In this edition, we look at the importance of sustainability and its role in creating better futures:
● The environmental and biological effects of micro and nano plastics
● Sustainable horizons: navigating the renewable energy landscape
● Urban sustainability: green infrastructure and smart solutions
Welcome to the Fourth Edition of Origins.
I am delighted to introduce our three new STEM Seniors, Janice, Rebecca and Kayla. Together, we are thrilled to present this new edition of our annual STEM magazine, Origins. As we continue to explore the fascinating world of science, technology, engineering, and mathematics, this edition promises to be the most engaging and interactive one yet. This year, we have expanded our focus to not only showcase insightful STEM-related articles written by our talented students but also to include fun puzzles and quizzes designed to make learning an enjoyable experience for everyone.
In this edition, you will find a diverse collection of articles that delve into cutting-edge research, innovative technologies, and restoring environmental systems. Our students have poured their curiosity and passion into these pieces, and their work reflects the vibrant STEM culture at Downe House.
We hope you enjoy this edition of Origins as much as we enjoyed putting it together. Whether you are a STEM enthusiast or new to these subjects, we believe there’s something here for everyone. If you feel inspired and want to be part of our next edition, please reach out—we are always looking for passionate contributors to join our team!
Happy reading and enjoy exploring the wonders of STEM!
Warm regards,
MAGAZINE TEAM
Editors Janice, Kayla, Rebecca (UVI) and Mr Charles Littledale.
Our thanks to Pixabay and Pexels for the use of images.
Cover image Shutterstock.com
Mr Charles Littledale Head of Science
Laurena Horatio Jones (UVI)
Tanaya Budhwani
Yuwen Ge (LVI)
Nga
CIRCADIAN
Petchnapa (Nampetch)
Lauren
Chada
Cheuk-Yi Cherie (Sage) Lau (LVI)
Zimo (Emily) Huang (LVI)
PATH
Davida (Seyi) Opaleye (UVI)
SUSTAINABILITY: GREEN INFRASTRUCTURE AND SMART SOLUTIONS
Zhi Yu Tiffany Cheong (LVI)
Janice Lee (UVI)
SOCIAL BIAS
Charlotte Trew (UVI)
OR THORIUM?
Janice Lee (LVI)
Jemima Booth (UVI)
Pearl (Ivie) Avwenagha, LVI
As a society, we depend on engineers of all types to create devices that increase our safety and quality of life. Medical accelerators are such devices. They destroy tumours and cancerous cells, with minimal damage to the surrounding ones. Perhaps the most infamous medical accelerator was the Therac 25, which has a tragic reputation due to a course of events that shaped this case study.
The event itself entailed six people being massively overdosed with radiation from this machine between June 1985 and January 1987. With three people dying from being dosed with over one hundred times the intended amount, many in the medical industry consider this the worst accident ever in the field of medical cancer treatment. This happened, not because of the practitioners managing the machine, but rather the negligence of the engineers who built the new model in the first place.
To visualise this better, I would like you to imagine you are the operator in this situation. It is 1985, and you are operating on a terminally ill cancer patient named Katy Yarborough. This new Therac model has only been part of your hospital for a few weeks, and from the instructions you were given, it seems very straightforward. The programming manual is full of indecipherable instructions anyway, so you hope you won’t have to use it.
You have already started the process when suddenly, the Therac shuts down after five seconds, and displays a ‘NO DOSE’ error message. It also indicates that the treatment has been suspended. So, what do you do? You press the key for a second attempt and tell Katy that everything is under control.
The computer gives you the same error message three more times and then you restart it three more times. However, what you don’t know is that the machine did not suspend even once. Instead, you just injected your patient with 17,000 rads. It should have been 200. 50 percent of the time, 500 rads can kill a person.
A while after Katy left the hospital, she died as a result of radiation poisoning. Hearing of the news, you immediately suspect the Therac 25 as the cause, reporting it and having it sent back to the manufacturers (AECL) for repairs.
What you don’t expect is for AECL to tell you that the Therac was not responsible. Despite them refining the model and eliminating many errors, increasing the safety by 9 million percent. Fast forward to the future, and we now have all the details of this horrific event. Whilst AECL was in denial initially, it quickly came to light that Therac 25s all over America had been experiencing the same errors, resulting in the multitude of deaths that eventually resulted in it being recalled. But what were the problems with the model anyway?
Well, there were several problems with the model. The most well-known and dangerous of which relates to the software engineering. The Therac 25 essentially worked by targeting accelerated electrons (mode one) to destroy shallow tissue, or focusing X-ray photons (mode two) that are used on deep tissue. Before the Therac 25, there were two predecessors, the Therac six and Therac 20. The Therac 6 only worked in mode two while Therac 20 worked in both modes. The same bug that caused the error in the Therac 25, upon further inspection, was actually present in the Therac 20. However, the inbuilt override system meant it didn’t cause any harm before. The Therac 25 did not have this override system, meaning the bug only started to become apparent upon its operation and not prior.
Moreover, starting the machine required a combination of buttons that operators slowly became very acclimatised to pressing. Eventually the operators become so fast that the machine could not keep up, which triggered more bugs. As many as forty error messages would be shown per day, so operators would become jaded to malfunctions, since they seemingly did not affect patient safety. The operators in charge would simply restart the machine and continue, which resulted in the detrimental effects. The programming manual given to them was also very unclear and could not be understood by anyone other than the creator.
The software code itself was only created by one person, a huge error on AECL’s part, as good programming practises include having a team of people to fix bugs and highlight errors in the code. When programmers began investigating the accident, this was one of the first things discovered to be a root cause.
Through this accident, it becomes clear that the engineers should have reduced the amount of inadequate software engineering practices and increased external testing. Reusing old software can also often be a recipe for disaster, if you put too much faith in a programme without rigorously testing it. AECL clearly did not put emphasis on the risks of the medical accelerator they were creating, and that was demonstrated by the hasty production, poor decisions and reluctance to be held accountable for the consequences.
REFERENCES
Coursera, 2023. Ethics in engineering [online]
Available at: https:// www.coursera.org/ learn/ethics-inengineering.
Hilts, P.J., 1986. Fatal radiation dose in therapy attributed to computer mistake. The New York Times, [online]
Available at: https:// www.nytimes. com/1986/06/21/us/ fatal-radiation-dose-intherapy-attributed-tocomputer-mistake.html.
Computing Cases, 2023. Therac-25 case history. [online]
Available at: https:// computingcases.org/ case_materials/therac/ case_history/Case%20 History.html.
Tanaya Budhwani, DH 2024
Wood frogs (Rana sylvatica) in a subarctic population have recently been described as having an extraordinary capacity for freeze tolerance. They are a North American species that ranges from the Southern Appalachians to within the Arctic Circle. Research from an article published by the National Library of Medicine has talked about wood frogs and their remarkable freeze tolerance to harsh temperatures ranging from at least 10-13°C below regular survival temperatures for the species.
Frogs from the Upper Midwestern United States and southern Canada can tolerate freezing to temperatures as low as -3°C to -6°C. Whereas frogs from Alaska, in experimental freezing, have survived to temperatures around -16°C. The article published by the National Library of Medicine has hypothesised that extreme freeze tolerance comes from an enhanced cryoprotectant system that uses urea and glucose to reduce the amount of ice forming in the body. The urea is accumulated in autumn and early winter, before freezing occurs and the glucose is quickly mobilised from the liver glycogen after freezing begins. They both also enable cells and tissues to prevent stress on the heart that is caused by freezing and thawing.
Amphibians, which includes the wood frog, produce more urea when dealing with things like dehydration. This helps them to retain water as under normal conditions the levels of urea are quite low. In wood frogs anticipating the arrival of winter, their levels of urea can be very high even if they are retaining lots of water. This increase in urea is aided by breaking down muscle proteins. The reason for this is yet to be fully understood, but is either due to a controlled process, or a handy outcome of fasting in preparation for winter.
The ability of wood frogs to survive freezing temperatures depends on the volume of glucose produced during freezing. Experiments have shown that the frogs’ blood sugar levels increased when exposed to temperatures like -2.5°C for fortyeight hours. However, they don’t use all of their glycogen stored in their liver, leading us to believe that they can make even more glucose in their liver if the freezing lasts longer and is more intense.
This is important because in Alaska, where these frogs live, they face extended periods of freezing with temperatures dropping to -9°C to -18°C.
Furthermore, the frogs have high blood sugar levels for many days after thawing, suggesting that frogs experiencing multiple freeze/thaw cycles could end up with more glucose than those going through a single freezing event.
A study carried out by the National Library of Medicine tells us more about how frogs in a cold subarctic environment survive extreme freezing temperatures. The increase in urea (a substance that helps with freezing tolerance) in frogs getting ready for hibernation is supported by the controlled breakdown of muscle proteins, influenced by their water balance. It was also observed that glucose mobilisation from hepatic glycogen reserves depends on how severe the freezing is. Interestingly, going through multiple freeze-thaw cycles isn’t necessary for high glucose production, but it does help in spreading protective substances to different parts of the frog’s body.
The Journal of Experimental Biology also looked at the freeze tolerance in the northern population of wood frogs. They also had similar results, as in winter they found that there was a 233% increase in the hepatic glycogen store and an accumulation of urea. In contrast, frogs from a cool-temperature population stored less glycogen and had lower levels of urea. Alaskan frogs survived freezing at temperatures as low as -16°C, some 10-13°C below temperatures tolerated by other species of frogs. This intense freeze tolerance is presumably due to their high level of organic osmolytes and water in their bodies, which limits ice formation.
Yuwen Ge, LVI
The inevitable death of everything seemed to be the ultimate conclusion of the mechanism of entropy, but the discovery of black holes seems to bring a glimmer of hope to the situation. The escape velocity of black holes is greater than the speed of light, capturing everything within its reach, yet they leave no information relevant to them. Does the existence of black holes contradict the nature of quantum information? Does its existence truly defy the second law of thermodynamics?
Firstly, as a helpful reminder, entropy is a concept employed to describe the measure of disorder and randomness in a system. In information theory, entropy is like a measure of uncertainty. The higher the entropy of a system, the more unpredictable the information it contains. Conversely, low entropy signifies more expected information. The measure of entropy quantifies the amount of randomness in a dataset.
In 1916, just months after Einstein proposed the famous “Einstein field equations”, a German soldier stationed on the front lines provided a better solution to these equations. Introducing non-traditional coordinate systems, he derived the exact solution known as the Schwarzschild metric. In a subsequent paper, Schwarzschild presented the “Schwarzschild interior solution”, yielding the formula for calculating the black hole event horizon radius, now termed the “Schwarzschild radius”. His significant contribution to astrophysics led him to describe a celestial body with the Schwarzschild metric, devoid of electric charge or angular momentum (non-rotating). When a celestial body of such type gains enough mass, its escape velocity exceeds the speed of light. Consequently, nothing can escape its attraction, rendering it invisible – an entity now known as a “black hole” (more specifically, a “Schwarzschild black hole”).
Initially, it might seem that a black hole formed through the gravitational collapse of a massive star has no apparent entropy. When this occurs, scientists can now only measure the lowest characteristics of the figure, signifying the loss of the star’s structure. The most complex details of the star’s composition disappear, suggesting the absence of apparent entropy.
The formation of a black hole poses a challenge to fundamental physics laws. The “no-hair theorem” was proposed by John Wheeler, suggesting that a black hole can only be described by its mass, charge, and spin — all other information is expunged from our vision. The fundamental tenet of quantum mechanics is that quantum information can never be destroyed. However, the classical view of the “no-hair theorem” indicates the loss of any detailed information of past matters, violating the conservation of information. This controversy triggered the formation of the information paradox.
This conflicting situation led Jacob Bekenstein, a graduate student at
Princeton in the ‘70s, to think prudently and propose the notion of the presence of entropy in black holes in his Ph.D. thesis. Bekenstein believed that to conserve the second law of thermodynamics, entropy must be present in black holes.
In thermodynamics, entropy is a measure of the thermal energy per unit of temperature in a system that is unavailable for work. Consider the process of burning coal to generate electricity, wherein energy transfers as heat from the coal’s chemical store to turn the turbine, generating electricity through a generator. During the process, scientists recorded that only around 33% of the heat energy contained in the coal was converted into electricity, implying an average efficiency of around 33% in coal-fired power plants. Almost 67% of the energy is consumed in the conversion process, and this energy is consumed and can no longer be utilised — the concept known as entropy.
The second law of thermodynamics asserts that the entropy of an isolated system tends to increase over time. That implies that energy disperses, and particles randomise, making it increasingly challenging to understand their microscopic states.
When Bekenstein was researching for his thesis, his conversation with his Ph.D. advisor, John Wheeler (who proposed the “no-hair” theorem), inspired him to believe in the presence of entropy in black holes. Wheeler suggested that a hot cup of tea has entropy, but a black hole doesn’t according to the “no-hair theorem”. It was being uniquely described by macroscopic quantities such as mass, angular momentum, and electric charge. Wheeler was puzzled, and their famous conversation led him to ask Bekenstein, “what if I throw the cup of tea into the black hole?” Originally, the cup of hot tea had its entropy, but after the tea has fallen into the black hole, the overall entropy turns to naught as only the black hole remains. However, the entropy in a closed system can only increase, as the second law of thermodynamics states. Has the second law been violated after all?
Wheeler’s question struck Bekenstein’s intuition. Finally, Bekenstein proposed the presence of entropy in black holes. He stated that when something has fallen into a black hole, like a cup of tea, the black hole gains mass. The black hole’s mass is directly proportional to its area, as the area of a black hole can only increase according to Stephen Hawking. Bekenstein realised that the non-decreasing nature of the area was reminiscent of the nature similar to that of entropy. If the mass increases, the entropy also increases. The gain of the black hole’s entropy counteracts the loss of the tea’s
entropy. Bekenstein concluded that entropy is not only related to its surface area but that it should be proportional to the area itself.
Bekenstein came extremely close to getting the actual value of the constant of proportionality right, except the exact value was accidentally determined by Hawking two years later, who wanted to prove Bekenstein wrong. Initially, Hawking thought if entropy exists in black holes, then temperature must exist, as well as radiation. It seemed quite impossible, as it contradicts the nature of a classical black hole, described by general relativity. However, Hawking was soon able to show that black holes radiated temperature, proving Bekenstein’s predictions. Hawking believed radiation introduces the concept that black holes are not completely “black” but emit radiation due to quantum effects near the event horizon. This involves the spontaneous creation of particle-antiparticle pairs near the event horizon, and one particle of the pair might fall into the black hole while the other escapes as radiation. The particle falling into the black hole contributes negative energy, reducing its mass. At last, Hawking had to accept Bekenstein’s proposition and calculate the exact constant of proportionality right of a quarter. Bekenstein and Hawking both contributed to the understanding of black holes entropy, establishing the Bekenstein-Hawking formula that describes the crucial links between black holes and thermodynamics.
After nearly half a century of debate, this battle has brought people’s awe of entropy to the forefront. Even celestial bodies as powerful as black holes cannot escape the fate of entropy. In this battle, scientists reexamined the growth of the universe and its possible endings – could it be possible that the universe is doomed to death? Heat energy transfers from the object at the higher temperature to the object with the lower temperature, unless additional energy is forcibly consumed to interfere, or else the energy will guide things from order to disorder. As early as 1851, Lord Kelvin proposed the possibility of heat death, and a century later, people seem compelled to reconsider the feasibility of this proposal.
Schrödinger also mentions in his lectures “What is Life” that, “life feeds on negative entropy, ultimately heading towards extinction”. The accumulation of entropy in any system is irreversible. When the value of entropy approaches the maximum that a system can bear, the system dies. Not only in the human body, but also in the universe, entropy continues to increase, and with the passage of time, it will only grow closer to the maximum value. And once it reaches a state of thermal equilibrium, death
REFERENCES
Devlin, H. ‘Black holes and soft hair: Why Stephen Hawking’s final work is important’ (2018). [online]
Available at: https:// www.theguardian.com/ science/2018/oct/10/ black-holes-and-softhair-why-stephenhawkings-final-work-isimportant.
Brooks, M. ‘Is life the result of the laws of entropy?’ (2018) NewScientist [online]
Available at: https:// www.newscientist.com/ article/2323820-is-lifethe-result-of-the-lawsof-entropy/.
Betz, E ‘The big freeze: How the universe will die’ (2023) Astronomy [online]
Available at: https:// www.astronomy.com/ science/the-big-freezehow-the-universe-willdie/.
Encyclopedia Britannica, ‘Second law of thermodynamics’ (2023) [online]
Available at: https:// www.britannica.com/ science/second-law-ofthermodynamics. Institute of Physics, ‘Schwarzschild’s war’, (2023) [online]
Available at: https:// spark.iop.org/ schwarzschilds-war.
Nga Yee (Amelia) Tam, UVI
In our rapidly advancing world, a rising number of people are trying to prolong their lives. To find the secrets of a long-life expectancy, a spotlight has been placed on “Blue Zones”. These are regions in the world with the highest concentrations of nonagenarians and centenarians. They include Sardinia; Italy; Okinawa; Japan; Nicoya; Costa Rica; Loma Linda; California; and Ikaria in Greece. Sardinia hosts the highest concentration of male centenarians globally, and Okinawa is home to the longest-living women in the world.
These places all share a number of similarities. The inhabitants have lower levels of chronic disease and health conditions. As studies have shown that genetics play a mere 20% – 30% role in longevity, this begs the question: how do these people live for as long as they do? What are they doing that the rest of the world is not?
The first commonality they share is their close community. Each region has a strong social network, where the old and young are very close. It is not uncommon for grandparents to live with their families. In particular, there is a name for the bonding culture in Japan: groups of five called ‘moai’ have a life-long commitment to each other. These tight-knit social groups help each other in various ways and are shown to lower disease rates as their support network encourages healthy behaviors, thus Okinawans can live long lives alongside their friends.
The second commonality they share is their diet. All of these regions adhere to a plant-based diet; studies suggest they follow a 95% whole-plants diet. This means inhabitants rarely consume red meat or processed foods, instead opting for locally sourced vegetables and legumes. Tropical fruit that are rich in antioxidants comprise a large part of Nicoyans’ diet. In addition, their water is rich in calcium and magnesium which is thought to prevent heart disease and support strong bones.
The third commonality they share is daily exercise. To people in Blue Zones, exercise is not something they have to consciously force themselves to do; it is built into their lifestyles. Whilst we haul ourselves to the gym, physical activity is part of their everyday routine; for instance gardening, walking, and cooking. There are plentiful mountainous regions in Sardinia, and this constitutes a large part of the residents’ daily exercise. Furthermore, tai chi is a form of gentle movement in which Okinawans partake and is a social activity that builds into their communal spirit as well.
The fourth commonality they share is their sleep. A significant part that contributes to their good health is that they get enough sleep. Regular naps are commonplace in these regions; there is in fact a special name for daytime naps in Mediterranean countries called ‘siestas’. However, research has warned that naps should last no longer than 30 minutes. Exceeding this timeframe leads to an increased risk of death.
The fifth commonality they share is their life purpose. Specifically, Nicoyan’s have a guiding life principle called ‘plan de vida’ which translates to ‘why I wake up in the morning’. Similarly in Asia, Okinawans call their life purpose ‘Ikigai’ which has the same meaning. Those in Loma Linda are Seventh-day Adventists and go to church which sparks kinship with their local community, enhancing the sense of rapport. Those in Ikaria also have a fierce sense of island pride, bringing the people together, which again ties into the idea of social support. This is a pivotal factor of staying healthy in old age, as spiritual connection is suggested to strengthen our psychological wellbeing.
A factor that is still under investigation on whether it prolongs life is moderate alcohol consumption. All Blue Zone regions, besides from the Adventists in Loma Linda, drink regularly, and studies suggest that drinking 1-2 glasses of red wine everyday can lower blood pressure due to antioxidants from the grapes it is made from. There is a specific case study in Okinawa on a moai who had stayed together for 97 years, that revealed they drink sake during their daily meetups. However, recent research has found the effect is negligible once other lifestyle aspects are considered. Yet one thing research can prove for certain is that a higher consumption of alcohol increases the risk of death.
Living a long and healthy life, and enjoying our time with family and friends as we age, is something we all aspire to do. This is the reason for the great interest in longevity in Blue Zones, hence an official website for Blue Zones is available online for us to take inspiration from. There are countless tips that will enable us to be successful in making lifestyle changes, but most importantly, we need to be realistic about our goals and start small.
BIBLIOGRAPHY
Ducharme, J. (2018). 5 Places Where People Live the Longest and Healthiest Lives. [online] Time. Available at: https://time. com/5160475/bluezones-healthy-longlives/. Robertson, R. (2017). Why People in ‘Blue Zones’ Live Longer Than the Rest of the World. [online] Healthline. Available at: https:// www.healthline.com/ nutrition/blue-zones. McCallum, K. (2022). 9 Reasons People in ‘Blue Zones’ Live Longer, Healthier Lives. [online] www.houstonmethodist. org. Available at: https:// www.houstonmethodist. org/blog/articles/2022/ aug/9-reasons-peoplein-blue-zones-livelonger-healthier-lives/. Buettner, D. and Skemp, S. (2016). Blue Zones: Lessons from the World’s Longest Lived. American Journal of Lifestyle Medicine, [online] 10(5), pp.318–321. doi:https:// doi.org/10.1177/1559 827616637066.
Keira Chua, UVI
Teeth possess elastic memory, which enables them to revert to their initial positions. Regardless of how long braces are worn, there is a force that pulls the teeth back to their original positions like a magnetic field. The teeth could hold their new locations if they had retainers. Similarly, the hippocampal region of the brain, which is involved in memory, is stimulated as a person eats. A loss of teeth reduces the number of these signals that are sent.
Though it sounds fascinating, “teeth memory” is not a phenomenon that has been scientifically proven, unlike memory, which is believed to be a brain function. On the other hand, an intriguing area of study examines how tooth tissues, like enamel and dentin, can provide information about a person’s past experiences and exposure to the environment.
THE SCIENCE BEHIND DENTAL TISSUES
The adult tooth is a complex organ made up of four dental tissues. Enamel, dentin, and cementum are the three types of hard tissues. The tooth’s pulp, which is made up of connective tissue, blood vessels, and nerves, is the fourth tissue. Pulp is a soft, non-calcified tissue.
Odontogenesis, the process of tooth development, is highly intricate. Odontogenesis is the phrase used in medicine to explain how teeth grow and emerge. This process occurs in four stages to form the different parts of a tooth.
1. Bud Stage
During the eight weeks of pregnancy, tooth development begins with the dental lamina forming cells known as dental epithelium.
2. Cap Stage
In the cap stage, the tooth’s outer layer is created, while the remaining tooth bud forms the dentin and pulp, also referred to as the dental papilla.
3. Bell Stage and Crown and Root Formation
The enamel organ takes on a bell shape and forms the tooth’s enamel layer in the bell stage. Enamel and dentin are formed in the crown and root formation stage, with odontoblast and ameloblast cells originating from the dental papilla and enamel epithelium.
4. Eruption Stage
Finally, the tooth erupts into its proper position after the crown and root have formed in the eruption stage, with some jawbone resorption and connective tissue degradation.
Trace elements in enamel – the composition of human tooth enamel is 1% – 2% organic materials, 3% – 4% water, and 92% – 96% inorganic substance. Trace elements like F, Sr, K, Al, Si, Ni, B, Fe, Cu, Cr, Zn, Mn, Co, Se, Pb, Mo, and V are integrated into the enamel during mineralization and maturation.
Trace elements in dentin – the part of human teeth called dentin is shielded by cementum and enamel. It consists of 70% inorganic matrix, 20% organic
matrix, and 10% water. Dentin, in contrast to enamel, permits a physiological elemental exchange even after mineralisation. Due to collagen fibres are so abundant in dentin, trace elements including B, Co, Cr, Mn, Zn, Sr, Mo, Cd, Rb, and Pb tend to collect there. The concentrations of these components rise with age, according to Kumagai et al. Dentin’s high collagen content could be the cause of this.
Tooth wear, or tooth surface loss (TSL), is a common dental issue brought on by abrasion, erosion, and attrition. The loss of enamel that covers the outside of teeth is called erosion, and it causes discomfort, pain, and sensitivity in the teeth. Teeth grinding leads to attrition, which produces shorter teeth with sharp edges. The protective covering of enamel can also be lost due to abrasion from hard toothbrushing or eating gritty foods. Acidic foods and beverages frequently result in tooth wear because they weaken enamel and reduce its mineral content. Tooth wear may also arise from acid reflux or bulimia.
Dentoalveolar structures may be harmed by specific oral behaviours such as tongue thrusting, finger biting, and thumb sucking - how detrimental these are depends on the duration and intensity. Although stimulation of the tongue or fingers can be palliative, the mouth itself can provide relief. If thumb or finger sucking ceases before the age of five, dental alterations resulting from it don’t need to be treated. Thumb sucking is characterised by a severe contraction of the muscles and vigorous sucking. It can result in an open bite, cross bite, overjet, and other dental issues and the most effective course of treatment includes rewards-based learning, reminder therapy, orthodontic appliance therapy, and patient counselling by a dentist.
Bloom, D. (2020). What is tooth wear? [online] Top Doctors. Available at: https://www.topdoctors. co.uk/medical-dictionary/ tooth-wear#.
Kamdar, R.J. and Al-Shahrani, I. (2015). Damaging oral habits. Journal of international oral health : JIOH, [online] 7(4), pp.85–7. Available at: https://www.ncbi.nlm. nih.gov/pmc/articles/ PMC4409805/.
Mouthhealthy.org. (2023). Tooth. [online] Available at: https:// www.mouthhealthy. org/all-topics-a-z/ tooth#:~:text=Your%20 teeth%20are%20 composed%20of.
Khan, N. S. (2022). How Fast Can Your Teeth Shift After Braces? [online] How fast does your teeth shift after braces?
Available at: https:// neeshatkhandds.com/ blog/how-fast-doesyour-teeth-shift-afterbraces/#:~:text=Teeth%20 have%20elastic%20 memory%2C%20enabling.
Shaik, I., Dasari, B., Shaik, A., Doos, M., Kolli, H., Rana, D. and Tiwari, R.C. (2021). Functional role of inorganic trace elements on enamel and dentin formation: A review. Journal of Pharmacy And Bioallied Sciences, [online] 13(6), p.952. Available at: https://doi.org/10.4103/ jpbs.jpbs_392_21.
Thesleff, I. (2013). Current understanding of the process of tooth formation: transfer from the laboratory to the clinic. Australian Dental Journal, 59, pp.48–54. Available at: https://doi. org/10.1111/adj.12102. Colgate (n.d.).
Odontogenesis: 5 Stages Of Tooth Development. [online]
Available at: https:// www.colgate.com/en-us/ oral-health/mouthand-teeth-anatomy/ odontogenesis-5-stagesof-tooth-development.
Total Family Dental Group (n.d.). Tooth Loss and Memory Loss. [online]
Available at: https://www. totalfamilydentalgroup. com/blog/articles/ tooth-loss-and-memoryloss/#:~:text=People%20 have%20long%20 known%20of.
Each line of emojis represents a scientist. Not all emojis are clues to indicate an invention, some link to the environment the scientist was in at the time of a famous discovery, some are clues about their personal life. Best of luck!
1. The condition required for a free radical substitution to occur
5. The chemical name for burning
7. Electron-pair acceptor
8. A hydrocarbon that can decolourise bromine water
10. The process which joins slots of monomers together to form a giant molecule
14. Alkanes and cycloalkanes are both hydrocarbons
15. Benzene is an compound
16. Dioxide, a gas produced when metal carbonate reacts with acid that turns limewater cloudy
17. What colour does potassium dichromate become when it is reduced?
2. What type of fission is the free radical substitution?
3. Electron-pair donor
4. A species with an unpaired electron
6. Isomers that have the same molecular formula but differ in the spatial arrangement of atoms
9. The type of reaction when alcohols react with concentrated phosphoric acid to form alkanes
11. When a molecule is non-superimposable on its mirror image
12. Breaking long chain alkanes into smaller, more useful hydrocarbons
13. What type of alcohol doesn’t undergo oxidation?
Petchnapa (Nampetch) Bennett, DH 2024
Circadian rhythms, often referred to as the body clock, orchestrate a symphony of biological processes that guide the flow of life. These 24-hour cycles regulate our physiological, behavioral and metabolic activities and our sense of time, and are composed of proteins encoded by thousands of genes that switch on and off in a specific order.
Derived from the Latin words “circa” (around) and “diem” (day), circadian rhythms influence the important functions in the human body such as sleep patterns, hormone release, appetite and digestion, and temperature, which are heavily influenced by light and dark as well as other factors. Most living things have circadian rhythms, including animals, plants and microorganisms. In humans, almost every tissue and organ have their own circadian rhythm, tuned to the daily cycle of day and night. These rhythms are not mere whims of nature but rather intricate adaptations that have evolved to synchronize internal processes with the external environment.
Circadian clocks are synchronized to environmental time cues by zeitgebers which are daily oscillations in levels of environmental factors such as temperature and light or daily recurring feeding times and social interactions. This is advantageous so that daily rhythms are maintained even in the absence of the zeitgebers.
At the center of circadian rhythms lies the master biological clock, in the brain’s hypothalamus. This master clock is a large group of nerve cells that form the suprachiasmatic nucleus (SCN). The SCN sets the pace of our life and provides a rhythmic function to our sleep-wake cycle by coordinating with different organs through the hypothalamus so that our bodily functions and behavioral patterns align through the day and night. To do this, the SCN receives crucial input, primarily from light and darkness transmitted through the photoreceptors in the eyes, and then sends signals to different cells to indicate when it is time
to be sleepy or awake. Hormones such as melatonin (which makes you tired/ sleepy) and cortisol (which makes you more alert) also play a role as they can increase and decrease accordingly.
In a landmark discovery in 2017, Nobel Prize winning researchers identified a protein in fruit flies that controls these rhythms. During the day, a protein called PER was immediately broken down in the cytoplasm, so the levels remained low but when night fell, TIM bound directly to the PER, preventing this. These PER-TIM complexes enter the nucleus and stop the cell from making more PER. Then as the sun rises, PER-TIM complexes break down, so the transcription block is lifted and the cycle repeats in this way. PER regulates its own synthesis through a negative feedback loop (coordinated systems that link the output of a system to its input).
While babies do not develop a circadian rhythm until they are a few months old (which is often why they have erratic sleeping patterns), they develop one as they begin to adapt to the environment at around 3 months when melatonin will start to be released (with cortisol developing from two to nine months).
Unlike babies, teenagers experience a shift in their sleep cycle called the sleep phase delay where they do not get tired until much later in the night as melatonin rises closer to 10-11pm, whilst in adults, the circadian rhythm stabilises.
The circadian system exerts a profound influence over metabolic processes, including nutrient absorption, energy expenditure, and glucose regulation, contributing to homeostasis overall
(including glucose and lipid metabolism, body temperature, endocrine hormone secretion and cardiovascular health).
The importance of circadian rhythms extends beyond daily functioning to impact long-term health outcomes. Disruptions to these rhythms have been linked to a range of health issues, including cardiovascular disease, diabetes, and mood disorders.
Sleep is a vital activity that every organism needs to function properly, and it is known that a lack of sleep or poor sleep patterns can significantly impact essential day to day functions. Things such as memory consolidation, body healing and metabolic regulation occur during the sleep cycle and it can influence eating habits, digestion, body temperature, hormone release and other bodily functions.
Irregular sleep patterns can result in many sleep disorders and chronic health conditions. Two of these sleep disorders are advanced sleep phase and delayed sleep phase (as mentioned earlier). Advanced sleep phase disorder is the opposite of delayed where you tend to fall asleep a few hours before most people and awaken early in the morning. Age, jetlag, shift work disorder, irregular sleep-wake disorder and genetics can play a part in influencing these disorders. With genetics, you can inherit certain sleep traits and characteristics from one or both parents or certain genetic mutations can occur. Moreover, research also suggests that interference to circadian rhythms, such as those caused by irregular eating patterns or night-shift work, may contribute to metabolic disorders and obesity. Therefore, maintaining a healthy circadian rhythm through consistent sleepwake cycles, regular mealtimes, exposure to natural light during the day and exposure to artificial light at night can contribute to metabolic harmony and overall health.
Lauren Ting, UVI
In vitro fertilisation is a technique available to help people with fertility problems have a baby.
During the process of IVF, an egg is removed from the woman’s ovaries before ovulation and is fertilised with sperm in a laboratory. The embryo is then injected into the woman’s womb to grow and develop into a foetus.
The mitochondrion is an organelle, typically known as the powerhouse of the cell, as it produces energy to power the cell’s biochemical reactions. Mitochondrial disease is a group of disorders that affect the mitochondria, which require mitochondria to make more energy, particularly in high-energy demand organs such as the heart, muscles, and brain. When the number or function of mitochondria in the cell are disrupted, less energy is produced and organ dysfunction results. Mitochondrial disease can cause a vast array of health concerns, including fatigue, weakness, metabolic strokes, seizures, cardiomyopathy, arrhythmias, developmental or cognitive disabilities, diabetes mellitus, impairment of hearing, vision, growth, liver, gastrointestinal, or kidney function, loss of motor control and more. These symptoms can present at any age from infancy up until late adulthood.
As babies inherit all their mitochondria from their mother, harmful mutations in the “batteries” can affect all of the children a woman has. Hence, for affected women, natural conception is often a gamble
Three-way IVF is a reproductive technology used to allow mothers with mitochondrial disease to still have a genetically related child without the disease being passed on to the child.
This procedure comprises of pronuclear transfer and maternal spindle transfer.
Pronuclear transfer
– Eggs and sperm are collected from the mother and father respectively. As in normal IVF, fertilisation is carried out in vitro
– The pronuclei from a successful embryo which contains the mother’s faulty mitochondria are removed
– The donor egg is also fertilised and the pronuclei are removed and destroyed
– The parents pronuclei are then inserted into the donors fertilised egg
Maternal spindle transfer
– Eggs are taken from the mother but are not initially fertilised
– The spindle group is removed the nucleus is arrested in metaphase II
– The spindle group is then planted in the donor egg which also had its spindle group removed
– The egg is then fertilised by sperm and left to develop before inserting into the mother
– The resultant embryo contains a nucleus with the mother’s and father’s DNA as well as healthy mitochondria from the donor DNA
Although this procedure may seem like a wonderful way to prevent mitochondrial disease for future babies, there are some challenges and limitations:
1. It could make designer babies. Designer babies are embryos that are genetically engineered to have preferred characteristics. This may affect the future of genetic editing in babies and disruption in the social order as it could be used for aesthetic purposes rather than medical purposes.
2. It could influence a child’s personality and affect their mental health due to neurological changes and problems that may arise. The child may be confused on why he or she has three parents instead of two, which may be potentially damaging to their growth. Mitochondrial donors might also want social and legal rights and responsibilities for the child and could even want parenting rights, which may confuse the child even more.
3. Possible developmental disability, increased cancer risk and even death. For example, there is an increased health risk for the offspring in the form of malformations, functional disorders and a poorer peripartum outcome including deafness, blindness, diabetes and heart and liver failure.
4. There may be long term side effects that are still unknown as this reproductive procedure is still relatively new. Three cycles of this procedure can cost up to £12,000.
5. Affects the germline. The genetics from the swapped mitochondria will be passed down through future generations. If something were to go wrong, that mistake would be incredibly difficult to erase.
Chada Laohapongchana, LVI
The Mandelbrot Set is a fractal discovered by Benoît Mandelbrot and is a particular set of numbers that produce highly convoluted fractal boundaries when plotted. It displays an aesthetically pleasing fractal with unique shapes and colours. Apart from being one of the many fascinating things in the mathematical world, it also links to religious ideas, which makes it even more interesting because science and religion usually do not cross paths.
One of the Mandelbrot Set’s nicknames is ‘God’s Thumbprint’ as some believe that the Mandelbrot Set suggests the existence of God or a supernatural being. However, this is solely an imaginative theory, which is not entirely true, yet it is still interesting to explore. Although maths is a concept that only exists in the mind, many things or problems you may think of will most likely have a mathematical explanation behind them. For instance, maths can explain many laws such as Newton’s Law of Inertia. If maths only exists in the mind, yet it explains the world, where does it come from? The oldest written texts on mathematics were found in Egyptian papyrus as they are one of the oldest societies on earth; they were probably the first to discover the basics of maths. Some who believe this theory say that there are two possibilities: one is that we invented maths to explain the natural world, which does make sense if we link it back to the Egyptian papyri, and the second is that maths already exists, and it controls our world – we were just fortunate enough to discover it. According to some who believe in this idea, it must mean that math has a supernatural origin as maths contains infinite information such as Pi, and we did not invent it as we keep discovering the length of Pi as a number. Some state that our universe is finite, but maths is infinite, meaning that there could be information about everything in maths outside our universe. This is the idea that maths has a designer, which some
may believe is God, and they believe the Mandelbrot Set leads to this. Although it is not true that the Mandelbrot Set can prove the existence of God, it is a unique idea proposed by the complex features of the Mandelbrot Set.
The Mandelbrot Set is defined by a rather simple function ��(��)=��2+��f(z)=z2+c, which is fascinating considering how complex the fractal is. It displays several unexplained and fascinating features, which some may say are hauntingly beautiful. When the function is plotted, it displays a shape with a main cardioid and a main disk and smaller ‘islands’ and ‘coasts.’ As you zoom into smaller bits of the fractal shape, you can find replicas of the Mandelbrot Set, which are found infinitely as you keep zooming in. In other parts of the shape, you can find replicas of a spiral-like shape that repeat themselves infinitely as well. These smaller, infinite, complex loops and spirals are often referred to as ‘Mandelbrot hairs.’ This is a very interesting and complex shape, but it is hard to argue, outside all the theories, if this is a ‘man-made’ object or if we discovered it as the Mandelbrot Set does not occur in nature. You will not be able to spot the Mandelbrot Set unlike finding Fibonacci sequences in seashells, but it does contain self-similar geometry which we are able to find in nature. You may be wondering how the Mandelbrot Set works and how it is generated—it is generated by a process called iteration, which is to repeat a process over and over again.
The function ��(��)=��2+��f(z)=z2+c is iterated by having a value for ��z and ��c and then plugging it into the equation to produce a new value for ��z. For instance, we can explore the most basic example, which is to let ��z equal zero and ��c equal one – when we start iterating, the first new ��z will be 1, and if we continue iterating, it will be two, five, then twenty-six. It is noticeable that the value of ��z gets bigger each time; however, this will not be the case if we change the value of ��c to another number, for example, a negative number. It is possible to plot the set on Desmos although it would be rather tricky!
The Mandelbrot Set is a great example of beauty in the mathematical field and is a significant fractal in illustrating complex and infinite dynamics. By exploring the Mandelbrot Set, we have paved the way for other discoveries and theories.
Alice Gillham, UVI
Although we mostly hear about plastic waste accumulating on beaches or in a marine garbage patch six and a half times the size of the UK, there are also many lesser-known, large-scale effects of plastic, such as micro- and nanoplastics, and the washing and production of synthetic textiles.
Fragments of plastic, such as microand nanoplastics, have many negative effects on human health and the environment, such as being absorbed by the brain, accumulating in a fish liver, or causing mutations in DNA. Microplastics are often separated into two groups: “primary microplastics,” which are produced as raw materials, already on a micro scale, for consumer polymer goods such as toothpaste, exfoliants, and facial cleansers. The other category is “secondary microplastics,” which are formed because of abrasion and breakdown of larger plastic fragments, often from synthetic fabrics and tires. As they are made accidentally, it is much more difficult to prevent these microplastics from forming. Despite the possibility that these plastic fragments could be filtered using micro- and ultrafiltration methods, these processes are only being investigated now and are not yet accessible.
Reliable information and studies based on scientific research about this topic are difficult to find as little research has been done on the effects of nanoplastics, especially relating to health risks such as neurotoxicity. However, studies which have been carried out on small rodents show clear differences before and after exposure to nanoplastics.
In a study made by the American Chemical Society, it was found that abrasion of synthetic textiles, such as nylon or polyester, caused further fragmentation of fibres, leading to the formation of smaller and shorter fibres. Despite seeming less threatening the smaller they get, plastic fibres can often become more dangerous in a smaller size, due to the ability to enter the bloodstream of many animals and, as evidenced by recent studies, the ability to enter the brain. Once these plastics get to this nanoscopic size, it is extremely difficult to remove them as they can be found in water and the air, enabling them to get into food, drinking water, and the sea.
We still know little about the full effects of nanoplastics on the human body, but a study carried out by the Department of Biomedical Engineering at the Southern University of Science and Technology reveals the effects on smaller animals such as rats. This demonstrates how easy it is for plastics such as carboxyl functionalised polystyrene and amino functionalised polystyrene to enter the organs when at a nanoscopic scale.
The same study revealed that even without injection, polystyrene fibres of 80nm can reach the brain directly from the air via inhalation through the nose, while the control group inhaled water vapor. This suggests that humans are also inhaling nanoplastics that could also be deposited in the brain and other vital organs, and it is estimated that humans can inhale up to twenty-two million micro- and nanoplastics annually.
The study revealed many effects on the mice’s behaviour and activity that were not displayed in the control group, such as a decrease in average speed with both types of polystyrene.
There are hundreds of different environmental effects of micro- and nanoplastics and dangers to the health of other species, many of which are similar to those previously discussed about humans. However, there is much more research into these, and the effects are often more adverse than in mice or humans. Most of the known dangers of micro- and nanoplastics affect aquatic life. The most worrying effects on aquatic life, caused by microand nanoplastics at the moment, are the endocrine-disrupting properties, as this affects such a wide range of functions, one of which is the disruption of the normal metabolism, largely affecting growth and development, making it
much more difficult for the organism to survive as it did previously.
The Barcelona Institute of Biotechnology and Biomedicine found that nanoplastics of 44nm could penetrate the cell membrane. This is a very worrying outcome due to the genotoxic potential of nanoplastics, meaning they can induce DNA damage after both short and long-term exposures. This becomes particularly dangerous when the harmful forever chemicals within the nanoplastics diffuse into the nucleus, possibly altering the DNA. At the end of the study, it was found that the 100nm PS-nanoplastics (polystyrene nanoplastics) were able to induce DNA strand damage. This is a major concern because the accumulation of DNA damage in cells contributes to their mutagenic potential, which can lead to cancer, as well as degenerative conditions such as accelerated aging and immune dysfunction, setting off a snowball effect of other harmful conditions.
In light of all this research, it is clear that there is already compelling evidence of a major human health problem caused by micro- and nanoplastics. There is an urgent need for much broader and more detailed research to be done on humans, to match that already studied in other living models. Recently, there have been some discoveries and inventions into different ways of preventing and tackling micro- and nanoplastics, such as sponges made of starch and gelatin that can soak up around 90% of micro- and nanoplastics in a liquid, as well as bacteria that have evolved to eat plastics, using the carbon for energy. However, these bacteria work slowly, and we know little about them, meaning more research would need to be done into the complex engineering challenges of producing them on an industrial scale.
Freya Hanbury, UVI
Our environment embodies an exquisite world that greets us every morning. It represents a tapestry woven by every organism no matter how monumental or minuscule its contribution. An ecosystem is the way that we, as humans, interact with many other organisms and how they coexist in harmony (most of the time) with each other and our natural environment. Therefore, introducing an ecosystem engineer can have a profound effect on this delicate balance.
The formal definition for an ecosystem engineer is ‘an organism that modifies, creates or destroys habitat and directly or indirectly modulates the availability of resources to other organisms causing physical state changes in biotic or abiotic materials’. A quintessential example of an ecosystem engineer is a beaver. Beavers exhibit exceptional craftsmanship shown by their innate ability to construct dams along an instream habitat. The ability to construct impressive structures serve two main purposes. Firstly, to maintain the water depth in their territory to protect them from predation as they navigate it. Secondly, going beyond the direct benefits to the beavers, they have an immense significance on the surrounding organisms. This is
because when you have a beaver in an ecosystem, it makes the instream habitat more diverse as you have more varied water levels and temperatures which give the perfect conditions for a wider variety of vegetation to grow. The vegetation is of vast importance to other organisms like deer and elk which rely on this for nourishment. Hence, in the absence of beavers, the absence of their dams would follow resulting in a reduction of the diversity of vegetation. This would cascade down the food chains consequently dwindling the population of organisms feeding off this vegetation resulting in a diminished ecosystem. This showcases the consequences of the removal or introduction of an ecosystem engineer.
The British Isles is home to an astounding variety of species including the badger, beaver and grey squirrel. However, most significantly to this essay, it is home to two million deer whose sizeable populations wield a considerable impact on the British ecosystem, some not of favourable consequence. In recent years, the population of deer has skyrocketed. We can put this down to many factors including more affordable food which has curtailed poaching, and the year-round availability of crop plants, enticing deer to forage relentlessly. However, the most important factor is the scarcity of natural predators which are key in controlling the population of deer.
‘In many parts of the country, deer make the establishment of new woodlands or even maintenance of existing ones nigh on impossible’. This is due to the adverse effects of deer browsing, damaging young trees and plants, and inhibiting the flourishing of various other species. This is important because shrubs and herbs contribute significantly to the diversity of plant species found in our forests. Any decline in these species could potentially lead to a decrease in the overall diversity of plant life within the woodland environment. Furthermore, ‘high grazing pressure by deer supresses regeneration by severely reducing seedling density and by delaying the growth of the few remaining survivors’ which impedes forest regeneration and destroys the habitats and breeding habitat of many species –particularly birds (Woodland Trust, 2023).
Upon closer examination of the nightingale, which was once an abundant British bird species, it has become apparent that that their population underwent a staggering decline between 1996 and 2021. A significant portion of this decline can be attributed to the impact of an increase in the number of deer. Studies conducted by the BTO and the University of East Anglia have revealed that nightingales tend to congregate in restricted zones within woodlands where deer access is limited, underscoring the adverse impact of deer browsing on nightingale numbers (Guardian, 2023). Not only do deer destroy their habitat and breeding grounds, they also deplete avian food sources. Several studies have demonstrated that browsing by deer can limit the numbers of invertebrates present. These invertebrates are vital food resources for insect-eating birds throughout the year and are also crucial for the chicks of many bird species. Furthermore, excessive grazing can limit the flowering of woodland plants, resulting in a decrease in fruit production and denying these items as food sources for many birds, thus resulting in a decrease in population.
‘Half of the world’s ten thousand-odd bird species are in decline, and one in eight faces the threat of extinction - with catastrophic effect on ecosystems and a direct impact on humans. Pest management is one example of the highly significant role birds play. Birds can identify insects infected with parasites and opt to bypass the afflicted prey, amplifying the impact of of parasitism in reducing insect populations. Furthermore, their parental instincts drive them to seek out large, juicy insects to nourish their young, curbing reproduction rates and thus depleting insect populations. The lack of natural management of insect populations can directly impact human health due to transmission of arthropod-borne viruses, such as Lyme disease, to humans. Moreover, insects have the ability to infest and pollute food and animals feed supplies, devastate cultivated crops and affect livestock resulting in food shortages.
Bearing in mind the impacts on human and livestock health which are linked to the rise in deer population, the subsequent decline in bird numbers, and the resultant increase in pest populations, the species I propose to introduce is the coyote. Coyotes are indigenous to North America and their population saw a rise after humans nearly wiped out the wolf around the 1930s. This surge in coyote numbers led them to become the dominant canine predator in Maine. Coyotes are known to hunt deer fawns, posing a threat to their survival. As a result, an abundance of coyotes can directly influence the number of fawns that survive to adulthood, consequently affecting the overall deer population.
‘Studies have confirmed that coyotes affect whitetail deer populations…the study focused on two thousand acres where twenty-two coyotes and ten bobcats were removed during fawning season’. The result was a doubled fawn population. In the late 1980s, coyotes expanded into South Carolina, and by 2006, the deer population had decreased by 36% emphasizing the fact that coyotes are useful predators of deer which would have many positive impacts in the UK.
The introduction of wolves into Yellowstone National park offers insight into how the potential introduction of coyotes could impact the British Isles. In 1920, the last pack of wolves was eradicated, leading to unprecedented degradation of the ecosystem. ‘The elk and deer population exploded, and they grazed their way across the landscape killing young bushes and trees’ (Yellowstone National Park). Most importantly, they preyed upon young willows which were habitat to songbirds and meant that beavers could
no longer build their dams. Nevertheless, upon the reintroduction of wolves in 1995, there was an immediate restoration observed, with riverbanks and rivers experiencing recovery, and the return of songbirds, eagles, and beavers. This is a transformation we aim to replicate in the British Isles and, in my opinion, coyotes would be the best candidate for this.
Considering this perspective, the introduction of coyotes, as a non-native species, might potentially bring adverse effects. Section 14(1) of the WCA makes it an offence to release or allow to escape into the wild any animal which is not ordinarily resident in Great Britain. This is because nonnative species pose significant threats to global biodiversity. In the United Kingdom, they cause damage to the environment and native wildlife, resulting in an annual economic cost of nearly £2 billion and potential health risks. This implies that the introduction of coyotes has a potentially signficant negative impact on biodiversity and the economy. We owe this to the fact that coyotes might not fulfil their intended role of controlling deer populations and instead could target agricultural crops, leading to unintended consequences. Moreover, coyotes may harbour transmissible diseases and parasites like rabies, posing potential risks to human health and safety if the coyotes occupy habitats near people. This risk may deter some scientists from supporting the introduction of coyotes therefore explaining why it has not been implemented yet.
The apprehension of scientists may also stem from the catastrophic outcomes observed when grey squirrels were initially introduced to England from North America in 1876. In 2000, a study conducted by the Forest Commission in Britain found that vulnerable woodlands had experienced significant damage from grey squirrels with sycamore trees entirely affected, destroying the habitat of many avian species. Research carried out by the Game Conservancy and Wildlife Trust demonstrates that grey squirrels have had an adverse impact on many native woodland birds, reducing fledging rates by an average of 15%. Additionally, the introduction of the invasive non-native grey squirrel from North America is the main reason behind the sharp decline of the native red squirrel species since the 1800s. This occurrence is likely due to grey squirrels prevailing in the competition with red squirrels for food and habitat, alongside them carrying the squirrel pox virus. While grey squirrels remain unaffected by this virus, its fatal consequences for red squirrels underscore the complexity of ecological dynamics.
This is significant because it suggests that a comparable situation of competition could arise between coyotes and red foxes. Research done by North Carolina State University suggests that a competitive relationship between coyotes and foxes could lead foxes to be unable to occupy prime habitat, compelling them to settle in less resourcerich areas. This would degrade our ecosystem as foxes serve as important controllers of urban pests like rodents and insects - helping regulate their populations, and enhancing ecological balance in urban landscapes. Moreover, unintentional seed dispersal by foxes is crucial to the growth of urban vegetation promoting biodiversity - this highlights their vital role in maintaining our ecosystem and the loss of them could have grave consequences.
Ultimately, the introduction of coyotes could be a potential solution to mitigate the unfavourable effects of deer overpopulation, thus restoring ecosystem balance as illustrated by the successful restoration efforts in Yellowstone National Park. However, concerns surrounding the introduction of non-native species, like the coyote, highlight the need for careful planning before implementing such initiatives. As we have explored how a seemingly minor alteration in an ecosystem can have significant ramifications like out-competition of our native red fox and the significant impact of deer overpopulation on bird populations and pest dynamics. Despite this, I remain convinced that in the future, the coyote should be introduced to regenerate our British ecosystem, and the exquisite world that greets us every morning will once again be restored.
Cheuk-Yi Cherie (Sage) Lau, LVI
Perfumery, in itself, is an art form showcasing the craft intertwined with the intricacies of chemistry. Perfume, derived from the Latin word “per fumum” meaning “through smoke,” has dated back millennia, spanning various ancient empires. To uncover and appreciate these olfactory masterpieces to the fullest extent, we must unravel the science behind the scents that have played an integral part in human culture for centuries.
Although many are familiar with the name Marie Curie when considering female pioneers of science, we rarely talk about the woman accredited as the world’s first recorded chemist, and her name is Tapputi-Belatekallim. Through uncovering the cuneiform tablet KAR 220 written in 1239 BCE in the ancient library of Aššur (“TappūtīBēlet-Ekallim: The First Perfumer?”), we can understand the methods she utilised and a bit about her role. In ancient Babylon, perfumes were held in special regard for medicinal purposes, cooking, and religious rituals, irrespective of the cosmetic purposes we associate with the products now. Tapputi’s position as perfume-maker at the Mesopotamian court, denoted by “Belatekallim”, which refers to a female palace overseer, further emphasises her significance in her field at the time. Early forms of hydrodistillation and oil treatments are described on this specific cuneiform, alongside five other known Assyrian recipes, which suggest the ancient Babylonians had a comprehensive understanding of extracting aromatic compounds from various botanicals. At any one time, up to twenty litres of plants and aromatics could be processed during the initial heat infusion phase (Wills et al. 2023). Then, the oil mixture is left to macerate overnight, allowing the different fragrance oils to steep a unified scent. In the morning, the liquid is filtered through a sūnu, or fine cloth, multiple times to achieve a purer perfume. The highest quality Assyrian
perfumes, like those made by Tapputi and her coordinated team, would have been filtered forty times to suit the King. We still use these techniques in the industry (Levey, 1956). However, with enhanced technology, we can use these methods with greater ease and efficiency than previously. KAR 220, although solely accredited to Tapputi-Belatekallim, provides insight into the collective brilliance of all-female innovation. Women have frequently been excluded from traditional narratives of the history of science, and it is more important now than ever to follow in pursuit of these trailblazers.
In 1921, the audacious request of French designer Coco Chanel to design “a woman’s perfume, with the scent of a woman” sparked the creation of Chanel N°5, and thus, a new wave of cosmetic innovation began. It popularised the use of synthetic compounds in fragrances, such as aliphatic aldehydes mimicking certain scents of jasmine and citrus. Of the three thousand fragrances available to perfumers, it is estimated less than
5% come directly from natural sources. Additionally, synthetics are significantly cheaper too – fragrance represents 3% of the price of a perfumed product (Fortineau, 2004), consequently reducing the final cost of the perfume. Apart from aldehydes, esters, alcohols, and ketones are also common chemical compounds used in perfumery. Esters are characteristically associated with pleasant fruity smells and these arise from their molecular structure and ability to interact with olfactory receptors. Formed during reactions between an alcohol and an organic acid, a specific ester group is responsible for the distinct odour of these compounds. Moreover, its high volatility is ideal for the delicate top notes of one’s perfume.
REFERENCES
Fortineau, AD. (2004) Chemistry for Everyone. [pdf]
Available at: https:// homepages.gac. edu/~sbur/CHE251/ perfumes.pdf.
Levey, M. (1956) Babylonian Chemistry: A Study of Arabic and Second Millenium B.C. Perfumery. Osiris, vol. 12, p. 376-389. Available at: www.jstor.org/ stable/301716?seq=9.
“Tappūtī-Bēlet-Ekallim: The First Perfumer?” The Death Scent Project, The Death Scent Project, 12 July 2022, Available at: https://deathscent. com/2022/07/12/ tapputi-belatekallim/.
Wills, H, et al. (2023) Women in the History of Science a Sourcebook Edited By, pp. 18–20, Available at: https:// discovery.ucl.ac.uk/ id/eprint/10165716/1/ Women-in-the-Historyof-Science.pdf.
In 2016, the UN released seventeen sustainable development goals for the 2030 Agenda for Sustainable Development. Goal Seven outlined the provision of affordable and clean energy, with Target 7.2 urging nations to increase their renewable energy mix Sustainably by 2030. The UK government has itself set a target to cut back 80% of the country’s emissions by 2050.
Renewable energy is the process of generating electricity from natural resources that can be replenished at a higher rate than they are consumed. The main sources of renewable energy include: hydropower, solar energy, wind power, biomass/biofuels, geothermal energy and tidal power. So why is it important? Well, the earth is warming up at a rate like never before, with scientists warning of severe consequences such as more extreme weather events, worldwide drought, up to 50% of species extinction and worse if global temperatures continue to increase by 1.5°C by 2100. A major contributor to the environmental crisis is energy produced by fossil fuels, together with a global energy crisis exacerbated by the Russian invasion of Ukraine. Thus, it comes as no surprise that the world is moving closer towards alternative sources of energy. An industy which is massively benefiting from this is renewables, which garnered more And the UK itself aims to invest over £300 million in this industry. Nevertheless, renewable energy’s increasing popularity over the last three decades has meant its global mix has risen from less than 10% in 1990 to an estimated 35% in 2025.
In the remainder of this article, the pros and cons of hydroelectric power, solar panels and wind farms will be highlighted as well as some more niche methods of renewable energy generation.
The first recorded use of hydropower in England was in 1771, to spin cotton. The UK’s large supply of reservoirs and steep hills make the use of hydropower ideal. Yet it is not a popular source of energy across the UK, since it accounts for only 1.8% of the national capacity across England, Wales and Scotland, providing 1.65GW of energy. This is surprising because hydropower is the most used renewable energy source in the world.
The Advantages
– Hydro plants have high longevity as building equipment can last up to fifty years
– It’s emission free so it doesn’t accelerate the effects of climate change and global warming
– It’s one of the most reliable renewable energy sources
– It’s adjustable to the flow of water, allowing the plant to produce more or less energy when required
– Hydro plants can create reservoirs –which may be used for recreational purposes
The Disadvantages
– May disrupt aquatic life
– Limited places that are suitable locations and hydro plants require loads of space
– High initial costs
– Carbon and methane emissions from reservoirs created
– Susceptible to droughts and flood risks
Overall, the future of hydropower doesn’t look very bright in the UK as most hydro plants were built in the 1950s and 60s, and recent projects have not picked up enough track/investments.
Solar energy was mainly introduced to the UK in the early 2010s. It accounts for about 4.5% of the UK’s national capacity, providing about 18GW of energy. With an increasing number of rooftop solar panel installations in the UK, they are estimated to pay back their cost in 10 to 20 years, which is a stark improvement to over a decade ago when the sector first started receiving government subsidies.
The Advantages
– No carbon emissions
– Reduces electricity bill – long term savings
– Provides homes with more energy independence from the grid, due to emergency backups during outages
– Solar panels increase a home’s value
– Relatively low maintenance costs
The Disadvantages
– High upfront costs
– Sunlight dependent, energy provided is proportional to energy received from the sun in the area
– Tricky installation
– Takes up lots of space
– Scarcity of materials, the main component, photovoltaic cells, are rare
In 2018 the UK ranked third place amongst European countries with the maximum net solar capacity. However, in the UK the industry has been on and off, with the government retracting some of its subsidies in 2019.
The UK’s very first windfarm was introduced in 2000 and is still in operation. Wind power is the UK’s largest renewable energy source and provides almost 30% of the national capacity, with plans to increase wind energy capacity from 11GW to 50GW by 2030. With a combination of a long coastline and strong winds, wind power is typically favourable and ideal for the UK.
The advantages
– Emission free
– Cost effective – provides one of the lowest priced energy sources
– Wind farms can easily be integrated into rural or remote areas
– The energy used in manufacturing the turbines can be paid back quickly
– Maintenace is simple and only occasionally needed
The Disadvantages
– Turbines are a source of noise pollution
– Takes up a lot of space to produce a suitable amount of energy per kilogram
– Too reliant on wind
– Wind farms may impact local wildlife
Biomass/Biofuels
Accounting for roughly 5.2% of the UK’s national capacity. This energy source is formed from the conversion of biomass into liquid gas – biofuels. This unique source of energy aims to use ethanol and biodiesel as fuels. Ethanol can be made from plant materials (biomass) and is commonly derived from a process of fermentation. Biodiesel on the other hand is not typically acquired from used and new vegetable oils and animal fats and is used as a cleaner burning alternative for petroleum-based diesel fuel. Although biomass energy is abundant and carbon neutral, there have also been concerns about the use of limited land resources to grow biomass.
Geothermal energy
Although the UK has enormous potential to harness heat from below the surface, geothermal energy is not common in the country. Geothermal energy is a process that harnesses and converts heat from the earth’s crust to generate power and provide heating and cooling. It can be accessed by geothermal reservoirs or by drilling holes into hot rocks. Depsite geothermal energy being a reliable source it comes with its own disadvantages such as: triggering earthquakes, being extremely location specific and is an expensive resource to tap into.
Tidal power
Currently there are only four tidal energy sources in the UK providing a combined national capacity of 10.5MW. Although unpopular in the UK and globally (mainly due to the limited number of settlements near the sea with high tides), this source of energy is created using the up and down movement of tides to spin turbines and generate electricity. Overall tidal power has a high-power output but has high upfront costs and is too reliant on tides.
Hydrogen storage for Renewables
To combat the loss of excess energy produced by solar and wind energy, any extra electricity gets redirected
into producing hydrogen through electrolysis. This is then stored as a backup, to generate electricity when renewable sources are unavailable. There are currently three hydrogen storage caverns in the UK, which have been in use since 1972.
Since the winter period of 2020-21 energy prices have drastically increased by almost 65% as the supply of fossil fuels does not meet demand and an estimated six million UK households now live in fuel poverty as a result of this. Moreover, it also comes as no surprise that the Russian-Ukraine invasion has had a significant impact on the UK’s energy mix, as oil imports from Russia declined, having a knock-on effect on the energy crisis. All this demonstrates the UK’s need for self-reliant energy and less dependence on international energy imports. This has led to further investment and government policies encouraging renewable energy agendas in the UK.
Concluding notes:
Forecasts predict that renewables may make up to 42% of the global energy market by 2028. It seems with global warming, and climate change, and depleting oil supplies there has been significant moves towards renewable energy. More and more countries are converting to renewables to improve their self-sustainability whilst being able to provide energy for future generations. The future of renewables has never looked more promising, with new and improved renewable technology constantly in development, and this lucrative industry providing millions in employment globally.
Dane Valley Community Energy, 2023. Hydroelectric Power in the UK. [online] Available at: https:// congletonhydro.co.uk/about-dane-valley-communityenergy-dvce-benefit-society/hydro-electricenergy/#:~:text=Hydroelectric%20Power%20in%20 the%20UK,1.8%25%20of%20our%20national%20 capacity.
EnergySage, 2023. Pros and cons of hydropower. [online] Available at: https://www.energysage. com/about-clean-energy/hydropower/pros-conshydropower/
Cladco Decking, 2023. What percentage of UK energy is renewable? [online] Available at: https:// www.cladcodecking.co.uk/blog/post/renewableenergy-percentageuk#:~:text=2035%20(currently%20 14GW)-,What%20percentage%20of%20UK%20 energy%20is%20renewable%3F,4.5%25%20and%20 hydro%201.2%25.
Brighton Energy Coop, 2023. The History of Solar Energy. [online] Available at: https://www. brightonenergy.org.uk/solar-energy/#:~:text=The%20 History%20of%20Solar%20Energy,and%20the%20 Renewable%20Obligation%20Certificate.
U.S. Department of Energy, 2023. Advantages and challenges of wind energy. [online] Available at: https://www.energy.gov/eere/wind/advantages-andchallenges-wind-energy.
U.S. Department of Energy, 2023. Biofuel basics. [online] Available at: https://www.energy.gov/ eere/bioenergy/biofuel-basics#:~:text=Unlike%20 other%20renewable%20energy%20sources,first%20 generation%20of%20biofuel%20technology.
Solar Reviews, 2023. Biomass energy pros and cons. [online] Available at: https://www.solarreviews.com/ blog/biomass-energy-pros-and-cons.
TWI (The Welding Institute), 2023. Pros and cons of geothermal energy. [online] Available at: https:// www.twi-global.com/technical-knowledge/faqs/ geothermal-energy/pros-and-cons
National Energy Action (NEA), 2023. Energy crisis. [online] Available at: https://www.nea.org.uk/energycrisis/#:~:text=Since%20the%20winter%20period%20 of,now%20living%20in%20fuel%20poverty.
Action Renewables, 2023. Everything you need to know about tidal energy. [online] Available at: https:// actionrenewables.co.uk/news/everything-you-need-toknow-about-tidal-energy/#:~:text=Tidal%20energy%20 is%20created%20using,a%20turbine%20to%20 generate%20electricity.
Solar Reviews, 2023. Tidal energy pros and cons. [online] Available at: https://www.solarreviews.com/ blog/tidal-energy-pros-and-cons#:~:text=Tidal%20 turbine,-Tidal%20turbines%20are&text=Tidal%20 turbines%20are%20able%20to,them%20more%20 expensive%20to%20manufacture.
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RIDDLE 1
I hang from the ceiling, cold and bright, Formed by water dripping, day and night. In caves, you’ll find me, glittering white, Growing slow, out of sight. What am I?
RIDDLE 2
In dark and damp places, I make my home, Feeding on matter that’s dead and alone. Not a plant, nor an animal, I can be big or small. With my hidden network, I quietly digest. What am I?
RIDDLE3
Which animal is not a mammal?
A ladybug wants to crawl from one edge of a 9cm x 9cm Rubik’s cube to the opposite diagonal edge (see diagram). What will be the shortest path?
1. Loss of electrons
2. The site in a cell for protein synthesis
3. The unit for energy
4. Flame colour of potassium
7. The unit for resistance
8. An indicator used for titration that is colourless under acidic conditions and pink under alkali conditions
12. The process of particles moving from an area of high concentration to low concentration
13. The process of protein synthesis that happens in the nucleus
15. The number of waves that pass a fixed point per second
5. An atom of the same element with the same number of protons but a different number of neutrons
6. The process by which a single parent cell divides to make two new daughter cells
9. A product of anaerobic respiration in plant cells
10. The process of the rising of warm air
11. A component that only allows current to flow through in the forward direction
14. The process through which a substance changes from solid to gas
16. Calculated as mass x gravitational field strength (g) x height
17. An element with atomic number 11
18. The section of DNA that codes for a protein
We are interested in exploring and discovering how things work, which is the fundamental aspect of STEM. We are also excited to discover ways to improve people’s lives through discoveries and innovation.
ARE YOUR FAVOURITE MEMORIES OF STEM AT DOWNE?
Rebecca and Kayla – We are really grateful to have had the opportunity to take part in the Schools’ Analyst Competition this May with one other Lower Sixth pupil. We did a total of three experiments including quantifying the amount of vitamin C in vitamin tablets; determining whether there were illegal dyes in coloured sweets and determining the percentage composition of baking powder. It was a great experience to home in on our practical skills and working as a team.
Janice – I have particularly enjoyed the Environmental Research Group as it gives me the opportunity to do detailed research on topics I find interesting that relate to the environment, whilst improving my research and essay writing skills which I don’t practice very often with my A level subjects. So far, I have looked at the use of thorium instead of uranium for nuclear energy as well as the use of solar geoengineering to reduce the rate of climate change. I have thoroughly enjoyed researching about these topics and I look forward to researching even more topics!
YOU HAVE BEEN SELECTED AS STEM SENIORS FOR NEXT YEAR, WHAT CAN STUDENTS EXPECT YOU TO BRING TO THE ROLE?
We are hoping to make STEM soc as well as Engineering soc as engaging and exciting as possible. Next year, we are aiming to look at a variety of topics, such as: Organic Chemistry, Smart Materials, Renewable Energy and much more. We hope to see lots of you there!
HAVE YOU READ ANY STEMRELATED BOOKS THAT YOU WOULD RECOMMEND?
A book we recommend is “Stuff Matters” by Mark Miodownik which explores a range of everyday materials from concrete, porcelain and plastic, to chocolate. This book is packed with fascinating details about each material’s structure, their properties and the history of their invention.
If you are interested in chemistry, we would recommend “Why Chemical Reactions Happen,” as it explains the role of thermodynamics and kinetics and it will also give a deeper insight into the fundamental principles that drives a reaction. Also definitely check out Organic Chemistry if you are interested in the mechanism behind chemical reactions.
And if you want an intellectual challenge and to improve your problem-solving skills, we highly recommend Thomas Povey’s “Professor Povey’s Perplexing Problems”!
IN TERMS OF THE FUTURE, HAVE YOU THOUGHT MUCH ABOUT CAREERS OR FIELDS YOU WOULD LIKE TO WORK IN?
Rebecca – I am hoping to study natural science with a focus in material science.
Janice – I am hoping to study engineering, specifically mechanical engineering but I am still not sure what I want to do in the future.
Kayla – As I am applying for chemistry for university, I would definitely like to work on something chemistry related but maybe more on the pharmaceutical side.
Zimo (Emily) Huang, LVI
A chord is produced when two or more notes are played simultaneously. Chords make up harmony that wields emotional influences and gives music its distinctive character. Normally, a piece of music will include both horizontal and vertical dimensions. The horizontal dimension relates to elements that happen over time, for example, melody and counterpoint. Alternatively, the vertical dimension encompasses the sum of notes, such as the chordal support for a melody. Although harmony seems to be predominantly a vertical construct, due to its basis in chords or note combinations, it also possesses the horizontal dimension. Therefore, by thoughtfully selecting and sequencing harmonic sounds, a composer can lead the listeners through moments of anticipation and satisfaction.
Beneath the sensory experiences of music lies the framework of mathematical relationship and physical principles. An interval is the distance between two notes. It can be described as linear or melodic if it refers to successively sounding tones, and harmonic if it refers to simultaneously sounding tones (i.e. in a chord). The harmonic intervals are the essential elements of a scale.
The invention of scales can be traced back to ancient Greece, where Pythagoras walked to a town and observed a blacksmith’s forge. He heard blacksmiths hitting their anvils as notes and noticed that the hammers were harmonious with one another. Pythagoras then began his research into primitive harmonic analysis. He initially used many different sound-emitting objects and eventually built a basic instrument called the monochord. This instrument is made of a small, rectangular box with a hole in it. A string was fixed at the ends of the box, and a moveable bridge was added for adjusting the length of the string. Pythagoras recorded the distinct sounds produced when he plucked the string at different lengths. During his research, he discovered that a full-length string (with the bridge at the very end) and a half-length string (with the bridge at the measured halfway mark) both produced the same tone, but the one produced by the half-length string was one octave higher. It can be concluded that string length ratio of 1:2 produce an octave, and that different ratios give out different harmonies. For example, the ratio 2:3 is called a perfect fifth, and 3:4 is called a perfect fourth. Moreover, the string length ratios
(i.e. 1/2, 2/3 and 3/4) are inversely proportional to the frequency produced. The frequency ratios would be two (i.e. when two frequencies have a ratio of 2:1, they are n octaves apart), 3/2, and 4/3, all within the range of one octave. Since frequencies are equivalent to wavelengths, if middle C is 262Hz, then the C an octave higher is 524Hz (262*2). In a graph, the higher C has twice as many peaks and toughs as the lower C. Eventually; by stacking fifths and adding or subtracting octaves, he developed a seven-note scale that became the predecessor to the modern Western Major Scale. This scale is called the Pythagorean diatonic scale. One can therefore argue that the fourth, fifth, and octave are named because of their placement in the fourth, fifth, and eighth pitches in this scale. Pythagoras called these intervals perfect consonants due to their pleasing sounds to the ear. On the other hand, dissonant sounds are produced when the ratios consist of much larger numbers. For instance, 65536:59049 would be dissonant. It is a diminished third produced by reducing a minor third by a chromatic semitone.
After the Pythagorean diatonic scale had been invented, it became the standard tuning system. However, it is the equal temperament tuning system that people use today. Pythagorean tuning is no longer ideal, and the reason for that can be explained using the circle of fifths. The circle of fifths consists of twelve chromatic notes arranged in a circle, as a sequence of perfect fifths. This pattern was followed by Pythagoras when he was dividing the string length by taking fifths. Apart from the notes found in the Pythagorean diatonic scale, the circle also contains enharmonics (e.g. E#/F or A#/ Bb), notes that share the same pitch, but different notations. If we compare the standard circle of fifths against a Pythagorean circle of fifths that accounts for the Pythagorean comma, it is clear to see the discrepancy in ratio as the octave increase. The Pythagorean comma is the small interval between two enharmonically equivalent notes, and it exists in Pythagorean tuning. Its rounded value is equal to 1.013643, which is similar to a quarter of a semitone. Furthermore, the concept of overtones can also provide evidence for the faultiness of Pythagorean tuning. In music, harmony is described as the accompanying notes that support the melody, which is often the main theme of the musical piece. The overtones of a note determine whether the harmonies sound “appealing” to the listeners (this is highly subjective; therefore, it can be referred to the consonants). If one note is played, and the next note sounded has an integer-multiple frequency of the first one, they harmonise with each other. For example, the overtone sequence can be written as: 1f, 2f, 3f, 4f…then it becomes clear that the
Pythagorean scale did not have a perfect octave (i.e. the octaves were not equal to powers of two of the original frequency). The idea of overtones proved that a single wave can be represented by the sum of multiple waves.
These inaccuracies result in the invention of equal temperament tuning system. It is called the equal temperament as the interval between each half tone is the same. The scale contains twelve half tones, and each whole tone consists of two half tones. When listening to it, we can hear this since every octave has the frequency ratio of 2/1 exactly (and the intervals for equal temperament have a frequency ratio of √2:1), whereas in Pythagorean scales, the intervals between the octaves increases. However, to have a mathematically accurate octave, the intervals between the octave should not be represented by integer ratios such as the ones suggested by Pythagoras. Instead, the involvement of irrational numbers hid the Pythagorean comma between the half tones. This equal temperament tuning system has therefore resolved the problem of tuning and modulation by making everything except the octaves slightly out of tune.
Fundamentally, the connection between mathematics and music is extensive. The concept of overtones can also lead into further research on the Fourier Series and sound waves. Additionally, the interplay between mathematics and music can be developed in many topics. For example, the ideas of a Golden Ratio have been proved in pieces composed by Mozart and Bach, Pythagorean Dodecaphonic Scale has constructions that can be related to graph theory, and countless more mathematical concepts. Research into these areas will help to deepen the understanding of how these two subjects are involved in one another.
REFERENCES:
The Physics Classroom, (2023). Fundamental frequency and harmonics. [online] Available at: https:// www.physicsclassroom. com/class/sound/ Lesson-4/FundamentalFrequency-andHarmonics
Rich, A. Britannica, (2023). Harmony. [online] Available at: https://www.britannica. com/art/harmonymusic
Poulish, D., 2023. The Mathematics of Music. [pdf] Available at: https://www.math. drexel.edu/~dp399/ musicmath/assets/ MathMusicWk2.pdf
Amir, M. I., 2019. Fabrication and Characterisation of Flexible and Highly Conductive PolyanilineCoated Carbon Nanotube Hybrid Films. Ph.D. Mississippi State University. Available at: https://scholarsjunction. msstate.edu/ cgi/viewcontent. cgi?article=6428& context=td
Davida (Seyi) Opaleye, LVI
The term “stem cell” was originally invented by zoologists to describe cells committed to forming gametes in sexually reproducing organisms. Since then, scientists have continued to work with primarily two types of stem cells; embryonic stem cells and non-embryonic somatic stem cells, from both humans and animals. One zoologist, Boveri, theorised that cancer cells originate from cells with scrambled chromosomes leading to a continuous and uncontrollably dividing cell. This idea supports the embryonic tumour aetiology theories by various scientists who proposed a common cell template for mature blood cells; therefore, introducing the idea of polyblasts (Gollwitzer, Marshall, Wang, Pearlman, Bargh, 2021).
Stem cells are essentially dynamic promoters of modern biology, bridging the gap between science and medicine. These remarkable cells have the ability to differentiate into multiple types of cells, which makes them vital to human life. New developments in technology make for more possibilities in biomedical research, allowing further understanding of how important these cells really are, and the different ways they can be utilised to their full potential. The key properties of stem cells were first identified by Ernest McCulloch and James Till in the early 1960s. The hematopoietic stem cell (blood forming stem cell) discovered was investigated by injecting marrow cells into irradiated mice, tracking nodules that grew on their backs in the weeks later (Butt, Omer, Yan, Shaikh, Mayr 2021). Following the discovery of these biological protagonists, scientists continued to work with stem deriving embryonic stem cells in mice in the 1980s leading to the derivation of embryonic stem cells from human embryos about a decade later (UNMC, 2023). This revelation won them the 2007 Nobel Prize, paving the way for
further discoveries in the bioengineering field, like the detection of human induced pluripotent stem cells which were found by converting skin cells into cells that closely resemble human embryonic stem cells. This stimulated the research which led to the discovery that mature cells can be converted to stem cells; essentially manipulated to become pluripotent.
Adult Stem Cells (ASCs) are undifferentiated cells that are found within specific differentiated tissues in our bodies that can renew themselves, for example: bone marrow tissue. These tissues need ASCs because they need to be able to renew themselves and generate new cells that can replenish dead or damaged tissues. Despite being highly functional, they are relatively scarce in native tissues therefore rendering them difficult to study and extract for research purposes. Low population of ASCs generate cells to replace those lost in disease, injury or everyday repair and are found in umbilical cord tissue, placenta tissue, bone marrow tissue, muscle tissue, brain tissue, fat tissue and many others. Despite having a lot of knowledge about these cells, studies proving the accuracy of ASCs are debatable as some show that ASCs can only generate in the cell types of their resident tissue whereas other studies show that ASCs may be able to generate other tissue types than those in which they reside; however not enough studies have provided conclusive evidence. In the days following fertilisation, before implantation; the blastocyst contains an inner cell mass that is capable of generating all the specialised tissues that make up the body. After implantation, the inner cell mass of the developing blastocyst follows the differentiation programme giving rise to derivatives of three germ layers (gastrulation). Embryonic stem cells play a significant role in gastrulation as they are pluripotent. During gastrulation these pluripotent embryonic stem cells differentiate into cells that form the germ layers that essentially give rise to
specific tissues and organs, laying the foundation for the development of the entire organism. Another type of stem cell is the Induced Pluripotent Stem Cell (iPSC). These are created in vitro and are a medium between adult stem cells and embryonic stem cells. Through the introduction of embryonic genes into a somatic cell, these iPSCs are created allowing them to revert back to a “stem cell like” state. These cells similar to ESCs, are considered pluripotent, however they are considered less “stable” and more prone to genetic mutations depending on method of reprogramming (NCBI, 2023).
The discovery of self-renewal cells which have the potential for differentiation into difference cells without senescence is a scientific phenomenon that has been applied to modern medicine. However, an even greater breakthrough was the creation of these stem cells in vitro discovered in 2006. Without this discovery, the use of stem cells in modern medicine would only be available in the short time period following implantation in which embryonic stem cells are completely undifferentiated. Since the discovery of iPSCs, they have played a crucial role in the diverse research and clinical applications ranging from disease modelling to drug discovery. iPSCs are also extensively used in regenerative medicine to generate tissue specific cells for transplantation, offering potential treatments for injuries and degenerative diseases. These cells offer a promising approach for the repair of degenerated or injured tissues. Whilst the traditional treatments of gene therapy come with associated challenges, these can be alleviated by iPSCs which are generated by an individual’s somatic cells, already having differentiated. This approach has proven extremely effective to treat patients with degenerative disorders, e.g. hematopoietic disorders or spinal cord injuries. Similarly, they have also been used to correct genetic deficiencies in diseases like Duchenne muscular
dystrophy (DMD) a genetic disorder characterised by progressive muscle deterioration and weakness (MDA, 2023). iPSCs were generated from a DMD patient and by using fibroblasts, Human Artificial Chromosomes were used for the expression of the complete Dystrophin sequence providing a potential therapeutic possibility.
Fundamentally, stem cells can be argued to be the basis of life as we see it today. Given their unique regenerative abilities, stem cells offer new potentials for treating many diseases as research continues. The study of stem cells enables scientists to learn about the properties specific to these cells and what sets them apart from specialised cell types. Nowadays, scientists are using stem cells to screen new drugs and develop model systems to study normal growth and identify the primary causes of birth defects. Stem cell research remains one of the most fascinating areas of contemporary biology since its discovery; however, research on stem cells raises more and more scientific questions as it rapidly generates new discoveries. Yet at the intersection of scientific insight and moral introspection, the ethical responsibilities that accompany stem cell use are important. The use of ESCs and iPSCs present ethical considerations, sparking debates within medical and ethical communities. The ethical implications surrounding the use of ESCs are the destruction of human embryos, raising the question of who has the rights to the embryo initially. This has led to the exploration and development of alternatives such as iPSCs. These too pose ethical challenges as they involve the use of genetic modifications increasing the risk of tumorigenicity. Managing the balance between scientific progress and ethical considerations remains difficult in stem cell research, requiring continuous dialogue and ethical oversight (UNMC, 2023).
Gollwitzer, A., Marshall, J., Wang, Y., Pearlman, A. and Bargh, J.A., 2021. Relating pattern deviancy aversion to COVID-19 vaccine hesitancy. Proceedings of the National Academy of Sciences of the United States of America, [online] 118(20), e2024944118. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/ PMC8105090/
Butt, A.A., Omer, S.B., Yan, P., Shaikh, O.S. and Mayr, F.B., 2021. SARS-CoV-2 Vaccine Effectiveness in a High-Risk National Population in a RealWorld Setting. Mayo Clinic Proceedings, [online] 96(3), pp.626-637. Available at: https://www. mayoclinicproceedings.org/article/S00256196(21)00063-X/pdf
University of Nebraska Medical Center (UNMC), 2023. History of Stem Cells. [online] Available at: https://www.unmc.edu/stemcells/educationalresources/history.html#:~:text=Scientists%20 discovered%20ways%20to%20derive,the%20 cells%20in%20the%20laboratory.
National Center for Biotechnology Information (NCBI), 2023. The embryo. In: The Developing Human: Clinically Oriented Embryology. Available at: https://www.ncbi.nlm.nih.gov/ books/NBK546679/#:~:text=The%20second%20 and%20third%20weeks,the%20neurulation%20 process%2C%20resulting%20in
Gholipour, C., Kheirkhah, J., and Kiani, Z., 2014. “Innovative Techniques in Management of Osteochondritis Dissecans of the Knee.” World Journal of Orthopedics, [online] 5(3), pp. 233-238. Available at: https://www.ncbi.nlm.nih.gov/pmc/ articles/PMC3947934/ ScienceDirect, 2023. Blastocyst. [online] Available at: https://www.sciencedirect.com/topics/neuroscience/ blastocyst#:~:text=Blastocyst%2Dstage%20 embryos%20consist%20of,both%20fetal%20and%20 extraembryonic%20tissues.
Centers for Disease Control and Prevention (CDC), 2023. Blastocystis Infection. Available at: https:// www.ncbi.nlm.nih.gov/pmc/articles/PMC4313779/ Muscular Dystrophy Association (MDA), 2023. Duchenne muscular dystrophy. [online] Available at: https://www.mda.org/disease/duchenne-musculardystrophy
University of Nebraska Medical Center (UNMC), 2023. Pros and cons of stem cell research. [online] Available at: https://www.unmc.edu/stemcells/ educational-resources/prosandcons.html
Zhi Yu Tiffany Cheong, LVI
What even is green infrastructure? I’m sure you will have heard of the phrase every now and then, but have you actually understood its true meaning (and I don’t mean the dictionary definition…)
Green infrastructure (GI) or blue-green infrastructure refers to green or blue spaces in urban areas to help solve urban and climatic changes by building with nature. It is highly important to us, as it provides for the protection and management of our environment as recent human activity has resulted in pollution of so many parts of nature at a scale and rate never experienced before.
Bioswales are landscape features that help collect polluted stormwater runoff from impervious surfaces such as tarmac, soak it into the ground, and filter out pollution; roadside vegetation being a key feature.
With many benefits, roadside vegetation has been shown to impact the air quality downwind and near roads. Some studies have discovered that air pollution concentrations decrease where vegetation is present, however this is not the case for all studies. It also supports rare and threatened species of plants and animals and provides good erosion control.
Bioswales not only have ecological impacts, but a Polish study discovered the impacts of this feature on people, specifically drivers. The study shows that roadside vegetation influences the safety of road users, and it is worth noting that a significant number of road accidents occur due to collisions with trees; especially under varying environmental circumstances. By employing the standards of woodlot shaping (controlling the areas around trees), it becomes feasible to maintain the positive effects of vegetation in the area while ensuring the safety of road users.
Singapore is Asia’s greenest city, nicknamed the ‘City in Nature’. Setting an amazing example, many landscaping architects participate in the project of ‘greenifying’ the city.
Bishan-Ang Mo Kio Park by Ramboll Studio Dreiseitl is one of Singapore’s most popular heartland parks and is part of a longterm initiative of Singapore’s Public Utilities Board, aiming to transform the country’s water bodies beyond their functions of drainage and water supply into vibrant spaces for community bonding and recreation.
Man-made (grey) infrastructure is designed to provide essential urban functions, but it hinders many natural processes such as the migration of animals and destruction of food chains. On top of that, cities only make up 2% of Earth’s total land surface, but produce over 70% of CO₂ emissions, thus making the need for smart solutions more vital than ever. As a result of increased carbon emissions, climate change is also increasing. Extreme weather has resulted from this impacting not only temperatures but natural disasters.
In England, parks and green spaces deliver an estimated £6.6 billion of health, climate change and environmental benefits every year, indicating the important role green spaces play, and that any loss of these spaces will come at an environmental and social cost.
The UK has a Green Infrastructure Framework (GIF) that provides a structure to analyse where green spaces in urban environments are needed most – a great beginning to a more sustainable future.
The framework integrates GI tools, principles, standards, and design guidance, structured by five key standards:
Urban Nature Recovery Standard
This standard aims to boost nature recovery, create and restore wildlife habitats, and build resilience to climate change. Incorporating nature-based solutions into the designs of towns and cities to increase carbon capture, this prevents flooding and reduces temperatures during heatwaves.
Urban Greening Factor (UGF) for England
Aims to increase the level of greening in urban environments, such as green roofs or green walls.
Urban Tree Canopy Cover Standard
Aims to increase the tree canopy cover in urban environments, resulting in increased carbon capture and can mitigate flood risk as they absorb excess water during flooding incidents.
Accessible Greenspace Standards
Aims to promote access to good quality green and blue space within fifteen minutes’ walk from home. 82% of adults agree that being in nature makes them very happy, however one third of people in England do not have access to green space within this distance.
Green Infrastructure Strategy
This supports the National Planning Policy Framework’s stipulation that local authorities should develop strategic policies for green infrastructure.
Integrating green infrastructure into urban environments is crucial for creating sustainable and resilient cities. Although I have only outlined the framework of Singapore and the UK in this article, many other countries in the world are highly aware of this. By prioritising green infrastructure, cities can mitigate climate change, improve air quality, and enhance community well-being.
It is essential for governments to embrace these standards and develop strategic policies and structures that prioritise the preservation and development of green spaces in our cities.
Janice Lee, UVI
“Scientists must work urgently on predicting the effects of climate geoengineering,” said the chief of the US atmospheric science agency. Geoengineering could potentially be a viable solution to climate change, and discussions of its feasibility are gathering pace as the threats of climate change grow. However, thorough research is imperative before any action takes place, as geoengineering could have huge impacts that would be hard to control and would be impossible to confine within country borders.
Solar geoengineering, also referred as solar radiation management, refers to a set of technologies designed to reduce the average temperature of the planet by blocking intense sun rays and reflecting a small fraction of sunlight into space or increasing the amount of solar radiation that escapes back into space to cool the planet. However, this technique does not address the root cause of climate change.
This idea is not particularly new. In 1965, President Lyndon Johnson’s Science Advisory Committee warned it might be necessary to increase the reflectivity of the Earth to offset rising greenhouse gas emissions. The committee went so far as to suggest sprinkling reflective particles across the oceans.
However, the best-known type of solar engineering – “stratospheric injection” has been demonstrated in nature. Most famously, the massive eruption of Mt. Pinatubo in the summer of 1991 spewed 20 million tons of sulfur dioxide into the sky. By reflecting sunlight into space, the particles in the stratosphere lowered global temperature by about 0.5 °C over the next two years. Soviet climatologist Mikhail Buduko had suggested in 1974 that we could counteract climate change by mimicking this volcanic phenomenon.
Stratospheric aerosol injection:
This type of solar geoengineering uses tiny reflective particles or aerosols to reflect sunlight into space to cool the planet, by spraying reflective sulphate aerosol particles into the stratosphere with high-altitude airplanes, tethered balloons, high-altitude blimps or artillery. The stratosphere is a layer of the Earth’s atmosphere that ranges between 10-50 km above the ground between the troposphere and the Mesosphere. The stratosphere is an ideal target for atmospheric geoengineering as it is relatively isolated from human populations and doesn’t have weather such as rain that would cause the injected particles to fall back to the ground after a short period. It is also not too high above the ground so is accessible by the technology available. This is a promising solution as it is feasible with existing technologies; it could be implemented in a very short period and at a relatively low cost – at around $1500 per ton of material deployed, resulting in average costs of $2.25 billion per year over the first 15 years of deployment. This technology is also considered relatively safe for the environment because volcanoes have been injecting sulphate aerosols into the stratosphere. Thus, these particles naturally fall out of the atmosphere after 1 to 2 years, so the benefits or effects are temporary.
Marine Cloud Brightening (MCB) involves seeding low-lying clouds using seawater as condensation nuclei, which may increase the concentration of cloud droplets. The reflectivity and possible longevity of the clouds would then increase, essentially “brightening” the clouds.
Some key advantages to MCB are that it can be terminated quickly if there are any negative consequences and there is a degree of flexibility in which areas to seed with clouds. The ability to localise this technology might enable it to be used to weaken hurricanes or protect coral reefs by cooling certain areas of water. However, currently, there are no fully established designs for some of the tools necessary for condensation nuclei production. There is a level of uncertainty as to whether the nuclei will be small enough to scatter at the right wavelengths and the possibility of the nuclei causing a decrease in ozone. Currently, researchers at UCL are looking into possible methods to conduct Marine Cloud Brightening.
Cirrus cloud thinning:
Cirrus cloud thinning seeks to reduce the thickness of ice clouds 6-13 km above the Earth’s surface, as they tend to trap more heat in the atmosphere than they reflect into space. This is because cirrus clouds are formed in cold temperatures and consist of ice crystals; if these crystals are numerous and small, the cirrus clouds prevent long-wave radiation from escaping into space, causing a similar climate impact to greenhouse gases. Thinning these clouds would allow more heat to escape from Earth’s atmosphere, producing a cooling effect.
Therefore, scientists are proposing to inject ice nuclei, such as bismuth triiodide or aerosol particles as sulfuric or nitric acid, into regions where cirrus clouds form. An ice nucleus is a particle which acts as the nucleus for the formation of an ice crystal in the atmosphere. This would lead to cirrus clouds with larger ice crystals with shorter life spans, reducing their optical depth, which means more long-wave radiation would be transmitted back into space.
However, over-injection of ice-nuclei particles into cirrus clouds may produce the opposite effect; more and thicker clouds may be produced, so that even more heat is trapped, which could lead to an increased global temperature.
Solar geoengineering has huge potential to reduce the rate of climate change around the globe when used in moderation. Its viability is shown consistently by climate models, reducing the effects of climate change such as extreme temperatures, changes in water availability and intensity of tropical storms. However, the side-effects of solar geoengineering are often unpredictable. It could impact weather patterns, causing large regional and seasonal changes to precipitation and disrupting monsoons. This could have detrimental effects on agriculture and the provision of basic needs of food and water. Thus, this could lead to a delay in the recovery of the ozone layer or lead to a dangerous spike in acid rain. Furthermore, the advancement in solar geoengineering might discourage the incentive to cut down emission levels, defeating the purpose of solar geoengineering. Reducing CO2 and CH4 emissions is imperative alongside solar geoengineering in order to maximise the rate of decrease of climate change.
Charlotte Trew, LVI
Autism Spectrum Disorder is a lifelong neurodevelopmental disability which affects how people communicate and interact with the world. It is a genetic disorder and has been linked with multiple different genes as a possible cause. It is a spectrum condition and so people experience it differently, though the ‘signs’ of autism fall into five key areas: social communication and interaction, repetitive and/ or restrictive behaviour, sensory sensitivity, special interests, and meltdowns and shutdowns.
Autistic people who have low support needs, and often are women, usually have a high ability to ‘mask’ their autistic traits. Nevertheless, research has demonstrated that neurotypical people can identify autistic people almost immediately upon meeting them, on the basis of thin slice judgements, although they do not recognise them as autistic but rather as different. This is because masking is a conscious effort for autistic people, and therefore they may not be able to fully replicate the correct body language and tonal intonation required, especially if the conversation is about something that interests them. This leads to neurotypical people perceiving them less favourably, as they subconsciously notice something ‘unusual’ about the autistic person’s behaviour.
From a very young age autistic people notice their different behaviour (often through adults correcting it) and try to hide it by ‘masking’. This is where they try to hide their natural behaviour and instead conform to neurotypical behaviour. This can be very detrimental to autistic people’s mental health, leading to higher anxiety, depression and frequency of suicidal thoughts, which all contribute to the average lifespan of an autistic person being around 56 (though research has found it could be lower). Notably, even as society becomes more aware of autism and that the ways autistic people communicate are different - rather than wrongthe onus is still on the autistic person to make up the perceived ‘deficit’ of communication when conversing with neurotypicals. We can see that it is a difference of communication and not a deficit as research shows that the transfer of information in a group of autistic people and a group of neurotypical people is roughly the same, but the transfer of information drops when the group is combined (both autistic and neurotypical people). This suggests that it is the difference in communication between the two that leads to misunderstandings, supporting the Double Empathy problem (which recognises that our different experiences make it difficult for neurotypical people to empathise and communicate with autistic people, as well as vice versa).
This can make it very difficult to fit into society, as often behaviour that autistic people display is at odds with social norms and neurotypical behaviour. This is easily seen when looking at people’s behaviour when lying. Some behaviours which autistic people naturally display are the avoidance of eye contact (they are more likely to listen and understand what someone is saying if they don’t make eye contact, which can be physically painful), fidgeting, moving
hands or feet, repetitive behaviour, repeating words, rocking in their chair, taking things people say literally, and becoming very anxious in social situations. This can often lead to autistic people often making up scripts of what to say in their head. Compare these behaviours to a list of the behaviours displayed by neurotypical people when lying: avoiding eye contact, fidgeting, moving hands more than usual, touching their hair or face as a self-soothing technique, repeating words, body language not matching what they say, and being too vague or too detailed. Lots of these behaviours cross over, especially when considering that autistic people don’t have innate knowledge of body language, meaning their body language will not match what they are saying. This leads to the assumption that autistic people are lying based on their behaviour, when in truth they are not - which is ironic given that autistic people are more likely to be honest than neurotypical people. Nonetheless, can make social interactions very difficult, especially for undiagnosed autistic people, as people do not know that the behavioural differences are due to a different brain wiring and not dishonesty.
This misunderstanding can become a major issue when it comes to crime. When police interrogate suspects or interview witnesses, they may use the ‘cognitive interview’. This is a trained method to try to get people to remember as much as they can about the crime committed, using four steps: report (everything), reinstate the context, reverse the story, and change perspective. The enhanced cognitive interview includes police being trained to recognise body language, which then may lead to prejudice against autistic people. This is because, as explained above, autistic people’s natural behaviour is often at odds with neurotypical behaviour, and so may lead to discrimination in the justice system against autistic people. Furthermore, autistic people may be incredibly detailed or unable to change perspective in the same way a neurotypical person would, possibly leading to incorrect conclusions by police. Again, this is a bigger issue for undiagnosed autistics, who will still demonstrate the differing behaviours but without the context of a diagnosis, which may then increase the likelihood of the police thinking they are lying. More generally, this can be applied to other situations other than the justice system, such as employment or school.
Overall, there is an inherent bias against autistic people in society. However, with the help of further research and increasing awareness and education around autism, the stigma and discrimination of autistic people in society can slowly be reduced until it is eventually gone, meaning autistic people can unmask and lead a happier and healthier life.
REFERENCES:
National Autistic Society, 2023. What is autism? [online] Available at: https://autism. org.uk/advice-and-guidance/ what-is-autism.
Sasson, N. J. et al. Neurotypical Peers are Less Willing to Interact with Those with Autism based on Thin Slice Judgments. Sci. Rep. 6, 40700; doi: 10.1038/ srep40700 (2016).
Crompton, C. J., Ropar, D., Evans-Williams, C. V., Flynn, E. G., & Fletcher-Watson, S. (2020). Autistic peer-to-peer information transfer is highly effective. Autism, 24(7), 1704- 1712. Available at: https://doi.org/10.1177/ 1362361320919286
Autistic Girls Network, 2023. The Basics. [online] Available at: https://autisticgirlsnetwork. org/the-basics/
Janice Lee, UVI
Concerns about the disposal of radioactive waste generated by conventional uranium-based nuclear reactors are escalating, and the pursuit of sustainable and efficient energy sources is becoming more and more relevant.
Nuclear energy plays a significant role in our energy matrix, yet its long-term viability is hindered by the challenges posed by radioactive by-products. Consequently, exploring alternative nuclear fuels emerges as a promising option to address these pressing concerns. There has been growing interest in the development of thorium-based nuclear energy as a viable alternative to uranium-based nuclear energy. Therefore, this article seeks to delve into the promise and potential of thorium as a sustainable and safer fuel for nuclear energy.
Thorium is a metal that is slightly radioactive in nature, discovered in 1828 by the Swedish chemist Jons Jakob Berzelius, who named it after Thor, the Norse god of thunder. It is found in small amounts in most rocks and soils and is very insoluble, which is why it is plentiful in sands and rocks but not in seawater, in contrast to uranium. Furthermore, it is three to four times more abundant in nature than uranium – the Earth’s upper crust contains an
average of 10.5 parts per million (ppm) of thorium, compared with about 3ppm of uranium.
There is only one singular isotope of thorium that exists in nature – thorium-232. It decays very slowly (its half-life is about three times the age of the Earth). When pure, thorium is a silvery-white metal that retains its lustre for several months. However, when it is contaminated with oxygen, thorium slowly tarnishes in the air, eventually becoming grey or black. Thorium oxide is relatively inert and does not oxidise further, unlike uranium oxide. It has higher thermal conductivity and lower thermal expansion than uranium oxide, as well as a much higher melting point. Therefore, as a nuclear fuel, fission gas release is much lower than uranium oxide.
The role of thorium in nuclear energy is fascinating and sets itself apart from more traditional nuclear fuels. Thorium-232, the only naturally occurring isotope of thorium, is a fissionable material but not a fissile one, meaning that it needs high-energy neutrons to undergo fission, unlike uranium-235 or plutonium-239. When irradiated by thermal neutrons, 232Th (thorium-232) and 238U (uranium-238) follow similar processes. 232Th breeds 233U in a completely analogous way to that in which 238U breeds 239Pu. These two processes of neutron “radiative capture” (n,γ) reactions, followed by consecutive radioactive decays (n,γ) represent the two practical “fertile/fissile fuel cycles”; the 238U/239Pu fuel cycle and the 232Th/233U fuel cycle.
One of the reasons why thorium is better for the environment than uranium is that the waste produced in the thorium fuel cycle has significantly shorter half-lives compared to the waste produced by traditional uranium reactors, reducing the environmental impact and the need for long-term storage solutions. The radioactivity of the waste in the thorium fuel cycle drops down to safe levels after just a few hundred years, compared to tens of thousands of years needed for current nuclear waste to cool off. Thus, in a typical uranium reactor, uranium-238 is emitted which could eventually become other elements, such as plutonium. Plutonium is most dangerous when it is inhaled due to its emission of alpha particles. When plutonium particles are inhaled, they lodge in the lung tissue. The alpha particles can kill lung cells, which causes scarring of the lungs, leading to lung disease and cancer. The maximum amount of plutonium-239 that can be indefinitely maintained in an adult without significant injury is 0.008 micro-curie (equal to 0.13mg [1mg = 10−6g]).
Furthermore, thorium is safer and more efficient to mine than uranium, thus making it more environmentally friendly. The percentage of thorium found in its ore is generally greater than the percentage of uranium found in its ore, so it is also more cost-efficient. Thus, thorium can be extracted from open-pit monazite deposits, which are easier to mine than most uranium-bearing ores. Management of left-over materials from mining is also much simpler because of the much shorter half-life of one of its daughter products – 220Rn (fifty five seconds), compared to the equivalent daughter product of uranium, 222Rn (almost four days).
The technical feasibility and advantages of using thorium as a fuel component in power reactors have been shown in numerous studies. Thorium has very promising physicochemical characteristics, especially in the form of thorium dioxide (thorium) such as having a low thermal expansion coefficient, high thermal conductivity and high melting temperature, which make it well-suited for use as a fertile fuel. It is estimated that one ton of thorium can produce as much energy as thirty five tons of uranium in a liquid fluoride thorium reactor. This makes thorium a more efficient fuel than uranium.
However, there are disadvantages to thoriumbased nuclear power. Huge investments are needed for a thorium nuclear power reactor, as it requires a rigorous amount of testing, analysis and licensing work. The uncertainty in the return of profits discourage companies to invest in thorium-based nuclear energy.
Whilst the waste produced in a thorium fuel cycle have shorter half-life’s than uranium fuel cycle ones, irradiated thorium is more dangerously radioactive in the short-term. The thorium cycle invariably produces some U – 232, which decays to TI – 208, which has a 2.6MeV gamma ray decay mode.
Furthermore, the process of utilising thorium fuel is more technologically challenging than uranium fuel. Thorium dioxide melts at 450°C higher than traditional uranium dioxide, so very high temperatures are required to produce high-quality solid fuel. Additionally, thorium is relatively inert, increasing the difficulty of the chemical process.
The world’s first commercial thorium reactor has been approved in China. The reactor, TMSR-LF1 is a 2MW molten salt reactor located in Wuwei City, Gansu province, in China’s remote northwest. The project began in 2011 at a cost of CNY 3 billion, and construction commenced in 2018 and was completed in 2021. In 2022, a commissioning plan was approved, and the reactor will operate for the first 5-8 years in batch mode, before converting to continuous operation.
The TMSR-LF1 will use fuel enriched to under 20% U-235, have a thorium inventory of about 50kg and conversion ratio of about 0:1. A fertile blanket of lithium-beryllium fluoride (FliBe) with 99.95% Li-7 will be used. The project is expected to start on a batch basis with some refuelling and removal of gaseous fission products but discharging all fuel salt after 5-8 years for reprocessing and separation of fission products and minor actinides for storage. It will proceed to a continuous process of recycling fuel salts, and the reactor will work up from about 20% thorium fission to about 80%. If the TMSR-LF1 proves to be successful, China plans on building a reactor with a capacity of 373MWt by 2030.
Jemima Booth, UVI
Venom, a virulent secretion consisting of a deadly mixture of carbohydrates, nucleosides, amino acids, lipids, proteins and peptides, is used as a trophic weapon by many species of predator, most notably reptiles, to commit chemical warfare on potential threats, prey, and as a means of self-defence. Venom is produced by specialised glands, and is most commonly secreted through tubular or channelled fangs and glands below the eye (mandibular glands) in certain snake species; stingers in insect species; or other piercing devices such as spines.
Different species deliver poisonous secretions into target animals for separate reasons, including most commonly anti-predator defence, in some cases parasite defence, and peculiarly intraspecific competition. An example of intraspecific competition is the platypus (Ornithorhynchus anatinus), one of the only confirmed venomous mammals. Only the male of the species is venomous, deterring potential competition for mates throughout breeding season by injecting venom during intraspecific fighting between males. Interestingly, crural (venom) systems in platypuses are used solely for intraspecific competition between males during breeding seasons, unlike other species in which venom
delivery systems (VDS) are used year-round during interspecific predation and defence. More commonly associated with the quality of being venomous, of the 3900 species under the class ‘Reptilia’, only 725 are venomous. The trait of venomosity in reptiles is thought to have originated only once within the entire lineage of reptiles, approximately 170 million years ago. As species diverged however, venoms of the different lineages then evolved independently, including the independent evolution of front-fanged VDS, facilitating the rapid injection of a higher volume of venom present in modern snakes from the previous rear-fanged delivery system. This hypothesis of a ‘single origin’ of venom delivery systems also suggests that some systems were completely lost in species in a number of lineages, hence reptiles without venomous traits. From this single ancestor, many species of venomous reptiles diverged, with duplication of gene coding for other tissues diversifying the venom found in different species. The genes were then expressed in the venom glands (which are thought to have originally been salivary glands, repurposed for killing, rather than lubricating), the proteins then evolving into various proteins making up venom through natural selection. However, it is thought that venomosity and the possession of VDSs in snakes and lizards may be analogous –evolved by coincidence to perform the same function with different evolutionary origins,
as opposed to homologous, where the similarity in venom is based upon their descent from a common evolutionary ancestor. The evidence for this lies in differences between VDSs in snakes and lizards being quite apparent, in particular how they utilise their venoms: lizards primarily as a defensive strategy, whereas snakes to immobilise prey. Regardless of the origins, venom clearly has one principal purpose: murder.
To understand why venomous mammals are scarce and venomous birds non-existent, one must first examine the reasons behind why an abundance of reptiles possess venom, which is clearly of great advantage to the species under the ‘Reptilia’ class due to the intergenerational preservation of this trait through natural selection. Although in most cases venom functions in predator-prey interactions (predation as well as defence against predators), they fulfil additional, relatively poorly understood functions; mainly due to the fact that historically, venoms were only studied to either further understand the detrimental effects on humans to prevent mortality, or in the context of medicinal, toxin pharmacology. Venoms have proved to be extremely progressive in the drug discovery and pharmacology industries, being recognised as an emerging source of peptide-based therapeutics, as well as chronic pain treatment in patients intolerant to systemic analgesics or morphine used in regular practices. However, most venoms are proven to have the opposite effect, and are more commonly lethal, rather than alleviating.
Most of the venomous snakes lethal to humans, for example vipers and cobras, bite simply in self-defence. This same behaviour is seen similarly in many lizard species, regardless of family and size. Spitting behaviour is also a common behaviour seen in African and Asian cobras, which is again, purely a defensive strategy. Most carnivorous reptiles have non-specialised diets, and incapacitation using venom is a common predation strategy in venomous snakes. Snake venom has evolved to target the specific diets different snake species consume, with specific genes coding for toxins mutating to overcome the issue of venom resistance in prey. An example of venom use for predation is the Russell’s viper, whose bite focuses more on the vascular system as opposed to the nervous, with its venom bringing about coagulation of the blood and clotting in the pulmonary arteries in order to kill and later consume prey. This is one of a plethora of techniques employed by reptiles to incapacitate prey. To conclude, reptiles seem to possess the chemical tool of venom predominantly as a means of self-defence and an aid for predation, notably in response to threat.
Venomous mammals are deemed a controversial group within venom research, and the scientific community are in disagreement on which species are venomous and vice versa. This is due to several reasons: difficulty in obtaining adequate samples, protected status of certain mammals, and ongoing disputes on whether venomous mammals exist at all. In comparison to reptiles, where venom has evolved homologously from a single common ancestor, mammals which are believed by some to be venomous do not have a common theme when it comes to venom distribution. In other words, venom seems to be distributed within four completely unrelated groups of mammals, without an obvious common ancestor, suggesting that the evolution of venom in this case is analogous. Of the approximate 6,400 species of mammals, it is estimated that there are fewer than 20 confirmed venomous mammals, all of which have different VDSs. Mammalian venoms are present in three classes of mammals: Insectivora, Monotremata, and Chiroptera, and a fourth order, Primates, is proposed to have venomous specimens, with ‘needle-like tooth comb incisors’, and a “brachial” venom gland on the ventral side of the upper arm. Eight species of slow lorises (Nycticebus spp) are currently the only primates that are known to be venomous. The venom delivery system is located in a relatively hair free, slightly raised area on the flexor region of the upper arm, and when threatened, the loris raises its arms over its head to combine its brachial gland venom with saliva, biting the threat, causing, in extreme cases, severe anaphylactic shock. The sharp tooth comb incisors were originally believed to aid in feeding and grooming, but have now been shown to enable venom to travel upwards to the top of the tooth by capillary forces. This enables lorises to deter threats through a mixture of saliva and venom, interestingly a melange
also lethal to arthropods, with this twostage venom being unique in the animal kingdom. Another, more recent discovery of venomous mammals has been the vampire bat. As the name suggests, the venom delivery system is activated through large, sharp incisors, which inflict crater-like wounds to the prey animal, and submaximally (located along side of the lower jawbone) venom glands secrete toxins with the aid of the bat’s tongue, which darts in and out of the wound to deliver venom. The venom of vampire bats possesses strong anticoagulant, delaying blood clotting for several hours by dissolving fibrin clots, allowing the bat to feed on the blood continuously. Their venom system developed to serve the ecological function of facilitating feeding, as animals that specialise in blood feeding have particular challenges obtaining their meals, thus require venom systems to promote continual blood flow.
I’ve explored the reasons behind the evolution and use of venom delivery systems in reptiles, and more infrequently mammals, however the question why so few venomous mammals exist and no known birds produce or inject venom still remains. Mark Dufton of the University of Strathclyde has suggested that the rarity of venom delivery in mammalia is due to the alternate, more elevated tools mammals possess in order to kill prey, including sharp teeth and claws, whereas venom, no matter how effective, requires valuable time to disable prey. Furthermore, birds already possess an energetically inefficient way of movement: flight, and additionally, the majority of birds are primarily herbivorous, and those omnivorous ingest small invertebrates, so do not require a VDS to kill prey. Mammals, in general, have brains up to ten times larger relative to body size than those of reptiles, proposing that reptiles, having smaller brains, may not have the sufficient cognitive ability to calculate a scheming attack on prey, thus require a quick method of disabling prey or potential threats without previous tactical thinking. Mammals, such as big cats, adopt more premeditated approaches to hunting, with strategies including stalking, ambush hunting and chasing and pursuit, demonstrating some form
of premeditation or cognition in their ambushes. Reptiles, on the contrary, do not often demonstrate active hunting strategies. Another argument stands that venom is energetically costly to make. Mammals and birds, unlike reptiles, have adapted the tool of homeostasis, maintaining an optimal bodily temperature in order for metabolic processes requiring enzymes to function, which is energetically costly. Conversely, reptiles are poikilothermic, or ‘coldblooded’, and maintain homeostasis not through their somatic cells’ energy sources, but through behavioural and physiological adjustments, such as basking in the sun during the day, or contrarily seeking shade underground to cool down. This is significantly less energy consuming than thermoregulation in mammals, hence, reptiles conserve energy, leaving the possibility of venom production more feasible in terms of natural selection and evolution.
Ultimately, why there are so few venomous mammals and no birds whereas so many reptiles are venomous amounts to three key factors: evolution, cognition, and energy. Simply the fact that mammals and birds have greater cognitive ability than reptiles allows them to adapt and survive without the need for venom delivery systems, as well as their possession of weapons which are arguably more valuable than chemicals, such as sharp claws and teeth to cause collateral damage to prey. In mammals, energy seems to be a more valuable resource, and therefore must have been conserved in the past by not evolving the ability to produce venom, a proven costly production process. And finally, the fact that mammals and birds have not (yet) evolved venom delivery systems is proof that the need for these systems is not crucial for the survival of species thus far, however, this fact may change, and more mammal and bird species may evolve to adopt venom as a chemical weapon to aid survival and predation in the future.
18. Gene – The section of DNA that codes for a protein.
16. Potential Energy – Calculated as mass x gravitational field strength (g) x height.
18. Gene – The section of DNA that codes for a protein.
17. Sodium – An element with atomic number 11.
14. Sublimation – The process through which a substance changes from solid to gas.
11. Diode – A component that only allows current to flow through in the forward direction.
10. Convection – The process of the rising of warm air.
9. Ethanol – A product of anaerobic respiration in plant cells.
6. Mitosis – The process by which a single parent cell divides to make two new daughter cells.
5. Isotope – An atom of the same element with the same number of protons but a different number of neutrons.
15. Frequency – The number of waves that pass a fixed point per second. ACROSS
13. Transcription – The process of protein synthesis that happens in the nucleus.
12. Diffusion – The process of particles moving from an area of high concentration to low concentration.
8. Phenolphthalein – An indicator used for titration that is colourless under acidic conditions and pink under alkali conditions.
7. Ohm – The unit for resistance.
4. Lilac – Flame colour of potassium.
3. Joule – The unit for energy.
2. Ribosome – The site in a cell for protein synthesis.
1. Oxidation – Loss of electrons.
3. Penguin
WHICH ANIMAL IS NOT A MAMMAL?
Explanation: Fungi thrive in dark, moist environments and play a crucial role in decomposing organic matter. Their network of hyphae helps them absorb nutrients from their surroundings.
2. Fungi
Explanation: stalactites are formed by minerals deposited by dripping water, typically in caves, and they hang from the ceiling. They are known for their slow growth over time, creating unique and beautiful formations.
1. Stalactite
13. Tertiary – What type of alcohol doesn’t undergo oxidation. RIDDLES
12. Cracking – Breaking long-chain alkanes into smaller, more useful hydrocarbons.
11. Chiral – When a molecule is nonsuperimposable on its mirror image.
9. Dehydration – The type of reaction when alcohols react with concentrated phosphoric acid to form alkenes.
6. Stereoisomers – Isomers that have the same molecular formula but differ in the spatial arrangement of atoms.
4. Radical – A species with an unpaired electron.
3. Nucleophile – An electron-pair donor.
2. Homolytic – What type of fission is the free radical substitution.
17. Green – What colour does potassium dichromate become when it is reduced. DOWN
16. Carbon – Dioxide, a gas produced when metal carbonate reacts with acid that turns limewater cloudy.
15. Aromatic – Benzene is an ______ compound.
14. Saturated – Alkanes and cycloalkanes are both ________ hydrocarbons.
‘STEM
CROSSWORD’ DOWN
A ladybug wants to crawl from one edge of a 9cm x 9cm Rubik’s cube to the opposite diagonal edge (see diagram). What will be the shortest path?
MATH QUESTION
10. Polymerization – The process which joins lots of monomers together to form a giant molecule.
8. Alkene – A hydrocarbon that can decolorize bromine water.
7. Electrophile – An electron-pair acceptor.
5. Combustion – The chemical name for burning.
The condition required for a free radical substitution to occur.
1.
