57
Can our health be affected by circadian rhythms? The health benefits of garlic What are the Northern lights? issue 04 | Summer 2013 qmsci.wordpress.com

Issue 04 - Summer 2013 - qmsci

  • Upload
    qmsci

  • View
    218

  • Download
    2

Embed Size (px)

DESCRIPTION

qmsci's first fully digital issue - issue 04! Released in Summer 2013.

Citation preview

Page 1: Issue 04 - Summer 2013 - qmsci

Can our healthbe affected bycircadian rhythms?The health benefits of garlic

What are the Northern lights?

issue 04 | Summer 2013 qmsci.wordpress.com

Page 2: Issue 04 - Summer 2013 - qmsci

contentsspecial features

3

6

8

12

15

33

37

39

41

43

Giving a spit

The Leveson inquiry

Lurking beneath the surface

The science of waves

20

23

27

31

45

47

50

52

55

The health benefits of garlic

Women in science

Interview with Prof. Cox

The double-slit experiment

The humble origins of the mitochondrion

The greatest scientist?

The Placebo effect

Human living extremes

Circadian rhythms

What’s the point in doodling?

Editor in ChiefJenni Toes

Design editorIsmail Uddin

Copy editorCaroline Page

Photog’ editorPippasha Khan

Features editorMichael Willis

News editorDev Thaker

Almira KhaliqSam SykesNikita VasisthaPhoenix FitchTahrima RahimBahga Said Mo-

hammudHannah McCartneyIndigo DeanEleanor MatthewsAndre da LuzPaul Milne

Viral MistryHarriet SpeedAlex HamiltonRulank Kotencha

Which pet is brainier?

Personalised prescriptions

Does music make us fell emotion

What are the Northern lights?

Interview with Prof. Russell Foster

articles and features

Editorial team Contributors

Page 3: Issue 04 - Summer 2013 - qmsci

Giving a spitThe science behind

bone marrow donationAlmira Khaliq

Just how much do you know about bone marrow donation? Bone marrow

donation is a procedure that is relatively unknown to most people. Where people have heard of it, it is often shrouded in misinformation. Read on to understand the real science behind bone marrow donation and how to ‘give a spit’.

Stem cells are undifferentiated cells that have not yet specialised to form a specific function. Some stem cells differentiate to form blood cells in a

process called haematopoiesis. As blood cells have a short life span, this is a continuous process and therefore requires a constant supply of stem cells. In adults, stem cells are sourced from the bone marrow, a soft jelly-like tissue found in the centre of bones

in the body.

The need for bone marrow donation arises when the bone marrow is damaged. For instance in individuals with leukaemia, dysfunctional white blood cells are produced (by dysfunctional stem cells) which do not

3

Page 4: Issue 04 - Summer 2013 - qmsci

fight infection as they should and instead actively inhibit the production of other blood cells and platelets. A combination of chemotherapy and radiation therapies can be used to remove the damaged stem and blood cells but in the process normal, healthy stem cells are also removed. This is when a bone marrow transplant may be needed to replace the damaged bone marrow so that healthy stem cells can be produced.

However, leukaemia is not the only disease that bone marrow transplants can be used for. Chemotherapy and radiotherapy cannot currently be targeted at specific cells; they damage healthy stem cells whilst also destroying cancerous ones. So there are other types of cancer where a bone marrow transplant may be needed. Additionally, in some extreme forms of anaemia such as aplastic anaemia, not enough blood cells are produced in the bone marrow so a transplant may be required. There are also some genetic disorders, such as osteopetrosis where bones harden

and become dense. This means the bone marrow does not form properly which also limits the number of blood cells that the body can produce. Bone marrow transplants can be used to treat a range of conditions.

So what about the actual donation process? Expecting mothers can give consent for stem cells to be sourced from umbilical cord blood which would otherwise be discarded as clinical waste. According to statistics from Anthony Nolan 65,000 litres of cord blood were discarded last year in the UK. That’s 65,000 litres of potential life saving stem cells - and it’s being thrown away!

The other way stem cells can be sourced is through adult stem cell donation. This is a two step process. The first step involves joining the bone marrow register. To join the register you have to be aged between 16-30 years of age and be generally fit and healthy (a full list of excluding criteria can be found on the Anthony Nolan

65,000 litres of cord blood were discarded last year in the UK

4

GIVING A SPIT

Page 5: Issue 04 - Summer 2013 - qmsci

website). You then fill in an application form and provide a spit sample. Anthony Nolan then processes the sample to assess your tissue type.

You then remain on the register until the age of 60. If anytime between now and then, your marrow is found to match that of some-one who needs a transplant Anthony Nolan would contact you and ask for some blood tests to check you are still a match. A full health screening is conducted before any marrow is taken to ensure that you are healthy so that no infection would be transmitted to the patient. Once that has been verified you can donate!

Around 80% of donations can be collected peripherally through a vein in the arm. In this instance, a nurse will come to your home and give you an injection every day for three days to promote stem cell growth to increase stem cell count. You would then go to a stem cell clinic and be ‘hooked up’ to a cell separator machine which would take your blood, separate out the stem cells and then return your blood back via the other arm. Some side effects of this can include flu-like effects and a general aching in the arms.

In some instances, it is safer for the patient for the marrow donation to be collected from bone marrow in the hip. This accounts for just 20% of cases and a general anaesthetic will be used prior to removal of the marrow. A general feeling of tiredness and achiness in that hip area can be expected although painkillers are provided.

All in all, you have just done something amazing - you have saved someone’s life! Currently only 2% of the UK population are on the bone marrow register and with 37,000 worldwide waiting on a transplant. Anthony Nolan desperately need more people to sign up. So what can you do to find out more? Well, Marrow is the student branch of Anthony Nolan and here at Queen Mary and Bart’s campuses, we try and raise awareness of bone marrow donation and encourage people to sign up. We hold donor recruitment events throughout the year so if you are interested in finding out more (there is no commitment at this stage!) you are more than welcome to come along to one of our events. To keep in touch with the work we’re doing, I’d recommend joining our Facebook group at https://www.facebook.com/groups/267602993275363/.

5

GIVING A SPIT

Page 6: Issue 04 - Summer 2013 - qmsci

The health benefits of garlicHannah McCartney

Would you be willing to smell a little worse to feel a little better? Garlic has a history of being used to cure ailments such as high blood pressure or bacterial infections. The Ancient Greeks, for example, believed so strongly in the power of garlic that soldiers would eat it before entering the arena or battlefield as they thought it had strength-enhancing properties. Unfortunately, with the help of modern medicine and countless clinical trials, we know this is completely untrue.

Garlic can allegedly ward off bacteria like Listeria, E. coli, cryptococcal meningitis. It has been found that one clove of garlic has about one per cent of the potency of

penicillin. Its antibacterial properties are all due to a high concentration of thiosulfinates which react with certain enzymes of the pathogens. The most abundant of these thiosulfinates is called allicin.

Allicin is generated when the enzyme, alliinase, reacts with its substrate molecule, Alliin. This reaction can only take place when the garlic is crushed as the enzyme and substrate are located

Allicin, the active ingredient in garlic.

6

Gar

lic v

ecto

r im

age

from

vec

to20

00.c

om; c

hem

ical

stru

ctur

e di

agra

ms

from

Wik

imed

ia c

omm

ons

(Ath

uor:

Ben

Mills

).

Page 7: Issue 04 - Summer 2013 - qmsci

in different parts of the clove. Not only is allicin an antibacterial, it can also be described as an antioxidant as it promotes enzymes which fight against the effects of nicotine and slows the aging process of our liver. As an antioxidant, it naturally destroys free radicals that are believed to contribute to tumour growth and atherosclerosis.

Another important compound found in garlic is called ajoene. It is formed in a chemical reaction involving two allicin molecules when the garlic is crushed. Ajeone has strong anti-clotting properties by making our red blood cells less viscous. A study published in the Journal of Hypertension showed that participants consuming garlic had a reduction of one to five per cent in their blood pressure levels. This supposedly contributed to an up to forty per cent reduction in the possibility of having a stroke. Like allicin, ajoene can also decrease tumour sizes by inducing apoptosis, a process whereby a cell is degraded in order for it to be engulfed and recycled.

Not unlike the ancient Greeks, modern medicine has had plenty of

misconceptions regarding the health benefits of garlic. One of these being that garlic can improve cholesterol levels. In 2007, researchers at Stanford University refuted this claim when they found no significant improvement on the number of low-density lipoproteins (or “bad cholesterols”) in the blood of high cholesterol patients when administered garlic supplements and raw garlic.

Overall, garlic does some incredible things to our body and it’s definitely worth chopping some up next time you’re in the kitchen. Just don’t expect to have improved cholesterol levels or to suddenly transform into an invincible warrior.

The structure of ajoene

7

FURTHER READING

Why garlic is good for the heart - BBChttp://goo.gl/pxvGJ

Surprising health benefits of garlic and onions - The Huffington Posthttp://goo.gl/beUxJ

Benefits of garlic powder - LIVESTRONGhttp://goo.gl/ui4AJ

Page 8: Issue 04 - Summer 2013 - qmsci

The humble origins of themitochondrion

Sam Sykes

8

Page 9: Issue 04 - Summer 2013 - qmsci

Ask the nearest cell to name some of its favourite component organelles and you’ll be sure

to hear, right up there with the best of them, the humble mitochondrion. First identified in the 19th Century and often fondly described as the ‘power centres of the cell’, mitochondria are extremely important to the wellbeing of the plethora of cells found in eukaryotic organisms, regardless of size, shape or function. By providing useful ATP (the basic energy currency of the cell) in return for a steady supply of oxygen and nutrition in the form

of food, mitochondrial energy allows cells to perform both intracellular and extracellular actions such as a number of metabolic processes, active transport and cell division to name but a few.

Current hypotheses propose that an archaic union of two early and primitive cells formed the very first eukaryote with the ‘mitochondrial-like’ cell, relegated to the status of an organelle. Most importantly, this union meant that, despite having been engulfed by another cell, this proto-mitochondria

possessed its own genome. This symbiotic relationship proved so productive that it remained, and still remains to this day, an integral part of complex life as we know it - including in humans.

Today’s mitochondria still contain within them a considerable proportion of the genetic information required to successfully replicate in a form of DNA known as mitochondrial DNA (mtDNA) and, during cell replication, do so in a similar process to that of a number of proteobacteria . The larger

cell provided a degree of safety and the proteobacteria provided a more efficient source of energy – aerobic respiration.

Mitochondria are absolutely critical to a eukaryote and if something goes wrong cells can face very serious consequences. Sadly, it is estimated that almost 1 in 250 people are carriers of mitochondrial mutation with the capability to cause disease and at least 1 in 10,000 adults in the UK live with some sort of mitochondrial disease. Problems usually arise through the

9

First identified in the 19th Century and often fondly described as the ‘power centres of the cell’ mitochondria are extremely important to cells in eukaryotic organisms

Page 10: Issue 04 - Summer 2013 - qmsci

acquirement of an error in the genes coding for one or more of the numerous enzymes used by mitochondria, and dysfunctional mitochondria manifest themselves in a number of ways, making them hard to identify and even harder to treat.

An interesting quirk means that only mitochondria from the mothers egg cell are present in the zygote of newly fertilised babies – any mitochondria ‘donated’ by the sperm cells are ruthlessly destroyed by the ovum. This is useful to geneticists studying ancestry as it simplifies tracing of maternal lineages and has had profound implications in the analysis of early human migration patterns.

Unfortunately, however, it also means that any mutant mitochondria in the egg cell are almost invariably passed on to the offspring.

In 2010, the first tentative steps were made toward the development of preventative measures. Researchers working for the ‘Mitochondrial Research Group at the Institute for Ageing and Health’ in Newcastle used a technique coined ‘pronuclear transfer’ in an attempt to reduce the chance of embryos developing with mitochondrial disease. In essence, this entails the movement of nuclear DNA taken from a mother known to be a carrier of mitochondrial mutations into another fertilised ovum donated by a separate,

10

mitochondrial DNA

Structure of a typicalmitochondrion

matrixgranule

ribosome

ATPsynthase

cristae

outermembrane

innermitochondrial

membrane

Adap

ted

from

Wik

imed

ia c

omm

ons

imag

e by

Kel

vinso

ng.

Page 11: Issue 04 - Summer 2013 - qmsci

unaffected, woman. By limiting the transfer of mitochondria between egg cells, embryos developing after this treatment should make use of un-mutated mitochondria while still comprising of the original genetic material from the mother and father.

Last year, scientists in Oregon in the US used a similar, where the mothers’ genetic information was transferred to a donor egg cell prior to fertilisation. The cell was then fertilised using the fathers sperm and, according to the study published in Nature in autumn 2012, has had promising results – a number of the 65 manipulated eggs developed into embryos at the blastocyst stage normally at a rate similar to that of un-manipulated eggs undergoing IVF treatment.

Pronuclear transfer has been labelled as ‘three-person IVF’ and it is easy to see why – the technique makes use of genetic material from three unique adult humans. In the UK, a public consultation looking at the ethics of such a procedure is in the process of being conducted by the ‘Human Fertilisation and Embryology Authority’. However, that’s not to say human embryonic manipulation is anything new – strong preferences for male progeny in some countries has

led to spiralling numbers of aborted female embryos. History has shown that male babies are born frailer and, once matured, are more likely to take life threatening risks than their female counterparts and because of this, the natural ‘sex-ratio’ is usually considered to lie in favour of males at around 105 males for every 100 females (or 105:100).

Humankind has already demonstrated that it is willing to make decisions of great magnitude on the basis of a technological advancement. Three-person IVF shows great promise as a mitochondrial disease preventative measure but how long will it be before it, like the mitochondria, is mutated into something which could allow even greater embryonic manipulation? As a society, we must be very careful so as not to imbalance our ever greater medical technology, societies’ desires and the natural world.

11

FURTHER READING

Towards germline gene therapy of in-herited mitochondrial diseases - Nature (2012)http://goo.gl/BFGU1

Three parent IVF trialled - NHShttp://goo.gl/OOAAb

Page 12: Issue 04 - Summer 2013 - qmsci

Can circadian clocks affect our health?Andre da Luz

Page 13: Issue 04 - Summer 2013 - qmsci

E ver wondered what controls your sleep pattern? Or why you feel hungry at lunchtime? Day-to-day

rhythms. We never really think about these details until they stop working. In instances like time zone travel (east-west and west-east) the human body suffers through a few irregular changes. Feeling tired during the day but wide-awake during the night and then craving a juicy steak instead of breakfast are a few

examples. These occurrences are explained commonly by ‘jet lag’. This phenomenon can be explained by our internal body regulator: the circadian clock. When traveling, say from New York to Paris, the internal body clock now finds itself 6 hours behind. Just like the watch on your wrist, the circadian clock also needs adjusting. This disruption to internal time keeping has an effect on the regulation of sleep, hormone production, development, cell cycles, digestion (Gonnissen et al.,2012) and even behaviour (Yoon et al., 2012).

The center responsible for regulating the human circadian clock is located in the hypothalamus of the brain. Specifically a region called the suprachiasmatic nucleus or SCN. The genes active within the cells of the SCN encode for proteins that effectively regulate the biological clock of the human body. In the case of flies, period (per) and timeless (tim) genes encode for PER and TIM proteins, respectively. The concentrations of these proteins oscillate on a 24hr time frame. Concentration levels of proteins such as PER and TIM are the start of the series of cascades that dictate the cycles of the body. They are also self-regulating, this meaning that PER and TIM levels control PER and TIM production. In other words, high levels of PER and TIM proteins inhibit the activation of per and tim genes. Conversely, as soon as the levels of PER and TIM proteins decrease below a certain limit per and tim genes are switched on (Colorow, 2012).

The rhythm at which per and tim genes are activated/deactivated is an instinctive

Suprachiasmatic nucleus (SCN)

Hypothalamus

13

Page 14: Issue 04 - Summer 2013 - qmsci

and self-managing process. This is the reason why humans are able to spend long periods of time in surroundings without environmental cues (such as day and night). If environmental cues do not seem to play a role in this process, then there is the question of how humans overcome problems such as jet lag? In fact, Revell (2012) and colleagues have shown that exposure to bright blue light can be used to fix biological clocks that are unbalanced. Therefore, light appears to play some role in maintaining the internal body clock synchronization. The light provided by daytime enters through the retina in the eye and travels along the optic nerve, which in turn is located near the SCN. The intensity of the light is responsible for shifting the molecular cycle found in SCN cells so that it matches the environmental cycle (Avery, 2000). So, light from day and night helps maintain the cycle found in the SCN, in tandem with the rhythm of per and tim genes being activated and deactivated.

All in all, the human body has within itself the ability, along with environmental cues, to synchronize a series of seemingly random processes that are crucial in maintaining a normal, healthy body.

REFERENCES

1. Hanne KJ Gonnissen, Femke Rutters, Claire Mazuy, Eveline AP Martens, Tanja C Adam, Margriet S

Westerterp-Plantenga. (2012). Effect of a phase advance and phase delay of the 24-h cycle on energy

metabolism, appetite and related hormones. The American Journal of Clinical Nutrition. 96, p689-697.

2. Yoon J-A, Han D-H, Noh J-Y, Kim M-H, Son GH, et al. (2012) Meal Time Shift Disturbs Circadian

Rhythmicity along with Metabolic and Behavioral Alterations in Mice. PLoS ONE 7(8): e44053.

doi:10.1371/journal.pone.0044053

3. Colorow Dr.. (2012). The Time of Our Lives. Available: http://learn.genetics.utah.edu/content/begin/

dna/clockgenes/. Last accessed 30th November 2012.

4. Victoria L. Revell, Thomas A. Molina, Charmane I. Eastman. (2012). Human phase response curve to

intermittent blue light using a commercially available device. The Journal of Physiology. 590 (19), p4859-

4868.

5. David Avery. (2000). The Effects of Light on Circadian Rhythms, Sleep and Mood. Available: http://www.

scn.org/darksky/dec2_00_meeting/avery_abstract.html. Last accessed 30th November 2012.

14

CAN CIRCADIAN CLOCKS AFFECT OUR HEALTH

Page 15: Issue 04 - Summer 2013 - qmsci

Prof. Russell Foster

Jenni Toes

Professor Russell Foster is a world leading neuroscientist based at Oxford University, studying the mechanisms of circadian rhythms and how we can use this information in clinical settings. He spoke to QMSCI about his research into human body clocks regarding human health, and explained his often controversial proposition of a third photoreceptor in the eye.

Imag

e so

urce

: Bra

seno

se C

olle

ge, O

xfor

d Un

ivers

ity

Page 16: Issue 04 - Summer 2013 - qmsci

COULD YOU GIVE US SOME BACKGROUND ON YOUR RESEARCH INTERESTS? My overall interests are in how sleep and circadian rhythms, these 24 hour body clocks, are generated and regulated. Our original area of research was on how light sets the body clock of the sleep/wake cycle to local time. We discovered that in addition to the classical photoreceptors, the rods and the cones, there’s a third photoreceptor within the eye; these light sensitive cells project to multiple structures in the brain, including the body clock and sleep sensors. You could lose your classical rods and cones and still retain these photosensitive ganglion cells. Which means you can be visually blind but not clock blind.

We’re assessing the impact of ocular disease on the ability of patients to regulate their body clocks. An ophthalmologist will tell an individual what it’s like to go blind but they won’t have any idea about this other receptor. There is a tendency to say “well you know, you’re blind, clearly your eyes are now useless to you, let’s just take them

out and give you glass ones because they’re so much easier to look after”. But unwittingly, the clinician will have plunged this person into a timeless world, which is rather like unremitting jet lag for the rest of their lives.

The second area of my research is what happens when clock and sleep systems go wrong. In mental illness there is almost always 100% overlap between mental disorders and sleep disruption. We began to look at the rest activity cycles of patients diagnosed with schizophrenia. What was so breathtakingly striking was that this is not just mild sleep disruption; this is the worst sleep disruption I’ve ever seen.

We came up with an idea that maybe there is a mechanistic overlap between those bits of the brain that give rise to normal sleep, and those bits of the brain that give rise to mental health. We tested that hypothesis in a number of ways; first using a gene linked to human schizophrenia and look at mutant forms of that gene in a mouse.

16

“we engineered a mouse in which all of those rod and cone cells were turned off, and they showed a perfectly normal response to light”

INTERVIEW WITH PROFESSOR RUSSELL FOSTER

Page 17: Issue 04 - Summer 2013 - qmsci

The sleep cycle in those mice was completely shot, just like a patient. We showed that it’s the way that the clock cells in the brain are talking to the output cells in the brain. This is the first evidence that there is genuinely a mechanistic overlap, but there are other ways one could think about it. If we can consolidate sleep in individuals at risk of mental illness, or who are experiencing mental illness, we can alleviate the symptoms. The goal is to identify what the sleep phenotype is like in people with a range of different mental illnesses; how does it develop, how do you go from at risk to syndromal?

Again using mouse models, we’re getting a fundamental understanding of the mechanisms underpinning both normal sleep and normal cognition , and mental health. The fantasy here is that we would have a little wrist watch device using mobile phone technology and a clinical nurse monitoring maybe 200 people in the community. Then when you start to see a change in the pattern of sleep, you bring those individuals in pre-emptively to try and find out what is going on. We could use the abnormal sleep as an early warning of a possible impending mental health crisis.

HOW DO YOU DEFINE A CIRCADIAN RHYTHM? AND WHAT ARE THE MECHANISMS THAT DETERMINE IT? We have this 24 hour body clock, but in most humans it’s a bit longer. It’s a bunch of genes and their protein products, which form a feedback loop, and the rate of that feedback loop essentially determines the duration of the oscillator. Tiny changes in these genes are being increasingly associated with whether you’re a morning person or an evening person.

This clock fine tunes our physiology and behaviour to the varying demands of the rest/activity cycle. For example, in anticipation of wake, blood pressure, metabolism, and alertness is going up, which all prepare us for activity. If you’d waited until you’ve woken up to turn that physiology on, then you’ve wasted three hours of optimum performance. This clock has adaptive value, but it’s of no use unless it’s set to time. We need this exposure to the light dark cycle, and a photoreceptor to detect the cycle.

We used mutant mice, mice in which the visual cells had broken down as a result of naturally occurring genetic defects, until our amazement and excitement, these mice were visually blind, they had no way of detecting their environment visually, and yet

17

INTERVIEW WITH PROFESSOR RUSSELL FOSTER

Page 18: Issue 04 - Summer 2013 - qmsci

18

their clock was set by the light perfectly normally. If you stopped light getting to the eye then the clock would just drift and have no response to light. We proposed that maybe there is another receptor in the eye, and the response we got at that point was ferocious. The arguments against this were twofold:

One is, “We’ve been studying the eye for 150 years, are you seriously telling us we’ve missed an entirely different class of light sensing cell.” The other argument was “Your mutant mice are not the perfect model because they’ve got a few light sensitive cells left.”

So we engineered a mouse in which all of those rod and cone cells were turned off, and they showed a perfectly normal response to light. This model led to the discovery that we have these photosensitive ganglion cells. We have a sloppy clock, it needs to be regulated by light and it was just assumed that this was done by the rods and cones, that it was part of the visual system, and that never made sense to me.

HOW HAS THE HUMAN CIRCADIAN RHYTHM EVOLVED FROM OUR ANCESTORS? The molecular mechanisms that generate a clock in our cells are broadly conserved across the entire animal

kingdom. The way that the whole animal lineage has built its clock is early on and has been retained so we carry in our genes a form of the molecular clock which is broadly similar as it is in insects. There are some subtle differences. Species separated by 500-700 million years of evolutionary divergence are still building their clocks in the same way.

DO CIRCADIAN RHYTHMS CHANGE OVER YOUR LIFETIME? The way we align ourselves to the light/dark cycle does change quite rapidly as we age. From the age of about 10 there is a tendency to want to go to bed later and later, which in a male peaks at around the age of 21 and a half, and in a female at about 19 and a half. Then there is a turn and you start to go to bed earlier and earlier as you age. At the age of 55 you’re getting up and going to bed at about the same time you got up pre-puberty.

We know that for peak performance, teenagers need about nine hours of sleep every night, but because of this biological tendency to go to bed late and get up late, kids are going to bed later, but the alarm clock is still going off at the same time. If they’re going to bed late and the alarm clock is getting them out of bed early, they’re going to

INTERVIEW WITH PROFESSOR RUSSELL FOSTER

Page 19: Issue 04 - Summer 2013 - qmsci

19

fuel the waking day with caffeinated drinks. Of course, caffeine stays in your system for some considerable time it has a half-life of five to nine hours, so drinking strong caffeinated drinks in the afternoon delays bedtime. So then there is a tendency to combat this with alcohol or sleeping tablets to induce sedation.

Now those sorts of induced sedatives don’t mimic biological sleep, so you then lose some of the advantages of a good night’s sleep. The kids are then being woken up in the morning; they then have more stimulants and then more sedatives.

CAN WE EVER ADJUST TO NIGHT SHIFT WORK? The problem with night shift work is that you can be on the night shift for 20 years and you’ll never adapt fully to it, because you’re exposed to the same light dark cycle that the rest of us are. Shortly after dawn, environmental light is some 50 to 100 times brighter than average office and home lighting conditions, so you’re working in the factory at night under relatively dim lighting conditions, you then travel home and experience bright natural light. The clock will always defer to the brighter light signal, which is day time.

If you take a night shift worker and increase the amount of light in the factory and hide them from natural light during the day, they will adapt. But that is completely impractical. So the consequences are, how do you cope? Your physiology is adapted to the resting state, so you can’t possibly expect peak performance, so you see the accident rate on the night shift is much higher than the day shift doing the same job.

It’s very likely that the way you deal with this night shift work is that you override the clock by activating the stress axis, which has consequences. For example, cardiovascular problems are higher in night shift workers, as well as immunosuppression which means night shift workers are more susceptible to a whole range of infections, including things like cancer.

INTERVIEW WITH PROFESSOR RUSSELL FOSTER

Page 20: Issue 04 - Summer 2013 - qmsci

Lurking beneath the surface

Thames Water invasionAlexandra Williams

Page 21: Issue 04 - Summer 2013 - qmsci

K nown for its boating events and iconic surrounding architecture, the River Thames is one of the

most widely recognised rivers in the UK. Historically, the River Thames has had a reputation of spreading pestilence and disease - a communal garbage dump where Londoners of old would throw just about anything. This reputation is reflected in the literature of the time – poetry and stories depicting an aquatic waste land where seemingly nothing could thrive.

The modern Thames is less like this waste land of old, with increased efforts to clean up the environment and improve the habitat for the wildlife living there. But what exactly is living there? Amongst the native species expected to be found in the area,

scientists from a London university have discovered almost 100 invasive species in the Thames, ranging from parasites, and plants to many fish species, and this number is set to increase.

“A hundred and fifty years ago we’d find about one new species every decade, and at current rates we find about one new species every year, so the rate is increasing” says Dr Michelle Jackson, from Queen Mary University of London. Invasive species such as the red swamp crayfish, originally found in US swamps, can have devastating effects on the environment that they enter, consuming food, damaging plants, and outcompeting native species.

So where have these invasive species come from? Dr Jackson led a recent study documenting the invasive species found in the Thames, the date they were first discovered there, and how they were most likely introduced. While the species came from a variety of sources overall, the study found that approximately

10% of all invasive species in the Thames were introduced as a result of aquaculture – the farming of aquatic species for food purposes. Some species, such as the red swamp crayfish, were introduced intentionally to be farmed later. Others, such as nematode worms,

“A hundred and fifty years ago we’d find about one new species every decade, and at current rates we find about

one new species every year”

21

Page 22: Issue 04 - Summer 2013 - qmsci

were released into the surrounding environment after being introduced unintentionally as parasites in farmed fish.

As demands for fish protein far exceed the amount that global catch fisheries can sustainably provide, the farming of fish in lochs, fords and coastal waters may become a necessary alternative to the continued fishing of declining stocks, and so it must be managed effectively.

This report highlights the necessity for increased care and vigilance in aquaculture. With increasing rates of invasion, it is necessary that aquaculture policies and procedures be revisited to prevent the introduction of more invasive species into new habitats. Dr Jackson’s report suggests that as the number of invasive species in the Thames increases, the ecological effects of the invasions are greater. The Thames is not the only river to be affected by

invasive species. The human-mediated introduction of non-native species into ecosystems is a global problem: one that must be tackled on an ecosystems level.

22

LURKING BENEATH THE SURFACE: THAMES WATER INVASION

Procambarus clarkiiColloquially known as the redswam crayfish, it is an invasive species thought to be found only in London, within the UK. Apart from being a carrier of the plague, they are also consumed as delicacy in many countries around the world in a dish known as crawfish boil.

Imag

e by

Mike

Mur

phy,

Sept

’ 200

6, W

ikip

edia

Page 23: Issue 04 - Summer 2013 - qmsci

Prof. Brian CoxExclusive interview with:

at the British Science Festival

Interview byLucy Wyatt

Professor Brian Cox, OBE is a particle physicist, a Royal Society research fellow, and a professor at the University of Manchester. He is more widely known as a presenter on TV shows such as Wonders of the Solar System and Wonders of Life.

qmsci exclusiveIm

age

cred

it: B

BC, P

ictu

re s

hows

: Bria

n C

ox, T

X: B

BC Tw

o, M

arch

201

1, W

onde

rs o

f the

Uni

vers

e

Page 24: Issue 04 - Summer 2013 - qmsci

One of the biggest pieces of science news of late has been the discovery of the Higgs Boson. How did you feel at the moment you found out that these theories actually worked?It was really interesting actually, and I spoke to a lot of other physicists about this because it was kind of a real shock. We’ve grown up with the Higgs, it’s in the textbooks, and it’s been there since the eighties, so you learn it. But it’s a bizarre claim. The claim is that way less than a second after the Big Bang, the universe cooled and the Higgs field condensed out, into the vaccuum, as a condensate. You can picture space being full of Higgs particles, an immense amount of energy locked up in the binding energy in and that condensate. I mean the figure which is astonishing is that in every metre cubed there’s the equivalent to the Sun’s energy output of a thousand years, locked in the Higgs field.

Now that you have it, what would you like to be the end product of this whole project to be?Well, I’d love to pin down what kind

of Higgs it is. And I would love it not to be a standard model Higgs. The Higgs mechanism works in the supersymmetric standard model of five Higgses, I’d love it to be one of those. I’d love it to be one of more than one possible Higgs particles. I don’t know yet what the constraints are, because we haven’t even shown it’s a Higgs. We know it’s a boson, the results only show it in the photon channels; we haven’t seen it coupling into taus, electrons and things yet.

The Wonders of Life documentaries

qmsci INTERVIEW WITH PROF. BRIAN COX

“I didn’t know that biology was - because it wasn’t, when I last did it - such a precise, quantatative science.”

qmsci - Summer 2013

Wonders of LifeProf. Brian Cox and Andrew Cohen | BBC

Available as hardcopy book, as well as eBook on most major digital bookstores.

http://goo.gl/RIJKY

‘Wonders of Life’ is Prof. Cox’s latest book, tackling the story of how life evolved on our planet. This book ac-companies the widely acclaimed BBC TV series, entitled ‘Wonders of Life’. The program may be watched online on BBC’s iPlayer service.

24

Page 25: Issue 04 - Summer 2013 - qmsci

take you a little bit out of your comfort zone. What’s it like for you, as a physicist, to approach biology?The idea was based on Schrodinger’s book, ‘What is Life?’, a very influential book in which he predicted the existence of DNA and looked at the thermodynamics of life. It’s always been a favourite book of mine. The idea was to see how you could do, not natural history in a sense because that’s just about animals, where this is talking about things like the thermodynamics of life, there’s a lot of biology in it, you’re right. I had two advisors who are friends of mine, Matthew Cobb, who’s a professor at Manchester and Nick Lane from UCL. I did almost a crash course, particularly in evolutionary biology which I knew very little about. It’s actually remarkable, the progress since I last did biology is incredible, a lot of it to do with sequencing of genomes and things. But actually, we did a lot - because I got interested - about the evolution of the eye and in particular rhodopsins and choleopsins. So I didn’t know that biology was - because it wasn’t, when I last did it - such a precise, quantatative science. So I was just learning this stuff for the first time was very exciting because I hadn’t seen it before. Just things like photosynthesis: there’s quite a

lot of photosynthesis in it, oxygenic photosynthesis and symbiosis and things.

As a physicist, was it challenging to talk about Darwin’s Theory of Evolution?We filmed the evolutionary biology bit in Madagascar, which was the perfect place to do it. I’d never really understood Darwin’s theory of evolution by natural selection. Talking to Matt and Nick about it, (helped with) understanding the beauty and power of that theory. I hope it works; I’ve spent a lot of time with these two profs, trying to ensure that I understood it. So, I think it’ll work and go down well but you’re right it is a challenge.

Which episodes from your new program do you think best explain and illustrate the process of evolution.The best ones, I think the first two, there’s one about the evolution of the eye and the ear, the story about the jawbones and things with rhodopsins, and the fact that you see it in algae.

There’s a lot more to it than just the idea of natural selection. There are other stochastic processes like genetic drift that come into it - do

25qmsci - Summer 2013

INTERVIEW WITH PROF. BRIAN COX qmsci

Page 26: Issue 04 - Summer 2013 - qmsci

you go into that? Yeah, we certainly talk about those things. I suppose in the TV series the real centre of the story in evolutionary biology is we go to Madagascar and we tell the story of the lemurs, because they’re a very good example of just dumping a very small population in…

I had this idea. To me, it seems obvious in a way that if you’ve got a database of the genetics of the planet, which is distributed and bits of it are held in loads of different species. That’s the point. There’s only one genetic database. It seems kind of obvious to me that if you take a functioning bit of that database and put it somewhere else, and then let it have selection pressures et cetera and different mutations and those things, then you will get speciation. But it’s a data analysis problem, isn’t it? It’s just like I’ve got some bits of the database and put it there. We did film; actually it’s in there. On the end of a branch, it’s not geographic, there’s a little species of ant found, Crematogaster that build their nests, this particular species, on the end of a branch rather than burrowing into a tree.

Then there’s a beetle in there, no one knows why it’s there but it’s only ever

been found in those nests. So we use this to make the point that it’s not to be thought of as geographical isolation alone, it’s to be thought of as the population of a niche, with a bit of that database with just a limited set of it. Then it’s not surprising that it becomes a new species. I’ve written it in a kind of more information way because it’s the way I understood it, that you’ve just separated it off. So I’m going to see if Matt and Nick like it or if they say, ‘Oh Brian you’re a maniac!’

26 qmsci - Summer 2013

INTERVIEW WITH PROF. BRIAN COXqmsci

Page 27: Issue 04 - Summer 2013 - qmsci

The Placebo effectDoes it really exist?

Harriet Speed

Page 28: Issue 04 - Summer 2013 - qmsci

Some people hear the word Placebo and immediately think of the band, however the placebo

effect is not like ‘Beiber fever.’ A placebo is an inactive form of a drug used the treat symptoms on a subject whom usually does not know if they are taking a placebo. It can be in the form of a pill, capsule, injection or even surgical procedure. The placebo effect is when a patient experiences symptom changes due to placebo, negative symptoms are called the nocebo effect. This can be due to the belief that patients have, that the drugs they are taking will cure them. Some scientific evidence suggests that the placebo effect may be partly due to the release of endorphins in the brain as endorphins are the body’s natural pain killers. But not everyone is perceptible to the placebo effect so the results of studies can vary.

In 2012, Derren Brown aired a two part TV episode called ‘fear and faith’ one episode of which analysed the psychological impact placebos can have on the general population. The drug, Rumyodin was said to eradicate fear and was used on people with a fear of heights, singing public and social anxiety. The participants had an initial injection followed by regular drug dosage four times a day. The drug was in fact an anagram of ‘your mind,’ the injection

was saline solution and the capsules are filled with nothing more than sugar. The show portrayed the power of suggestion by even saying possible side effects of the drug which nearly all of the recipients experienced. Later it was revealed the success of this placebo at not only seeming to cure irrational fears but smoking addiction and improve allergy symptoms- Hayfever and dermatitis. This is by no means a scientific study and has to be viewed critically, however it does show the possible treatments in medicine with psychological disorders. If people believe they are getting the support they need they may have the will power to help themselves.

In clinical trials placebos are used as controls. A double blind trial is when the patient and the doctor do not know which patients are receiving the placebo and which are being treated with the active drug. Recently there has been an increase in the effectiveness of placebos in clinical trials and drug companies are

28

“74% of antidepressant success can be attributed to the

placebo effect alone”

Page 29: Issue 04 - Summer 2013 - qmsci

29

trying to discover why. One study shows that 74% of antidepressant success can be attributed to the placebo effect alone.

On the other hand some studies have shown no significant results of placebos being effective. The larger their sample size in the trials the lower the significance of the placebo effect, indicating that small sample size may show a statistical bias. Also placebos do not ‘cure,’ the placebo is not an active from of a drug and in illness treatment is needed. In studies preformed on tumour size placebos had almost zero effect on the tumour. However treatment of pain did seem to show significant results as pain is considered to be a psychological concept. Placebos seem to only be effective in alleviating symptoms if there is a psychological component.

It has also been shown that the effect of a placebo can be increased due to conditioning, when a learned response to a certain stimuli is due to past experience. An electric shock is administered to a patient and they feel pain, a high dose of pain killers is given to a patient and an electric shock is administered again, they feel very little pain. This event is carried out repeatedly over time, then the patient is given a placebo instead of the drugs they are used to, they will experience less pain as their body has been conditioned to receive drugs and feel no pain.

Several other factors can play a role in the placebo effect, for instance the disease in question may change over time. People also often see their doctor

THE PLACEBO EFFECT: DOES IT REALLY WORK?

Placebo Domino in regione vivorumPsalm cxiv

The word placebo is a Latin word, which means ‘I will please’. It is derived from a direct translation of the Septuagint phrase: “Ευχαρεστησω ενωπιον κυριον εν χωρα ζωντων”.

Letters to the Editor, Journal of the Royal Society of Medicine, Volume 93, April 2000

The sentence is first believed to have appeared in the Latin translation of the Bible by Jerome (~342-420 CE). This translation was based on an earlier Greek translation known as the Septuagint.

Page 30: Issue 04 - Summer 2013 - qmsci

or enter a clinical trial when their symptoms are present, at that point when the tests are done their ailment will be at peak and later readings may show improvement solely due to natural fluctuations. Also, patients in clinical trials may subconsciously change habits due to their awareness of taking part in the trial like eating a healthy diet or walking more.

Some recent studies have shown that patients improved even if they knew they were getting the placebo in comparison to no drug treatment at all. This could enable doctors to prescribe placebos and not risk deceiving the patient. Studies were done on sufferers of irritable bowl syndrome divided into two groups, one treated with a placebo and the other with no treatment at all. Almost twice as many patients in the placebo group felt relief from their symptoms. However this was a small study over a short period of time and more of a proof of concept idea for further research to be carried out.

There is no doubt that the placebo effect does exist for some but not all individuals and this could be a very powerful tool in aiding recovery of psychological disorders. However it is no substitution for treatment of

disease as it has no medicinal qualities. Placebos also show an interesting link between the mind and body and how medical issues can be perceive phytologically.

30

THE PLACEBO EFFECT: DOES IT REALLY WORK?

Page 31: Issue 04 - Summer 2013 - qmsci

P lato once said; “Music gives soul to the universe, wings to the mind, flight to the imagvination

and life to everything.” The importance of music in evoking emotions has been documented for centuries. Whether it is a dancy Calvin Harris tune to make the gym slog easier, or a classic Beatles song to wind down after a long day, music makes us feel certain emotions, according to what the artist intended.

The human brain responds to all sorts of stimuli such as those which are visual, olfactory, auditory and tactile. Information generated by stimuli cause chemical reactions to occur in the body and give rise to a variety of actions. These actions can take the form of emotions. With music, people

can automatically cheer up or will feel happy if, for example, they hear a beat that they like.

Dr Valorie Salimpoor, a neuroscientist at McGill University, has carried out research about exactly how music makes us feel these strong emotions. The study looked at brain activity of participants when listening to music. The results were intriguing. This inquiry brings to light the extent at which it affects us. It showed that there is a 20% increase in dopamine levels when listening to a piece of music. Dopamine is a neurotransmitter in the brain and is responsible for ‘reward driven learning’. It increases in levels in response to reward and ultimately is a pleasurable sensation.

Does music make us feel emotion?Tahrima Rahim

31

Page 32: Issue 04 - Summer 2013 - qmsci

“Music increases dopamine levels as much as cocaine”

32

To put this into context: dopamine levels increase by 22% in response to the drug cocaine, and 6% in response to food. Dr Salimpoor’s study highlights just how powerful music is for our psychology. There are chemical reactions occurring in the cerebral cortex of the brain, releasing more dopamine. It is this is set of chemical pathways that are responsible for the euphoric feeling we have when our favourite song comes on in a nightclub. This study shows just how important music is and how much of an influence it has on the brain.

This might explain why music is such a powerful tool in marketing and daily life. Music drives neurochemical reactions in the brain which influences our mood, so it makes sense that music is used –albeit subliminally- to influence other decisions in daily life. A catchy advertisement jingle may not stir the same deep emotive feelings as Leonard Cohen’s Hallelujah, but the mechanism that influences your reaction to both is the same.

Dr Salimpoor and her team will continue looking at what other chemicals in the brain may be affected by musical

stimuli and how behaviour could be dictated by music. The study emphasises how integrated and influential music is in all societies – be it a hymn, a tribal drum beat or an electronic dance track. Once we hear the notes, feelings are triggered by fluctuating dopamine levels – this is the wonderful mechanism that allows us to weep to an Adele track or get pumped up for an evening run with some Daft Punk.

Page 33: Issue 04 - Summer 2013 - qmsci

33

IN THE summer of 2011, what can only be described as an atom bomb exploded right in the heart of Fleet Street. It concerned the egregious practices that a large part of the British Media had been engaged in for years, namely: phone hacking. At first it seemed as if it was just celebrities who’d fallen foul of such journalistic skulduggery; but over the proceeding weeks and months, senior politicians and members of the Royal family seemed to have suffered the same fate. When it emerged that the phones of ordinary and innocent members of the public had been hacked, some of whom the relatives of high-profile murder victims, public furore really set

in.

The result of the public anger that ensued was the setting-up of the Leveson Inquiry into the Culture, Practices and Ethics of the Press; and as the title suggests, the inquiry did just that, by spending over a year scrutinising just about every aspect of the journalistic remit you can think of, no topic or subject was spared. Fortunately for us, the science community, that included the wonderfully controversial topic of how our subject is reported in the media.

The bulk of the submissions taken during the inquiry’s investigation into scientific reporting examined a

What does the Leveson inquiry mean for the future of science journalism?

Paul Milne

qmsci - Summer 2013

Page 34: Issue 04 - Summer 2013 - qmsci

34

lot of compelling anecdotal evidence, while hearing some oral evidence from experts. The inquiry recognised the work of ‘popular’ scientists like Professor Brian Cox, the D:Ream keyboardist turned particle physicist. Such scientists have an important part to play in contributing to the wider understanding of complex science. Prof Cox writes regularly for The Sun on complex issues such as the research he undertakes at the Large Hadron Collider, and digests them into very accessible chunks for the readers.

However, the inquiry learned that not all scientific reporting was being carried out in a sufficiently responsible and informed manner. All too often, scientific journalists were churning out article after article containing, quite frankly, ‘bad’ science. That’s not to say that the press deliberately fabricate the science, it’s that their reporting of it is just very poor and all too often misinformed. The inquiry highlighted what is now regarded as the classic example of deplorable media reporting, namely the ‘MMR-autism link’. In 1998, a rogue doctor claimed a link between the measles, mumps and rubella vaccine and autism. The story had been given unjustifiably front-page prominence in virtually every tabloid, leading to

panic among new-mums and mums-to-be. The link was based in no reliable evidence, and what’s more, the media claimed that there were mass conflicts in the medical community when, in fact, the original claim went against 99.9% of all mainstream scientific evidence. This serves as one of the best examples of where the media comprehensively let the public down. Unsurprisingly, the proceeding decade saw the number of cases of measles increase by twenty five times the number before the claim was reported. These stories, sensationalised in a manner only the media could, are extremely dangerous. Such scientific articles can be turned into ‘scare’ stories, whereby they create unnecessary public anxiety- and have a consequently detrimental impact on public health. One of my personal favourites from the inquiry was when the editor of the Daily Mail appeared, and defended a story that (wrongly) reported that switching on the light during a night-time toilet visit could cause cancer! The flipside to this of course is the overblown ‘breakthrough’. The media has a tendency to exaggerate the early findings of an investigation, proclaiming them to be ‘groundbreaking’ scientific

qmsci - Summer 2013

WHAT DOES THE LEVESON INQUIRY MEAN FOR SCIENCE JOURNALISM?

Page 35: Issue 04 - Summer 2013 - qmsci

advances that will transform the individual or cure a deadly disease; when in fact they are nothing more than a few promising results from some preliminary experiments on mice, or cells grown in culture. Needless to say, this style of reporting also is very damaging to the scientific community, as is not only gives false hope to patients, but also feeds a public perception that science is always promising but never delivering. I should say however, that on balance, the inquiry recognised that science reporting was, in general, responsible and accurate, but nonetheless is undermined by the inaccurate reporting that still exists and therefore demands attention, given the important public interest in science journalism. The potential of the media to influence and inform the public on science comes with a huge responsibility. When the media gets it wrong the impact is devastating and causes real harm to individuals and society. If more ‘real’ scientists, i.e., leading academics, had a greater input into how science is reported in a journalistic context, then perhaps the public could be spared some of the fundamentally erroneous science that they too often encounter in the daily tabloids.

The inquiry published its recommendations last November, most of which are still being scrutinised by the government as to which bits it wants to implement or not. A quick resolve, think again! My years of following politics have taught me that these things usually take years- so my follow up may be closer to QMSci’s 10th birthday rather than the next edition! In any case, Lord Justice Leveson collated the evidence from a wide range of academics, science reporters, journalists and editors and in his infinite wisdom gave us his ‘shopping list’ of recommendations, as some food for thought for how journalists should report science responsibly (a short overview on the next page).

Hopefully if these Leveson-recommended guidelines are adhered to we have a very exciting future to look forward to in scientific journalism. And yes perhaps the media hasn’t always given the noble and indispensable discipline of scientific endeavour the respect and credit it deserves, but in the words of one Prof Brian Cox: things can only get better!

35qmsci - Summer 2013

WHAT DOES THE LEVESON INQUIRY MEAN FOR SCIENCE JOURNALISM?

Page 36: Issue 04 - Summer 2013 - qmsci

An overview of the guidelines postulated in the Leveson inquiry on journalism practices.

36 qmsci - Summer 2013

WHAT DOES THE LEVESON INQUIRY MEAN FOR SCIENCE JOURNALISM?

State the source of the story – e.g. interview, conference, journal article, a survey from a charity or trade body, etc – ideally with enough information for readers to look it up or a web link.

Specify the size and nature of the study – e.g. who/what were the subjects, how long did it last, what was tested or was it an observation? If space, mention the major limitations.

When reporting a link between two things, indicate whether or not there is evidence that one causes the other

Remember patients: don’t call some-thing a “cure” that is not a cure

Give a sense of the stage of the research – e.g. cells in a laboratory or trials in humans – and a realistic time frame for any new treatment or technology.

If space, quote both the researchers themselves and external sources with appropriate expertise. Be wary of scientists and press releases over-claiming for studies.

Especially on a story with public health implications, try to frame a new finding in the context of other evidence – e.g. does it reinforce or conflict with previous studies? If it attracts serious scientific concerns, they should not be ignored.

On health risks, include the absolute risk whenever it is available in the press release or the research paper – i.e. if “cupcakes double cancer risk” state the outright risk of that cancer, with and without cupcakes.

Distinguish between findings and inter-pretation or extrapolation; don’t sug-gest health advice if none has been offered

Headlines should not mislead the read-er about a story’s contents and quota-tion marks should not be used to dress up overstatement.

Page 37: Issue 04 - Summer 2013 - qmsci

37

WOMEN HAVE often been overlooked throughout history, up until the women’s rights movement of the late 18th century. For example, in the 112 years since the inception of the Nobel Prize it has been awarded to men 541 times in the areas of Chemistry, Physics and Medicine while a meagre 15 women have been awarded this honour. Women make up more than half of the population yet are conspicuously absent from higher levels of research. In the life sciences, admissions statistics show that the university intake is balanced, with equal measures of women and men. This trend of gender balance remains even to PhD level; with women and men being awarded doctorates in equal measure. It is only when we examine the proportion of women publishing

significant research that we can see discrepancies. Many women are forced to forfeit successful careers in research to accommodate family pressures and because of enduring sexism within the structures of high level research institutions.Women have been making significant contributions to science since at least 2700 BCE when the first female physician was noted in Egypt. Since then women have constantly struggled against numerous obstacles to their participation in science. In the medieval period universities began to be established, but the first university to admit women is said to be the University of Bologna, which opened its lectures to women from its founding year in 1088. In Britain it took until 1878 for

qmsci - Summer 2013

W I S E

Women in scienceEleanor Matthews

Page 38: Issue 04 - Summer 2013 - qmsci

qmsci

38

universities to admit women; the first being the University of London. Florence Nightingale is widely known for being “The Lady of the Lamp” and nursing soldiers during the Crimean War. However, what is less widely known is that she was a brilliant statistician and developed a form of pie chart called the polar area diagram which is still in use today. She was the first woman to be invited to become a member of the Royal Statistical Society. Later in the 18th century, Lady Mary Wortley Montagu, a well-travelled aristocrat, returned to London with tales of smallpox inoculation and laid the foundation for Edward Jenner’s pioneering work with vaccines.The dawn of 20th century saw the first Nobel Prize in Physics awarded to Marie Skłodowska-Curie, arguably the most famous woman in science. Marie Curie undertook pioneering research into radioactivity and discovered two elements while teaching at the École Normale Supérieure. Here, she worked without funding as she was refused a place at the Kraków University in her home country of Poland. A woman who is thought of by many as a Nobel Laureate (that never was), is Rosalind Franklin who undertook ground-breaking work in the X-ray diffraction of DNA which later led to

the discovery of the DNA double helix structure. In her unpublished work, Franklin had noted that the phosphate groups in DNA must be on the outside of a ‘backbone’ structure, unlike the original ideas that Watson and Crick proposed. She was never fully credited with her work and contribution to the DNA structure until after her premature death at the age of 37. Another inspiring woman of science is Ada Yonath, the latest female winner of the Nobel Prize in Chemistry in 2009 and the first Middle Eastern woman to win a Nobel Prize in any scientific field. She has conducted pioneering work in the field of crystallography discovering more about the structure and function of the ribosome.It is clear to see that women in science are becoming more prevalent in higher funded research areas and being awarded more credit for their work and contributions. As always, there is still progress to be made which can be achieved through greater provisions in areas such as part time work and gradual change of attitudes. Queen Mary has an informal group for networking and discussions about the role of female participation in science called Women in Science and Engineering (WISE). Check it out, and be inspired!`

qmsci - Summer 2013

WOMEN IN SCIENCE AND ENGINEERINGqmsci

Page 39: Issue 04 - Summer 2013 - qmsci

qmsci

39

WHO WAS the greatest scientist? Can such acclaim even be given? How would you decide? To go about this task objectively is quite difficult – first you need exhaustive knowledge of just about every scientist to have lived on Earth. Second, you would need to rank them according to…what exactly? How many discoveries they made? How significant their contribution was? Is inventing calculus more important than discovering electricity?

I don’t possess even the first prerequisite to answer this question, but I’m going to do it anyway.

I think calculus is more important than electricity. I think Sir Isaac Newton was the greatest scientist to have lived. The (still alive) astrophysicist Neil deGrasse Tyson once described Isaac Newton as someone who was simply “plugged” into the Universe.

During his time, namely the 17th

The Greatest Scientist:

Isaac NewtonViral Mistry

qmsci - Summer 2013

Who was the greatest scientist? Though a very subjective question, it’s always interesting to view the perspective from different people, especially those in a science degree. In this article, Viral, talks to us about who he thinks to be the greatest scientist. Do you agree?

qmsci

Page 40: Issue 04 - Summer 2013 - qmsci

40

century, no one had ever heard of calculus. No one knew how to quantitatively describe the motion of a body, nor explain why the moon orbited the Earth the way it did, and still does.

Indeed, if you believe in the legend, the moon (and the innocuous apple) was what triggered his mind to ask: “If the apple falls to Earth, does Moon fall too?” When he realised that 17th century mathematics were no good to answer that question, he began working on a “new type” of maths – so to speak – and invented it at the same rate a first year undergraduate would learn it today.

From here he would discover that his calculations matched what he observed in the real world. When Halley’s Comet came around again, and while everyone else figured this was a message from God, he would invent the reflecting telescope to observe its projection and find that it also matched his calculations. He would expand this to elucidate for all of the celestial bodies in the solar system (at least of those he knew of at the time).

His three laws of motion are still used today to build cars, skyscrapers and even rockets. Isaac Newton could be attributed, quite validly, to have begun the industrial revolution. He provided the means to do so, and without his intellect there would be little of what

we have today. Calculus is so integral to physics that it practically is physics, and physics has brought us everything you see today.

Such is the power of his laws that you can literally calculate the force on every single brick of the empire state building. Even NASA use Newtonian physics to calculate the motion of their probes in space, because for the low speeds at which the probes travel there is no need to account for relativistic physics. In other words, Newton’s laws are more useful to us than even Einstein’s.

I think that Sir Isaac Newton was the greatest scientist because he more or less reinvented the wheel, which is to say that without him the greater discoveries we’ve made since then would simply not have happened. Or perhaps that’s an exaggeration. Maybe calculus would have been invented by someone else later on, or maybe someone before him found it first. Who knows, yet that doesn’t take away from what Newton did, and still does for us today.

qmsci - Summer 2013

THE GREATEST SCIENTISTqmsci

Page 41: Issue 04 - Summer 2013 - qmsci

qmsci

THE HUMAN race is still a little ways away from owning flying cars and robots that will do our bidding, but medical treatment that is tailored to your personal genome might just be possible in the near future.

Let me explain: your genome is basically the genetic blue print to making you. At this point in time when you go to the doctors with something like a standard chest infection, you are prescribed antibiotics and reassessed as to how you feel after two weeks. These types of prescriptions are given out based on a person’s age, weight and height. However as we know, we are genetically different, and one type of medicine might work brilliantly for someone else but be close to ineffective for you.

You may have noticed that you might need to have 2 shots of double espresso to feel the full effects of caffeine, but your friend next door might only need a few sips of coca cola. These differences in the responses to drugs can be explained by understanding pharmacogenomics.

Pharmacogenomicss can be defined as how our genetics affect how we respond to drugs. This field considers the rate at which we metabolise drugs and whether a drug is harmful or has reduced efficacy based on our genetics which determine the metabolic pathways these drugs use.

Drug metabolism is the process in which your body breaks down drugs, like caffeine or alcohol. However when there is reduced metabolism of a drug,

Personalised prescriptionsBahga Said Mohamud

41qmsci - Summer 2013

Imag

e ac

quire

d fro

m p

hotl.

com

/ La

fityo

r_ZX

qmsciqmsci

Page 42: Issue 04 - Summer 2013 - qmsci

it will accumulate to toxic levels which can cause cell damage and necrosis (cell death). The way the body copes with drugs can be studied in two phases.

Phase one is known as the detoxification part of the reaction. Here the drug involved is detoxified by the addition of a functional group (either –OH, -COOH, -NH2, -SH), which leads them to becoming hydrophobic (repellent to water). Phase two, tends to be where the products of phase one are made even more hydrophobic via conjugation reactions, which prepares the broken down drugs for excretion.

Harmful mutations in an individual’s genome can cause problems in the metabolism of a drug. For example, during the Korean War an antimalarial drug called primaquine was given to American soldiers. However, it was noticed that 10% of the African-American soldiers developed haemolytic anaemia. After analysing the genome of these adversely affected soldiers, scientists realised that they all had a mutation which meant that they were unable to produce an enzyme that reduced the levels of a harmful protein produced after the application of primaquine.

Other applications of genome sequencing can be to understand dosage

levels in respect to the metabolic rate of a person. Some people have very slow drug metabolism, and if they are given a normal dosage of a drug would not be able to break it down quickly enough. This means that drugs would accumulate in the tissues and become toxic. Therefore, lower dosages are administered to these people. There are also those with extremely fast metabolisms, known as Ultra Rapid metabolisers which require much higher dosages to get the same therapeutic effect.

By looking at how our individual genetics affect our metabolism of drugs, scientists are now able to work towards personalising medical treatments. This will drastically reduce the number of illnesses and fatalities due to drug overdose (and ‘underdose’, in some cases). Other future uses of this technology might include better ways to prevent or treat chronic illnesses such as cancer.

We may not have flying cars or robots to do the dishes, but maybe in the next 15 or 20 years we could be seeing a revolution in the way that patients are treated before, during and after they get sick. This will be owed to the development of perfectly personalised treatments with genome sequencing.

42 qmsci - Summer 2013

PERSONALISED PRESCRPTIONSqmsci

Page 43: Issue 04 - Summer 2013 - qmsci

43

EVERYONE FALLS victim to a lecturer they just can’t seem to focus on. With a pen already in hand and anticipating having to write notes, thoughts quickly wonder into daydreaming and doodling begins. But how exactly can such a distractive task be helpful to us?

To understand this affinity to draw when absent-minded, Professor Jackie Andrade, of the School of Psychology, at the University of Plymouth conducted research to test whether doodling could help aid a person’s cognitive performance. This was strangely by halting the day-dreaming. Where we would first presume that these two go hand in hand, it was found that each one

actually prevents the other.

Andrade’s research involved 40 participants who were prevented from popping off home for dinner after completing an unrelated psychological experiment by an extra five minutes for some “quick research”. Their purposely tedious task was to monitor a telephone message in which they had to remember and recall information. Amongst this data to be absorbed, were names of people attending or not attending the caller’s up-and-coming 21st birthday party. This included places as well as irrelevant details such as a cat at the vets and bringing peanuts to the celebration. Participants studied for doodling were

What’s the point in doodling?Indigo Dean

qmsci - Summer 2013

Imag

e by

orig

ami_

pota

to /

Nin

a H

elm

er fr

om fl

ickr

.com

qmsciqmsciqmsci

Page 44: Issue 04 - Summer 2013 - qmsci

44

allowed to draw shaded shapes, whereas the control group were only allowed to write target information on less exciting lined paper.

Results showed the doodlers were more successful with accuracy and increased recall of data than the control group. But why is this? Does this mean doodling is beneficial? Many explanations of these outcomes were provided. One suggested that the process of doodling when bored is simply to help us keep awake - which is advice many students could use! Doodling helps maintain our mental arousal at an optimal level by preventing us from dozing off, along with repressing the large levels of autonomic arousal we experience when uninterested.

More specific suggestions are that doodling aids scenarios where day-dreaming may be detrimental. Although it may seem like a task demanding minimal effort, day-dreaming requires a lot of power and energy of the brains processing system. It can start activity of the cortical networks within your brain that can stop you from paying attention to or remembering what’s going on. Simple thoughts can wonder rapidly and would normally be controlled by what psychologists call “executive functioning” – these are the cognitive processes that regulate, manage and

control other cognitive processes. On the other hand, doodling has very little demand on executive functions and provides you with just enough cognitive arousal to keep you from day-dreaming.

Although the word doodle originally means “simpleton” or “fool”, doodlers

aren’t quite so stupid. Famous mathematician Stanislaw Ulam invented the Ulam spiral for visualisation of prime numbers, whist doodling during a boring mathematics conference. So next time you’re in the lecture and your eyes don’t want to stay open, you know what to do. Grab a pen and doodle!

qmsci - Summer 2013

WHATS THE POINT IN DOODLING

“Doodling helps maintain our mental arousal at an optimal level by preventing us from dozing off”

qmsci

Page 45: Issue 04 - Summer 2013 - qmsci

45

THE BRAINS of cats consist of twice as many neurons as the brains of their domestic canine counterparts, and as a result of this, felines are often presumed to be as the more intelligent of the two, but some studies seem to suggest that this proclamation pure dog doo-doo.

The theory behind this assumption is that the larger the brain, the more intelligent the animal. Dogs have larger

brains than cats in relation to their body size. One study detailing this, carried out by researchers at Oxford University, analysed the evolutionary history of the brains of several extinct and extant species of mammals. They noted that the cat, often a recluse by nature, showed slower brain growth over time, in contrast to their sociable canine cousins, who showed dexterous evolution in

Cats vs. DogsWhich pet is the brainiest?

They are low-maintenance, self-sufficient, potty trained, and elegant pets. Indeed, I am talking about cats. All in all, these felines are charming creatures but when it comes to intelligence, the man’s best friend may be a paw ahead.

Nikita Vasistha

qmsci - Summer 2013

Imag

e ac

quire

d fro

m p

hotl.

com

/ Ph

otog

raph

er: lo

gnio

r

qmsciqmsciqmsci

Page 46: Issue 04 - Summer 2013 - qmsci

46

their brain growth.

Doctor Susanne Shultz, who led the research summarised; “dogs have always been regarded as the more social animals while cats like to get on with their own thing” in an interview with The Telegraph in 2010. Similar studies have also been conducted, that suggest that as dogs live in social settings they use their problem-solving skills every time they interact with other animals or humans. These problem-solving abilities involve reasoning and the development of such skills takes a lot of grey matter. The continuing interaction of dogs with humans and other species may indicate that the brain gap between cats and dogs is widening. However, not everybody gives a paws up to the idea of ‘the bigger the brain, the more intelligent the animal’.

Charles Darwin is quoted as saying “intelligence is based on how efficient a species became at doing the things they need to survive.” In response to Darwin’s claim, one may argue that by this definition, all species that avoid extinction are equivalently intelligent. Other criticisms arise when considering that on average men have bigger brains than women, but no assumption is made that men must consequently be more intelligent than women. Analogously,

the mental agility of African Grey parrots can easily rival the intelligence of an average 5 year old; such parrots could easily outsmart a dog, in spite of having a brain the size of a small bird. Antagonists could further add that whales, with their 7,800 gram brain are most certainly not more intelligent than humans, which have on average a 1400 gram brain. But, the controversy related to this theory, could continue infinitely. Therefore, we can deduce that brain size is not always a valid prediction of measuring intelligence.

Despite disagreements to the brain size theory, dogs certainly seem to be more ‘intelligent’ than cats. Humans have manipulated dogs’ intelligence and developed a wonderful dependence on dogs – through the use of the canines for tasks such as cancer detection, forensic investigations and assistants to the visually impaired. Only time and further dedicated studies will truly be able to tell us whether man’s best friend is truly more intelligent than cats, but for the time being dogs certainly seem to be the more proficient and perceptive pet pals.

qmsci - Summer 2013

CATS VS. DOGS :: WHICH PET IS THE BRAINIEST?qmsci

Page 47: Issue 04 - Summer 2013 - qmsci

47

WAVES ARE all around us, from classic surf in the sea, to sound waves we can hear, even the invisible radio waves that are constantly travelling through us. Despite the huge variety and their obvious differences, they all share the same basic principles and travel in the same ways.

Fundamentally a wave is an oscillating signal that moves through a medium, transferring energy as it goes. For example seismic waves transfer the energy released from a slipping fault line through the ground to cause an earthquake on the surface, often with devastating consequences.

There are different kinds of waves, most are longitudinal or transverse. To picture these, use the analogy of the heavily scientific slinky spring that

you haven’t played with in years. Hold both ends of the spring, stretching it under tension, push one hand towards the other over a short distance and you will see a compressed part of the spring travel along the length, do it quickly enough and you may even see it reflect and come back. These are longitudinal waves, compressions directed in the same direction as the wave’s energy is travelling, from one end to the other. This is how sound waves work, using the medium of air molecules instead of the spring; sound is a series of compressed and rarefied air regions, travelling outwards from the source. Transverse waves on the other hand, can be made on the spring by wiggling one end up and down, causing the classic up and down wave motion. These waves oscillate in a direction perpendicular to

THE SCIENCE OF WAVESTHE SCIENCE OF WAVESAlex Hamilton

qmsci - Summer 2013

qmsciqmsciqmsci

Page 48: Issue 04 - Summer 2013 - qmsci

48

the wave’s energy transfer.

One property all waves have is called wavelength, which is the distance from one peak to the next, and this is intimately related to the speed and frequency (oscillations per second) of the wave. Waves must travel through a medium, which may be physical like water or intangible like the electromagnetic field which is the medium of all light waves, including radio and X-rays. The medium can affect the types of wave that can be supported, as well as their speed. A difference between the wave types described above is that longitudinal waves can travel through a fluid (liquid or gas), while transverse waves can’t, as they require some mechanical side-ways strength to work (though they can travel through the surface of a liquid).

Propagation is the technical term for the direction in which waves transfer energy. They try to spread, like the ripples in a pond, but often can’t because they’re trapped in their medium- like our slinky waves. As they spread they get weaker,

but if they didn’t then theoretically they can go on forever, sadly the slinky makes noise and heat, so the waves die down over time, due to frictional energy losses.

We all know we can reflect light waves off a mirror and we can even bend or refract light using a lens. Refraction is an inherent property of all waves when changing from one medium to another; as the wave changes speed it will tend to bend towards the slower medium.

Waves also show a weird characteristic called diffraction. Here the wave will try to bend around corners, which is often the reason you can hear sounds even if you can’t see the source. For example: through a doorway, in another room to you, when the source is around the corner.

Perhaps the most difficult idea is that of interference: when two waves travel through the same medium and interact. One type of interaction is superposition, when two waves of the same type (wavelength and phase) can combine to make one stronger wave. Also the opposite is also true, if the waves are out

THE SCIENCE OF WAVES

λ λ

a

troughs

crests

qmsci - Summer 2013

qmsciqmsci

Page 49: Issue 04 - Summer 2013 - qmsci

of phase or have different wavelengths then they can combine to make a very different wave, often called a beat. They can even cancel each other out completely in what is called destructive interference. Musicians use this trick to help fine tune instruments: using tuning forks they can tell if they have the correct frequency by the change in pitch, as the sound waves of the instrument and fork interact.

All of the above properties mean some very important things: we can create, understand and predict waves very well which allow us to use them effectively. From playing music through your speakers to getting a mobile signal and even seeing inside the body using ultrasound and x-rays. We’re surrounded by and using waves every day, all the time.

+ =

THE SCIENCE OF WAVES

qmsci - Summer 2013

Diagram illustrating the principle of wave superposition.

49

qmsciqmsciqmsci

Page 50: Issue 04 - Summer 2013 - qmsci

THE DOUBLE-SLIT experiment is one of the first “real” experiments that physics students get taught and as early as in college too. I say “real” because every experiment done before had, most likely, been fairly straight-forward. For example, making varying sizes of parachutes and letting them drop to see which slows down an object or person the best. What we find, of course, is that the bigger the parachute (or bigger the surface area) the slower the object/person falls because there’s more air resistance.

So what makes the double-slit experiment different? Its set-up is actually quite simple: a narrow laser beam is shone onto a sheet that has two fine slits cut out, very close together. The laser is directed between the slits, and a few feet behind the sheet there’s a wall where you see what kind of pattern the laser makes after having gone through the slits. Simple.

At this point it’s important to understand what the laser, or rather what light actually is: packets of energy, much like a particle and not dissimilar from grains of sand. As such it’s not unreasonable to assume that a photon would behave just like grain of sand. If you shot a grain of sand towards the two slits, it would go through one and strike the wall behind. If you have a whole beach worth of sand and shot all the grains towards the slits, you’d begin to see a pattern appearing on the wall behind: two grainy lines. This is nothing strange, its common sense.

So Thomas Young, the scientist who first did this experiment, fires a laser towards the two slits. Instead of seeing a pattern of two lines, however, he sees multiple lines going across the whole wall! The implications of this aren’t immediately clear: what is exactly the significance of having more than two lines?

The only thing that can produce a

Viral Mistry

50

The infamous double-slit experiment

qmsci - Summer 2013

qmsci

Page 51: Issue 04 - Summer 2013 - qmsci

qmsci

pattern like the ones that photons produce are waves. A lot like waves on the surface of swimming pool. If you now imagine the two slits and the wall submerged in the pool, the ripples in the pool would hit the two slits and then proceed to interfere with itself, creating multiple lines on the wall behind. Are we to conclude that these “particles” of light are actually waves?

Not quite.

Young thought to see what exactly was happening when the photons passed through the slits by placing a measuring device next to them. This way he’d know which slit the photons were passing through, or if in fact the photons (somehow) passed through both slits like a wave. He repeated the experiment, and to his astonishment the pattern returned back to two lines – as if it were a particle.

So, photons are waves when we don’t look at them and when we do they’re particles. You might think that this is just some peculiarity with light, but no –

the same thing happens when electrons are fired towards the slits.

Truly fascinating and strange, for a long time this experiment demonstrated just how unintuitive the microscopic world of particles is and fuelled much debate. Today, we have an answer to this mystery through Heisenberg’s Uncertainty Principle and Quantum Mechanics, but those are whole articles in themselves.

51qmsci - Summer 2013

THE INFAMOUS DOUBLE-SLIT EXPERIMENT

1λ, Crest:

½λ, Trough:

qmsciqmsci

Page 52: Issue 04 - Summer 2013 - qmsci

Phoenix Fitch

HumanlivingEXTREMES

Icon

s by

Pix

elsD

aily

Page 53: Issue 04 - Summer 2013 - qmsci

53

THE REMARKABLE adaptability and ingenuity of the human race has allowed humans to migrate, settle and survive in all but the most hostile of environments. From Inuit populations surviving in the Arctic regions with temperatures nearing -50°C, to the South American Andeans who dwell at altitudes over 4000m, it is a unique set of cultural adaptations, ingenuity and even evolutionary changes that allow these populations of humans to thrive in such extreme environments.

The basic daily requirements for long term human survival in temperate climes are approximately: 3-4 litres of water, around 0.75kg of pure oxygen (absorbed through inhalation of near 11,000 litres of air) and the intake of 2000-3000 calories. Extreme conditions make survival much more strenuous as these requirements are often in short supply. This applied to a scarcity of water in extremely hot and dry areas or very low oxygen levels at high altitudes. Similarly, satisfying our needs can be markedly more difficult, as can be demonstrated by the fact that 150 square miles of Arctic tundra is required to sustain a single human compared to around two miles of arable/pastoral land.

The adaptations we see in human populations living in extreme cold or

heat can be considered societal changes or developmental adjustments. For example, Inuit tribes are able to keep body temperatures at constant levels through the technological adaptations they have made, such as clothing, igloo construction, or specialized hunting and fishing methods. Their diet meets the needs of the harsh climate, with over 75% of their calorific intake coming from animal fat.

Similarly, desert dwellers adjust to their climate through technological development or cultural practices. The majority of desert tribes have a nomadic culture, enforced through the constant need to travel in search of water and the lack of fertile land for farming. Clothing and shelter has evolved to reflect the need to keep cool during the day and prevent hypothermia at night.

Humans who have adapted to living at high altitudes, such as Andeans or Lhoba, have not only undergone unique societal changes but have also

qmsci - Summer 2013

HUMAN LIVING EXTREMES qmsciqmsci

“150 square miles of Arctic tundra is required to sustain a single human”

Page 54: Issue 04 - Summer 2013 - qmsci

had a significant evolutionary response to their climate. Andean populations have been observed to have adapted to the lower oxygen concentrations through the development of high affinity haemoglobin.

In contrast, Tibetan populations seem to have lower affinity haemoglobin in their blood. The adaptations of Tibetans are two-fold; they take significantly more breaths per minute than those of a medium altitude population and their lungs synthesise a much greater amount of nitric oxide than usual. Increased nitric oxide synthesis causes dilation of their blood vessels, allowing for more efficient oxygen delivery to respiring tissues. Even with these significant evolutionary changes, high altitude living has further limitations such as impaired reproductive success. Early European colonists of the Andes adapted well to living at altitude but struggled to reproduce successfully. Impaired reproductive success is a rapid selection pressure, and as such high altitude populations show certain differences in fertility profiles and features. Birth weights are lower and placental masses are higher: a response to balancing the oxygen demand of the developing foetus.

Reports also suggest that progesterone levels are higher and ovarian cycles are longer, increasing mean fertility.

Humans have found methods to live in conditions at the very end of their spectrum of tolerance. The ability to create technological solutions and develop cultural practices as a response to the unique selective pressures of an extreme environment has allowed the survival of humans in the most hostile of places. Human ingenuity and technological advancement may mean that one day human populations could survive in the vastly different climates of other planets, miles underground or in the vast spaces of the oceans.

HUMAN LIVING EXTREMES

54 qmsci - Summer 2013

qmsci

Page 55: Issue 04 - Summer 2013 - qmsci

REMARKABLE PHOTOGRAPHS have been taken of auroras both in the north and south poles, Aurora Borealis and Aurora Australis. These beautiful images show bright lights in the skies. They portray a dazzling display of green, pink, red, yellow, blue and violet that illuminates the horizon; a myriad of coloured patches, rippling curtains, shooting rays and clouds of light. Ever wondered exactly what they are?

Aurora Borealis, colloquially known as Northern Lights, refers to the lights seen above the magnetic North Pole. These lights are the result of electrically charged particles from the sun colliding with gaseous particles in the Earth’s

atmosphere. Variations in the colour depend on the type of gas involved in the collision.

Due to the high temperatures found in the Sun, collisions between particles are commonplace. Clashes like these result in the expulsion of free electrons and protons from the Sun’s atmosphere in streams called solar winds. Normally these electrons and protons are repelled by the Earth’s magnetic field, but the magnetic field is at its weakest at the poles. This means solar winds can penetrate the Earth’s atmosphere that at these locations. Oxygen and Nitrogen particles in the atmosphere are excited, or even ionized, by these solar winds.

Andre Da Luz

55

What are the Northern lights?

qmsci - Summer 2013

qmsciqmsciqmsci

Page 56: Issue 04 - Summer 2013 - qmsci

When gaseous particles, like oxygen and nitrogen, return to their ground-state they discharge energy in the form of photons: particles of light. This is the basic principle behind auroras.

The colour of the aurora can be related to the altitude at which the gas emitting the photon is at. When excited particles collide, the excitation energy is absorbed and therefore lost, which would mean that no light would be emitted if say, an excited oxygen particle collided with another atom or molecule. Also, the light emitted depends on how long a gaseous particle is excited for. Oxygen, for example, takes three-quarters of a second to emit green light and up to two minutes to emit red light. At high altitudes (approx. 200 miles above ground) particles are very scarce so there is a low chance of collision between particles, meaning that oxygen particles have sufficient time to emit red light. As we move closer to the ground the particle density in the atmosphere increases, and consequently so do these

“cancelling collisions”. Light continues to be emitted until the “cancelling collisions” are so frequent that green light can no longer be emitted. The relationship between altitude and aurora colour is shown by the spectrum of colours. Starting from the highest atmospheric altitude, the colours usually emitted are: Oxygen green, Oxygen red, Nitrogen blue and Nitrogen red. From this we can draw the intriguing conclusion that there is a clear correlation between altitude and aurora colour.

The beauty of auroras is a resultant of the combining of solar winds and weak magnetic forces. The particles thrown by the sun collide with the gaseous particles of the Earth’s atmosphere, exploding into an array of colours and shapes, depending on the gas particle and its altitude. One can find several colours streaked across the sky, providing one of the most beautiful natural spectacles known to man.

56

Ground state

Excited state

Electron inexcited state Photon emitted

with energyequal to thedi�erencebetween the excited andground state.

charged particles-

-- -

qmsci - Summer 2013

WHAT ARE THE NORTHERN LIGHTS?qmsci

Page 57: Issue 04 - Summer 2013 - qmsci

Queen Mary’s first science magazine — qmsci

We’re aiming high!

qmsci is always looking fornew recruits to our team. If

you’re a talented writer, graphic designer, or editor, then you’re

just what we need!

Contact us at:[email protected]

www.twitter.com/qmsci

www.facebook.com/qmsci.mag

www.qmsci.wordpress.com