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The secrets of the brain are secrets no longer; the field of neuroscience is rapidly expanding day by day. Read articles which discuss Parkinsonism, Huntington’s, degeneration, Alzheimer’s, and more. Neuroscience Articles The secrets of the brain are secrets no longer; the field of neuroscience is rapidly expanding day by day. Read articles which discuss Parkinsonism, Huntington’s, degeneration, Alzheimer’s, and more. You may also like: Biology , Immunology , Medicine Synaptic plasticity and London taxi drivers Synaptic plasticity and navigating our surroundings Stress and neurodegeneration And how the hormone cortisol plays a significant role Markers for Parkinsonism Exploring the role of TDP43 The wonders of the human brain A basic overview of brain function The brain-climate connection Can rising temperatures really affect our brains? Schizophrenia and accelerated ageing A complex medical phenotype Squid axons And how they were fundamental to discoveries in neuroscience Alzheimer's disease Its pathology and potential treatment Serial killers Their neurological basis Huntington's disease A rare, inherited, debilitating neurological disease Electricity in the body Luigi Galvani 's work PTSD and intrusive memories Article #1 in a series on Post Traumatic Stress Disorder and traumatic memories Mobility disorders Hypermobility spectrum disorders vs. Hypermobile Ehler-Danos Syndrome Brief neuroanatomy of autism Autism is a neurological and developmental disorder Oliver Sacks Who was this famous neuroscientist? A treatment for Huntington's disease Antisense oligonucleotide gene therapy PTSD and Tetris Article #2 in a series on Post Traumatic Stress Disorder and traumatic memories The dopamine connection The link between the brain and the digestive system Neuromyelitis optica (NMO)- Devic disease How is it different to Multiple Sclerosis? Article #8 in a series on Rare diseases. DFNB9 How was this form of deafness treated for the first time? Next

An individual may be restricted to a certain range of physical activities which they can participate in. Individuals are usually reliant on the surrounding environment and the maintenance of facilities. If they are not kept well maintained, individuals are usually discouraged. Go back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Influence of different environmental factors on exercise Last updated: 30/01/25 Published: 10/02/23 The characteristics of environmental factors: - Chemical safety - Air pollution - Climate change and natural disasters - Diseases caused by microbes - Lack of access to health care - Infrastructure issues - Poor water quality - Global environmental issues What are the impacts of these environmental influences on physical activity? An individual may be restricted to a certain range of physical activities which they can participate in. Individuals are usually reliant on the surrounding environment and the maintenance of facilities. If they are not kept well maintained, individuals are usually discouraged. The physiological effect on training: Climate change will disproportionately affect the most vulnerable in our populations, including the very young, the very old, and those with pre-existing health conditions. Training adjustments to compensate for the influence of environmental factors on training: - Treatments for heat stress- stop exercising / move to a shaded or air-conditioned area / remove excess clothing or equipment / drink cold beverages / sit in front of a fan / put a cool piece of cloth around neck / place entire body in cool water e.g. cool bath or shower - Treatments for cold stress- move to a warm environment / remove cold and wet clothes / find access to warm air such as heaters, or fireplace / use electric or non-electric blankets / drink warm beverages Written by Kushwant Nathoo Related articles: Impacts of negligent exercise on physiology / Physical and mental health / Environmental impact of EVs

Looking at modern society in terms of the food being consumed and the amount of exercise undertaken collectively, it is entirely inevitable that diabetes will become an epidemic. Now before delving into the above statement further, diabetes mellitus (from Greek ‘siphon’ and Latin ‘sweet’) is a non-communicable disease that occurs when blood sugar levels in the body are so high, that the pancreas is unable to produce adequate insulin in order to manage this problem. Go back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Will diabetes mellitus become an epidemic? Last updated: 07/11/24 Published: 18/05/23 Defining diabetes and its causes Looking at modern society in terms of the food being consumed and the amount of exercise undertaken collectively, it is entirely inevitable that diabetes will become an epidemic. Now before delving into the above statement further, diabetes mellitus (from Greek ‘siphon’ and Latin ‘sweet’) is a non-communicable disease that occurs when blood sugar levels in the body are so high, that the pancreas is unable to produce adequate insulin in order to manage this problem. Also, diabetes can be categorised into various types, but the most common are types 1 and 2 as well as gestational (which happens during pregnancy). There is also diabetes insipidus (from Latin ‘lacking taste’), and this is where the kidneys are unable to conserve water. The causes of diabetes mellitus can be divided based on the type. Since type 1 can be caused by the body’s immune system attacking the pancreas, this means that the beta cells are unable to make enough insulin because they are damaged. Not only can type 1 diabetes arise this way, it is possible that environmental factors such as diet and viral infections lead to the disease. As for type 2, it primarily comes from insulin resistance, meaning that the body does not respond to the hormone effectively compared to a person without diabetes. This in turn impacts insulin mediated glycogen synthesis and glycolysis leading to hyperglycemia as seen in figure 1. There are many reasons why diabetes is likely to become an epidemic. Firstly, there is a clear connection between obesity and type 2 diabetes which cannot be ignored; this is because an article found that people with both conditions are exacerbated perhaps due to increased non esterified fatty acids (NEFAs) and glycerol among other linked biochemicals. On the other hand, this same article stated that people with type 1 diabetes are not usually obese. Nevertheless, it is vital that in order to prevent the incidence of type 2 diabetes in later life, it is important to implement strategies such as regular exercise and lowering carbohydrate intake in the diet. Alluding to the previous paragraph, one of the major factors to the increase in obesity and type 2 diabetes diagnoses is the sedentary lifestyle or decreased mobility through sitting. A meta-analysis evaluated 10 studies with over 500,000 volunteers and concluded that there was a 112% cumulative increase in type 2 diabetes risk linked to watching TV. Additionally, a study showed that more sedentary time had raised body and trunk fat percentage while there was reduced appendicular skeletal muscle mass. Taking into account these findings among others, it is evident that exercise does play a role in reducing the risk of type 2 diabetes. Counteracting the previous paragraphs, it is equally plausible that diabetes will not be epidemic because there are current pharmaceutical drugs taken orally like sulfonylureas and meglitinides that cause the pancreas to release insulin aside from injection based ones such as amylin mimetics, which maintains blood glucose concentration, which are used for type 2 diabetes. As for those afflicted with type 1 diabetes, they mainly take insulin because they are in deficit of the hormone or they can have a pancreatic transplant, which has more than 96% and 83% survival rates after 1 and 5 years of the operations respectively, although it does have a major complication of rejection like any other type of operation. With regards to future treatments, a review discussed how newer drugs for decreasing blood glucose such as dipeptidyl peptidase-4 (DPP-4) inhibitors have been re-evaluated for cardiovascular outcome trials by showing patients experiencing a decrease in other non-communicable diseases like myocardial infarction and albuminuria, indicating that they can be useful for heart and kidney diseases associated with type 2 diabetes. Furthermore, there are other potential therapies such as probiotics and prebiotics that can be used along with faecal transplants to change the gut microbiome for type 2 diabetes patients. It is uncertain that diabetes will/won’t become an epidemic From a more neutral perspective, there is not enough certainty that diabetes will or will not become an epidemic simply because accurately predicting the future 100% of the time is impossible. As such, the future interventions for treating diabetes may not actually get to exist, perhaps due to prospective factors like politics and societal values with respect to science as well as taking into account the difficulty for a therapeutic method to be put onto the market for the patients to consider. Another point to address is the fact that the human body is so incredibly complex that it took humans thousands of years to truly discover all of the current facts known in relation to its anatomy and physiology along with having some level of understanding of them. Not only that, there are still observations about the human body that are still unclear to scientists today and so the drugs for treating diabetes may or may not be effective depending on who is receiving the therapy because each person is genetically unique. Conclusion Referring to all of the arguments made, it is evident that diabetes is a huge burden for modern and future societies because of its links to obesity or sedentary lifestyle and consuming foods high in carbohydrates. Yet, this issue may be prevented by exploring future therapies, exploiting current ones and implementing non-clinical interventions such as increased regular exercise and reducing carbohydrate intake. Therefore, it is the responsibility of each patient and health organisation to manage diabetes before it becomes even worse. Written by Sam Jarada Related articles: Pre-diabetes / Diabetes drug to treat Parkinson's / The world vs the next pandemic REFERENCES Diabetes UK. Types of diabetes. Diabetes UK. 2022. Paschou SA, Papadopoulou-Marketou N, Chrousos GP, Kanaka-Gantenbein C. On type 1 diabetes mellitus pathogenesis. Endocrine Connections. 2018 Jan;7(1):R38–46. Cersosimo E, Triplitt C, Solis-Herrera C, Mandarino LJ, DeFronzo RA. Pathogenesis of Type 2 Diabetes Mellitus. Nih.gov. MDText.com, Inc.; 2018. Algoblan A, Alalfi M, Khan M. Mechanism linking diabetes mellitus and obesity. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy. 2014 Dec;7(587–591):587. Barnes AS. The epidemic of obesity and diabetes: trends and treatments. Texas Heart Institute journal. 2011;38(2):142–4. Hamilton MT, Hamilton DG, Zderic TW. Sedentary Behavior as a Mediator of Type 2 Diabetes. Medicine and Sport Science. 2014;60:11–26. Li D, Yang Y, Gao Z, Zhao L, Yang X, Xu F, et al. Sedentary lifestyle and body composition in type 2 diabetes. Diabetology & Metabolic Syndrome. 2022 Jan 15;14(1). Mayo Clinic. Diabetes treatment: Medications for type 2 diabetes. Mayo Clinic. 2018. Bahar SG, Devulapally P. Pancreas Transplantation. PubMed. Treasure Island (FL): StatPearls Publishing; 2022. Bailey CJ, Day C. The future of new drugs for diabetes management. Diabetes Research and Clinical Practice. 2019 Sep;155:107785. Bailey CJ, Day C. Treatment of type 2 diabetes: future approaches. British Medical Bulletin. 2018 Jun 1;126(1):123–37.

Conservation, diseases, animal behaviour, adaptation and survival. Expand your knowledge on the incredible diversity of life on Earth with these articles. Zoology Articles Conservation, diseases, animal behaviour, adaptation and survival. Expand your knowledge on the incredible diversity of life on Earth with these articles. You may also like: Biology , and Ecology Deception by African birds The species Dicrurus adsimilis uses deception by flexible alarm mimicry to target and carry out food-theft attempts An experiment on ochre stars Investigating the relative fitness of the species Pisaster ocharceus Orcinus orca A species report Rare zoonotic diseases We all know about COVID-19. But what about the other zoonotic diseases? Article #1 in a series on Rare diseases. Marine iguanas Their conservation The cost of coats 55 years of vicuna conservation in South America. Article #1 in a series on animal conservation around the world. Conserving the California condor These birds live on the west coast of North America. Article #2 in a series on animal conservation around the world. Emperor penguins Kings of ice. Article #6 in a series on animal conservation around the world.

Resources specific to A-levels to help students with revision. A-levels Are you a student currently studying A-levels, or looking to choose them in the near future? Read below for tips and guidance! You may also like: IB resources , University prep and Extra resources What are A-levels? Jump to resources A-levels, short for Advanced Level qualifications, are a widely recognised and highly regarded educational program typically taken by students in the United Kingdom (UK) and some other countries. They are usually studied in the final two years of secondary education, typically between the ages of 16 and 18. A-levels offer students the opportunity to specialise in specific subjects of their choice. Students typically choose three or four subjects to study, although this may vary depending on the educational institution. The subjects available can be diverse, covering areas such as sciences, humanities, social sciences, languages, and arts. How are A-levels graded? The A-level grading system is based on a letter grade scale in the UK. Here's an overview of the A-level grading system: Grades: A* (pronounced "A-star"): The highest grade achievable, demonstrating exceptional performance. A: Excellent performance, indicating a strong understanding of the subject. B: Very good performance, showing a solid grasp of the subject. C: Good performance, representing a satisfactory level of understanding. D: Fair performance, indicating a basic understanding of the subject. E: Marginal performance, showing a limited understanding of the subject. U: Ungraded, indicating that the student did not meet the minimum requirements to receive a grade. What are the benefits of studying A-level? A-levels provide students with a variety of advantages, such as a solid academic foundation for further education, the chance to focus on interest-specific areas, and flexibility in planning their course of study. Transferable abilities like critical thinking, problem-solving, and independent research are developed in A-levels, improving both prospects for entrance to universities and future employment opportunities. These widely respected credentials encourage intellectual vigour, intellectual curiosity, and a love of lifelong study. A-levels provide students with a strong foundation for success in higher education and a variety of career pathways, thanks to their academic rigour and global renown. Resources for revision Web sites to hel p Maths / Maths and Further Maths Chemistry / Chemrevise / Chemguide Biology / Quizzes Physics: A-level Physics / Isaac Physics Computer Science topic-by-topic Teach Computer Science Psychology All subjects / Seneca Learning / Save My Exams Physics and Maths Tutor YouTube channels to hel p Chemistry- Allery Chemistry and Eliot Rintoul Past p apers Biology, Chemistry, Physics, Maths Textbooks (depend on exam board) CGP range for Bio, Chem, Phys, and Maths- exam practice workbooks

Resources such as: other websites, textbooks, YouTube videos, and books to help! Aiding university students studying STEM subjects. Extra Resources A masterlist of other websites, textbooks, YouTube videos, and books to help with your studies, research and revision. You may also like: A-level resources, IB resources, Entrance exam preparation, FREE CV check!, STEM book reviews Representation in STEM Sisterhood in STEM GENERAL INFORMATION Referencing guide: Cite Them Right Cite this for me ZoteroBib (fast, free reference generator) Phrasebank to help with essays Free notes and textbooks: Studocu Grammar checker: Grammarly (available as a browser extension) Money financing for students: Save the Student Others: New Scientist (print and online magazine) BBC iPlayer science and nature documentaries WEBSITES TO AID STUDIES Science and maths: MME Revise Cognito Resources Access Tuition Maths Genie LibreTexts: biology , chemistry , physics , maths , engineering , and medicine HELP WITH RESEARCH Databases: - PubMed - MEDLINE (by National Library of Medicine) - ScienceDirect - Web of Science - Literature search: Google Scholar - Participate in actual research: Zooniverse - citizen science - Top multi-disciplinary journal in the field: Nature Pharmacology sites: - Pharmgkb - Drug Bank - Check which drugs are in trial TEXTBOOKS FOR PHARMACOLOGY AND RELATED - Katzung's Basic & Clinical Pharmacology, 16th edition by Todd Vanderah, PhD - The Top 100 Drugs: Clinical Pharmacology and Practical Prescribing by Andrew Hitchings, Daniel Burrage, Dagan Lonsdale and Emma Baker BIOLOGICAL SCIENCES TEXTBOOKS Biology: - Campbell & Reece - Molecular biology and genetics: Molecular Biology of the Cell. 4th edition - Molecular Cell Biology by Lodish et al - Anatomy and physiology: Marieb - Principles of Animal Physiology by Moyes and Schulte - Animal Physiology by Hill, Wyse, and Anderson - Developmental Biology by Barresi and Gilbert - Cancer: The Biology of Cancer by Robert A. Weinberg Biochemistry: - Medical Biochemistry b y N. Mallikarjuna Rao Neuroscience: - Purves et. al - Kandel Immunology: - Immunobiology, 5th edition The Immune System in Health and Disease Genetics: - Emery's Elements of Medical Genetics and Genomics by Turnpenny & Ellard - Lewin’s Genes by Krebs, Goldstein, and Kilpatrick - Human Molecular Genetics by Strachan and Read CHEMISTRY TEXTBOOKS Physical chemistry: - Atkins Physical Chemistry (latest edition) - Solid State Chemistry (Fourth Edition) by Lesley Smart and Elaine Moore Organic chemistry: - Jonathan Clayden Organic Chemistry (latest edition) Inorganic chemistry: - Atkins Physical Chemistry (latest edition) - Housecroft Inorganic Chemistry (latest edition) - Electronic Structure (Basic Theory and Practical Methods) by Richard M. Martin - Two-minute Neuroscience - Amoeba Sisters (biology related) - Khan Academy (all STEM based) - TEDx Talk - Royal Society (range of science videos) - NumberPhile - patrickJMT (maths) - Tyler DeWitt (general chemistry) - Crash Course - Stanford Medicine (wellness) PHYSICS Resources: - Astronomy Picture of the Day - NASA STEM activities Textbooks: - University Physics by Young and Freedman - Introduction to Electrodynamics by Griffiths - Introduction to Elementary Particles by Griffiths - Introduction to Quantum Mechanics by Griffiths - Modern Quantum Mechanics (Third Edition) by J. J. Sakurai and Jim Napolitano - Introductory Statistical Mechanics by Bowley & Sanchez - Statistical Mechanics: A Survival Guide by Glazer & Wark - Electricity and Magnetism by Morin and Purcell - Concepts in Thermal Physics by Blundell and Blundell - Introduction to Solid State Physics by Mittel & McEuen - Solid State Physics by Ashcroft and Mermin - Space, Time, and Geometry by Sean M. - Density Functional Theory by David S. Sholl and Janice A. Steckel - The Physics of Semiconductors: An Introduction Including Nanophysics and Applications by Marius Grundmann MATHS Textbooks: - Mathematical Methods for Physicists and Engineers by Riley Benson and Hobson - Mathematics for Natural Scientists 1 and 2 by Lev Kantorovich - Advanced Engineering Mathematics by Kreyszig - Thomas's Calculus by George B. Thomas - Mathematical Methods for Science students by G Stephenson - Contemporary Abstract Algebra by Joseph A. Gallian Read this article on how to excel in maths COMPUTER SCIENCE AND RELATED Resources: - Codeacademy - W3Schools ( has tutorials for HTML/ CSS/ Javascript, Python, Java, and many other languages) - Adacomputerscience - TeachComputing - Codewars (practise coding with your friends) - freeCodeCamp ENGINEERING Resources: - eFunda- formulae - Engineering statistics handbook - The Engineering Toolbox - free tools, calculators, and more - Engineers Edge - Online Ethics - ethics in engineering and science PSYCHOLOGY Resources: - QMUL resource guides - Psychology Today - Royal Holloway activities and research - Verywell Mind INFORMATIVE YOUTUBE CHANNELS

On the 25th of May, 2020, the world was shocked by the brutal murder of George Floyd, a black American man, by four white police officers. This led to mass outrage among every creed and race and propelled the Black Lives Matter movement to new heights, even in places like Palestine Go Back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Micro-chimerism: a mother’s intuition and why do men call for their mothers near death? In collaboration with Dr. Aakila Sammy of Publett Last updated: 14/11/24 Published: 08/05/23 On the 25th of May, 2020, the world was shocked by the brutal murder of George Floyd, a black American man, by four white police officers. This led to mass outrage among every creed and race and propelled the Black Lives Matter movement to new heights, even in places like Palestine, a country already drowning in peril. While his last words were “I can’t breathe”, the transcripts revealed that he repeated several times, "Momma, I love you. Tell my kids I love them. I'm dead." As painful as it is to hear these words, especially for his mom, it's not surprising; calling out for your mom when death approaches. Many hospice nurses and soldiers recall that dying men call out for their “Mommy” or “Mama” in their last breath. Some have attributed it to its caregiver familiarity, primal instinct like calling out for your mom as a child or a Mary-Jesus connection. George Floyd (1973-2020). Image/ Publett We know that “the mother” is largely responsible for every life on earth, and most of them have the ability to make everything better, but what if that connection is more than something psychological or spiritual? I know, a physical connection to your mom outside the nine months of her carrying you? Like at this moment? Yes! Scientists call it micro-chimerism, and it may be able to explain why for most, the next greatest pain to losing a child is losing your mom. Micro-chimerism originates from the Greek mythical creature “Chimera”, a monster made up of three animals; a lion, a snake and a goat. In medicine, micro-chimerism was initially described as “alien cells”, and it is simply the circulation of cells from one individual in another genetically distinct individual. A Greek 'Chimera'. Image/ Publett And the culprit? There are several actually; natural cases like pregnancy and breast-feeding and artificial instances like organ or blood transplant. And it goes both ways! It could be responsible for that gut feeling you get when something is wrong with your child, also known as “a mother’s intuition”. And it doesn’t stop there; it has been observed in multiplet pregnancies like twins, which may be why twins have their own intuitive connection. So, in addition to nutrients and waste being exchanged, cells are also trafficked bi-directionally. The embryo/fetus receives cells from the mother and the mother from the fetus, and everyone coexists peacefully, sometimes spanning decades. And the burning question that might be in your mind right now is whether a biological female can have male DNA circulating in her body after carrying a male baby. Yes! Cells are also trafficked bidirectionally. Image/ Publett But what are the limits to this phenomenon? This answer is not clear-cut and varies among individuals and situations. Scientists have found maternal-fetal micro-chimerism is present as early as the embryo stage, and the further along, the more abundant it is. This allows non-invasive tests for genetic abnormalities or gender determination on the fetus using blood drawn from the mother. Another situation where it varies is trauma. We might all be familiar with the fetus releasing stem cells into the mother's circulation, which comes with healing benefits to maintain the well-being of the fetal host – and these cells can be detected up to 27 years after delivery. Even though they sound insignificant, fetal cells aren’t afraid of a challenge. Researchers have found them taking on the role of cancer immune surveillance, clustering around lung tumours in women decades after pregnancy and reducing risk of ovarian cancer in women who have later pregnancies. Now, in the case of abortions and miscarriages, the phenomenon might come as a source of comfort, heartache or both. It is unclear how early fetal cells enter the mother’s circulation; it can be when the placenta attaches around week eight or earlier. Commercial fetal blood tests start at weeks 7-8, but this is when they are abundant enough for testing, so it might very well be earlier. So, what does it mean if you have a miscarriage or abortion before week 8? No fetal cell acquisitions? On the contrary, the trauma of the process, especially in the first trimester, causes a massive acquisition of fetal cells by the mother. It is higher in the case of abortion and even higher in surgical abortions versus chemical abortions. Although the fetus is described as having parasitic nature, this last farewell release of healing benefits to its host is nothing short of pure. While controversy still exists around the role of maternal and fetal microchimeric cells, we still crave answers to questions like: How is the phenomenon affected when the fetus carries genetic abnormalities? Do fetal cells from a previous pregnancy enter the circulation of the fetus sibling in a subsequent pregnancy? It might also result in psychologists reframing questions they ask their male patients; are they worried about becoming your father, or should they be more concerned about becoming their mothers? Plus, we need more on the association between parous women and autoimmune diseases, especially in fetal Y-chromosome carriers. Micro-chimerism is a promising and exciting area of research with much to reveal for many fields. While no concrete evidence exists, we know that these cells are resilient to stress and trauma and offer a new perspective to inter-individual bonds and intuitions. Many scientists believe that individuals are calling out to these cells in times of survival, and maybe that’s why kids call out to their moms first or men their mothers near death. -- Scientia News wholeheartedly thanks Aakila Sammy , co-founder and CEO of Publett , for this fascinating piece of work on a lesser-known genetics topic of micro-chimerism. We hope you enjoyed reading this! Follow them @Dr.Publett on Instagram and/or @Publett Limited on Linkedin for more information. -- Related article: The Y Chromosome Unveiled

Lung cancer can be defined as the uncontrollable growth of abnormal epithelial cells that make up the lung. Smoking is known to be a main risk factor of lung cancer being responsible for at least 70% of lung cancer cases. Go back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Smoking cessation interventions Last updated: 18/11/24 Published: 10/03/23 Lung cancer can be defined as the uncontrollable growth of abnormal epithelial cells that make up the lung. Smoking is known to be a main risk factor of lung cancer being responsible for at least 70% of lung cancer cases. Burning cigarettes release multiple mutagens and carcinogens which are absorbed and metabolised by the body to cause cancer. The incidence of lung cancer is increasingly becoming worrying due to its high preventability rate of 79% according to the National Cancer Research Institute. This highlights the importance of reducing the incidence of lung cancer and consequently the deaths caused by it and the burden on the NHS and economy. There recently has been a surge in the use of E-cigarettes in comparison to cessation clinics as a cessation tool to prevent lung cancer. Clearly, there is a need to determine the effectiveness of E-cigarettes being used as a smoking cessation tool. Over the years researchers have investigated different cessation techniques such as specialist clinics, therapy, and patches. The purpose of this research was to evaluate the effectiveness of e-cigarettes as a smoking cessation tool to prevent cancer in primary care. The research suggests that E-cigarettes are more commonly and successfully being used as an effective smoking cessation tool in primary care. The research also suggests that the implementation of smoking cessation clinics has helped to reduce the prevalence of smoking. Both E-cigarettes and smoking cessation clinics are useful in reducing the prevalence of smoking and therefore the incidence of lung cancer. However, it is important to acknowledge some of the carcinogens that E-cigarettes possess such as nicotine which can adversely promote cancer growth. This begs the question of the efficacy of E-cigarettes in reducing lung cancer incidence. Predominantly not smoking at all remains the safest option to reduce the chances of lung cancer. Nonetheless, the reduction in funding for Smoking Cessation clinics in primary care should be reviewed given that it was an effective enough strategy in reducing lung cancer incidence. More research (particularly longitudinal studies) is also required into the efficacy of E-cigarettes in reducing lung cancer incidence and the potential long-term effects they could have. Written by Latilda Ajani Related article: Genetics of excessive smoking and drinking

Your brain is truly an extraordinary structure, and it’s the reason you can do all the amazing things you do. This mass of wrinkly material weighs only about 1.3 kilograms, yet it controls every single thing you will ever do. It’s the engine that drives our behaviour and allows us to interact with the world.  Go Back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Discovering the Wonders of the Human Brain Last updated: 18/11/24 Published: 13/04/23 Your brain is truly an extraordinary structure, and it’s the reason you can do all the amazing things you do. This mass of wrinkly material weighs only about 1.3 kilograms, yet it controls every single thing you will ever do. It’s the engine that drives our behaviour and allows us to interact with the world. Despite its relatively small size — the brain makes up only 2% of our body mass — it’s an incredibly energy-intensive organ. In fact, it consumes more than 20% of our oxygen supply and blood flow and uses more energy than any other tissue in the body. This is because it has a dense network of neurons, specialized cells that transmit signals throughout the nervous system. There are around 100 billion neurons in the human brain, each connected to thousands of other neurons, passing signals to each other via trillions of synapses. The human brain has more connections than there are stars in the Milky Way galaxy and it can process information at a speed of up to 120 meters per second! Even when you are asleep your brain never really “shuts off”! While you’re snoozing away, your brain is busy consolidating memories, processing emotions, flushing out harmful toxins and keeping your mind sharp and healthy. One more key feature that sets our brain apart is the cortex, the outer layer of the brain responsible for many of the higher cognitive functions that are unique to humans, such as abstract reasoning and language. While all mammals have a cerebral cortex, the human cortex is disproportionately large, accounting for 80% of our total brain mass, and it’s much more complex than any other animal. Now, have you ever wondered how the human brain compares to the brains of other animals? Some animals have much larger brains than we do. For instance, the brain of a sperm whale weighs around 8 kilograms, making it the largest brain of any animal on Earth. To put it into perspective, that’s about five times the size of a human brain! Similarly, the brains of elephants are also much larger than ours, weighing in at around 5 kilograms. Comparative neuronal morphology of the cerebellar cortex in afrotherians, carnivores, cetartiodactyls, and primates. We might not have the largest brain compared to other species however, the human brain is larger than most animal brains relative to body size. Why did humans evolve such large brains in the first place? The question has puzzled scientists for years, but there are a few theories that have gained traction. The “social brain” hypothesis suggests that our large brains evolved as a result of our ancestors’ increasingly complex social structures. As early humans began to live in larger groups, they needed to be able to navigate the complex social dynamics of their communities, for example cooperating for resources and maintaining social relationships. Another theory known as “ecological intelligence”, suggests that the pressure for larger brains was driven by environmental conditions. Our ancestors had to adapt to the challenges posed by the environment, such as finding food and shelter. Finally, the “cultural intelligence” hypothesis emphasizes the challenge of learning from different cultures and teaching their own. While each of these theories has some evidence to support it, there is still much debate among scientists about which theory (if any) is the most accurate. It is likely that all three theories played a role in the evolution of the human brain, to varying degrees. The human brain is a fascinating organ that has captivated scientists are researchers for centuries. Despite all our advances in neuroscience, however, there is still so much that we don’t know about how the brain works and what it is truly capable of. Written by Viviana Greco Related article: The brain-climate connection REFERENCES González-Forero, M., & Gardner, A., 2018. Inference of ecological and social drivers of human brain-size evolution. Nature, 557(7706), Article 7706. https://doi.org/10.1038/s41586-018-0127-x Jacobs, B., Johnson, N. L., Wahl, D., et. al, 2014. Comparative neuronal morphology of the cerebellar cortex in afrotherians, carnivores, cetartiodactyls, and primates. Frontiers in Neuroanatomy, 8. https://doi.org/10.3389/fnana.2014.00024

An introductory and comprehensive review of complex diseases and their environmental influences. Using schizophrenia as an example, we are interested in exploring one of the biggest questions that underlie complex diseases. Go Back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link The environment on complex diseases: schizophrenia Last updated: 18/11/24 Published: 08/05/23 An introductory and comprehensive review of complex diseases and their environmental influences. Using schizophrenia as an example, we are interested in exploring one of the biggest questions that underlie complex diseases. Introduction: Not Exactly a Yes or No Question Many things in science revolve around questions. It is remarkable to find the number of questions left for scientists to answer or those that will remain unanswered. Indeed, one of the most daunting tasks for any scientist would be to see through every detail of a piece of information, even if everyone has seen it, but with different sets of lenses and asking different sets of questions. After all, “why did the apple fall from its tree?”. However, asking questions is one thing. Finding answers and, more importantly, the evidence or proof that supports them does not always yield conclusive results. Nevertheless, perhaps some findings may shine a new light on a previously unanswered question. We can categorise the study of genetics into two questions: “What happens if everything goes well?” and “What happens if it goes wrong?”. Whilst there are virtually limitless potential causes of any genetic disease, most genetic diseases are known to be heritable. A mutation in one gene that causes a disease can be inherited from the parents to their offspring. Often, genetic diseases are associated with a fault in one gene, known as a single-gene disorder, with notorious names including Huntington’s disease, cystic fibrosis, sickle cell anaemia, and familial hypercholesterolaemia. These diseases have different mechanisms, and the causes are also diverse. But all these diseases have one thing in common: they are all caused by a mutation or fault in one gene, and inheriting any specific genes may lead to disease development. In other words, “either you have it, or you do not”. The role of DNA and mutations in complex diseases. Image/ craiyon.com Multifactorial or complex diseases are a classification geneticists give to diseases caused by factors, faults or mutations in more than one gene. In other words, a polygenic disease. As a result, the research, diagnosis, and identification of complex diseases may not always produce a clear “black-and-white” conclusion. Furthermore, complex diseases make up most non-infectious diseases known. The diseases associated with leading causes of mortality are, in their respective ways, complex. Household names include heart diseases, Alzheimer’s and dementia, cancer, diabetes, and stroke. All of these diseases may employ many mechanisms of action, involving multiple risk factors instead of direct cause and effect, using environmental and genetic interactions or factors to their advantage, and in contrast to single-gene disorders, do not always follow clear or specific patterns of inheritance and always involve more than one problematic genes before the complete symptoms manifest. For these reasons, complex diseases are infamously more common and even more challenging to study and treat than many other non-infectious diseases. No longer the easy “yes or no” question. The Complex Disease Conundrum: Schizophrenia Here we look at the case of a particularly infamous and, arguably, notorious complex disease, schizophrenia (SCZ). SCZ is a severely debilitating and chronic neurodevelopmental disorder that affects around 1% of the world’s population. Like many other complex diseases, SCZ is highly polygenic. The NHS characterise SCZ as a “disease that tends to run in families, but no single gene is known to be directly responsible…having these genes does not necessarily mean one will develop SCZ”. As previously mentioned, many intricate factors are at play behind complex diseases. In contrast, there is neither a single known cause for SCZ nor a cure. Additionally, despite its discovery a century ago, SCZ is arguably not well understood, giving a clue to the sophisticated mechanisms that underlie SCZ. To further illustrate how such complexities may pose a challenge to future medical treatments, we shall consider a conundrum that diseases like SCZ may impose. The highly elaborate nature of complex diseases means that it is impossible to predict disease outcomes or inheritance with absolute certainty nor rule out potential specific causes of diseases. One of the most crucial aspects of research on complex diseases is their genetic architecture, just as a house is arguably only as good as its blueprint. Therefore, a fundamental understanding of the genes behind diseases can lead to a better knowledge of diseases’ pathogenesis, epidemiology, and potential drug target, and hopefully, one day bridge our current healthcare with predictive and personalised medicine. However, as mentioned by the NHS, one of the intricacies behind SCZ is that possessing variants of diseased genes does not translate to certainty in disease development or symptom manifestation. Our conundrum, and perhaps the biggest question on complex diseases like SCZ is: “Why, even when an individual possesses characteristic genes of a complex disease, they may not necessarily exhibit symptoms or have the disease?”. The enigma surrounding complex diseases lies in the elegant interactions between our genes, the blueprint of life, and “everything else”. Understanding the interplay of factors behind complex diseases may finally explain many of the intricacies behind diseases like SCZ. Genes and Environment: an Obvious Interaction? The gene-environment important implications on complex disease development were demonstrated using twin studies. A twin study, as its name suggests, is the study of twins by their similarities, differences, and many other traits that twins may exhibit to provide clues to the influences of genetic and external factors. Monozygotic (MZ) twins each share the same genome and, therefore, are genetically identical. Therefore, if one twin shows a phenotype, the other twin would theoretically also have said genes and should exhibit the corresponding trait. Experimentally, we calculate the concordance rate, which means the probability of both twins expressing a phenotype or characteristic, given that one twin has said characteristic. Furthermore, the heritability score may be mathematically approximated using MZ concordance and the concordance between dizygotic twins (twins that share around half a genome). These studies are and have been particularly useful in demonstrating the exact implications genetic factors have on phenotypes and how the expression of traits may have been influenced by confounding factors. In the case of SCZ, scientists have seen, over decades, a relatively low concordance rate but high heritability score. A recent study (published in 2018) through the Danish SCZ research cohort involved the analysis of around 31,500 twins born between the years 1951 and 2000, where researchers reported a concordance rate of 33% and estimated heritability score of 79%, with other older studies reporting a concordance rate up to and around 50%. The percentages suggest that SCZ is likely to be passed down. In other words, a genetically identical twin only has approximately 1 in 2 risks of also developing symptoms of SCZ if its opposite twin also displays SCZ. The scientists concluded that although genetic predisposition significantly affects one’s susceptibility or vulnerability against SCZ, it is not the single cause of SCZ. Demographically, there have been studies that directly link environmental risks to SCZ. Some risk factors, such as famines and malnutrition, are more evident than others. However, some studies also associate higher SCZ risk among highly industrialised countries and first or second-generation migrants. For instance, few studies point out an increased risk of SCZ within ethnic minorities and Afro-Caribbean immigrants in the United Kingdom. Hypotheses that may explain such data include stress during migration, potential maternal malnutrition, and even exposure to diseases. With this example, hopefully, we all may appreciate how the aetiology of SCZ and other complex diseases are confounded by environmental factors. In addition, how such factors may profoundly influence an individual’s genome. SCZ is a clear example of how genetic predisposition, the presence of essential gene variants characteristic of a disease, may act as a blueprint to a terrible disease waiting to be “built” by certain factors as if they promote such development. It is remarkable how genetic elements and their interactions with many other factors may contribute almost collectively to disease pathogenesis. We can reflect this to a famous quote amongst clinical geneticists: “genetics loads the gun, and environment pulls the trigger.” Carrying high-risk genes may increase the susceptibility to a complex disease, and an environment that promotes such disease may tip the balance in favour of the disease. However, finding and understanding the “blueprints” of SCZ, what executes this “blueprint”, and how it works is still an area of ongoing research. Furthermore, how the interplay between genetics and external factors can lead to profound effects like disease outcomes is still a relatively new subject. The Epigenome: the Environment’s Playground To review, it is clear that genes are crucial in complex disease aetiology. In the case of SCZ, high-risk genes and variances are highly attributed to disease onset and pathogenesis. However, we also see with twin studies that genetics alone cannot explain the high degree of differences between twins, particularly when referring to SCZ concordance between identical twins. In other words, external factors are at play, influencing one’s susceptibility and predisposition to SCZ. These differences can be explained by the effects epigenetics have on our genome. Epigenetic mechanisms regulate gene expression by modifying the genome. In short, on top of the DNA double strands, the genome consists of additional proteins, factors, and even chemical compounds that all aid the genetic functions our body heavily relies on. The key to epigenetics lies in these external factors’ ability to regulate gene expression, where some factors may promote gene expression whilst others may prevent it. Epigenetic changes alter gene functions as they can turn gene expression “on” and “off”. Furthermore, many researchers have also shown how epigenetic changes may accumulate and be inherited somatically with cell division and even passed down through generations. Therefore, epigenetic changes may occur without the need to change any of the DNA codes, yet, they may cause a profound effect by controlling gene expression throughout many levels of the living system. These underlying mechanisms are crucial for the environment’s effect on complex diseases. Some external factors may directly cause variances or even damage to the genome (e.g. UV, ionising radiation), and other sources may indirectly change gene expression by manipulating epigenetic changes. The exact molecular genetics behind epigenetic mechanisms are elaborate. However, we can generally find three common epigenetic mechanisms: DNA Methylation, Histone Modification, and Non-coding RNA. Although each method works differently, they achieve a common goal of promoting or silencing gene expression. All of these are done by the many molecular components of epigenetics, altering the genome without editing the gene sequence. We refer to the epigenome, which translates to “above the genome”, the genome itself and all the epigenetic modifiers that regulates gene expression on many levels. Environmental factors and exposure may influence epigenetic mechanisms, affecting gene expression in the cell or throughout the body, sometimes permanently. Therefore, it is clear how the epigenome may change throughout life as different individuals are exposed to numerous environmental factors. Furthermore, each individual may also have a unique epigenome. Depending on which tissues or cells are affected by these mechanisms, tissues or cells may even have a distinct epigenome, unlike the genome, which is theoretically identical in all cells. One example of this is the potential effects of DNA methylation on schizophrenia epidemiology. DNA methylation can silence genes via the enzymes DNA methyltransferases (DNMT), a family of enzymes capable of catalysing the addition of methyl groups directly into the DNA. The DNMT enzymes may methylate specific nucleotides on the gene, which usually would silence said gene. Many researchers have found that the dysregulation of DNA methylation may increase the risk towards the aetiology of numerous early onset neuro-developmental disorders. However, SCZ later-onset development also points towards the influence of environmental risk factors that target DNA methylation mechanisms. Studies show links between famines and SCZ increased prevalence, as the DNMT enzymes heavily rely on nutrients to supply essential amino acids. Malnutrition is thought to play a considerable role in DNA methylation changes and, therefore, the risk of SCZ. Small Piece of a Changing Puzzle Hopefully, we can see a bigger picture of the highly intricate foundation beneath complex diseases. Bear in mind that SCZ is only one of many complex diseases known. SCZ is ultimately not a pristine and impartial model to study complex disorders. For instance, concordance rates of complex diseases change depending on their genetic background. In addition, they may involve different mutations, variance, or dysregulation of differing pathways and epigenetic mechanisms. After all, complex diseases are complex. Finally, this article aimed to give a rundown of the epigenetics behind complex diseases like SCZ. However, it is only a snapshot compared to the larger world of the epigenome. Furthermore, some questions remain unanswered: the genetic background and architecture of complex diseases, and ways to study, diagnose, and treat complex diseases. This Scientia article is one of the articles in Scientia on the theme of complex disease science and genetics. Hopefully, this introductory article is an insight and can be used to reflect upon, especially when tackling more complicated subjects of complex diseases and precision medicine. Written by Stephanus Steven Related articles: Schizophrenia, Inflammation, and Accelerated Ageing / An Introduction to Epigenetics