Sciencegate - Science Week 2010 by Max Jamilly

Sciencegate - Science Week ’10

From the Editors Welcome to Science Week 2010 and a brand new issue of Sciencegate. As always, this issue contains a wide variety of articles by some of Highgate’s finest scientists. From elusive antimatter to the mysterious nature of rigor mortis, you’re sure to find something that intrigues you.

Science Week at Highgate grows bigger and better from year to year, and this one is no exception. Are

you a sci-fi buff? Do you long to make bacteria glow in the dark? Have you always wondered about fractals? Whatever your curiosity, you are bound to find something fascinating this Science Week - don’t forget to look at the timetable of events (opposite).

This issue also marks a turning point in the prestigious history of Sciencegate, for it is Max Jamilly’s last as Editor. Though Cambridge may have gained a valuable student, Sciencegate stands to lose one of its founding fathers. We, his successors, would like to

In this Issue

Articles

Alex Beaton reveals that bio climate change and malaria could become a deadly duo on p.12. Turn to p.5, where Chris Liu investigates whether Alzheimer’s can be passed down between generations.

The science of CSI: Harry Mitchell explains the stiffness of death on p.8. Where did all the antimatter go? Jamie Worthington gives Dan Brown a run for his money on p.6.

Also: On p.14, Henry Why has South Titheridge-Stone Africa fallen behind tells the story of in the battle against ancient Greece’s HIV? Simon Lack greatest scientific reports from the philosopher. front line on p.10. 2

wish Max all the luck in the complex plane as he moves on to exponentially greater things. But with new eras come new ideas. This issue, we are excited to introduce some new features, in particular the very first “Scholar of the Issue”. The editors would particularly like to thank Dr Edwards for his help in producing this magazine, and are, as always, indebted to all contributors – without whom there would be no Sciencegate. Many have contributed for the first time this issue, and

Regulars

Who knew that you could have so much fun with glass rods and baby oil? We show you how in Do try this at Home on p.5. Fed up with textbooks? Whether you’re a keen surfer or worried by the web, check out our Websites of the Isuue on p.13. Finally, the legendary Last Call returns on the back

we hope that you enjoy their writing as much as we have enjoyed working with them. Thanks also to Zack Wellin for his final masterpiece as Sciencegate’s cover designer extraordinaire. All contributions are welcome! Please feel free to speak to the editors or send an email to sciencegate@ gmail.com. We hope that your copy of Sciencegate complements a fascinating Science Week, Max Jamilly, Worthington and Titheridge-Stone

Jamie Henry

cover with the hottest gadgets, unmissable cartoons and mindbending puzzles to frustrate even Highgate’s finest.

Sciencegate - Science Week ’10

Highgate Science Week 2010 Friday 12 March

Research. 3.05-4.00pm, Big School

GCSE Science Live - Fascinating talks for Y11 by British scientists. Westminster Central Hall, London

Chemical Analysis Competition - Can Y9 discover the identity of chemical X during their Chemistry lessons?

Making a Science out of Agriculture - Miss Sherbrooke discusses the work of Dr. Norman Bourlag. 1.35pm, GG1 Monday 15 March Avalanches - Mr Brandt looks at the science behind whiteouts. 1.35pm, GG1 Moon Landing: Poetry and Aesthetics of Science - Mr Catherwood explores the links between Art and Science. 1.15pm, E43 Dogs and their effect on the human race - Charlotte Boundy explores the connection between dogs and humans. 1.05pm, B1 PCR workshop - Drs Weston and Crawford demonstrate how to copy and analyse DNA by techniques widely used in medical research. 4.05pm, B3 Make your own DNA necklace - In biology lessons, create a necklace of your DNA and impress your friends. Tuesday 16 March William Harvey: The Past, Present and Future - A talk by Dr James Whiteford from the William Harvey Research Institute. 1.05pm, B3

La Bioéthique - Highgate students and their French exchanges to deliver presentations. Period 4, Undercroft Wednesday 17 March Green Chemistry - Dr Ed Marshall from Imperial College talks about environmentally friendly chemistry. Periods 1 and 2, Big School All the Power in the Universe - Mr Pearce explains the fundamental nature of powers during Maths lessons. Big School Making sweet flavourings - Care for something sweet? During Chemistry lessons. Sci-fi essay competition - Winners to be announced by Mrs Heindl. Science Club Extravaganza - An opportunity to perform some interesting experiments. 4.155.00pm, SBR3 Extraction of Strawberry DNA - Y10 use a speedy technique to extract DNA from strawberries during Biology lessons.

Comets - Mr Smith talks about the mysterious occupants of the night sky during science lessons. Thursday 18 March

Science Fiction: a genre for today, not tomorrow - Mr Bovey and the Highgate Film Society explore the Sci-Fi genre. 1.10pm, AV room, Mills Centre Like a Staggering Drunk: From Atomic Theory to Financial Markets - Hugh Lindsey explores the miraculous significance of Brownian Motion. 1.05pm, B1 Caudwell Xtreme Everest: lessons from life at the limit? Dr Mike Crocott, UCL, describes his expedition to the summit of Everest in the aid of Medical

Wind turbines - Y9 optimise the electricity output of a wind turbine in the Mills Centre Savage Earth: Volcanoes and Disaster Science - Globetrotters society takes an active look at the science behind plate tectonics and volcanic activity. 1.00pm, GG1 Science and Philosophy Highgate’s Philosophy Society goes scientific. 1.00pm Room 16

of fractals and fractional dimension. 1.00pm, M3 The Art of Animal Photography Terence Ma reveals the trade secrets of animal photography. 1.15pm, B3 Mind Reading with Magnets Douglas Perkins explores the use of MRI scanners to allow coma patients to communicate. 1.05pm, B1 Nuclear Fusion - Highgate’s Physics Society are treated to a talk by Professor Steven Cowley on this important topic. 4.15pm, P3 Friday 19 March Miraculous Messages of Water Farnoush Golshirazi and Shi Shi discuss this controversial subject. 1.05pm, B1 Christiaan Huygens - The Highgate History Society hear Mr Smith talk on the prominent scientist and writer of early Sci Fi. 1.30pm, Room 11 The Climate Change Debate: Fact or Fiction? - An analysis of the causes and potential impacts of the phenomenon. 1.00pm, GG1 Autism: Just a Behavioural Disoder? Dr Patrick Johnston, Kings College London, explores this question. Period 5, B1 Genetic Engineering: Making Bacteria Glow in the Dark - Dr Welch treats students to an exciting hands-on practical to make bacteria glow in the dark. 4.05pm, B2

Into the 2.5th Dimension - Max Jamilly explores the strange world

Sciencegate - Science Week ’10

News

Malaria and matrices - what’s going on in the world of science

RISE OF THE MACHINE - The US military has commissioned its scientists to create a robot which can rescue fallen troops in battle. According to the Pentagon, one of the main dangers in combat lies in retrieving casualties from the battelfield, so it is hoped that a ‘saviour robot’ will do the job without putting healthy soldiers at risk. But this will be no stroll in the park: as well as rough terrain - not to mention bullets - the robots will have to handle ‘the large number of body positions and types of locations in which casualties can be found’. The research is the latest addition to a series of projects, all sharing the goal of creating an army of ‘Robot Soldiers’. On an equally futuristic note, researchers have also developed a pill to deal with massive blood-loss during combat, which accounts for almost 50% of lives lost at war. Containing a drug used to treat epilepsy, the capsules won’t heal the victim, but do promise to extend the survival window from minutes to hours: in trials, pigs given the drug after losing 60% of their blood have survived for over four hours. LAB-ON-A-CHIP BECOMES EVEN SMALLER - In chemistry, just like in computing, miniaturisation is all the rage. A chemist working at Harvard University has created a prototype chip that could help diagnose HIV, malaria, tuberculosis and other diseases for just a penny each time. The stamp-sized device may help usher in instantaneous diagnosis of the world’s killer diseases. Water-repellent comic-book ink helps to channel a tiny sample of blood on one side of the paper into a colourful tree-like pattern that indicates whether the patient is infected. ONE STEP CLOSER - We may not yet be able to see through walls, but researchers reporting in the journal of the American Physical Society have come one step closer. Objects such as sugar cubes are translucent: if you hold them to the light, some light passes through. The problem, though, is that the light is scattered, so we cannot see clearly what’s on the other side of the translucent object. Nonetheless, optical physicists have developed so-called transmission matrices, vast arrays of up to 70,000 numbers that model the scattering of light by a particular object. By mapping the light passing through a thin layer of zinc oxide, they used the transmission matrix to determine what the light looked like before it was scattered. In the future, cameras may use miniature translucent lenses, which avoids the added cost of manufacturing transparent materials. Even biologists hope to use the technique to see through cell walls. It may not be x-ray vision, but it’s no less exciting. 4

Sciencegate - Science Week ’10

Alzheimer’s: in your genes?

bio Chris Liu Alzheimer’s is the most common form of dementia. Sufferers of dementia are literally ‘deprived of a mind’: these diseases cause impairment in cognitive ability (the ability to process information). Alzheimer’s is also known as a neurodegenerative disease, a progressive brain disease that continues to get worse over time. Eventually it becomes more aggressive and begins to damage the brain.

Alzheimer’s is thought to be caused by genes on chromosomes 1, 14, 19 and 21. Deposits of amyloid proteins in the brain cause Alzheimer’s because they induce the build up of a protein called tau, which triggers the symptoms ofAlzheimer’s. Chromosome 21 codes for Alzheimer’s precursor protein (APP) and is therefore particularly responsible for these amyloid deposits. APP builds up to form beta amyloid plaques in the sulci and gyri of the brain, blocking proper transmission of nervous impulses. This damages a person’s cognitive processes by delaying communications within the brain - as a result, sufferers of Alzheimer’s take a very long time to perform simple cognitive tasks. Alzheimer’s typically affects older members of the population: 99.9% of people with Alzheimer’s are over 65. The nature of onset of the disease can be broadly placed into three categories: 1. Sporadic late onset (most common) – when

someone randomly develops the disease past a certain age 2. Familial late onset (uncommon) – an increased risk of developing Alzheimer’s given a family history of the disease 3. Familial early onset (rare) – as familial late onset, but at a younger age But can Alzheimer’s be predicted? Fascinatingly, cutting-edge research seems to suggest that a gene called Epsilon 4 significantly increases the chances of developing Alzheimer’s disease. Epsilon 4 is also associated with increased intelligence, so the gene is only a disadvantage to the elderly. Many famous scientists such as James Watson, the co-discover of DNA, and neuroscientist Stephen Pinker have sequenced their entire genomes apart from the region containing epsilon 4, preferring not to know what their old age may hold in store. On the other hand, tearaway biologist Craig Venter was happy to acknowledge that his single copy of epsilon 4 may be responsible for his intelligence and - in the future - for his intellectual decline. Alzheimer’s is notorious for causing severe memory loss. Over the years, neuroscientists have discovered that although every case of Alzheimer’s is unique, certain parts of the brain are nearly always affected most and these are mainly the areas concerned with long-term memory. The temporal

lobe, which plays a key role in forming our long-term memories, degenerates rapidly due to Alzheimer’s. The parahippocampal gyrus, important for the recognition of scenes or our environment, becomes so damaged that Alzheimer’s sufferers can even forget they are in their own home. Sufferers appear vacant and unexcitable due to problems caused in the frontal lobe, which is also used for long-term memory - specifically for emotions and events. In addition the frontal lobe also helps verbal and figural fluency. Alzheimer’s, therefore, often causes symptoms such as paraphasia (decreasing vocabulary and fluency and mixing of words). What’s more, decay of the parietal lobe, central to people’s ability to manipulate objects, results in clumsiness in everyday tasks such as using a knife and fork. At present, there is no cure for Alzheimer’s disease and research on the subject has often produced inconsistent results. However, besides Epsilon 4, there does appear to be a link between certain aspects of a person’s lifestyle and their likelihood of contracting Alzheimer’s. Key areas include regular exercise - both mental and physical - as well as a healthy diet. So, how to avoid Alzheimer’s? You can lower the risk by eating well, exercising, and playing chess. But for now, there is no escaping the fact that Alzheimer’s runs in the family. sg 5

Do try this at home! Science needn’t be scary. Grab your labcoat, grow a crazy beard and jump right into the world of experimental science. Who needs research grants, anyway? Sciencegate makes proper experimental science easy. #43.2 - ‘Disappearing Act’ Make solid glass objects disappear and reappear with ease. David Blaine, take that! How? You need two Pyrex bowls or cups of different sizes, where one will fit inside the other, and some glycerol. If you don’t have glycerol lying around (why would you?), then baby oil works just as well. 1. Make sure that the small and large glass objects are very clean. If you don’t know how to use the dishwasher, learn! 2. Put the smaller cup inside the larger cup or bowl. 3. Start pouring glycerol or baby oil slowly into the inner container. 4. When the inner container is full, keep pouring and allow it to overflow into the outer container. Have a look from the side - the smaller object disappears as the fluid level rises! 5. Try putting a glass rod or plastic ruler into the inner container. Why? Try doing the same thing with water - it isn’t very exciting. We see the glass in normal water because glass has a higher refractive index than water, so light rays bend when they enter and leave the glass and light is reflected into our eyes at the glass/water interface. Pyrex glass and baby oil, however, have very similar refractive indices so the light rays are barely refracted. SCIENCEGATE tests every experiment thoroughly but is not responsible for their outcomes. Be careful.

Sciencegate - Science Week ’10

How did we lose Half the

Jamie Worthington Physicists pride themselves on studying what they consider to be the fundamental science. Ernest Rutherford famously said that “All science is either physics or stamp

positively-charged anti-electron was named a positron. In the years that followed, experiments discovered anti-protons, anti-neutrons, and so on: this group of new

the antimatter go? Physicists love symmetry because it allows for easier and more elegant calculations. Therefore, when they discovered a whole

would not change at all: this idea was known as parity symmetry (the first erroneous assumption!). Unfortunately, experimental work by two physicists (Lee and Yang) using radioactive

Charge-parity symmetry: the idea that particles are symmetrical when both their charge (positive or negative) and their spin (left-handed or right-handed) are reversed

collecting”. But one of the biggest problems for “fundamental scientists” lies in solving a worrying result from quantum theory, their most prized theory of particle behaviour: the prediction that we should not exist, that planets should not exist and that the universe should simply be full of nothing more than electromagnetic waves. In 1928, Paul Dirac predicted the existence of an anti-electron, which he said would have exactly the same mass as an electron but would have an opposite charge. His prediction was confirmed a few years later and the newly discovered, 6

particles was labelled antimatter. A particle’s only difference to its antiparticle is (more or less) that it has an opposite charge. When a particle meets its antiparticle, they annihilate one another and create photons (‘packages’ of light energy). Theoretically, the Big Bang should have created equal amounts of matter and antimatter. Can you think of the major problem that arose for quantum theory? Exactly: physicsts began to wonder why there was any matter left at all. Why isn’t the universe just a sea of photons? Where did all

new group of particles - antimatter - which were almost identical to normal particles apart from opposite charges, they became rather excited. Hoping to solve another piece of the cosmic puzzle in one easy move, physicists made a fatal error: they /assumed/ symmetry. All particles have a quantity known as spin. Although not completely accurate, you can imagine a particle like a spinning top in that it can spin in more than one direction. Until 1950, physicists had never questioned the idea that if you flipped the direction of every particle’s spin, the physics of the universe

cobalt-60 demonstrated that parity symmetry is not conserved in the weak interaction (the force which causes radioactive decay) and this destroyed the hypothesis of parity symmetry. Lee and Yang’s work was extremely irritating because the assumption worked so well for everything else. Faced with this difficulty, physicists then remembered antimatter and thought, “What if we reversed both the spin of a particle and its charge?” At first that seemed to work. The idea that the universe would be identical if particles were swapped for their

Sciencegate - Science Week ’10

Universe? antiparticles and the spin axes of all particles were flipped was branded CP symmetry (charge-parity symmetry). So, what does this have to do with the abundance of matter in the universe? Surely CP Symmetry only reinforces the idea that we should not exist? Well, luckily for us, the physicists’ assumptions were wrong – again. Experiments at CERN in the 1990s showed that one particular exotic particle, the kaon, turned into its antiparticle slightly more often than the reverse happened, creating a tiny imbalance between the two. This phenomenon was branded “indirect” CP violation because it was slightly controversial. In fact, “direct” CP Violation was later observed in the decay of B-mesons (close relatives of the kaon) during the BaBar experiments

in California.

processes.

Some physicists believed that CP violation alone proved that the universe has an innate preference for matter over antimatter and, therefore, that it was obvious why matter exists in larger quantities. But this hypothesis remained unproved, so the search to explain the existence of matter continued.

The first condition is that Baryon number cannot always be conserved. Every baryon (a particle such as the proton or neutron) has a baryon number of one and every antibaryon has a baryon number of negative one. Sakharov simply said that, for baryogenesis to be possible, there must exist particle interactions where the baryon numbers before and after the interaction are different.

Have we made any more progress? Yes! The disastrous fate of physicists’ prized CP symmetry inspired fantastic insight from the Russian scientist Andrei Sakharov. In order to explain the production of far more protons and neutrons than antiprotons and antineutrons during the Big Bang (now called baryogenesis), Sakharov proposed that certain conditions, now known as the Sakharov conditions, govern physical

The second condition is CP Violation, which had already been observed (discussed above). The third condition dictates that whatever the mechanism which generates more baryons than antibaryons, it must happen at a slower rate than that at which the universe is expanding. This stops matter and antimatter

achieving thermal equilibrium because they are moved further away by the rapid expansion, reducing the amount of annihilation. To this day, these conditions are considered the starting point for most theories of baryogenesis. If Sakharov’s conditions are correct, there must be a mechanism which generates more matter than antimatter. This appears to violate a key idea in physics, namely that energy can create matter but it must create an equal quantity of antimatter. But we exist: so is the basic physics wrong or do we just not understand it correctly? Or both? sg

An electron and positron annihilate to release photons

Sciencegate - Science Week ’10

bio

Rigor mortis

Harry Mitchell

Everyone wants to know what happens to our minds and souls after death. No one is able to answer these philosophical questions, but we are a lot more certain about what happens to the human body itself. When a person dies, the vital organs like the heart, lungs and brain stop functioning. Often, organ failure is the actual cause of death. Nonetheless, this does not mean that all activity has stopped in the body.

the most interesting, and most gruesome, process that occurs posthumously in the body is rigor mortis. Rigor mortis is Latin for ‘stiffness of death’, where chemical changes that occur inside the muscle fibres make the muscles stiffen up. This stiffening, especially of the skeletal muscle, fixes joints in place and prevents a body from being easily moved. The only way to move the limbs or other body parts once rigor mortis has set in is to use extreme force but this usually ends up by breaking bones. In humans, bodies begin to stiffen about three hours after

When the heart stops, blood drains from surface capillaries and the skin goes pale (this is known as palor mortis, the ‘pallor of death’) and then blood gravitates to the lowest parts of the body, where it pools. The resulting red-blue discoloration is livor mortis. There is also a reduction in the body’s temperature (algor mortis). But as any self-respecting fan of CSI would agree, 8

dies, no respiration can take place in the body’s cells because the supply of oxygen runs out. As adenosine triphosphate (‘ATP’, the universal energy currency of cells) is mostly a product of aerobic respiration, metabolism eventually slows to a halt. Most importantly, an ion pump called the SERCA runs out of energy and stops functioning. As a result, calcium builds up in the sarcoplasmic reticulum, an organelle specific to muscle cells, and diffuses into the sarcoplasm (muscle cell cytoplasm). There are two special types of protein in the sarcoplasm: actin and myosin. The sudden influx of calcium ions promotes cross-linking between actin and myosin fibres, which makes the muscles stiff and causes rigor mortis because the proteins cannot slide past each

death and the muscles are at their hardest after half a day. There are several causes of rigor mortis, which is what makes it so fascinating. Above all, when a person

other to make the muscle relax.

Relaxation would be possible if energy were available, but as it isn’t the only way for rigor mortis to end is for the muscle tissue to be broken down by digestive enzymes from microorganisms in decomposition. On average this happens about 3 days after death has occurred. So, in brief, rigor mortis is the stiffening of the muscles due to a lack of ATP after death. Only temporary, the condition is believed to occur in all grown humans after death. Famously, rigor mortis plays an important role to scientists examining the bodies of murder victims. Pathologists can determine the time of death by viewing how the extent of rigor mortis in the body. This simple measurement allows suspects to be placed at the crime scene and has massively increased the reliability of forensic science in murder investigations. sg

Sciencegate - Science Week ’10

Scholar of the Issue

An all-new feature. Even more scholarship in one magazine! On 28th September The solemnity and complete, Confucius 2009, the world cel- splendor of this act emerged from this ebrated the 2560th made a huge impact on formative period as a anniversary of the fellow-citizens and many changed man. With birth of the esteemed chose to honour their the goal of spreading Chinese philoso- dead in the same way his own philosophical pher, thinker and afterwards. But Con- teachings throughout teacher known as fucius’ grief did not stop China, he preached “Confucius”. here: he endured three to his compatriots far years’ solitude, during and wide. Confucius’ Born Kong Qiu two which he mourned his disciples gradually and a half millenia ago, mother and devoted the grew in number as they Confucius lived in what remainder of his time to came to appreciate the is now the Shandong philosophical study. simplicity and practicalprovince of China, un- Although his search for ity of his philosophy. der the control of the wisdom was far from Confucius’ ideas were infamously amoral Chou dynasty. Confucius learned to face the hardships of life from a young age, living in poverty with his mother after the death of his warrior father. Throughout most of his young life, Confucius appeared to lack any remarkable traits at all. He may have been intelligent and hard-working, but no-one imagined that he would grow up to become such an influential sage, whose impact was to be felt for thousands of years after his death. Indeed, with the aphorism for which he is now so well known, Confucius once said, “I was humble when I was young, so I did many despicable things.” When Confucius was 23, his life reached a major turning point after the death of his mother. He honoured her by invoking ancient Chinese burial rituals which had, even in Confucius’ day, long since fallen out of use.

not ill-founded religious laws, but sensible moral guidelines. His wisdom was so widely sought that, by the end of his life, Confucius had risen from lowly origins to become one of the most well-known sages in China. Interpretations of the finer points of Confucianism – as this great man’s philosophy is now known – have varied widely throughout the ages. But the core body of beliefs remains the same. Confucius preached family loyalty, respect for elders and universal empathy – all values that are immediately necessary, if frequently absent, in modern-day society. Without support from passionate philosophers such as Confucius and his disciples, these central moral precepts may well have faded into obscurity. Today, Confucius’ legacy is clear at a glance. Rather than a dusty, irrelevant philosophy, Confucius’ insight and deliberate approach created a framework which seems immortal. Our day-to-day interactions are full of perfect examples of Confucianist practice, showing the sheer scale of this man’s influence.

Study the past, if you would define the future. - Confucius

Confucius was a scholar with few equals: undoubtedly an appropriate candidate for our first ever ‘Scholar of the sg Issue’.

Sciencegate - Science Week ’10

bio

HIV: a national Curse

Simon Lack South Africa has the highest HIV infection rate of any country in the world. With 13% of the population infected, this translates into a staggering 5.3 million people and comprises 17% of global HIV sufferers.

epidemic. Furthermore, there was a severe lack of antiretroviral drugs (ARVs) so that people did not always receive the treatment they needed; indeed, he even

Last February, I was fortunate enough to work with Dr Harold Amaler in Cape Town at the medical clinic where he provides care for the workers of a metal-recycling factory, many of whom are HIVpositive. The experience demonstrated first-hand the severity of South Africa’s AIDS problems. Thabo Mvuyelwa Mbeki was the President of South Africa from 1999 to 2008. By the end of his term in office, the rate of annual HIV/ AIDS-related deaths had risen by 85%. Needless to say, Mbeki had faced great challenges in his attempts to tackle HIV/ AIDS. Nonetheless, must Mbeki’s government be held responsible for this systematic failure to reduce the infection rate? In that case, where did it all go wrong? Mbeki employed Manto Tshabalala-Msimang as his Minister of Health and together they adopted a set of incoherent policies which, on the one hand, failed to provide sufficient support for the infected population; on the other hand, their policies actively obstructed all attempts by clinics to curb the spread of the disease. Firstly, Mbeki did not set aside enough money for sufficient research and treatment of the 10

attempted to ban the use of ARVs in public state hospitals. The hospitals themselves were also unable to cope with the high numbers of HIV patients admitted, again due to a lack of government funding. Not enough doctors on site, a lack of drugs, and a lack of space and general infrastructure made going to the hospital a fruitless exercise. Only people with enough money to see a private doctor (who would have his own drug supplier)

received medical care.

sufficient

Many wonder how Mbeki managed to justify such absurd policies. It seems that Mbeki and Tshabalala’s resistance to tackling HIV stemmed from their own idiosyncratic beliefs about the pathogenesis of AIDS, which were (unsurprisingly, given their policies) at odds with the scientific evidence. Mbeki consistently denied that there was any link between HIV and the development of AIDS. He thought that poverty was largely responsible for the disease, and as a result

focused more attention on reducing the causes of poverty than addressing the disease itself. Some speculate that his attitudes arose during a life in exile, when he came to blame the domination and exploitation of South Africa - particularly at the hands of the racist Apartheid government - for most of the ills of his nation. These views were further fuelled by the unfortunate reality that HIV was a sexually transmitted disease. He argued: “The Western world is convinced that we are but natural-born, promiscuous carriers of germs,

unique in the world. They proclaim that our continent is doomed to an inevitable mortal end because of our unconquerable devotion to the sin of lust.” Nor was the situation helped by Tshabalala’s conviction that the most effective cure to HIV/ AIDS was the consumption of garlic and beetroot. Indeed, by the end of Mbeki’s presidency, his HIV policies had caused hundreds of thousands of deaths and Buti Manamela (leader of the South African communist party) suggested that both Mbeki and Tshabalala should be charged with mass genocide. However, in the 17 months since the end of Mbeki’s Presidency, there has been a sea-change in governmental policy, with more resources, energy, money and coherent policies directed towards combating the HIV epidemic. Kgalema Motlanthe was the intermediate president of South Africa for eight months, during which time he appointed a new minister of health, Barbara Hogan, and removed Mbeki’s restrictions on the use of ARVs. Then Jacob Zuma stepped into office, with a ‘’nononsense’’ approach, planning to tackle the problem of HIV very enthusiastically: he made Hogan the minister of public enterprises and replaced her with Aaron Motsoaledi, who has a background in both medicine and finance, skills which make him particularly apt for the position.

Sciencegate - Science Week ’10

Motsoaledi has so far been successful. He implemented a hospital revitalization programme, spending billions on the refurbishment and expansion of public hospitals and employment of new staff. He has also overseen grants of 7.5 billion rand to each of the South African provinces, specifically for the treatment and prevention of HIV. Furthermore, Motsoaledi has provided free access to ARVs for pregnant mothers prior to the time of delivery. This policy is dramatically reducing cases of mother-child infection (so-called ‘vertical transmission’). Previously, HIV-positive mothers had a higher chance of giving birth to HIV-positive infants, who would rapidly become HIV-positive orpahns. The use of antiretroviral therapy is now effectively treating the disease in pregnant mothers, preventing its spread to the newborn and breaking the cycle of infection. However, despite all these changes and the progress made by the South African government, there remain some important hurdles to overcome in the battle against HIV, according to Dr. Amaler, the doctor whom I visited. Firstly, there is a cloud of uncertainty that surrounds the whole HIV epidemic; people are scared by the idea of HIV and a natural human reaction to fear is mistrust, which can lead to wild conspiracy theories. Also, the nature of the HIV virus is such that sufferers may feel no physical symptoms for

up to 25 years following infection. Consequently they feel that there is nothing wrong with them and, like Mbeki, start to doubt that HIV has anything to do with AIDS. Eventually, and inevitably, some come to perceive HIV as a western concoction, invented in order to portray black people as promiscuous. There are several cultural obstacles. Many South Africans, educated or not, will originate from one of the many tribes in South Africa, the major ones being the Zulus, the Xhosas, the Ndebeles and the Swazis. An integral part of tribal life is visiting a Sangoma (a type of Shaman or witch-doctor), and these Sangomas disregard all conventional medicine, advising their patients to perform rituals to connect with their ancestors as a common method of self-healing; this can completely undermine the words and advice of a doctor. In addition, members of certain tribes may be afraid of being tested for HIV as some tribes such as the San regard it as something deeply shameful and have stoned HIV sufferers to death in the past. That said, the President Zuma hardly sets a good example. He has four wives. He has at least twenty children and publicly stated (incorrectly, of course!) that ‘a shower’ is enough to prevent HIV infection. Dr. Amaler points out that an integral part

of his work in overcoming these hurdles is to spread the message that HIV is a treatable disease, and to convince people to be tested. He holds up Uganda as an example of a successful HIV programme; there, HIV prevalence has fallen from 16% in 1990 to almost zero, largely due to compulsory sexeducation programmes and free distribution of contraception all over the country. It is clear from the examples of other SubSaharan nations that science-based policies and rational medical treatments are most effective in combating HIV. The tragedy of South Africa is that the spread

of this devastating virus was not due to a lack of scientific knowledge, but resulted from politicians’ failure to act on sound scientific advice. The tension between scientific advisors and career-minded politicians is by no means unique to South Africa: in the UK, for example, we recently witnessed the scandal when Prof. David Nutt was sacked because his conclusions contradicted Labour drugs policy. Both examples serve as important reminders that public health policies must have a firm scientific basis, must be independent, and - most of all, when millions of lives are at stake - be free of political and cultural prejudice. sg

An election poster for Jacob Zuma, the current South African president. There is only one problem: his next wife will be his fifth.

Sciencegate - Science Week ’10

Global Warming and Malaria: a

bio Alex Beaton Melting ice caps, stranded polar bears and flooded cities. The apocalyptic threat of climate change is endlessly discussed and debated. However, global warming has one potential consequence of which the public is far less aware: malaria.

Malaria is spread when female Anopheles mosquitoes bite humans or animals that are infected by the parasitic protozoan of the genus Plasmodium. When the mosquito takes a socalled ‘blood meal’, it ingests the parasites as well. The parasites reproduce in the mosquito’s intestinal walls, eventually migrating to the salivary glands, where they

high fever, nausea, chills, sweating and weakness. Especially in less economicallydeveloped countries where standards of treatment are poor, a single bite from an infected mosquito can lead to death. Malaria is most prevalent in subSaharan Africa, where a large proportion of people who contract malaria die from the disease. The global mortality rate of malaria is almost

population growth. But the WHO has recently predicted that global warming will lead to renewed epidemics of insect-vectored diseases such as

malaria – not only in Africa, but also in Britain and continental Europe. The average temperature in Europe increased by roughly 0.8°C during the twentieth century, and it has been estimated that by the twenty-second The malarial Plasmodium parasite

remain dormant until the next blood meal. As a result, when the mosquito bites an uninfected person, the parasites will enter the victim’s bloodstream along with the mosquito’s saliva, making it very likely that the individual will contract malaria. The symptoms of malaria include periodic 12

impossible to measure, as the majority of deaths are not reported to hospitals, but the World Health Organisation (WHO) estimates that around one million people worldwide die from malaria every year. Until now, however, the mortality due to malaria has been fairly stable, notwithstanding

century, the temperature could rise by another 3.5°C. This would cause sustained increases in precipitation, leading to changes in rainfall patterns and humidity levels, and an increased risk of flooding. The Anopheles mosquito, which lives in warm climates and breeds in humid conditions, may soon be able to live and reproduce in areas where previously it could not. In Europe, mosquitoes could potentially migrate from malarial areas such as in Turkey to Eastern European countries and then on to countries

further west, including the UK. The Norfolk Fens are ideal! Increased temperatures affect the development of Plasmodium, so they may heighten the risk of becoming infected after being bitten by a malarial mosquito. Most adult

female mosquitoes live for only two or three weeks, so malaria parasites must develop and become infectious within this period in order for the disease to be spread. If the parasite’s incubation period is longer than the life of the mosquito, the mosquito can never pass on the disease to a human. Research has shown that the warmer the ambient temperature, the faster the malarial parasite develops, making it more likely that it will become infectious within the mosquito’s lifetime. This seems to support the claim that global warming could lead to a spread of the disease in areas where it was not prevalent before. As will all novel theories, this one attracts many sceptics. Some affirm that most western countries have adequate health care infrastructure for the disease not to spread even if it did make a return. Others believe that the effect of

Sciencegate - Science Week ’10

dangerous duo? increased temperatures on the infected mosquito populations is not as straightforward as it may seem. Matthew Thomas, a professor of entomology at Penn State University, recently carried out research into the incubation period of the Plasmodium parasite. He showed that Plasmodium is very sensitive to fluctuations in temperature. Importantly, Thomas points out that most previous studies on the impact of climate change on the global spread of malaria consider only average monthly temperatures, not the daily fluctuations that the mosquito experiences. He found that under warmer conditions, daily temperature fluctuation effectively slows down the parasites’ growth. Also, extreme daily fluctuations in temperature, such as swings between colder nights and hotter days, can be fatal to the premature parasite’s development in its first 12 hours: “If climate change increases the frequency of days when the

temperature quickly exceeds the threshold temperature, then entire cohorts of mosquitoes could fail to develop the parasite.” The WHO is alarmed that, perhaps surprisingly, few countries seem to have considered the onset of malaria with much care. Since malaria was eradicated in temperate climates by around 1970, developed countries have dedicated very little research towards the absolute elimination of malaria (as with smallpox, for example). Bill Gates, for one, is very concerned. In fact, he is so concerned about the prevalence of malaria in less economicallydeveloped countries that, as a stunt at a conference in 2009, he released live mosquitoes into the audience. Gates notes that “less than 10% of the money spent on research into baldness is spent on malaria”. The WHO calls for greater co-operation and coordination between the countries most at risk, and stresses the “urgent need to consider how to improve research

and monitoring and how to minimise adverse health impacts”. As history has shown countless times, mosquitoes and Plasmodium itself can quickly develop resistance to chemical methods of malaria prevention. It seems unlikely that we will gain control over global warming in the foreseeable future. In this case, the countries under threat must take serious steps to limit the spread of malaria into their territory, or prepare for the worst. So is the malarial mosquito coming to Britain? Since many factors influence the spread of malaria and since the extent and effects of future climate change can only be predicted, an increased spread of malaria as a consequence of global warming is not necessarily a foregone conclusion. As Matthew Thomas notes, “we need higher-resolution environmental and biological data to understand how climate change will affect the spread of the malaria parasite”. Nonetheless, the repercussions of a global spread of malaria may be too disastrous to ignore, especially for countries that do not have sufficient infrastructure to combat the disease. Global warming seems inevitable, so preparation in the face of a new epidemic of malaria is essential. sg

Websites of the issue The internet has entered its third decade, and web 2.0 is faster and more frightening than ever. We have navigated the labyrinth to reveal some of the bestkept secrets of the online world. Sign out of Facebook, say goodbye to Google and let Sciencegate show you what the web really has to offer. www.wired.co.uk After the success of its big brother in the USA, Wired magazine faced off stiff competition (from Sciencegate, that is) to become the UK’s Launch of the Year in 2009. The website, featuring news, gadget reviews, and some serious tech analysis, is almost as slick as the magazine itself. Discoblog Discovery’s quirky science blog covers the more unusual and more useless - pieces of scientific research. Our favourite section, called NCBI-ROFL, has regular updates about scientists who are paid to give cocaine to bees or show fine art to pigeons. sg 13

Sciencegate - Science Week ’10

Aristotle: the Father of

Henry Titheridge-Stone

If you travelled back almost two and a half thousand years to a small academy in Athens called The Lyceum, the revolutionary Greek philosopher come scientist known as Aristotle probably wouldn’t be in. Unlike the scholarly sages of his day, including his former tutor Plato, Aristotle would not be found at his desk contemplating important questions. No, you would probably find him wandering outside in one of his many gardens or abroad on a quest to learn of new things exciting and beautiful. Indeed,

many feel that his real contribution to the development of science as we know it today was to put forward a heretical view: if you want to know about the world, you must dissect and scrutinise it, not just think about it. It was he who said: “It is the mark of an educated mind to be able to entertain a thought without accepting it.” Even the most casual scan of Aristotle’s writings reveals a formidable intellect that captured everything from moral and political theory to logic, physics and biology. It is in biology, however, that this genius allowed himself to dive the deepest and explore most fully. In

contrast to his studies in the more logical realms of physics, Aristotle’s

biology stands out due to an extreme emphasis on observation at a time when philosophy and abstract thought were considered to be the highest forms of scholarship. “In all things of nature there is something of the marvellous.” As far as the ancient Greeks were concerned, interfering with nature and life in the real world was disgraceful and certainly not something to attract a respected teacher. The Greeks came closest to a logical exploration of nature in the rituals of soothsayers: messing around with the innards of sacrificed sheep in order to predict the future. Aristotle broke free from the constraints of convention and paved the way for factual biology - the study of life. With the cultural norms of scientists and philosophers in ancient Athens being questioned, he felt obliged to devote a large chunk of one of his works, On the Parts of Animals, to justifying his empirical approach. Ultimately this method and

The man himself (384 bc – 322 bc) 14

Sciencegate - Science Week ’10

DIY Science philosophy for discovery meant that time after time, Aristotle got it right. It is for this reason that his major biological pieces (On the Parts of Animals, On the History of Animals and On the Generation of Animals) have stood the test of time in a way that his thoughts about physics could not. Any Highgate pupil today would find that the biological treatises read much like an AQA or OCR textbook. Aristotle’s meticulous method was surpassed only by the variety of his interests and desire to acquire more knowledge of the world around him. During his life (384-322 BC), Aristotle recorded numerous observations in biology that were indisputable and diligently described. He realised from his thorough studies of anatomy that dolphins were in fact mammals and not fish (this was not appreciated by some of the most skilful taxonomists of the modern era like Charles Bonnet, even towards the end of the 18th century). He discovered that some sharks, for example the Bowfin shark, Amia calva, give birth to live young. This was not formally known until it was described by Steno, a pioneer in anatomy, in the 1650s. Aristotle understood that the seeds of plants are the equivalents of embryos in animals;

that the mammalian foetus is fed directly from the umbilicus (not from the wall of the uterus as was previously thought); that some reef fish and wrasses only exist as a species in the female form; and that the sex of an embryo is determined very early on at the start of its development. He correctly described the Eustachian tube that links the middle ear with the throat: the next man to do this was Bartolommeo Eustachio in 1550. (Fittingly, perhaps, the Italian stole the credit from the Greek.) Aristotle’s work on the issue of inheritance caused Max Delbruck, a molecular geneticist at work in the 1940s, to attribute him with the discovery of DNA. Aristotle discussed at great length the difference between epigenesis, the idea that an embryo develops gradually from a single undifferentiated egg cell, and preformation , the long-since discredited theory that an egg contains a fully formed miniature individual (like those toy aliens in the jelly!). Aristotle did make some errors which seem schoolboyish in hindsight, but I think we can forgive him. For example, he did understand that the male and female organisms each make a separate contribution to procreation and that the male’s contribution comes in the form of sperm. But he thought that the female contribution took the form of blood. Such was his influence

that people today, 2350 years later, still speak of certain traits as being “in the blood” and of “blood lines”. Bizarrely enough to us, Aristotle reasoned - based on his observations - that small insects were spontaneously created out of mud; that eels don’t breed at all (indeed the European eel does not breed in Europe but rather in the midAtlantic, discovered by Columbus in 1492); that nerves are full of blood; and that mice are so prolific that an embryo is already pregnant. We can understand Aristotle’s mistakes about tiny details like the development of fleas and bugs because, as clever as the ancient Greeks were, such powerful tools as microscopes had not yet been invented. In fact, if you analyse where Aristotle was right and where he was wrong, the difference simply depends on whether something was visible and readily examined, or invisible due to inaccessibility or microscopic size. Essentially, Aristotle endeavoured to discover all that a man could without the technology we enjoy today. We can be certain that modern science owes far more than it first appears to the ‘look and learn’ philosophy of this revolutionary heretic, experimental nonconformist and timeless genius. sg

Sciencegate - Michaelmas ’09

Last Call

Science week and Sciencegate. What more could you want?

The Knowledge Scientists have all the fun.

Mind-benders

Gadget UAV online... After five years of

development, the Draganflyer X6 has arrived. Remote control doesn’t come much cooler than this. Six rotors and onboard stability control allow flight up to an altitude of 400m. As if that wasn’t enough, it uses GPS to navigate and relays hi-definition video to the ground in real time. Yours for $15000.

Can you trace this entire figure using only one continuous line?

ABCD is a square and its side length DC is a multiple of 11. ED = 23 and EFB is a straight line. What is the area of the red triangle CEF?

(You don’t need trigonometry and it’s a nice answer!) C

This is a fiveroomed house. Draw a single continuous path that visits every room, using each door only once.

Interested in writing for Sciencegate? Speak to the editors or email sciencegate@gmail.com for ideas. Research is what I’m doing when I don’t know what I’m doing. – Wernher von Braun 16