop a whole new suite of technologies to complement ours, so I have set up a collaboration with a synchrotron beam scientist who specialises in diffraction experiments. The whole community is converging on this idea because it is clear that small crystals are easier to make than bigger ones. Where do you see microfluidic technology going in the future? SF: Microfluidics will have applications in a large set of devices, but they will definitely be under-the-hood as components. The first ten years of the field were focussed on building extended microfluidic devices, but the future is going to be integration into larger systems.

Easter 2011 Focus 19 There is even potential for preventative health quantities, so growing nanoparticles more accurately, care using detection devices built with microfluidic even at a small scale, is desirable. technology. Devices used to detect particular pathogens Microfluidics is ideal for meeting this requirement. are known as immunoassays. They make use of Not only does it allow rapid and controllable mixing, antibodies, which are proteins that bind to specific but variables such as temperature, concentration molecules, particularly those present on the surface gradients and pressure can be manipulated to produce of a pathogen. Microfluidic devices allow bound and particles of specific size. Nanoparticles themselves have unbound antibodies to be discriminated according a wide range of applications: from drug delivery and to their different properties, indicating presence or medical diagnostics, to optical coatings and catalysis. absence of a pathogen. As with DNA sequencing, The efficiency and accuracy that microfluidic devices microfluidic devices are smaller, more portable, and lend to nanoparticle synthesis will allow us to make faster at this specific task than a whole research lab full technological progress in diverse fields. of equipment. It is claimed that immunoassays can Chemical detection is another area where detect E. coli in ground beef at a resolution of just one microfluidic principles can be applied, especially cell per gram. Perhaps in a few years’ time, these wallet- where the chemical of interest is present in a complex sized immunoassays will become an essential travel mixture at trace level. The primary focus for this accessory, just like clean water tablets. type of technology is to optimise sensitivity and While microfluidic chips have been applied to solve specificity of measurement in forms that are low cost, many biological problems, its initial use in analytical fully autonomous and miniaturised for portability. chemistry has flourished and diversified. Now we have One of the main techniques targeted is that of gas devices that are capable of advanced chemical synthesis chromatography (GC), a highly sensitive chemical and detection, even beyond the Earth. analysis which is used to detect and quantify chemicals The basic techniques and equipment in the in air, water and soil. chemist’s toolkit have remained largely unchanged A key part of existing GC systems is the since the first laboratory synthesis of urea in 1828, fractionation column, which separates samples into and in macroscopic situations miniaturisation of these their chemical components. These then pass through processes is not necessary. However, one area where a detector to produce a chromatogram identifying the the importance of microfluidics is noticeable is in various chemicals. Typically the column is between synthesizing nanomaterials. 1.5 and 10 metres in length, making it far too bulky The properties of nanoparticles are dependent on to transport. their size and shape. Current systems for growing For environmental testing, in particular atmospheric nanoparticles show severe limitations, producing monitoring, samples are currently collected at remote generally broad size distributions, leading to mixtures locations and then returned to a laboratory for analysis. with unpredictable properties. The requirement for a A small-scale, portable gas chromatography system specific particle size can supersede the need for large would enable air quality to be analysed and recorded

Nanoparticles need to have a well-defined f ol c h a lb e rt range of size and B y e o n gdu Lee tory,

shape to function Chris Ni e ls & as catalysts (left) At microfluidic tio na l La bor a quantities, fluids

flow smoothly Argo n i ne N a and do not mix easily, allowing finetuned manipulations and control (right)

20 Focus Easter 2011 FOCUS V Y t f olch Tho m as M e i r r, U S NA Kyl e Ste c k l r, ls & alb e r chris ni e ls &

at the site of measurement, increasing the speed of substances that new microfluidic devices are able to test The ExoMars response to any adverse changes. Microfluidics makes for, including chemicals such as ricin and sarin which rover will be such a device possible as it enables miniaturisation of have both been associated with the military activities of equipped with the GC column onto a single 10 centimetre square the Cold War. a miniaturised piece of glass. The USA has a strong focus on developing device to search Microfluidics has also allowed the miniaturisation microfluidic technologies for defense applications. A for life (left) A combinatorial of capillary electrophoresis, a separation technique number of American companies have invested and microfluidic that uses narrow-bore capillaries to separate developed commercial biodefense solutions built mixer (middle) molecules based on differences in charge, size and on a microfluidic technology. The US Department Biological defense hydrophobicity. This is one of the proposed devices to of Homeland Security, as early as 2005, had already can be enhanced be included on the European ExoMars rover mission expressed interest in upgrading slow manual by microfluidic scheduled for launch in 2013. The martian soil will atmospheric testing facilities with automated technology be analysed for traces of biological compounds such microfluidic systems across major cities. (right) as amino acids, the building blocks of proteins. The There seems to be no end to the new ways in proposed experiment would separate amino acids which the use of microfluidic technologies can be from a soil sample, then use microfluidic capillaries to integrated into our everyday activities. Earlier this identify them by charge, size and crucially, chirality. year, researchers from Purdue University (Indiana, This refers to the handedness of the amino acids which USA) discovered a new technique for conducting can exist in two mirror image forms, left-handed or microfluidic analysis on paper. Using lasers to carve right-handed. In simple chemical reactions, these channels in the hydrophobic coating, it is hoped molecules behave in the same way, but when it comes that this innovation will provide an even more to complex biological reactions involving enzymes, inexpensive method to bring microfluidic technology the chirality matters. This is shown by the fact that all to mainstream markets. proteins on Earth are made up of left-handed amino Microfluidics has established itself as an exciting acids. If the device on Mars finds an excess of amino field from which we can be sure that even more acids of one particular chirality, it will be a clear sign applications will emerge. As established technologies they are biological in origin. become ever more efficient and economical, the It would be impossible to send into space the imaginative application of microfluidics to new amount of equipment required for this type of analysis technology will enrich and inform our understanding in conventional setups, but with a microfluidic device, of our world and beyond. weighing only about two to three hundred grams, the search for life will be carried out right there on Mars. Helen Gaffney is a second year Natural Sciences A bit closer to home, devices based on the Tripos student same technology are being used to police our own atmosphere. As many nations continue to be Wendy Mak is a PhD student in the Department concerned about the threat of biological weapons, of Physics microfluidic methods are beginning to provide Lindsey Nield is a PhD student in the Department attractive antidotes to fear. of Physics Small-scale detectors can now identify a broad range of chemical and biological agents. By protein Vivek Thacker is a PhD student in the Department fingerprinting, harmful bacteria and viruses are singled of Physics out. Biotoxins also feature in the vast catalogue of

Easter 2011 Focus 21 Women Who Led the Way Jessica Robinson uncovers some of the pioneering female scientists

t h i s y e a r m a r k s 100 y e a r s since Marie Curie Marie Curie is was awarded the second of her two Nobel Prizes, one of only four an accolade which places her in a very select group people to have of only four individuals in the entire history of won two Nobel Prizes the Nobel Prize. This centenary provides an ideal opportunity to reflect upon the achievements of some of the earliest pioneering female scientists. These women made significant contributions to vital areas of modern science, including astronomy, computing and medicine despite the barriers held against them at the time. Up until recent times, academia was a ‘man’s no be l foundation world’. Cambridge only awarded its first degrees to women in 1921 and did not allow women to be full Caroline Herschel (1750-1848) was one of university members until 1947. However there were these talented assistants. Thought to be unlikely many individuals who pursued life-long careers in to marry due to her stunted growth, she was put the sciences during the previous two centuries. at her brother’s disposal. She went on to discover The field of astronomy provided one of the first eight comets, including the catchily named 35P/ opportunities for women to become scientists. This Herschel-Rigollet, and perfected complicated was because the work always required two people; equations on spherical trigonometry which allowed one person to operate the telescope, and one to the position of stars to be calculated. She even record the findings. In this way, some women found received a small salary from King George III for themselves assisting their father, brother or husband her work, making her the first paid female scientist. in his research. Some assistants turned out to be Interestingly, it was said that Herschel never learnt more talented than their male counterparts, making her multiplication tables, and always had to carry significant findings themselves. them with her on a piece of paper, despite her marvellously analytical mind. Who says you need to The Maria know your 12 times tables? Reactor in Women made developments on modern Poland, which is a calculations and computation methods as early as research nuclear reactor named 1843, as shown by Augusta Ada King. She was the after Marie Curie only legitimate child of the poet Lord Byron, the Countess of Lovelace, and possibly the first ever computer programmer. As a skilled mathematician, she was a good friend of Cambridge professor Charles Babbage, the ‘father of the computer’. Babbage invented, but failed to build, many steam-driven, mechanical calculating machines. Among these was the Analytical Engine, which he envisaged producing long logarithms. King was asked to translate a French article about the Analytical Engine into English, and Babbage suggested she write her own notes on the subject. These notes turned out to be three times as long as the original article, and included an algorithm devised by King to be used on the machine, which is in essence the first computer program. Inspired by the cards with punched holes used by weavers to produce intricate patterns in cloth, King thought m i Ns ka Ru A . the same technique could be used to dictate the

22 Behind the Science Easter 2011 workings of the Analytical Engine. Indeed, the first Augusta Ada computers of the 20th century were programmed King, often said by punched cards. It could be argued that King to be the world’s was more of a visionary than Babbage, who only first computer wanted to create a machine for number crunching, programmer whereas she foresaw other potential functionality such as creating music. While modern computing is still dominated by men, no one is surprised any more by the sight of a female doctor. Yet the field of medicine used to be an exclusively male profession, and the first female doctors in the end of the 19th century faced many challenges—leading to the true sex of the first woman medic not actually being revealed until after her death. Much to the disbelief of many, Martha Stuart, or Dr James Barry as she was known, was said to have had a very hot temper and was incredibly flirtatious with beautiful women—perhaps out of frustration, or perhaps overcompensating in her disguise. She was an excellent doctor who was promoted to t e ddington a l g ll e ry, s ic Inspector General, the highest rank possible for an army physician. tion a l phy It is impossible to talk about great females in n a medicine without mentioning the ‘Lady of the burns and sickness from years of working in such Lamp’, Florence Nightingale. Nightingale is close contact with radioactive materials. famous for bringing about a drastic reduction in The Curies’ hard work was rewarded in 1903 with Charles death rates in the Crimean War hospitals, from a joint Nobel prize in Physics with Becquerel, after Babbage’s 42% to 2%, by enforcing cleanliness and better which Pierre was made Professor at the Sorbonne. Analytical Engine nursing practices. Moreover, she started the first Life looked quite perfect for Marie: two beautiful arguably owes women’s college of nursing in London, and was an daughters, a loving husband and the highest more to the expert statistician. Her reports were very influential acknowledgement for her contributions to science. visionary insight in the sanitary reforms of the late 1800s. Sadly, in 1906 Pierre was hit by a horse-drawn of Augusta Ada Moving from medicine to back to the physical vehicle in the street and killed instantly. Marie was King than to sciences, 1867 takes us to the start of Marie Curie’s devastated but did not give up on her career; she Babbage himself career. Born in Poland as Maria Sklodowska, she took over Pierre’s Sorbonne chair, becoming France’s moved to Paris in 1867 to study for a degree in first female professor. She continued characterising Mathematics and Physics. There she met Pierre her new element, radium, and was awarded her Curie, and they were married within the year. They second Nobel Prize in 1911, this time in Chemistry. shared a love for science and worked together on The Curies’ work was critical in the development radioactivity, a term coined by Marie herself. of X-rays for medical use. At the break of World For her doctoral studies, Marie Curie worked War One, Marie set up a Red Cross Radiation Unit, on the uranium-rich ore, pitchblende, which equipped ambulances with X-ray machines and she discovered to be more radioactive than worked on the front lines, nursing injured soldiers pure uranium. Reasoning that new radioactive with her daughter. elements must be present in the ore, she focussed Her legacy lives on in numerous ways; be it in on its chemical separation, while Pierre studied the many universities, the charity, or even the road its radiation properties. Through this work, she in Paris named after Marie and Pierre. However, discovered two new elements: polonium, named perhaps her biggest legacy is her example for after her home country, and radium, which Pierre women and men with scientific aspirations: with o b i as Sch ae f e r T showed could kill cancerous cells. hard work and true devotion, it is possible to o It took Marie four years to purify 0.1 gram of achieve the impossible. Mir k radium from 8000 kilogram of pitchblende. She wrote, “I had to spend a whole day mixing a boiling Jessica Robinson is a PhD student in the mass with a heavy iron rod nearly as large as myself. Department of Oncology I would be broken with fatigue by the end of the day.” Marie and Pierre both suffered from radiation

Easter 2011 Behind the Science 23 Common Knowledge Tim Middleton gives his perspective on access to data and the recent scandals

“Why should I make the data available to you, when Indeed, there are persuasive arguments for open your aim is to try and find something wrong with it?” access to scientific information. It forces scientists Dr Phil Jones, head of the Climatic Research Unit to think about the best way to communicate their at the University of East Anglia findings to those beyond the ivory tower. It also enables a much more complete peer-review process: information i s controversial . From Climategate absolutely anyone can check scientists’ conclusions to WikiLeaks, the issue of access to information has against their original observations. Open access been forced to the forefront of public debate. But is useful for other scientists too. Scientists rarely how should scientists deal with information? Should publish the results of experiments that don’t work, all scientific information be made publicly available? believing that they lack impact. But there is often In 1676 Robert Hooke published the anagram: just as much value in knowing what does not work “ceiiinosssstuv”. It was not until two years later as in knowing what does. Scientists in another that he revealed what he had discovered about the institution may waste time and money pursuing an properties of elastic springs: “ut tension, sic vis”—as approach which is known to be flawed, unless such the extension, so the force. This seems bizarre practice information is made freely available. to us today, but in Hooke’s time scientists commonly The growing sentiment of the ‘public right to published their results in the form of a cipher; others know’ culminated in the introduction of the UK such as Leonardo, Huygens and Galileo did the same. Freedom of Information (FoI) Act in January In doing so, they bought themselves time to work on 2005. The Act enables anyone to submit a request their ideas without running the risk of being pipped to a public body, such as a university, for any to intellectual glory. information they like. The institution must But science is no longer about hoarding your results respond to any requests within twenty days and until you have developed a grand theory to explain it the request must ultimately be granted unless an all. Science today prides itself on large collaborations exemption can be satisfied. Exemptions can be for the benefit of the whole of society. Meanwhile, granted if the data is available elsewhere, intended the multimedia revolution, in particular the explosion for publication, deemed to prejudice public affairs of material in online blogs, encourages an ethos of or too costly to make available. The Act has had instant access to all forms of information. This has profound consequences for science. Some people been accompanied by an increasing political drive claim that FoI requests usefully facilitate the much- for ‘transparency’: openness has become associated needed move to greater openness, but there are also not only with good science, but also with well- reasons to be cautious. functioning democracies. The leaked emails of the Climategate scandal revealed correspondence about FoI requests for data Robert Hooke between scientists at the Climatic Research Unit is one of the at the University of East Anglia. In one such email leading figures Dr Phil Jones, head of the Unit, said “why should of the scientific revolution. I make the data available to you, when your aim Hooke, like many is to try and find something wrong with it?” Dr others of his Jones was severely criticised for this position. What day, published he says contradicts the accepted consensus that the his results in the peer-review process is a vital part of the scientific form of ciphers method; your science must be analysed critically to protect his by others to validate its truthfulness. Professor Paul discoveries Nurse, President of the Royal Society, goes further and advises that research scientists should be “the worst enemy of their own ideas”. A healthy sense of scepticism is what ensures that the majority of published science is accurate. But Dr Jones was right to be cautious. Scientists a g reer r i t are justifiably uneasy about sharing their work with

24 Perspective Easter 2011 the general public unless it is on their own terms, not least for fear of being misrepresented. Scientists had spent twenty-five years collating the data that was being requested. Dr Jones didn’t want to comply with vexatious FoI requests only to find untrained polemics throughout the blogosphere ranting about the data. On one particular weekend in 2009 Dr Jones received sixty FoI requests, each asking for data from five countries, listed alphabetically. Dr Jones had made mistakes in the way he had handled previous requests, but such coordinated hassling of scientists seems inappropriate. Climategate was a much-needed wake-up call for the scientific community, but amidst the ensuing arguments the focus was often lost. One commentator wryly summarised affairs saying: “are we more interested in reading scientists’ emails or in shaping the values that guide their work?” Contrastingly, there are other academics who regularly use FoI requests to conduct their own c h r i s k amk e n research. Ironically, Martin Jones of Glasgow of them are not. The latter are not in a position Institutions don’t Caledonian University is using the FoI process to confirm or challenge scientists’ conclusions. have to comply to investigate how many vexatious FoI requests Worse, if a scientist’s job becomes simply to with Freedom are received in the public sector! However, convey data from the point of observation to the of Information this phenomenon is largely confined to the public sphere, where it is then discussed by an requests if they arts. Academic scientists in the same discipline army of unqualified bloggers, then there remains can show that it would be very typically share data amongst themselves outside little incentive to become a scientist. The value of time-consuming the FoI system and it would be considered poor scientific training and the appeal of proposing and or expensive to form to do otherwise. testing your own theories would be lost. make the data Whilst the arguments for greater openness are Rather than letting the mutually distrustful available compelling, FoI requests are not the best method process of FoI hold sway, scientists should look for for broadening the uptake of scientific knowledge. proactive ways to make their work available to the The type of information that can be extracted general public. Funding from research councils via FoI requests is in some senses far-reaching, is increasingly contingent on some sort of data but in other ways inherently limited. What use is release scheme. A plan to publish data in the future raw data to the general public if they don’t have avoids premature disclosure but ensures that the the scientific training and expertise to interpret information will reach the public domain for those it? Although some of the eager journalists and that are interested. Also, expert deliberations, for sceptics out there are scientific experts, or at example discussions of the Intergovernmental Panel least well-informed amateurs, a large number on Climate Change, should be made public events. Some say that this engagement is necessary to ensure that science is socially beneficial. But such The Hubert a utilitarian view of science serves to perpetuate Lamb Building, the feeling that everyone has an immediate right home of the Climatic to know. Instead, what must be cultivated is the Research Unit at opportunity for scientists to explain their research the University of and why it is exciting in a respectful environment, East Anglia and with room for grown-up discourse on any potential the centre of points of disagreement. Scientific research should the Climategate be made common knowledge not because of controversy dictatorial policy, but because scientists want to share their fascination with the universe.

Tim Middleton is a 3rd year undergraduate in the Department of Earth Sciences c h r i so

Easter 2011 Perspective 25 Shadow Catchers Stephanie Glaser discovers how shadows caught by camera-less photography bring light to an image

p a i n t i n g w i t h o u t c o l o u r ? Writing without a solved by William Henry Fox Talbot with the help pen? Singing without a voice? None of these seem of Sir John Herschel in 1834, when they fixed to be possible. But what about photography without images using a sodium hyposulphate solution and a camera? Is there a way to capture an image, the made the artwork durable. This also led to the light, a mood, or a person directly onto paper? This development of the first real, if simplistic camera, rare thought experiment was recently addressed at by placing light-sensitive paper into a ‘camera the London Victoria and Albert Museum exhibition obscura’, basically a box with a lens. Shadow Catchers, which featured the work of five In the late 19th century advances in camera- contemporary artists who use camera-less photography development were fast, and dominated by techniques in their work. commercial and practical pressures. Only a few Photograms of Your first steps into the darkened exhibition room artists such as Talbot and Anna Atkins kept the movements welcome you into a new world you have never experimenting without the use of a camera to of a snake (top) experienced before. Being used to natural or artificial create art or botanical illustrations in true scale. and the development bright lights and the colourful life outside, it makes Much later, in the early 20th century, Christian of spawn you feel uncomfortable initially. Your first gaze falls Schad rediscovered the use of camera-less photography (middle, bottom) on what seems to be the shadow of a woman leaning as an artistic medium, which led numerous artists over a chair, and after only a moment you realise that to revive the nearly forgotten technique. After 1922, the image cannot be a real shadow, as no one is sitting Man Ray and László Moholy-Nagy became the in the room. Looking further, shadows of people in two artists to adopt the techniques into their art. various different poses, somehow appearing three Man Ray was an American artist best known for his dimensional, are captured in true size. Images with modern photography. He described photography as fine lines like broken glass and pictures which appear “a comfort, because it reproduces what is known” and to be made of waves of water come into view. Scenes implemented camera-less photography as a means captured with careful thought, people and objects of creating a “sensual realisation of dreams and the arranged precisely, and pictures that are beyond subconscious”. The images he created and called reality; all created by camera-less photography. ‘Rayographs’ often contained recognisable objects and The basic techniques of camera-less photography geometrical forms but in new ways of visualisation can be traced back through history. As early as as light and shadows. He also used variable exposure a m FUSS the 8th century the Arab alchemist Jābir ibn times on single objects and exploited the effect of © Ad © Hayyān made the discovery that silver nitrate movement in Rayographs. In contrast to Ray’s realism, changes its colour upon exposure to light. In the László Moholy-Nagy, a Hungarian painter and 16th century Georg Fabricius experimented with photographer, created images that were more abstract, silver chloride and also found that under certain showing dynamic white forms in black space. “The circumstances a darkening of the material can be light can play a central role as the pigments do in a observed, although the nature of the chemical painting”, Maholy-Nagy stated. reactions involved was still unknown. In 1725, the After the Second World War, photography was German researcher Heinrich Schulze proved that heavily used for documentation of political and the reaction of silver compounds was due to light social events and the art of camera-less photography © SU s AN D ERGES exposure. The use of an artistic technique based again was close to being forgotten. Only between on these chemicals was first described in 1802 in a 1950 and 1960 did artists and photographers revived publication by Thomas Wedgewood and Humphry their interest in experimentation and alternative Davy. Leaves and other small objects or paintings techniques. Two of the protagonists at the Shadow on glass were placed onto surfaces covered with Catchers exhibition started their careers during silver nitrate. After exposure to sunlight, only this time: Floris Neusüss, a German Professor of the painted or covered areas were not affected by Photography, and Pierre Cordier, a Belgian artist. light. However, the ability to fix the images was The five artists of the Shadow Catchers exhibition still lacking, so they disappeared immediately exploit different strategies to capture light and © SU s AN D ERGES when fully exposed to light. This problem was shadows on light-sensitive surfaces. The most intuitive

26 Arts and Reviews Easter 2011 technique uses gelatine-silver prints and creates pictures termed ‘photograms’. In this technique, photosensitive surfaces, mostly coats of gelatine containing silver salts, change colour upon exposure to light and subsequent development. Objects that are placed onto these surfaces in certain light conditions will produce pictures of their shadows. Parts of objects, as seen in Floris Neusüss’ ‘Körperfotogramms’ (whole- body photograms), can partially block out light and therefore give rise to lighter shadows, while other parts that are in close contact with the surface create dark shadows of complete light exclusion. This creates a 3-dimensional effect in the picture and gives Neusüss’ images a surreal quality. The full-sized nude females he t mus e um recorded as photograms are an example of his ability to create “a feeling of surreal detachment, a sense of disengagement from time and the physical world.” er Alb r i a & Vi c to Another technique of camera-less photography What is seen has never been in a camera. Life itself is Camera-less involves creating ‘chemigrams’ by treating the image. Viewers sense it. They feel the difference.” photographs can photographic paper with varnishes, oils or His pictures seem to capture movements frozen in capture shadows photographic chemicals. It has been adopted by time. Recurring motifs in his work include animals with eerie effects another of the exhibition artists, Pierre Cordier, such as snakes and butterflies, babies and water. For who has perfected his techniques over fifty years this exhibition, he placed a child onto photographic through experimentation and research. Describing paper which was submerged in shallow water and his work as painting, he makes the pictures step- fired a flashlight onto the paper. The resulting image by-step, usually by carefully blocking the light captures the baby and its movements as reflected in the sensitive surfaces with wax or plastic patterns and wave patterns the movement created in the water. applying developer and fixer to unblocked regions. Bristol-born artist Garry Fabian Miller’s work The pictures Cordier creates are often technical, is influenced by the properties of light and time. including labyrinths and tiny details nearly invisible His images are simple, yet energetic. His early without a magnifying glass. works included leaves collected during spring In contrast to Cordier’s exquisitely planned detail, as they change their colour from pale yellow to Susan Derges’ images are created by the forces of green or petals recorded over a day’s time span. In nature. She mostly uses gelatine-silver and dye- recent works he created more abstract minimalistic destruction prints, which use positive colour paper pictures emphasising strong colourful shapes on that is bleached out upon development where the dyes a black background. Today he mostly uses dye- were not exposed. She employs various techniques to destruction paper, beams of light or water-filled create magnificent effects on her pictures: by exposing glass vessels to create the desired effects. For Miller, photographic paper to moonlight, flashlight, or light “is not a symbol for something else but the immersing the paper in a river before exposure to light. very embodiment of creative energy.” Her images often involve an element of chance and Without any real sense of dimension in the are influenced by the wildness and unpredictability of images, objects seem to float above the pictures the elements. In her early work in the 1970s, Derges rather than resting on the surface. This unusual used sound waves to form geometrical patterns in experience makes the viewer uneasy, giving rise to carborundum powder on light sensitive paper, thereby unexpected curiosity. Each picture is formed by creating a visual representation of waves. In her series the creative vision of one of five artists who use on the development of frog spawn into frogs, she camera-less photography to portray what Floris placed spawn-filled jam jars on an enlarging lens which Neusüss describes as “the tension between the she exposed to light in a darkroom and recorded on the hidden and the revealed.” paper below; the cycle of life was captured without a Leaving the rooms of the exhibition, you return camera. Derges has an intimate connection to science to normal life, leaving the warm darkness and and many of her images make commonly hidden dreamy landscapes behind you. What remains is the forces of nature visible to the imaginative human eye. discovery of a photographic art that always creates Adam Fuss is an English photographer who originals directly, without negatives involved. discovered camera-less photography in 1986 and has since used this technique to create photograms that, Stephanie Glaser is a PhD student in the as he describes it, “give the alphabet unfamiliar letters. Department of Biochemistry

Easter 2011 Arts and Reviews 27 Immortal Hearts and Henrietta Nicola Stead looks back at the beginnings of cell culture

i t w a s l a t e January 1951 when a young African- of frog lymph fluid on a coverslip. The coverslip American woman walked into Johns Hopkins was inverted over a glass slide with a well in the Hospital complaining of a “knot on her womb”. middle, allowing the clotted lymph droplet to hang Her name was Henrietta Lacks and unbeknownst suspended from the coverslip. Within this droplet, to her, or her family, this event changed the face of Harrison was able to maintain the cells alive in the medical and biological research. Her treatment for tissue and observe the active outgrowth of nerve cervical cancer resulted in the creation of the HeLa fibres from them—thus settling the debate. cell line, the first immortal human cell line—a major While Harrison’s work had solved the debate, accomplishment in the new and rapidly growing his work would prove of foremost importance in field of cell and tissue culture. establishing the field of cell culture. Using his skill Fascination with cells has engaged scientists since and training as a surgeon, he had solved the basic the 17th Century, when Robert Hooke looked down problems of culturing tissues: through his choices of a microscope at cork bark and saw the basic building growth medium, culture vessel and surgical methods blocks of life for the first time. He named these for preventing contamination, he provided scientists repeating blocks “cells”. Soon afterwards, in 1674, with the basic tools for culturing cells and tissues. inspired by Hooke’s work, the Dutchman Anton van Harrison was a modest man, and his groundbreaking Leeuwenhoek observed living and moving, single- experiment went largely unnoticed by the public celled microbes. By the early 1800s, many scientists and the media. However the scientific community including Robert Koch and Louis Pasteur had were very interested, and cell culture developed with pioneered the culture and study of microbes. great pace. As with any newly emerging field, cell However, a breakthrough in culturing cells from culture was at times surrounded by controversy. This multicellular organisms would not occur until almost simultaneous furtherance and hindrance of the field a century later. In 1907 Ross Harrison found himself is no better embodied than by the French surgeon involved in a debate over whether or not nerve fibres and biologist, Alexis Carrel, who pursued the work were outgrowths of individual cells. The study of Harrison had started. the nervous system had traditionally been purely After receiving much acclaim for his novel observational. Harrison decided to resolve the debate surgical techniques, Carrel turned his attention to by studying nerve fibre growth in vitro. To do this, cell culture. Under the tutelage of fellow scientist he adapted the hanging drop technique developed Montrose Burrows at the Rockefeller Institute, for the culture of microbes. Harrison cut fragments Carrel began to culture tissues from many different of frog neural tube, the embryonic precursor of the animals. He used methods that Burrows had learnt central nervous system, and placed them in a drop while visiting Harrison’s lab, adapting and perfecting

Early cell culture labs required their workers to dress all in black in darkened rooms to ‘protect’ cells from the light T e rry SHA Y E R NATIo n AL CANCE INSTITUTE

28 History Easter 2010 Hopkins University was determined to be the first. A modern cell He regularly received tissue samples from African- culture carried Americans receiving free treatment for cancer. Up out in a small until 1951 he had no success in maintaining any disposable plastic of these cells; Henrietta changed everything. While petri dish carrying out an operation on her, the surgeon cut a slice of her malignant cervical tissue and sent it to Gey. Soon afterwards Gey had the first rapidly a r 87 proliferating human cell line, one that would be in K a ib demand from scientists the world over. these techniques. Progress was fast, and soon Carrel Henrietta’s cells have provided unparalleled insight and his colleagues were able to subculture tissues into into the biology of human cells. As a consequence of new plasma clots by carefully cutting the tissues into studying these cells, we have a better understanding smaller fragments. In doing so, they created the first of what goes wrong in many diseases such as cancer. cell lines. The use of HeLa cells has also significantly reduced Carrel was awarded the Nobel Prize in 1912. In the need for animal experimentation. For example, the same year, he published a controversial paper in 1952 millions of HeLa cells were grown to test claiming he had managed to culture an “immortal” the safety and effectiveness of the new polio vaccine, cell line from a chicken heart. His Nobel Prize thus avoiding the use of primate testing. HeLa cells ensured Carrel became an instant celebrity, and have also caused us to consider ethical practice to a although his prize was in recognition of his surgical greater degree. Henrietta’s cells were taken without efforts, much attention was given to Carrel’s cell her consent, and her family were left unaware of culture research. It was often misrepresented, and their existence for many years, during which time many journalists believed that Carrel had managed many people made millions of dollars selling and to grow an entire immortal chicken heart from using HeLa cells. In the mid-1960s, as a direct these cells. The American public developed a keen result of experiments using HeLa cells, stricter rules interest in his work, believing Carrel had found a regarding human experimentation were put in place, way of cheating death. Carrel cultivated his celebrity with informed consent now a standard requirement status, and each year on the 17th January he would in any human study. gather his lab members, morbidly dressed head to Although HeLa cells are still used in many labs toe in their black gowns—which he wrongly believed today, researchers have since isolated over 3400 protected the cells from light—to sing ‘Happy different cell lines from 80 species. While scientists Birthday’ to the cells. There was scarcely a year when have not yet cultivated an ‘immortal heart’, they the coming of age of this ‘immortal’ cell line was not are now much closer to being able to repair heart reported in a newspaper or magazine, although many tissue. The discovery of stem cells, which have the scientists remained sceptical and resented his fame. ability to grow into different tissue types, provides Carrel’s work incontrovertibly advanced the much promise for the treatment of many diseases, field of tissue culture. His fame attracted many from Alzheimer’s to diabetes. The ability to culture talented scientists to his lab, even the famous stem cells, or indeed any cells, would not have American aviator Charles Lindbergh. Lindbergh was been possible without the pioneering work of these instrumental in designing much early cell culture scientists, who through their simple experiments apparatus thanks to his engineering skills. However, made cell culture what it is today. Carrel’s claim of an ‘immortal’ cell line which supposedly lived for 36 years, seems to have been, Nicola Stead is a PhD student at the Babraham at best, an experimental oversight or, at worst, an Institute embellishment of the truth. In 1961 Hayflick and Moorhead showed that cells taken from a normal HeLa cells being organ have a limited ability to divide and grow; in used in a study the case of the chicken heart cells they could only be where they are infected by an sustained for 60 to 80 days without actively inducing adenovirus an event known as transformation, whereby cells become cancerous and able to replicate indefinitely. The first irrefutably immortal cell line is accredited to the L cell line derived from a mouse cancer in 1948 by Wilton Earle, a former Carrel lab member. The race was now on to create an immortal human cell line, and George Gey at Johns I LY FAM THE LACKS

Easter 2010 History 29 Computationally Challenged? Anders Aufderhorst-Roberts examines the demands of the digital economy

THE SUCCESS of the fi lm e Social Network reminds of how computers work. Without this understanding, us that a programmer with a bright idea can land students are not inspired to imagine what computing extraordinary opportunities. Veteran British games designer is capable of. It is this issue that those in the computing Peter Molyneux has just been awarded a fellowship at industry cite as being the most pertinent.  e pioneering the BAFTA video games awards. From an economic computer scientist Edsger Dijkstra neatly summed up this perspective the value added to the EU economy from IT feeling by noting that “computer science is no more about products and services was estimated to be around £480m computers than astronomy is about telescopes.” each year. For those with friends studying computer science It is diffi cult to tell how things will go.  e Royal at university, you will fi nd they are unlikely to be as worried Society is due to report back later this year, but no one about fi nding a job as the rest of us. expects things to change overnight. For comparison, Yet computing is facing a serious supply problem; over the decline in school-level physics began in the mid- the last ten years applications to university computer 90s and improvements have only been seen in the science courses fell by around 60%. In response to last few years. It might well be that “a week is a long this, the Royal Society commissioned a study into the time in politics”, but when it comes to making lasting state of computing teaching in schools.  ere are a changes, a decade is not long enough. number of possible reasons. Some of these were certainly Either way, it is diffi cult to dismiss this problem out of predictable. For example, the political planning and hand; a recent survey by the Science Council indicated campaign on science, technology, engineering and that almost all science and technology jobs in the mathematics (STEM) did not include computing coming years will depend increasingly on computing. explicitly as an area for focus. At a time where the economic future is uncertain and An even larger issue is the way that young people are we look to science as the way forward, better computing taught computing. School curriculums focus on menial teaching will surely take us a long way. tasks such as how to write spreadsheets, rather than Anders Aufderhorst-Roberts is a PhD student in the looking at the more technical and fundamental aspects Department of Physics.

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30 Technology Easter 2011 Medical Writing Andy Shepherd talks to Richard Thompson about working at Caudex Medical

c a u d e x m e d i c a l is a global medical communications agency, supporting pharmaceutical companies with their scientific communications. We provide writing and editorial support for papers, posters, presentations and websites. In addition we support the planning and running of meetings and congress activities, and work closely with international academic and clinical experts in a range of disease areas, coordinating their work in the development of new medicines with the pharmaceutical companies providing the funding. Medical communications may seem like a small field y s h e ph r d

compared to research, but it has an important role in a n d helping to bring new medicines to the patients who need them. applied and was offered a trainee position with Caudex Medical soon after. I have not looked back since! What are your responsibilities within the company, and how do you spend your average working day? What is your favourite part of the job? As a medical writer my job has a focus on content It is important to have a broad, detailed and up-to-date generation, working on papers from clinical reports, knowledge of the therapy area you are working on. I and writing reports on scientific congresses and like staying on top of the science and getting to grips meetings. I also meet with clients and authors with new topic areas as you work with new clients. to discuss new or ongoing projects, mostly by The fixed short-term goals and the associated sense of teleconference, but there are some opportunities for progress and achievement provide a satisfying contrast travelling in person. to life in academic research. When reporting clinical trials, I work closely with The office where I work has a friendly atmosphere the academics and medics who carried out the research that carries over into various social events and activities. to make sure their views are accurately represented. I also like the fact that there always seems to be cake Negotiation skills can be important; there are often available in the office! several parties with an interest in a piece of work, and their views may differ. The writer’s job is to try and What advice would you give to young scientists find a solution that is acceptable to all parties. Work hoping to get involved in medical writing? is frequently deadline-driven and it is important to While there are often jobs advertised for experienced stick to timelines and liaise with editors, commercial medical writers, trainee places rarely seem to be offered. managers and others working on your account, to Do not wait to hope to see an advert, be proactive and ensure that projects are finished on time and to the contact the agency directly. Remember that you are required specifications. applying to be a writer, so write a proper cover letter saying why you are interested in a career in medical How did you get involved in medical writing? communications, and send it along with your CV. I was working as a postdoc doing laboratory research “Why have you applied to us?” is a common interview when I started looking for a new job that would use question, so make sure you are well prepared. Not all my scientific background, but would not require agencies are the same—take time to find out as much relocating every few years. I started making enquiries as you can about the agency you are applying to. Look about careers in industry as a regulatory writer, when for an agency that will invest in training you, because two of the companies I was speaking to recommended this training will be the foundation of a successful that a year of experience with a contract research career as a medical writer. organisation or in medical communications could Andy Shepherd read Natural Sciences at Trinity Hall, help my career. Having never heard of medical completed a PhD in microbial genetics, then took a communications, I went away and investigated. Very three-year postdoc before starting at Caudex. Andy quickly, I decided it sounded much more interesting was interviewed by Richard Thompson, a PhD student than the jobs I had previously been looking at. I in the Department of Earth Sciences.

Easter 2011 A Day in the Life of... 31 Weird and Wonderful A selection of the wackiest research in the world of science

No headache for woodpeckers

t h e b r a i n o f a w o o d p e c k e r undergoes severe decelerations of nearly 12,000 ms-2 as it scours a tree for its meal. Hammering away with rates of 22 beats per second would leave the best of us with more than a concussion, yet the woodpecker can do this without suffering any brain damage. Scientists are now looking into ways of harnessing the woodpecker’s special abilities to build better shock-absorbers. Using computer tomography scans and video footage of these birds in action they found that the birds possess properties that help absorb mechanical shocks efficiently: a layer of fluid between the brain and skull to attenuate vibrations, a hard but slightly elastic beak, a springy structure called the hyoid that extends behind the skull, and a c o m

section of soft skull bone. By using materials, . such as rubber and aluminium, as artificial analogues of these four absorbers, a ‘woodpecker- alexhahnillustrator inspired shock absorbing system’ that was able . to offer effective protection against bullet blows w w w up to 600,000 ms-2 was created. The implicated uses of this new technology are in aeroplanes’ Seeing through the blindfold? black boxes (flight recorders currently in use can withstand shocks of about 10,000 ms-2), cars and a t e a m a t t h e d o l p h i n r e s e a r c h c e n t r e as protection for satellites against space debris. So in Grassy Key, Florida, has witnessed dolphins before banging your head against a brick wall next mimicking the movements of other dolphins time, consider imitating a woodpecker! g w without being able to see them. Tanner, a male bottlenosed dolphin, was given the signal by Dr Life in the slow lane Kelly Jaakkola to imitate its partner dolphin, Kibby. Tanner was then blindfolded with opaque e v e r b e e n a p a s s e n g e r in a car, and wished goggles, but remarkably, was still able to copy the driver would slow down a little? Russ turns and tricks from Kibby. The team tested Branaghan of Arizona State University might 19 motor and 8 vocal behaviours. Dr Kelly said have a neat solution. In a study on young drivers Tanner must have been able to follow Kibby of both sexes, it was found that the surreptitious “either by recognising the characteristic sound suggestion of words and sentences to do with that the behaviour makes, like you or I may being elderly resulted in a lower maximum recognise the sound of hands clapping, or by speed and longer driving times. The words were using echolocation”. Also known as bisonar, introduced to the driver as scrambled sentence echolocation is predominantly used by bats and problems, posed via heads-up display while the dolphins to ‘view’ objects around them using the vehicle was stationary at traffic lights. Measured echoes of sound waves. The study, published in the c o m

. against a control with non age-related phrases, International Journal of Comparative Psychology, it seems that while participants reported no shows that dolphins can adapt the senses they use realisation of any themes, to think age is to drive when imitating an action, the first time this has alexhahnillustrator . aged—careful you don’t catch the bug! No blue been shown in an animal other than humans. t b w w w rinse required... m k

32 Weird and Wonderful Easter 2011 The Cambridge University science magazine from The Cambridge University science magazine from Michaelmas 2010 Issue 19 Cambridge University science magazine www.bluesci.co.uk Lent 2011 Issue 20

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Evolution Inside Us FOCUS Gene Therapy - The beginnings, challenges and triumphs FOCUS . . Scurvy Life in the Universe Test Tube Babies. Modern Art . Einstein’s Life Space Elevator . Tutankhamun Biodiversity . Science of Significance Music Therapy . Out of Body Experiences . Triangulation of India Henry Cavendish

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Lent 2011 Issue 20 Cambridge University science magazine www.bluesci.co.uk Feature articles for BlueSci magazine > 9 1 Shadow Catchers 0 0

0 Stephanie Glaser discovers how shadows caught by camera-less photography 2 9

6 bring light to an image 8 4 7 1

7 can be on any scienti c topic. They 7 painting without colour? Writing without a solved by William Henry Fox Talbot with the help ISSN1748-6920 9 pen? Singing without a voice? None of these seem of Sir John Herschel in 1834, when they fixed to be possible. But what about photography without images using a sodium hyposulphate solution and a camera? Is there a way to capture an image, the made the artwork durable. This also led to the light, a mood, or a person directly onto paper? This development of the first real, if simplistic camera, rare thought experiment was recently addressed at by placing light-sensitive paper into a ‘camera the London Victoria and Albert Museum exhibition obscura’, basically a box with a lens. Shadow Catchers, which featured the work of five In the late 19th century advances in camera- should be 1200 words and written contemporary artists who use camera-less photography development were fast, and dominated by techniques in their work. commercial and practical pressures. Only a few Chemigrams of Your first steps into the darkened exhibition room artists such as Talbot and Anna Atkins kept the movements welcome you into a new world you have never experimenting without the use of a camera to of a snake (top) experienced before. Being used to natural or artificialSuperheroes, create art or botanical illustrations in true scale. fact or fiction? and the bright lights and the colourful life outside, it makes Much later, in the early 20th century, Christian development Mark nicholson discovers how nature has turned fantasy into reality of spawn you feel uncomfortable initially. Your first gaze falls Schad rediscovered the use of camera-less photography (middle, bottom) on what seems to be the shadow of a woman leaning as an artistic medium, which led numerous artists over a chair, and after only a moment you realise that to revive the nearly forgotten technique. After 1922, for a wide audience. the image cannot be a real shadow, as no one is sitting Man Raywhat and László abilities Moholy-Nagy spring to became mind when the someone says three different mechanisms to increase their lift in the room. Looking further, shadows of people in two artists‘superhero’? to adopt the The techniques ability tointo fly? their Walking art. on walls? beyond that predicted by simple fluid mechanics. various different poses, somehow appearing three Man RayOr was an an uncanny American talent artist for best surviving known for against his the Firstly, their wings beat at a sharp angle to horizontal, dimensional, are captured in true size. Images with modern photography.odds? Although He Marveldescribed Comics photography have been as writing creating an effect known in aviation as stalling. In fine lines like broken glass and pictures which appear “a comfort,far-fetched because it tales reproduces about characters what is known” with superhumanand aircraft, this is disastrous, causing huge loss of lift to be made of waves of water come into view. Scenes implementedpowers camera-less for decades, photography evolution as has a means turned fiction into due to separation of the air flow from the wing and captured with careful thought, people and objects of creatingreality a “sensual and provided realisation us of with dreams living, and breathing the and often causes the plane to crash. In insects however, arranged precisely, and pictures that are beyond subconscious”.indeed The flying images proof he thatcreated it gotand there called first. So how do the act of stalling creates a vortex (think miniature reality; all created by camera-less photography. ‘Rayographs’animals often effortlessly contained recognisableachieve these objects things and that humans whirlwind) immediately above the leading edge of the The basic techniques of camera-less photography geometricalmerely forms dream but in of? new And ways can of we visualisation replicate them? wing, which provides a large lifting force, almost as if can be traced back through history. As early as as light and Ashadows. huge number He also of used species variable across exposure the animal the insect is being sucked upwards. Secondly, as their the 8th century the Arab alchemist Jābir ibn times on kingdomsingle objects can andfly, exploitedfrom buzzing the effect midges of to lumbering wings travel through the air, they rotate. This rotation © AdAm FUSS AdAm © Hayyān made the discovery that silver nitrate movementvultures. in Rayographs. But not Inall contrast fliers are to createdRay’s realism, equal. Most creates an additional down-current, which helps to changes its colour upon exposure to light. In the László Moholy-Nagy,birds are only a Hungarianable to fly painterforwards, and and are often keep them aloft in a manner analogous to a tennis 16th century Georg Fabricius experimented with photographer,relatively created ungainly images in that the were air, atmore least abstract, as compared to ball with backspin. Finally, in addition to creating Deadline for next issue is silver chloride and also found that under certain showing dynamictheir smaller white brethren: forms in theblack insects. space. Insects “The are often the leading edge vortex, any wing beat will inevitably circumstances a darkening of the material can be light can capableplay a central of flying role asbackwards the pigments or hovering do in a on the spot, create smaller trailing edge vortices behind the wing. observed, although the nature of the chemical painting”,more Maholy-Nagy like a helicopter stated. than an aeroplane, and possess These usually sap energy from the flier, but insects reactions involved was still unknown. In 1725, the After thea fine Second control World over War, flight photography that many was birds lack. This have adapted to sweep their wings back through FOCUS Test Tube BabiesGerman . Space researcher Elevator Heinrich . SchulzeMusic provedTherapy that heavily usedallows for themdocumentation to land on of your political skin withoutand detection, the turbulent air, recapturing energy that would the reaction of silver compounds was due to light social eventsor even and landthe art on of water. camera-less But how photography do they accomplish otherwise be lost. All these mechanisms contribute © SUSAN dERGES . . Life in the Universe Einstein’s Life Scienceexposure. of Significance The use of an artistic Triangulation technique based of Indiaagain wastheir close feats to being of aerial forgotten. acrobatics? Only between to a system far more innovative than our brute-force on these chemicals was first described in 1802 in a 1950 and 1960It turns did outartists that and insect photographers flight is a complexrevived methods of getting into the air. One complex enough publication by Thomas Wedgewood and Humphry their interestphenomenon, in experimentation and is still and poorly alternative understood. that we’re unlikely to be replicating it any time soon. Davy. Leaves and other small objects or paintings techniques.According Two of theto someprotagonists researchers, at the insects Shadow use at least So perhaps insect-like flight is out of our reach, but 10th June 2011 on glass were placed onto surfaces covered withInsect flightCatchers is exhibition started their careers during walking on walls is a different story. Many species silver nitrate. After exposure to sunlight, onlyfar more agilethis time: Floris Neusüss, a German Professor of possess the ability to hang around obnoxiously on the painted or covered areas were not affectedthan by birds Photography,or and Pierre Cordier, a Belgian artist. our ceilings and walls. Their methods may vary, but light. However, the ability to fix the images wasaeroplanes The five artists of the current Shadow Catchers OakleyOrIgInalS a couple of unifying themes emerge. Small insects, still lacking, so they disappeared immediately exhibition exploit different strategies to capture light often flies, tend to take the rather obvious route of © SUSAN dERGES when fully exposed to light. This problem was and shadows on light-sensitive surfaces. The most having sticky feet. They have tiny glands which slowly secrete an oily adhesive that literally glues them to the 26 Arts and Reviews Easter 2011 surface in question. Spiders have claws on their feet that hook into grooves too small for us to see (which, incidentally, is why they struggle to get out of very smooth containers such as baths and sinks). Yet clever as these two options are, the most ubiquitous and ingenious method is yet to come and proves that you don’t have to be an insect to have superhero qualities. This number is showcased by a friendly little creature: the gecko.

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