Overriding your desire for fat

England, for all its independence catches a cold when the US sneezes. From economy to culture, England absorbs elements of its ally over the pond. Obesity in the US has increased yearly for the last 15 years to the point where 64% of the adult population is overweight, and just over a quarter are clinically obese. In comparison, in England 46% of men, and 32% of women are overweight with a further 17% of men and 21% of women being obese. These numbers are a damning insight into the lifestyle and diet of the nation in the modern world. What is happening to our bodies? Maybe the biochemistry of obesity might shine a light on the situation.

One pound of human fat is the equivalent to 3500 calories, or 7 large milkshakes at McDonalds. In mathematical terms, one could assume that if I were to increase my milkshake intake by 2 a week, in less than a month I’d gain a lb of fat. However, this isn’t biologically correct. The body has the capacity to match our energy output, such as exercise and our basal metabolic rate, to our energy input, our diet.  In a normal situation your body will work hard to keep your body fat within a certain healthy range. A Cambridge study from 1992 shows exactly that; two groups of volunteers were split into “overweight” and “lean”, and both groups made to eat 50% more calories than their daily needs for 6 weeks in controlled conditions. Unsurprisingly, both groups underwent excessive weight gain, predominately fat. After these 6 weeks, both groups were then asked to return to normal eating habits. Lo and behold, both groups lost a significant amount (61%) of the fat mass they had accumulated, telling evidence that the body has no desire to keep body fat high. So how has it gone so wrong?

A biochemical malfunction may give an interesting insight into how we can override our body’s natural desire for limited fat. Adipose tissue (tissue composed of fat cells) is part of the endocrine (hormone producing) system, not just a bit of blubber. One of the hormones it produces, leptin, is essential for fat regulation. Leptin has a number of fat burning physiological effects, from decreasing appetite to triggering fat breakdown. This is the body’s fat feedback system, so the more adipose cells, the more leptin you have in the body and hopefully the more fat burning, keeping the body in a nice equilibrium. Consider mice with the leptin gene knocked-out become vastly overweight due to uncontrolled eating as good evidence.

Leptin’s main site of action is in the hypothalamus, located in the brain just above the brain stem. Upon leptin binding, it controls energy expenditure, appetite and insulin sensitivity (the more insulin sensitive you are, the less insulin required to lower blood sugar and therefore less fat gain). Furthermore, it has been shown in rats and mice that leptin resistance in the hypothalamus causes obesity; it is very likely that this is true of humans as well. So what causes leptin resistance? There are a number of probable causes, two of which look interesting. Firstly, hypothalamus inflammation appears to stop leptin from working and secondly, not enough leptin passing into the brain. These are not mutually exclusive, but what is causing this? A genetic cause is very unlikely for the vast majority of cases because of the sheer numbers of overweight and obese people, so there must be another cause. This cause must be relatively new to humans since such widespread obesity is a very new human phenomenon.

The standout candidate for this would be the shift of our diet. Recent diet changes such as an increased intake of processed carbohydrates (like refined sugar and fructose syrup); decreases in our fibre intake and not enough vitamins in our diet – which can cause abnormal “friendly” bacteria growth and an increase in gut permeability. Both of which appear to increase the number of inflammatory agents in the body, which in turn may lead to hypothalamus inflammation.

The quality of our food has taken a turn for the worse as well; along with the terrible refined sugars which litter our food, we have terrible quality fats. Less omega-3 fatty acids and more processed omega-6s have lead to an imbalance in the ratio. There are a number of studies which show that omega-3 deficiencies lead to leptin resistance, and diets with high omega-3, even with plenty of other fat, show decreases in leptin resistance. There is a link between the two; humans on the whole have moved away from what is arguably our natural diet. Lots of fruit, vegetables, protein and natural food sources. We have started to treat our bodies as rubbish bins rather than organic beings.

What of the future? Obesity is still rising in England, despite the best efforts of the healthcare system and TV chefs. Education is the only way to stop this. Gastric bypasses, pharmaceutical drugs like Alli, and fad diets will have no significant beneficial effect. People need to learn to eat again, head back towards the natural diet of our species and care for themselves. Fruit and vegetables aren’t expensive, so next Tuesday pick-up a few more apples and carrots at the market.

The Monty Hall Paradox

Predictable is the look on people’s faces when I tell them I am reading mathematics. You see, to them mathematics only ever represented an irrepressible demon, something akin to a chore rather than a passion. Mathematics is a labyrinth of challenges and puzzles, dedicated towards achieving the utmost in perfection.

An example of this inexplicable passion concerns the problem known as the Monty Hall Paradox. The problem goes something like this; suppose that you’re on a game show given a choice of three doors. Behind one door is a car, behind the other two, goats. You pick a door, say No. 1; the host, who knows whats behind every door),opens another door, say No. 3, which has a goat. He then offers you the option to switch your choice to door No. 2. Is it in your advantage to switch your choice?

Now, whilst this problem is very interesting mathematically, the response when it was published in Parade magazine in 1990 is equally as interesting. No less than 10000 readers, including nearly 1000 with PhD’s, wrote to the magazine claiming the solution was wrong.

This question often catches people out, as most people assume each remaining door has equal probability, since the player cannot be certain which is the winning door. In actual fact, the player should switch, as doing so doubles the chance of winning from 1/3 to 2/3.  Consider each of the situations when the door you choose contains the car, or the first goat or the second goat respectively (the number you choose is immaterial, since the probabilities remain the same regardless).  If you choose the car (with probability 1/3), the host will reveal the remaining goat, and switching will make you lose. However, if you choose a goat (with probability 2/3), the host MUST reveal the other goat, hence, switching will always get you the car. Switching doors wins the car with a probability of 2/3, and so the player should always switch.

Those writing to Parade were not some students with half an understanding of statistics, they were highly esteemed experts in their field, misunderstanding what is, in effect basic variable change. But so passionate were they about their subject, and what they deemed to be an egregious slight to their profession, that they were willing to risk their reputations on what is only a very simple problem. Such passion for a subject is what to me makes mathematics so interesting. Even in the simplest of situations, people will do whatever it takes to put forward their case. And why would we want it any other way.

Imagination in the subconscious dusk

(Photo: Geff H)

If only we could hypnotize ourselves into studying for exams instead of surfing through random websites. The strange thing is – we do. Hypnosis is a strange phenomenon that scientists still can’t explain, which may be a good thing considering the power one would wield with such knowledge. Psychiatrists have however, broken down pieces of the puzzle to explain what may be happening. Hypnosis is a combination of heightened imagination, suggestibility, and relaxation; much like day dreaming. So when you are pouring over existential philosophy, and you’re able to forget about the test in 12 hours, that is actually a form of hypnosis. The common theory of how hypnosis works has to do with the power struggles of the conscious and subconscious mind. When you read, the process of identifying letters, putting them into words, and going from one sentence to the next is subconscious. Thoughts on reasons to not kill yourself, brought on by Sartre’s essays, are conscious. If they aren’t you aren’t doing a very good job of reading. Psychiatrists theorize that the deep relaxation and focusing exercises of hypnotism work to calm and subdue the conscious mind so that it takes a less active role in your thinking process. In this state, you’re still aware of what’s going on, but your conscious mind takes a back seat to your subconscious mind. Effectively, this allows you and the hypnotist to work directly with the subconscious. Your subconscious mind does not filter through things as logically as the conscious. It is a lot like a kid, open to bizarre interpretations and easier to subdue with imaginative media.

Think back to when you were four, and you actually thought that when you grew up you would be a mermaid, or a dragon slayer. When one gets lost in thought, this is similar to someone in a hypnotic trance. Your subconscious mind reacts instantly to commands, because one is not thinking through every aspect; such as how exactly you plan on turning your legs into a tail, or the possibility of getting hurt fighting a 30 foot beast. However, due to your survival instinct, there are certain things like hurting someone else, or performing weird deeds in hypnosex, that cannot be forced. This fact isn’t usually made clear, creating a stigma for those into hypnosis. However, since the subconscious directs your sensory apparatus and your emotions; causing someone to feel cold or feel as though they are in love is possible. This is also where all your memories are stored. Psychiatrists sometime use this method to trigger repressed feelings. However, it can also be possible, to create false memories. There are many physiological signs that prove that hypnosis isn’t a large joke, like the Ouiji Board (see the ideomotor effect). Studies of the cerebral cortex have shown that there is a decrease in left hemisphere activity, while activity in the right hemisphere often increased during hypnosis. Neurologists believe that the left hemisphere of the cortex is the logical control center of the brain; it operates on deduction, reasoning and convention. The right hemisphere, in contrast, controls imagination and creativity. An examination of the electrical rhythms produced through frequency waves also show signs similar to intense relaxation, but not of sleep.

The hard part in all of this is actually getting one into this state. Three criteria need to be met, in order to make this possible. The subject must want to be hypnotized, the subject must believe he or she can be hypnotized and the subject must eventually feel comfortable and relaxed (this is also the trick to studying well). Once these prerequisites are in place there are three common methods of inducing a hypnotic state. The first is eye fixation, in which one is so focused on a moving object (not on whether they will be hypnotized or not) to the point that one actually goes into deep relaxation. This however, does not work on most people. The second method is harsh commands. When the pressure from these commands is actually induced to a point that the person gives in, one surrenders conscious control. Other forms are similar to one going to sleep, but with a second party giving you commands that you follow. Finally, a method causing one to rock back and forth creates a loss of balance. This form of being induced into strong relaxation can be felt on some twirling rides, and is similar to how adults put their babies to sleep. Due to the many physical and conscious obstacles with hypnosis, reprogramming one to stop smoking usually fails. Although hypnosis seems too good to be true, the fact is that it is simply a trance, of the same type that one falls into during intense studying, and is fragile as such.

Questions, comments and corrections can be sent to sabeen.sidiqui@yahoo.com

Mouse trap universe

The atmosphere is electric. All eyes are on eight-year-old Louise, to whom I have bestowed the momentarily ultimate honour of being master of ceremonies. A countdown worthy of mission-control cuts through the excited murmurs; my inner ten year old boy squirms with excitement. Will it work?  Louise flicks the all-important trigger and the ultimate machine kicks into action. In its sixth major iteration of the afternoon, the product of the collective mind of a room of twelve-year-olds (and several overexcited fathers too, who boast wistfully of their Meccano creations of youth) is wacky, hilariously complex and, to my joyful pride, works pretty darn well, maybe with an occasional prod en-route. A (by now, disturbingly leaky) can of spam wobbles toe-curlingly down a ramp, nudging a seesaw whose action pushes a plastic superman down a zip-wire to decapitate a Barbie, whose head tumbles onto a toy car, which rolls majestically down an incline to set off the next table of events. A bewildered mother enters the room with her sprog and asks me what I’m doing. After a brief moment of existential crisis, I welcome them to the Science Festival and explain that we are building a Heath-Robinson contraption, whose ultimate aim is to make a cardboard frown in the corner become happy (obviously…). (I overhear a boy utilising impeccable pre-pubescent logic to explain the same to a pal: “We’re boys, so we don’t like girls, so we are trying to kill as many Barbies as possible.”) I begin to wonder whether our universe is like a big game of mousetrap – whether, in theory, if we had data on the initial states of every fundamental particle, we could predict exactly what were to happen in, say, half an hour’s time. To answer the question, I went to speak to Dr. David Seery, theoretical cosmologist here at Sussex, who would be my guide on a journey into the extraordinarily weird happenings of the very small.
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What Is the ‘X’ Factor?

With a record 200,000 people applying for the X Factor this year it seems the nation can’t get enough of the talent show. The winners this season have varied in age, gender and arguably talent – but could there really be a genuine and quantifiable ‘X’ factor? And if there is, could we create a formula to predict the next winner? Or even enter ourselves statistically and scientifically  engineer ourselves to win?

In fact, if we were to try and create a formula for success, we wouldn’t be the first. The show’s 2009 sponsors came up with the following attributes: appearance, charisma, a back-story, resilience, singing talent, misplaced self-belief, self-centredness and determination. However, after scoring all of the contestants on the show, they predicted Danyl Johnson to be the overall winner revealing a slight flaw in the research as he received 4^th place.
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The chemical of motivation

What fascinates and troubles me about the brain is what it wants and desires. I’m always acutely aware of the limits of my own free will: eat less, exercise more, study more, be more social, dare to do this, stop doing that; it seems like a never-ending struggle! I know I’m not the only one frustrated by this experience, especially now, with new year’s resolutions failing left and right. Why is this happening?! What can you do about it?

In the middle of your brain you have half a million neurons that release dopamine into your frontal lobes. These neurons form the core of your brain’s reward system, which generate motivation. Rewards like food, drink, play, sex and addictive drugs, raise dopamine concentrations in your brain just like earned rewards such as money. Unexpected rewards are particularly effective – dopamine builds up in anticipation of uncertain rewards, making everyone at the bus stop stare at the bend where the bus will appear. Low dopamine concentrations on the other hand make you distracted and disinterested.

Different behaviours are produced by different groups of neurons in the frontal lobes. These neuronal groups run on dopamine, and the behaviour you feel most motivated to perform at any given moment is that of the group that generates the most dopamine. Eating sweets is easy: with a few simple muscle movements, your dopamine neurons are activated. Studying for a distant exam is hard: it requires your full attention and activates your dopamine neurons only indirectly, through your prefrontal cortex, which simultaneously has to inhibit more immediate urges like surfing the web, going out or watching a film.

New year’s resolutions fail because we make them considering only the wonderful goal, which by itself produces plenty of dopamine, especially when it’s new and feels like a fresh start. We don’t realize how hard it will be for our prefrontal cortices to provide the new neuronal groups with enough dopamine to make us run regularly, or read in the library, or go to the gym, or in any way compete with the entrenched neuronal groups that have us sit on the couch, or over- eat, or smoke. On a normal day, the further away a goal is, the less attractive it seems, because the further away a reward is, the less dopamine it generates. For example going for a run will give me a shot of dopamine but its such an unlikely occurrence that sitting on the sofa eating a large bar of chocolate will give me a bigger surge, at least in the short term.

So the trick to keeping new year’s resolutions: be nice to your prefrontal cortex. Quitting smoking is knowing that the urge is strong because dopamine neurons are covered in nicotine receptors, but the brain will change in a few months because it can reorganize itself through plasticity – the ability for the brain to reorganise and reassign neurones for a new skill – and the urge to smoke goes away. Understand your brain, the possibilities are endless; you might even keep your resolutions.

Snowflake physics

Britain is under siege. Forget terrorism, forget recession. The snow is here. Anxious parents queue for hours stocking up on 40 jumbo-sized loo rolls and loaves of bread. Previously benign neighbours steal salt for their driveways. Camera crews aim their sights at the elderly, the gangly and the irresponsible in cynical hope of dramatic collapse and newscasters talk in hushed, alarmist tones, professing apocalypse. There is no doubting it: there is nothing we love more than to complain about our weather.

Not wanting to look outward at the world, I stared at the snow. This got me thinking; can it be that no two snowflakes are identical? The answer is a resounding no. Because water is not isotopically pure the probability of two crystals, with unimaginable numbers of molecules having exactly the same distribution is vanishingly small; in fact, so small that it probably has never happened. What of the wonderfully intricate crystals that adorn knitwear? Mathematical permutation can answer this. Suppose we have 15 snowflakes on a scarf and there are 15 positions for the first snowflake, 14 for the second, and so on, which multiply to over a trillion orderings! If you could ‘build’ a snowflake using but a 100 ‘pieces’, the number of permutations would exceed the number of atoms in the observable universe! Hence, no two complex snowflakes have looked, or will ever look, identical.

Nakaya, a Japanese nuclear-physicist-turned-snow-crystal extraordinaire, painstakingly classified the crystals into 41 different morphological types, from hollow columns to sharp needles, to curious columns capped on either end. How on earth do we explain such diversity, and indeed, what is the cause of the beautiful six-fold symmetry?

Let me take you on a journey, far up in the clouds. Inside each snow crystal, there is a dust particle which along with other gases, is required for the initial attraction of water molecules. The fate of the flake depends on the temperature and the Supersaturation (a measure of water concentration). A slight change in either direction has a beautiful effect on the form.

On a molecular level, the corners of a snow crystal stick out so water molecules more rapidly diffuse and condense upon them. For a while, the edges can keep up, as they become rougher and rougher as the corners extrude outwards. But eventually, they’re as rough as it gets, and the corners win out. The snow crystal has grown arms! This keeps happening, arms growing arms resulting in fractals.

As the snow crystal flutters about in space, its microclimate changes, so its pattern of growth changes. Due to the diminutive size of the crystal, all arms are exposed to the same environment, and thus, symmetry is maintained. No two snow flakes take exactly the same path, and so no two are exactly alike. thus, in principle, one should be able to infer the ‘history’ of a snowflake from its form; or to quote Nakaya, “Snowflakes are hieroglyphs sent from the sky.” Snow isn’t a time to fret and moan, it’s a time to awe at the beauty of the natural world.

Read more at http://www.its.caltech.edu/~atomic/snowcrystals/

Have humans stopped evolving?

In a time where survival of the fittest means relatively nothing and most humans live to procreate despite illness, poverty and infertility, scientists are asking themselves the question: are we still evolving or have we come to an evolutionary standstill?

Evolution was pioneered by the renowned scientist Charles Darwin in his book The Origin of Species and defined as the theory that groups of organisms change with passage of time, mainly as a result of natural selection, so that descendants differ morphologically and physiologically from their ancestors. In the case of humans, the theory suggests that we descend from African ape ancestors. Many fossils including the infamous “Lucy” fossil of a complete body found in Ethiopia in 1974 dating back 3.2 million years old are evidence of this theory.

As is well known, evolution is accountable for many characteristic human traits, such as bipedalism (walking on two feet) and opposable thumbs. From a biological point of view, evolution is the change in genetic material of a population of organisms from one generation to the next. This means that very small alterations in Human DNA (called mutations) occur from one generation to the next which can, over time, lead to a substantial change in the population’s genetic data. This can thus lead to the formation of different species. Although there has been much debate as to how evolution functions, a number of genetic mechanisms can now be held accountable for these changes. The first is natural selection, which is the process by which beneficial mutations enhance a population’s reproducibility and increase their change of survival. It follows three simple rules: heritability, variation and survival. The other is genetic drift is the change in allele frequency from one generation to the next due to random sampling. It is a totally random mechanism.

As to the topic in question: are humans still evolving? Although there are opposing views on the subject – some scientist say we stopped evolving around 50,000 years ago when modern humans and culture began to emerge – it is quite difficult to completely deny that we humans still under the influence of evolution. It has been discussed and famously argued by geneticist Steve Jones that the process of natural selection has been undermined by modern technology. The survival of the fittest is not longer applicable, as almost everyone is likely to survive to reproductive age and procreate. Others argue that natural selection no longer has a direct effect on physical survival but that the “fittest” individuals can be described by their intellect. This theory is supported by writer Christopher Wills and the discovery in 2005 by Bruce Lahn of two supposedly new genes involved in brain development. Some, including the evolutionary biologist Steven Pinker, would even argue that technology has created “reverse evolution”. This means the “weaker” traits are no longer selected out of the human genome, possibly making us more susceptible to illness for example. Geoffrey Miller believes evolution is being driven by sexual selection and that by the means of assertive mating for intelligence, personality traits and health, new beneficial mutations are likely to be greatly selected for.

Some examples of the human gene pool currently evolving cannot be ignored. The discovery that a gene called CCR5-32 which can protect from the HIV-1 virus has greatly increased in parts of Africa where the disease is particularly widespread is one. Studies at the University of Chicago have shown that around 700 genes have been favoured by evolution over the past 15,000 years. These adaptations can be small, like genes increasing our ability to process lactose as the cow became more domesticated and the lightening of some Europeans skin in response to a general northward movement with less sunlight. Some very recent research (2009) by Stephen Sears has predicted the future women by studying some 14,000 women spanning three generations in Massachusetts. Following his findings, the future women will be shorter and curvier, be generally healthier and have higher fertility.

But there are some question marks which are difficult to answer. For instance, why has one form of the dopamine receptor gene developed a very high frequency in the human gene pool when it does not offer any beneficial mutations? On the contrary, it is associated with attention deficit hyperactivity disorder! A slightly more political view point is that many scientists including Pinker would rather believe that human evolution stopped thousands of years ago; guaranteeing that all racial and ethnic groups and still biologically equal.

At this point in time, most scientists will agree that yes, humans are still evolving, even if their definitions of evolution diverge. They also agree that is it impossible to predict the direction of evolution at this point in time. So whether we shall become futuristic cyborgs as suggested by Ray Kurzweil, simply more “beautiful, intelligent, symmetrical and healthy” as projected by Miller, develop a whole new species by colonising other planets as Wills point of view proposes or “befoul our planet that only an eccentric and hardy remnant of our species will remain” as proclaimed by Daniel Dennett is up to your personal view of our future as the human race.

The first discoveries of the 21st Century

As we approach the end of the first decade of the 21st century, I thought it would be interesting to go over the discoveries and advances this past decade has brought us.

One of the most fascinating and ground baking achievements of the decade so far is the successful completions of the full Human Genome in 2003. The Human Genome is the full DNA found in each cell of a human’s body. It characterises us from head to toe and although is different in each individual, has an overall map by which we can analyse traits and genes. This blueprint is stored over 23 chromosome pairs which each hold different genes in different domains. A chromosome can be broken down to its basic component – DNA – by several levels of unwrapping of the compact molecule. DNA itself is composed of two chains of molecules called nucleotides which pair up forming the double helix discovered by Watson and Crick. The sequencing of the Human Genome is the process by which scientists have created a database containing every single nucleotide sequence contained in each gene in each chromosome. As well as providing us with a huge amount of information on the human genome, this achievement allows scientists to analyse and study different genes and find out more about how we work and why. Other genomes have been recently fully sequenced – that of the mouse and the horse – allowing us to compare differences and similarities. The mouse genome is particularly useful in genetics studies as it is very similar to that of the human and can thus be analysed.

Continuing in the medical sector, the discovery of a cervical cancer vaccine in 2006 by Dr Ian Frazer has been followed by a worldwide implementation of this vaccination. The HPV vaccine (Human papillomavirus) has been shown to prevent the infection via a species of human papillomavirus associated with cervical cancer and other less common cancers. As HPV is the most sexually transmitted diseases worldwide, this is a very important discovery. It has been recommended as a vaccination of young women in Australia, Canada, Europe and the United States in the hope of reducing the amount of cervical cancer worldwide which is a painful and costly disease to treat.

The 21^st century has also been host to the first successful face transplant in France in 2005. This procedure is still in an experimental phase and most successful transplant cover smaller areas of the body. It is aimed at people disfigured following burns, disease or even birth defects. Up till now the only alternative – using the skin from a patient’s back in over 50 operations – has not been very attractive, neither from a pain or an esthetical point of view. The first successful facial transplant was performed by Jean-Michel Dubernard, plastic and microsurgeon. The skin for the transplant was taken from a triangle of tissue from a brain-dead’s human nose and mouth. Although reports say that the whole procedure was complicated and left the patient’s immune system severely depleted, Isabelle Dinoire (whose face was ravaged by her dog) has said that she is happy with the results.

More discoveries have been made in the astronomy area. In 2004, Mars Exploration Rovers discovered evidence that there was once water on Mars. This finding was later proved, in 2008, when tests reveal evidence of ice on Mars. In a ruling to change all primary science lessons from now on, Pluto was re-classified as a dwarf planet in 2006, lowering the number of planets in the Solar System to 8. In 2001, Dennis Tito – the first space tourist – entered the International Space Station for the modest sum of $19 million.

Many other discoveries and events have filled the beginning of the 21^st century in all science areas, although going through all of them would take the next decade! Here are a few more of this decade’s fascinating findings. In 2003, a human dwarf species was unearthered – Homo thoresiensis. 2004 was home to the first ever hurricane in South Atlantic and on the 22^nd of July 2009, we experienced the longest solar eclipse of the century. What more to come?

Sussex students win top science awards

Two students from Sussex have won prestigious Science prizes at the annual Science, Engineering and Technology (SET) awards. The SET awards provide a showcase for educational excellence by publicly recognizing the exceptional achievements of both students and universities.  Read more