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Emanuel Science Journal Winter 2018 Edition

What's Inside?

From the Editors

The Emanuel Science Journal is a student run paper, written and edited by the students, all about science.

This edition includes articles on subjects studied in school such as Biology, Chemistry, Mathematics, Physics

and Psychology as well as further subjects such as Engineering, Medicine and Environmental Science. The

writers of this journal are some of the best scientists Emanuel School has to offer and we hope you

thoroughly enjoy articles we have prepared for you.

Stuck in a Rut? What are neural pathways?

And why do we form habits?

Antibiotics

Why is a once lifesaver

becoming the cause of a

killer?

The Earths Radius

How can you calculate the

Earths radius using simple

mathematics?

Mobiles and Manual

Dexterity Is technology leading to a

decrease in fine motor

control?

An Unsolvable

Paradox

What is the mathematical

paradox that puzzled

mathematicians for

centuries?

How are memories

formed and lost? An insight into the processes

of memory formation and

memory loss.

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How do you get to school? On foot, car, bus, train? Or maybe even bike? Ok, now think of your route. Do you always go the same way? Do you even have to think about which way you will go or is it just automatic? That is the effect of your neural pathways.

Neural Pathways have been a popular topic for discussion for a while now as more and more attention is focussed on mental health in the modern world. The general message is: the more you do or think something, the more likely you are to do or think it without reflecting.

Think of a horse and cart. A cart travels down a path. This path then splits so that it goes through the woods on one side and past a river on the other. The two branches arrive at the same destination, but the riverside one is shorter. The driver of the cart has always gone down the woodland path, but the horse knows that the riverside path is shorter, so one day it decides to walk down that one instead. This isn’t easy, though, as where the path branches into two the cart has created deep ruts towards the woodland path from weeks of going down it, so the horse has to make an enormous effort to get the wheels out of the ruts and onto the different path.

Once the horse has finished its journey down that path, the cart driver then realises that this way is shorter after all and so starts following the river path instead. Again, the more journeys they make the more the wheels dig into the ground and the more naturally the wheel-rims fall into the ruts that have been made in the riverside path. A new and better pathway is being used.

But what actually is a neural pathway?

Neurons are nerve cells which transmit electrical impulses to and from the brain. The routes along which these signals travel, are called neural pathways.

A lot of programming in our bodies is already installed but some has to be developed.

Every time you experience or do something new, your brain creates a new neural pathway. Most people would agree that the more new experiences you have, the more you learn and grow and the more prepared you are to be able to deal with many, varying situations.

There are many positive examples of neural pathways at work, but also some negative ones.

If a new born baby smiles and her mother smiles back in delight, the baby learns that if she smiles, her mother appears to be happy, so smiling is good. If a child touches a hot oven it hurts his hand and so he decides not to touch it again.

If a child is ‘rewarded’ by being given sweets or fatty foods, then they will see this as a good thing and it may become a habit, something that in this case, is not ideal. Ever wondered why it is so hard to break a habit? Because you have created very strong neural pathways in doing it. The deeper the cart track, the harder it is to get out of it.

Why would you want to change your neural pathways? and how would you go about this?

Some pathways serve us well but there are some that can be harmful. These can be linked to school, relationships or even how we see ourselves, both in body and mind. By changing these, we become healthier and potentially more confident and proud of ourselves. These can be much harder to change than your route to school but the more you try, the more naturally it will come to you.

Try creating a new neural route: identify the new path

you’d like to follow, and whenever you catch yourself

automatically setting out in the old accustomed

direction, consciously change that direction onto

your new pathway because repeatedly having certain

thoughts or doing certain things can physically

change the structure of your brain.

Stuck in a Rut? By Miranda B, Y11

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Antibiotics

Antibiotics are perhaps the greatest medical discovery of the 20th century. They have not only saved patients’ lives, they have played a vital part in achieving major advances in medicine. They have successfully treated infections on patients who have had complex surgeries such as organ transplants, joint replacements, or cardiac surgery. Antibiotics have also helped to extend expected life spans by changing the outcome of bacterial infections. In 1920, U.S citizens were expected to live to only 56.4 years old. Today, however, the average U.S life span is nearly 80 years. Antibiotics have had similar beneficial effects worldwide; in developing countries where sanitation is poor, antibiotics decrease the death rate caused by poverty-related infections.

Antibiotics kill or inhibit the further spread of pathogenic bacteria by targeting specific organelles or processes within the bacterium. If a bacterium experiences a mutation which make drugs less effective, it develops a resistance. There are a number of mechanisms of resistance. For example, some penicillin resistant bacteria produce beta-lactamase enzyme, which inactivates the drug.

Mutations arise randomly due to DNA copy error as bacteria divide. Mutations which give a survival advantage such as antibiotic resistance get passed on. Bacteria reproduce very quickly so the resistant trait spreads rapidly. Bacteria can also acquire mutated genes from other bacteria. One way of doing so is a simple mating process called "conjugation," whereby the genetic material is

transferred between two bacteria along a rod-shaped organelle called a pilus. Viruses can also pass resistance traits between bacteria. This is called horizontal genetic transfer. Horizontal gene transfer is possible between different bacterial species. Resistance can also spread through bacteria populations vertically, when new generations inherit antibiotic resistant genes. Environmentally, antibiotic resistance spreads as bacteria themselves move from place to place; bacteria can travel via airplane, water and wind. People can pass the resistant bacteria to others; for example, contact with unwashed hands.

The problem with constant

incorrect use of antibiotics is that a

low-level form of natural selection

can occur within bacteria. This is

because antibiotics kill the weakest

bacteria and any mutated resistant

bacteria survive. These are then

able to thrive as the antibiotics have

acted as a form of selective

pressure and destroyed their

competition. As this continues to

happen, only the mutated bacteria

are left to reproduce and

perpetuate the mutation. A major

cause for this rapid rise in

superbugs is from the use of

antibiotics in agriculture and fish

farming. Antibiotics are used widely

in farming because they promote

accelerated growth, increasing

farm yield. It is estimated that half

of all antibiotics used in the UK are

for agricultural purposes. This

means that meat distributed all

over the country contains

antibiotics, which causes the low-

level natural selection (as

previously mentioned) in the

bacteria of the person who

consumes the meat. The overuse of

antibiotics in farming also means

that around 75% of them pass

through the animal and enter the

environment as faeces. Eventually

through leeching these antibiotics

will enter the water supply and

reach the population.

Another major cause for the rise in

superbugs is uncontrolled or

incorrect human use. In many

countries, antibiotics are dealt over

the counter without prescription by

a doctor, meaning

people often took them

unnecessarily or did not complete

the full course. Another problem

arising from over the counter

antibiotics is that people often use

them to self-medicate against viral

infections when antibiotics are

useless. Over the counter

antibiotics are still used in many

third world or developing countries

like India, where 63% of all

antibiotics are bought without a

doctor’s supervision.

By Tom M,

Y12

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Antibiotics Continued The threat that these superbugs pose can be best seen in hospital, in the superbug called Methicillin-Resistant Staphylococcus Aureus. The MRSA bacteria is resistant to many antibiotics, and is an infection that is often fatal. The rate of MRSA infections recorded at US academic hospitals doubled between 2003 and 2008. In 2015 the World Health Organisation, revealed that post-operative infections had increased by around 20% since 2000 in the third world. In first world countries the problem is also serious. Since 2000 Canada has reported a 4.1% annual increase in post-operative infection deaths, around 80% of which were from resistant bacterium.

Antibiotic resistant infections are a huge problem because they threaten to change modern medicine. This is because most operations and treatments will have to be completely changed if they risk exposing people to untreatable infections. For example, bacterial infection is one of the most common complications among cancer patients, as radiation therapy and chemotherapy kill not only cancer cells, but also immune cells that fight infection. These patients often develop infections that require treatment with antibiotics. For example, last year 16,000 people died of bowel cancer in the UK, of whom 3000 died of an MRSA infection post-surgery. If we cannot rely on antibiotics it may render many of the medical advances of the 20th and 21st century useless.

Antibiotic-resistant infections are a substantial health and economic burden to national health care systems. They commonly occur in hospitals, due the concentration of vulnerable patients, use of invasive procedures, and high rates of antibiotic used there. The rising

levels of resistant bacterial infections has cost the U.S health care system an estimated $8 billion. The medical costs per patient with an antibiotic-resistant infection range from $18,588 to $29,069. When common antibiotic treatment options are unavailable, doctors may be forced to use more toxic and often more expensive drugs. Even when alternative treatments exist, in most cases patients with resistant infections require significantly longer hospital stays, more doctor visits, all adding to increased strain on the healthcare system. The duration of hospital stays for patients with antibiotic-resistant infections was found to be prolonged by 6.4 to 12.7 days, collectively adding an extra eight million hospital days.

The total economic

burden placed on the

U.S. economy by

antibiotic-resistant

infections has been

estimated to be as high

as $20 billion, due lost

work days and reduced

productivity.

The problem posed by antibiotic

resistance is exacerbated by the

fact that the development of new

antibiotics by the pharmaceutical

industry has almost stopped. This is

due to lack of economic incentive

and strict regulatory obstacles. As

figure 1 shows, of the 18 largest

pharmaceutical companies, 14 have

abandoned the antibiotic research

field. Antibiotic development is no

longer considered to be an

economically wise investment for

pharmaceutical companies

because antibiotics are used for

relatively short periods. This

means that antibiotics are not as

profitable as drugs that treat

chronic conditions e.g diabetes.

Another factor that causes

antibiotic development to lack

economic appeal is the relatively

low cost of antibiotics. Antibiotics

are generally priced at a maximum

of £1,000 to £3,000 per course,

compared with cancer

chemotherapy that costs tens of

thousands of pounds. Antibiotic

research conducted in universities

has also been scaled back. As a

result, there is a lack of new ideas

among research teams.

Antibiotic resistance is a global

crisis, both in terms of how

antibiotics are misused and the

problems this poses. It is especially

difficult to solve because it requires

global cooperation across a range

of areas, such as regulation on

antibiotic use outside strict medical

control, and increased scientific

investment. The biggest problem is

the bacteria themselves, who

reproduce so quickly that they are

able to mutate faster than scientists

can develop treatments for them.

Figure 1: Graph showing decline in Pharmaceutical companies

researching Antibiotics.

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In this example, taken from ‘Universal’ by Brian Cox and Jeff Forshaw, a person is

standing on the beach. The base of a buoy appears to be sitting on the horizon.

Over small distances, we can ap-proximate the Earth as being flat, and therefore this is a right angle triangle.

Manual Dexterity and Mobile Phones By Ima S, Y13

A leading surgeon at Imperial College London has expressed his concerns about the impact of mobile phones on the future of surgeons. Professor Roger

Kneebone describes that students arriving at medical

school have worse manual dexterity and hand strength

which could be linked to more time using mobile phones and

less time doing creative activities at school.

The overuse of phones and tablets has also meant that children are even struggling to correctly hold stationery due to less control over the muscles in their fingers. They have fewer opportunities to develop these

movement skills. The head paediatric occupational therapist at the Heart of England foundation NHS trust, Sally Payne, has mentioned that the nature of play in primary schools is partly to blame. Children are using tablets as a learning tool and this means they do not spend as much time doing activities to train the muscles in their fingers. To combat this, some children are receiving therapy to increase their dexterity and improve their grip and handwriting.

Professor Kneebone has proposed that more creative

and hands-on task should be introduced to the UK

school curriculum to ensure that future generations of

doctors are able to perform surgery to a high quality. It

is unclear what other impacts technology is having and

soon other issues may arise as a result of the overuse

of technology in primary schools.

Calculating the Radius of the Earth Using

Pythagoras’ Theorem By Izzy T,

Y 13

B

R

h

A

B D

h

A – height of camera

B – base of buoy

h – height

R – radius of Earth

D – distance to buoy, found by look-ing on map

R² + (AB)² = (R + h)²

R² + (AB)² = R² + 2Rh + h²

1 (AB)² = 2Rh + h²

Using second triangle

2 D² + h² = (AB)²

1 = 2

2Rh + h² = D² + h²

2Rh = D²

R = D²/2h

In this example, h = 1.3m, D=4150m

What is the experimental value for the radius of the Earth?

(Real radius is 6,371,000m)

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By Jessica L, Y13

The Tortoise and Achilles

Back in 5th century BCE a Greek philosopher, Zeno of

Elea, posed a seemingly unsolvable paradox in order to

prove that motion is an illusion. The paradox goes as

follows:

A tortoise challenges Achilles, the greatest warrior, to

a race. Achilles accepts and generously gives the tor-

toise a metre head start. Achilles runs at a metre a sec-

ond, while the tortoise runs at half that speed. The race

starts and in merely a second, Achilles has caught up to

where the tortoise was. But by the time he reaches that

point, the tortoise has moved ahead by half a metre. In

half a second Achilles again catches up to where the

tortoise was but now the tortoise is ahead by a quarter

of a metre. In a flash (a quarter second) Achilles makes

up this distance. But the tortoise has progressed in that

time by an eighth of a metre. No matter how close

Achilles gets to the tortoise, by the time he catches up

to where the tortoise was, the tortoise has moved.

Smaller and smaller distances, but Achilles never

catches up. The tortoise is always ahead.

Upon hearing this paradox a fellow philosopher named

Diogenes the Cynic simply stood up, walked around,

and sat back down again.

We all know that in actual practise, Achilles would

quickly overtake the tortoise. But Zeno’s logic seems

impossible to disprove. Does this mean motion is in fact

impossible? Surprisingly, no.

In order to solve this problem, imagine a one metre

piece of string. Now imagine cutting that piece of string

into an infinite number of lengths. Adding these lengths

back together will once again make the string one me-

tre long.

This is known as an infinite series. Which is the result of

when we have an infinite sequence of values which fol-

low a rule (e.g. each term is half the previous one) and

we add them all up. In order for the result to converge

to a finite result, the terms being added together must

approach zero. However, if we look at a harmonic se-

ries:

The terms go to zero too slowly so the terms don’t con-

verge to a finite number but instead diverge.

Now using

this

knowledge,

we can easily solve Zeno’s paradox. The steps that

Achilles takes get smaller and smaller, and closer and

closer to zero. Simply put, these terms are approach-

ing zero therefore making zero the limit. In the same

way, the sum of the steps gets closer and closer to 2.

making 2 the limit.

Achilles runs 2 metres in catching up to the tortoise,

even though he takes an infinite number of steps to do

it.

Its pretty hard to wrap your head around at first, it will

probably even take you an infinite series of time.

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In the words of Oscar Wilde, “Memory… is the diary we all carry

about with us”; it defines who we are. But how do we convert

tangible experiences into an abstract memory so delicate yet

unfathomable? And how do these insubstantial memories

disappear from the labyrinth of the human mind? In this article, I

will explore how memories are formed by encoding, storage and

retrieval, and I will discuss the concept of retrieval cues and

psychological effects related to memory. Subsequently, I will

demonstrate some perplexing theories about memory that

scientists are yet to fully comprehend.

If you propose the given question to any doctor or psychologist,

one name usually comes to mind: Henry Molaison, an ordinary

man whose story revolutionised understanding of the human

brain. Having suffered a head injury at the age of seven, Molaison

was afflicted with unpreventable, frequent epileptic seizures. In

the 1950s, he underwent surgery after all other attempts to treat

him failed and two sections of brain tissue were removed.

However, the doctors were oblivious that they were removing

tissue from the hippocampus which has a vital responsibility to

convert short-term memories into long-term memories.

Unfortunately, the surgery thus had unforeseeable consequences

and Henry Molaison suffered detrimentally from anterograde

amnesia – the inability to form new memories. Before his death,

he allowed doctors to continue researching on his brain giving

rise to Project HM; the aim of this research project was to map out

the brain by slicing it into 2,401 sections and explore which parts of

the brain carry out specific functions. It is therefore evident that

although we still do not know exactly how we form and lose

memories, scientists are exploring this perplexing phenomenon

and learning more about the enigma that is the human brain.

To form and process a memory, the three main processes that

must occur are encoding, storage and retrieval. Memory encoding

involves selectively registering and processing information when

perceived for the first time. After a memory has been encoded, it

must be stored in the cortex in the form of an engram, also known

as a memory trace by a method known as consolidation. The final

step is retrieval, where a memory is recalled, and it is

unequivocally a salient part of remembering an event. A mistake

in any of the three processes results in the loss of a memory. The

most common reason why we fail to remember a piece of

information, such as a name, is because we failed to encode it in

the first place, in other words we were not fully paying attention!

However, even if a memory is properly encoded, it may still be

subject to storage decay in which the memory naturally fades over

time. The third process, retrieval, may not occur without error.

Other memories can interfere with a stored memory thus it cannot

be retrieved. The two types of interference are proactive

interference – in which prior knowledge impedes the retrieval of

information, and retroactive interference in which subsequent

memories effect the ability to retrieve information.

As

described by Hank Green,

“memories are [like]

spiderwebs in the dank

catacombs of your mind, a

series of interconnected

associations that link all sorts

of diverse things, as bits of

information get stuck to other bits of information”. Although, as

aforementioned, memory remains a recondite subject, as

technology continues to develop, scientists are discovering more

about how memories are formed and lost. In any given scenario,

there are certain retrieval cues which are associations that one

has formed, often without realising and are usually related to

olfaction, gustation and somatosensation. This type of retrieval

cue is context-dependent as it relies on the environment in which

one is in when forming the memory. Memories can also be state-

dependent or mood-congruent, i.e. our state or sentiments can

trigger retrieval cues.

Psychologists have also been studying different effects regarding

remembering details. If I were to present to you a list of objects,

you would be apt to remember the first few and last few objects

rather than the ones in the middle. This is as a result of the serial

position effect and is a consequence of the combination of the

primary effect (the idea that remembering the first objects is

uncomplicated as it is more likely to be rehearsed) and the

recency effect (the idea that remembering the final objects is also

effortless as they were the final words you heard me dictate).

Whilst it may seem as though scientists do have a complete

understanding of how we form and lose memories,

neuroscientists are still ambivalent about some of the esoteric

nuances. In fact, it is not yet understood how the brain’s storage

systems work to store different memories associated with

different senses. Likewise, neuroscientists are still researching

into the way that we remember and recognise faces. Researchers

have discovered a remarkable phenomenon in which neurons are

fired in response to a subject seeing a specific face. For example,

one neurone fired in response to the image of Jennifer Aniston but

remained inert when they were shown other celebrities.

Scientists have hypothesised explanations to the abstruse

discovery such as the theory that specific neurones are

associated with specific concepts.

To conclude, we do have a rather profound insight into how we

form and lose memories yet there are still some unascertained

explanations that scientists are currently trying to research.

Memory plays such a significant role in our lives; it influences all

our decisions and we would be nothing without it. What would it be

like if we could no longer remember who we are? If we could not

remember the events of the past that will inevitably shape our

future? However, memory is much more than that; memory is

everything, it is a bridge connecting our past to our present

without which, the lives we live now would not even truly exist.

How are memories formed and lost? By Ima S, Y13

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Useful Links

Cambridge Masterclasses

https://www.undergraduate.study.cam.ac.uk/events/masterclasses

Royal Society of Chemistry

http://www.rsc.org/

Exploratorium

https://www.exploratorium.edu/explore

Royal Institution

http://www.rigb.org/

A-level Physics revision

https://www.alevelphysicsonline.com

Science and Maths A-level and GCSE revision

http://www.physicsandmathstutor.com

Mr Rintuoul’s A-level Chemistry page

https://www.youtube.com/user/MrERintoul

Acknowledgements

Editor:

Ima Silva

Assistant Editor and Designer:

Jessica Large

Editorial Team:

Zoe Corel