|
Saturday, 01 October 2005 |
|
In this edition of BlueSci, we explore in detail some of the questions associated with human organ donation and transplantation. Magi Sque looks at the possible reasons behind the severe shortage of organ donors in Britain and the issues related to obtaining consent from the relatives of deceased potential donors. The scarcity of donated organs has driven several areas of scientific research to develop alternative treatments for organ failure. A century after a pig kidney and a goat liver were unsuccessfully transplanted to two different women in France, Roger Barker investigates the challenges facing the promising and extremely controversial area of xenotransplantation, the grafting of tissue from one species into another. Finally, Ben Hanson describes the development of an artificial device designed to assist cardiac function which is being developed in Leeds. Along with stem cell technology, xenotransplantation and artificial organs promise to open avenues previously considered purely fictional, but which may hold great benefits for human health. Challenges and advances in xenotransplantation The shortage of organs and tissues for donation has made xenotransplantation a realistic approach for the treatment of organ failure and disease. In the context of human xenotransplantation, it is envisaged that in the future, whole organs (heart, kidney) or tissue (pancreatic, islet cells or neural tissue) from pigs may be transplanted into human recipients.The comparable size of pig organs to their human equivalents and ease of breeding makes this animal the optimal donor for xenotransplants.These features also facilitate research into the immunology of xenograft rejection, and have led to the development of a number of genetically engineered pig lines. |
|
Read more...
|
|
|
Friday, 30 September 2005 |
|
In 1954 a Boston doctor called Joseph Murray carried out the first successful organ transplant. The patient, a 23-year-old man who received a kidney from his identical twin, was able to enjoy another eight years of life. His donor brother is still alive today. The success rates of kidney, heart, lung, cornea and liver transplants have improved steeply since this pioneering surgical intervention, yet hundreds of people die every year in the UK waiting for organs.We tend to feel uncomfortable thinking of our own death, and so few people register as organ donors. Moreover, medical advances and a decrease in the death rate of healthy individuals in road accidents mean that only a very small number of people become suitable donors. |
|
Read more...
|
|
|
Friday, 30 September 2005 |
|
Jamie Horder finds out why looks can be deceiving
The ancient Greeks knew that if they wanted a stone column to appear straight when viewed from a distance, they had to construct it with a slight bulge in the middle. What they didn’t know was how our eyes were tricked in this way. Today psychologists describe these effects as an optical or visual illusion and experimental psychology and neuroscience have revealed some of the brain processes behind them. Although many illusions are still as mysterious as ever, some of the simpler ones are well understood. |
|
Read more...
|
|
|
Saturday, 01 October 2005 |
|
Anand Kulkarni and Swanand Gore puzzle out computer chess
Britain’s highest ever ranked chess player, Michael Adams, recently suffered an overwhelming defeat by Hydra, the world’s most powerful computer. With this the most recent in a string of computerized triumphs, the chess world is gradually accepting that machines have essentially ‘solved’ the game. Until now, tasks like playing chess required human intelligence, an attribute that has taken millennia to emerge through countless cycles of evolution. In stark contrast, machines designed by us reached their current state within just two human life spans. Does the triumph of machine over man on the chessboard imply that machine intelligence has surpassed human intelligence? Could the successful replication of human intelligence in machines jeopardize our existence on Earth? |
|
Read more...
|
|
|
Saturday, 01 October 2005 |
|
Tom Walters puts risk and rationality under the spotlight
The London bombings of 7 July 2005 and the attempted attacks two weeks later caused many people to abandon travelling by bus and tube. Those who chose to stay away from the tube network did so because they perceived the risk of travelling on public transport as too great. But what governs our perception of risk and how easy is it to be misled by the statistics we hear? |
|
Read more...
|
|
|
Sunday, 02 October 2005 |
|
Swanand Gore on a whole mosaic of disciplines
Science often seems like a maze of very specialized disciplines, but there are some universal ideas that transcend its boundaries. Tessellation is one such idea, in the league of other all-pervasive themes like potentials, graphs, memes and entropy. Tessellation is the division of space without gaps or overlaps between the resulting regions. Flexible or growing entities compete for space; a gas expands to fill its vessel and cells grow in a petri dish until space or nutrients run out. This competition frequently results in tessellation, for example, beehives have hexagonal chambers because each bee grows its chamber in all directions until the hive is filled. A source of inspiration to scientists and mathematicians for centuries, tessellation offers both a way of describing the world and an effective tool.Tessellations have been rediscovered in different fields and rechristened; Thiessen polygons in geography, Blum’s transforms in biology and the domain of action in crystallography. This ubiquity demonstrates tessellation’s utility as well as its place as a fundamental, unifying principle. |
|
Read more...
|
|
|
Saturday, 01 October 2005 |
|
Helen Stimpson weighs up the facts behind the "obesity epidemic"
We are a nation obsessed by our weight:
Celebrity Fat Club and Dr Gillian McKeith’s You Are WhatYou Eat are television staples and gossip magazines are full of reports documenting Pop Idol Michelle McManus’s weight loss. Obesity is now regarded as a major public health issue and talk of an ‘epidemic’ is everywhere. So, what are the facts? How heavy are we and why? |
|
Read more...
|
|
|
Tuesday, 04 October 2005 |
|
Owain Vaughan and Neta Spiro explore the biological and cultural phenomenon that is music Music. Emotional, ineffable; an enigmatic and ethereal art form. Such descriptions are commonplace, and whilst there have been some attempts in the past to uncover the scientific basis of music, these have been limited and in some cases led only to exasperation and resignation. Take, for example, Claude Lévi-Strauss, who tried to describe the influence of music on human nature, including how we perceive musical time and its effects on the internal organs. Eventually he gave in, concluding that “music will remain the supreme mystery of human sciences”. But the mystery is slowly being unravelled as science meets music head on. |
|
Read more...
|
|
|
Tuesday, 04 October 2005 |
|
Emily Tweed and Victoria Leung investigate the history of the Cavendish Laboratory
Imagine a university that taught science degrees but did not have any laboratories. Imagine studying for a degree in science that did not involve any practical work whatsoever. Welcome to Cambridge in the midnineteenth century. |
|
Read more...
|
|
|
Sunday, 02 October 2005 |
|
Cambridge scientists discuss networks for women in science, engineering and technology
Did you think gender inequality in the sciences was a thing of the past? These statistics may make you think again.Women still make up less than 20% of lecturing staff in science, engineering and technology (SET) at the University of Cambridge. Although females account for approximately 50% of undergraduates studying biological sciences, this figure is much lower when one considers the physical sciences. The proportion of women involved in SET disciplines is lower at the graduate level, and declines yet further at more senior levels. These figures are not confined to the University of Cambridge; nationally, less than 10% of those elected to Fellowships of the Royal Society are female. |
|
Read more...
|
|
|
Sunday, 02 October 2005 |
|
Will Flynn investigates global pollution on holiday in the Azores When asked if I would like to spend three weeks on a field trip in the Azores, I didn’t have any hesitation in saying, “Yes please!” |
|
Read more...
|
|
|
Sunday, 02 October 2005 |
|
Samia Mantoura gets cold in the name of science
Located on the Western Antarctic Peninsula, surrounded by high mountains and glaciers, Rothera is the largest British Antarctic Survey base on this continent. For eight weeks, this outpost of a hundred or so people was to be my home, and the deep blue sea littered with giant icebergs, my office. |
|
Read more...
|
|
|
Sunday, 02 October 2005 |
|
Nerissa Hannink talks to Ann Kershaw about her work as a genetic counsellor
The range of genetic tests available today mean we can learn more than ever about the medical conditions we, and our children, may develop. But for every test, patients need support and accurate interpretation of results, a role often fulfilled by a genetic counsellor. With the sequencing of the human genome, and the new information we may gain from it about our health, their role will be increasingly important. Ann Kershaw works as a counsellor in the Genetics department at Addenbrooke’s NHS Foundation Trust hospital, Cambridge. |
|
Read more...
|
|
|
Sunday, 02 October 2005 |
|
Tarek Mouganie, the scientist behind our cover image, talks to Tamzin Gristwood
Knowing nothing more about superconductors than the dictionary definition (materials with zero electrical resistivity at temperatures close to absolute zero), it was with some trepidation that I approached the Department of Materials Science and Metallurgy to meet Tarek Mouganie, the scientist behind our cover image. Thankfully Mouganie, a third year PhD student in the department’s Applied Superconductivity and Cryoscience Group, was not at all fazed by this and set about explaining to me what superconductors are, why he’s interested in them, and of course how his research came to produce the stunning image you see on the cover. |
|
Read more...
|
|
|
Friday, 30 September 2005 |
|
Art meets science in a collaboration between Professor Roberto Cipolla and Dr Carlos Hernandez-Esteban from the Department of Engineering, and Antony Gormley, the sculptor famous for creating the ‘Angel of the North’ in Gateshead. Viewing sculptures in 2-D images is never the same as seeing them for real, so Cipolla and Hernandez-Esteban came up with a way of using a series of photographs of an object taken with a standard camera to create accurate 3-D computer models that can be viewed from any angle. The Digital Pygmalion project relies on a computer program which detects the important features of the object and its silhouette from multiple pictures, and then uses this information to calibrate the position of the camera. An algorithm creates an underlying ‘mathematical mesh’ which forms the basis of the 3-D reconstruction; next, the texture of the original sculpture can be laid on top and additional lighting effects can be added. Specially designed software allows viewing of the finished product. Among other applications, this technique will revolutionize the digital archiving of museum collections and can be used to create low-resolution 3-D models to help shoppers choose products sold online. Gormley plans to use the high-resolution 3-D representation of one of his own sculptures produced by this technique to help him scale up the life-size original into a version more than 25 metres tall. LB www.eng.cam.ac.uk www.antonygormley.com |
|
|
Friday, 30 September 2005 |
|
A group of Cambridge archaeologists have begun a novel collaboration with researchers from the Czech Republic to study how hunter-gatherers lived 28,000 years ago. Professor Martin Jones and a group of archaeological scientists from the McDonald Institute and the Department of Archaeology are working with colleagues from the Academy of Sciences of the Czech Republic at the site of Dolní Vestonice in the Czech Republic.The area, which is approximately the size of central Cambridge, has been the focus of research since the 1920s and is an “amazing site” to study, according to Dr Tamsin O’Connell, one of the project’s researchers. The group have made important discoveries about life in this era; finding for example that the hearth of the house was a focus of craft activities such as clay modelling and weaving as well as cooking and eating. Interestingly, many of the dwellings excavated in this area are constructed from mammoth bones, believed by archaeologists to be the best building material available at the time due to harsh weather conditions and a lack of nearby trees. What makes the contribution of the Cambridge group to this collaboration so groundbreaking is that they are using scientific techniques that have never been applied to a site this old.The team will be using the latest biological and chemical methods to discover more about people’s diet and life in the cold and hostile Paleolithic environment. These include soil micromorphology, which allows investigation of soil structure, and phytolith analysis, which gives researchers information on vegetation cover and plant use by humans. In addition, isotopic analysis of excavated bones will show what kind of diets people might have had.The team intend to return to the area for at least the next two years to unearth more information about the life of our species 28,000 years ago. FM www.arch.cam.ac.uk |
|
|
Friday, 30 September 2005 |
|
Professor Harry Coles and Dr Mikhail Pivnenko of the Centre of Molecular Materials for Photonics and Electronics in the Department of Engineering have announced the discovery of a class of ‘blue-phase’ liquid crystals that remain stable over a wide range of temperatures. Liquid crystals are substances with properties between those of a conventional liquid and a solid crystal; the liquid crystal may flow like a liquid but the molecules may have a highly organised structure, like in a solid crystal.The most common applications of liquid crystals are in liquid crystal displays, but they are also important in the manufacture of superstrength polymers such as Kevlar. The blue phase of a liquid crystal refers to the thermodynamically stable state of the crystal and — despite the name — can be almost any colour. Blue-phase liquid crystals have a number of potential applications in photonics (the technology of generating and harnessing light) such as electrically switchable colour displays, but until now their sensitivity to temperature had hindered their widespread use. The Cambridge researchers have discovered a solution to this instability. They made 30 different mixtures of bimesogens (molecules that exhibit a liquid crystal phase) that show blue phases over a temperature range of 40°C – 50°C. It is the unusual structure of these bimesogens that give the blue phase its stability. They consist of two rod-like components linked by a flexible chain, unlike normal blue phases in which liquid crystal molecules are arranged in a helix.The molecules are of the correct dimensions to reflect visible light, and by adjusting the twist of the molecule, red, green and blue reflections have been demonstrated.The researchers believe these materials will lead to a new generation of low-power-consumption liquid crystal displays. Another application is for tuneable optical filters, which could be used to sort through signals travelling at many different wavelengths down a single optical fibre in a fibre optic cable. FM Further information can be found in H. J. Coles, M. N. Pivnenko, 997–1000 (2005) Nature, 436: http://www-g.eng.cam.ac.uk/CMMPE |
|
|
Friday, 30 September 2005 |
|
The circadian clock that governs key biochemical activities within plant cells enables plants to optimize their rates of photosynthesis and metabolism, according to research from the Department of Plant Sciences. Plants possess an internal molecular clock which ensures that various physiological processes, such as stomatal opening, are cyclic, with a period of approximately one day-night cycle.This particular length of cycle was expected to hold a selective advantage on the basis that it would be optimal for plant metabolism. Researchers at the University of Cambridge decided to directly test this concept using plants with mutations in genes controlling periodicity. By growing wild-type, ‘long-period’ and ‘short-period’ mutants of the cress Arabidopsis thaliana under light-dark cycles of varying length, they measured the impact of periodicity on plant fitness. Fitness was assessed using indicators such as chlorophyll concentration, photosynthetic rate and degree of biomass accumulation. It was found that plants thrived best when the intrinsic biological rhythm of the plant matched that of the external light-dark cycle, a condition known as circadian resonance. The fitness benefits of circadian resonance were also evident in competition experiments, in which ‘long-period’ mutants out-competed ‘short-period’ mutants under long lightdark cycles and vice versa. The molecular pathways through which the circadian clock controls the processes in question have yet to be elucidated. Further research in this area is likely to provide insights into ways of maximising crop yield and of increasing productivity in situations where lightdark cycles may vary.WD Further information can be found in Dodd et al., Science. 309: 630-633 (2005) |
|
|
Friday, 30 September 2005 |
|
Researchers from the Department of Genetics have won a prestigious grant from the Bill and Melinda Gates Foundation to investigate ways to reduce the incidence of malaria by targeting the insect which carries and transmits the parasite. Professor Michael Ashburner and Dr Steve Russell will share the £5 million award with colleagues at Imperial College London, the University of Washington and the Fred Hutchinson Cancer Research Centre in Seattle as part of the Gates Foundation project ‘Grand Challenges in Global Health’. Dr Russell describes the statistics on malaria as “frightening”: it is the second largest killer in the world, with 3 million deaths annually and 40% of the world’s population at risk.The most deadly form of the malarial parasite, Plasmodium falciparum, is transmitted in the bite of the female Anopheles gambiae mosquito. There is no vaccine to protect against the parasite, and control efforts have been hampered by rapid increases in resistance of the parasite to anti-malarial drugs and of the mosquitoes to insecticides. Researchers are now turning to genetic strategies to reduce the Anopheles mosquito population. “Most of the methods that have been tried to control the insect population have been spectacularly unsuccessful”, says Dr Russell. He and his team are, however, “very excited with this award and are hopeful that working with our colleagues in London and Seattle will yield significant results”. Over the next five years, the international team hope to develop a new technique which will disrupt genes essential for female reproduction, leading to female infertility and a population decline. Another approach under investigation is genetic manipulation of the mosquitoes so that they can no longer transmit the parasite.CD www.gen.cam.ac.uk www.grandchallengesgh.org |
|
|
Friday, 30 September 2005 |
|
 A new hi-tech laboratory is to be built in Antarctica for the Cambridge-based British Antarctic Survey (BAS). Construction of Halley VI is due to start on the Brunt Ice Shelf in January 2007. The laboratory is ingeniously designed to survive the hostile Antarctic conditions, including temperatures as low as 40°C, 80 mph winds, annual snowfall of 1.5 metres and days of near total darkness. The building’s unique feature is that it will stand upon a set of collapsible ski-footed legs, permitting it to be moved around by bulldozer.This mobility will protect the base from being swept out to sea on an iceberg.The new installation, which will be continuously inhabited by a dedicated team of scientists and engineers, will enable the groundbreaking research performed by the BAS to continue at this invaluable site.The hole in the ozone layer was discovered due to observations and measurements taken on the Brunt Ice Shelf. Future work at Halley VI will include experiments to predict the weather in space — important for preventing damage to satellite communications and power systems — and investigations into the interactions between snow, air and sunlight and their resultant effects on the lower atmosphere. The director of the BAS, Professor Chris Rapley CBE said, “Our current research programme is attempting to answer big questions about the Earth’s climate system — so this remote and challenging place is vitally important for understanding our world.”WD
http://www.antarctica.ac.uk |
|
Read more...
|
|
|
Friday, 30 September 2005 |
|
New term, new BlueSci! Welcome to the latest edition of Cambridge’s popular science magazine. Among the articles awaiting you in this issue is the FOCUS section, where we take an in-depth look at a particular scientific debate. This time, experts discuss the future of organ transplants, a thriving area of medical research encompassing topics as diverse as ethics and bioengineering. On page 26, however, the focus is on the past, with a look at the history of the Cavendish, one of Cambridge’s most famous labs. |
|
Read more...
|
|
|
Friday, 30 September 2005 |
|
Happy First Birthday, BlueSci! It’s hard to believe how quickly things have evolved — not only have we set up a magazine and all its infrastructure, but we have also created a website with events listings and news articles not available in the print edition (www.bluesci.org). There is also a subscriptions service (subscriptions@bluesci.org) to get your own hard copies delivered each term.We have just begun a campaign to forge links with local schools to promote enthusiasm for science and offer local school students a chance to see their science writing published here in the future (schools@bluesci.org). |
|
Read more...
|
|
|
Tuesday, 04 October 2005 |
|
Dr Hypothesis needs your problems! If you have any worries (of a purely scientific nature, obviously) that you would like Dr Hypothesis to answer, please contact him by email at drhypothesis@bluesci.org . He will award the author of the most intriguing question a £10 book voucher. Unfortunately, Dr Hypothesis cannot promise to answer every question, but he will do his best to see that the most fascinating are discussed in the next edition of BlueSci. |
|
Read more...
|
|
|
