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Luigi Galvani was an Italian physician and biologist, and is known for his work on bioelectricity, and for laying the foundations of electrophysiology- the branch of science focusing on electricity in the body. He was born in 1737 in Bologna, Italy, and died in 1798 when the age of electricity was approaching. Go Back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Electricity in the body: Luigi Galvani Last updated: 07/11/24 Published: 05/12/23 Luigi Galvani (1737- 1798) Luigi Galvani was an Italian physician and biologist, and is known for his work on bioelectricity, and for laying the foundations of electrophysiology- the branch of science focusing on electricity in the body. He was born in 1737 in Bologna, Italy, and died in 1798 when the age of electricity was approaching. Galvani began his career as a doctor after he graduated with a thesis in 1762, at the University of Bologna. The same year, he became a Reader in Anatomy at the university. He was then given the Chair of Obstetrics at the Institute of Sciences, owing to his surgical skills, and became its president in 1772. He held his chair for 33 years but was dismissed in 1797 when Napoleon’s army invaded but was reinstated sometime later. Galvani's discovery Galvani was performing experiments on frog legs at the University of Bologna, when his assistant touched his scalpel to the crural nerves of the frog, when he was drawing spark from the brass conductor of the electrostatic machine, and the frog leg twitched. Due to the current, muscular spasms were generated throughout the body. Galvani was intrigued and performed more experiments to see if he would get the same result. He did- the experiment was reproducible. Galvani used a Leyden jar (a device which stores static electricity, an early form of capacitor), and an electrostatic machine to produce this electricity. He knew that metals transmitted something called electricity, and a form of this electricity was presumably generated in the frog tissue to allow muscular contraction- he named this ‘animal electricity’. He believed this ‘animal electricity’ was different from static, and natural electricity e.g. lightning. Indeed, in 1786, during a lightning storm, he touched some frog nerves with a pair of scissors and the muscle contracted. Galvani thought ‘animal electricity’ as a fluid secreted by the brain, which flows though nerves and activates the muscles. This is how his experiments helped pave the way for electrophysiology in neuroscience. In 1786, during a lightning storm, Galvani touched some frog nerves with a pair of scissors and the muscle contracted. Galvani's experimental setup consisted of frog legs, a Leyden jar, and an electrostatic machine. He knew that metals transmitted something called electricity, and a form of this electricity was presumably generated in the frog tissue to allow muscular contraction- he named this ‘animal electricity’. A first step in the branch of electrophysiology. Galvani's progress in the field Galvani’s work was accepted by all his colleagues except for Volta, the professor of physics at the University of Pavia. Though Volta could reproduce Galvani’s experiments, he did not like Galvani’s explanation of ‘animal electricity’. Volta believed it was the two dissimilar metals producing the electricity, he named it ‘metallic electricity’, and there was no current running inside the frogs- there was no ‘animal electricity’. Galvani argued that there were electric forces inside organisms, and in 1794 he published an anonymous book Dell’uso e dell’attivita dell’arco conduttore nella contrazione dei muscoli (“On the Use and Activity of the Conductive Arch in the Contraction of Muscles”), where Galvani described his work on how he obtained electricity inside the frog, without the use of any metal. It was reported that he did this by touching the exposed muscle of one frog with a nerve of another, and the muscle contracted (Dibner 2020). This seems doubtful as Galvani’s forceps must have been in contact with spark for there to be movement. Still, it was the first attempt to demonstrate the existence of bioelectric forces. Outside of neuroscience The term ‘animal fluid’ Galvani used, is reminiscent of ‘animal spirits’, which was used by Rene Descartes, French philosopher, in the 1600s. Descartes described ‘animal spirits’ as a fluid flowing through the brain and the body, and Galvani unwittingly built on this belief with his findings on bioelectricity; the spirits ‘became’ “electricity”. There was a paradigm shift as Descartes thought that nerves were water pipes, but they were electrical conductors. This illustrates how Galvani was able to build on existing ideas in science. Limitations Even with the vigorous experiments and support, there was one limitation. For a direct correlation between frog muscle contraction and electricity generation, Galvani needed to be able to quantitatively measure the electrical currents generated in the muscle. This was difficult to do at the time since there was not enough technology to measure the currents- the currents were too small. Eventually, in the early 1900s when there were major advances in technology, Muller, Bois-Reymond, and Helmholtz, three German physiologists, managed to successfully measure the conduction of electrical activity along the nerve axon. This breakthrough furthered the branch of electrophysiology which Galvani had started. Summary In conclusion, Luigi Galvani was an influential physician and biologist, who founded the branch of electrophysiology with his experiments on frogs and metals. His results were crucial to the development of neuroscience, particularly the beginning of understanding electrical activity along the axon. Written by Manisha Halkhoree Related article: Nikola Tesla and wireless electricity

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Search Index All (250) Other Pages (231) Forum Posts (19) 250 items found Other Pages (231) The dopamine connection | Scientia News Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link The dopamine connection How your gut influences your mood and behaviour Introduction to dopamine Dopamine is a neurotransmitter derived from an amino acid called phenylalanine, which must be obtained through the diet, through foods such as fish, meat, dairy and more. Dopamine is produced and released by dopaminergic neurons in the central nervous system and can be found in different brain regions. The neurotransmitter acts via two mechanisms: wiring transmission and volume transmission. In wiring transmission, dopamine is released to the synaptic cleft and acts on postsynaptic dopamine receptors. In volume transmission, extracellular dopamine arrives at neurons other than postsynaptic ones. Through methods such as diffusion, dopamine then reaches receptors in other neurons that are not in direct contact with the cell that has released the neurotransmitter. In both mechanisms, dopamine binds to the receptors, transmitting signals between neurons and affecting mood and behaviour. The link between dopamine and gut health Dopamine has been known to result in positive emotions, including pleasure, satisfaction and motivation, which can be influenced by gut health. Therefore, what you eat and other factors, including motivation, could impact your mood and behaviour. This was proven by a study (Hamamah et al., 2022), which looked at the bidirectional gut-brain connection. The study found that gut microbiota was important in maintaining the concentrations of dopamine via the gut-brain connection, also known as the gut microbiota-brain axis or vagal gut-to-brain axis. This is the communication pathway between the gut microbiota and the brain facilitated by the vagus nerve, and it is important in the neuronal reward pathway, which regulates motivational and emotional states. Activating the vagal gut-to-brain axis, which leads to dopamine release, suggests that modulating dopamine levels could be a potential treatment approach for dopamine-related disorders. Some examples of gut microbiota include Prevotella, Bacteroides, Lactobacillus, Bifidobacterium, Clostridium, Enterococcus, and Ruminococcus , and they can affect dopamine by modulating dopaminergic activity. These gut microbiota are able to produce neurotransmitters, including dopamine, and their functions and bioavailability in the central nervous system and periphery are influenced by the gut-brain axis. Gut dysbiosis is the disturbance of the healthy intestinal flora, and it can lead to dopamine-related disorders, including Parkinson's disease, ADHD, depression, anxiety, and autism. Gut microbes that produce butyrate, a short-chain fatty acid, positively impact dopamine and contribute to reducing symptoms and effects seen in neurodegenerative disorders. Dopamine as a treatment It is important to understand the link between dopamine and gut health, as this could provide information about new therapeutic targets and improve current methods that have been used to prevent and restore deficiencies in dopamine function in different disorders. Most cells in the immune system contain dopamine receptors, allowing processes such as antigen presentation, T-cell activation, and inflammation to be regulated. Further research into this could open up a new possibility for dopamine to be used as a medication to treat diseases by changing the activity of dopamine receptors. Therefore, dopamine is important in various physiological processes, both in the central nervous and immune systems. For example, studies have shown that schizophrenia can be treated with antipsychotic medications which target dopamine neurotransmission. In addition, schizophrenia has also been treated by targeting the dysregulation (decreasing the amount) of dopamine transmission. Studies have shown promising results regarding dopamine being used as a form of treatment. Nevertheless, further research is needed to understand the interactions between dopamine, motivation and gut health and explore how this knowledge can be used to create medications to treat conditions. Conclusion The bidirectional gut-brain connection shows the importance of gut microbiota in controlling dopamine levels. This connection influences mood and behaviour but also has the potential to lead to new and innovative dopamine-targeted treatments being developed (for conditions including dopamine-related disorders). For example, scientists could target and manipulate dopamine receptors in the immune system to regulate the above mentioned processes: antigen presentation, T-cell activation, and inflammation. While current research has shown some promising results, further investigations are needed to better comprehend the connection between gut health and dopamine levels. Nevertheless, through consistent studies, scientists can gain a deeper understanding of this mechanism to see how changes in gut microbiota could affect dopamine regulation and influence mood and behaviour. Written by Naoshin Haque Related articles: the gut microbiome / Crohn's disease Project Gallery How does moving houses impact your health and well-being? | Scientia News Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link How does moving houses impact your health and well-being? Evaluating the advantages and disadvantages of gentrification in the context of health Introduction According to the World Health Organization (WHO), health is “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity". Another way to define health is an individual being in a condition of equilibrium within themselves and the surrounding environment, which includes their social interactions and other factors. Reflecting on historical views of health, ancient Indian and Chinese medicine and society in Ancient Greece thought of health as harmony between a person and their environment, which underlines the cohesion between the soul and body; this is similar to the WHO’s definition of health. Considering these ideas, one key determinant of health is gentrification (see Figure 1 ). It was first defined in 1964 by British sociologist Ruth Glass, who witnessed the dilapidated houses in the London Borough of Islington being taken over and renovated by middle-class proprietors. The broader consequences of gentrification include enhanced living conditions for the residents, differences in ownership prerequisites, increased prices of land and houses, and transformations in the social class structure. Also, these changes cause lower-income inhabitants to be pushed out or go to poorer neighbourhoods, and the conditions in these neighbourhoods, which can include racial separation, lead to inequities and discrepancies in health. For example, a systematic review discovered that elderly and Black residents were affected more by gentrification compared to younger and White citizens; this highlights the importance of support and interventions for specific populations during urban renewal. Given the knowledge provided above, this article will delve further into the advantages and disadvantages of gentrification in the context of health outcomes. Advantages of gentrification Gentrification does have its benefits. Firstly, it is positively linked with collective efficacy, which is about enhancing social cohesion within neighbourhoods and maintaining etiquette; this has health benefits for residents, like decreased rates of obesity, sexually transmitted diseases, and all-cause mortality. Another advantage of gentrification is the possibility of economic growth because as more affluent tenants move into specific neighbourhoods, they can bring companies, assets, and an increased demand for local goods and services, creating more jobs in the area for residents. Additionally, gentrification can be attributed to decreased crime rates in newly developed areas because the inflow of wealthier citizens often conveys a more substantial sense of community and investment in regional security standards. Therefore, this revitalised feeling of safety can make these neighbourhoods more appealing to existing and new inhabitants, which leads to further economic development. Moreover, reducing crime can improve health outcomes by reducing stress and anxiety levels among residents, for example. As a result, the community's general well-being can develop, leading to healthier lifestyle choices and more lively neighbourhoods. Furthermore, the longer a person lives in a gentrifying neighbourhood, the better their self-reported health, which does not differ by race or ethnicity, as observed in Los Angeles. Disadvantages of gentrification However, it is also essential to mention the drawbacks of gentrification, which are more numerous. In a qualitative study involving elderly participants, for example, one of them stated that, “The cost of living increases, but the money that people get by the end of the month is the same, this concerning those … even retired people, and people receiving the minimum wage, the minimum wage increases x every year, isn’t it? But it is not enough”. Elderly residents in Barcelona faced comparable challenges of residential displacement between 2011 and 2017 due to younger adults with higher incomes and those pursuing university education moving into the city. These cases spotlight how gentrification can raise the cost of living without an associated boost in earnings, making it problematic for people with lower incomes or vulnerable individuals to live in these areas. Likewise, a census from gentrified neighbourhoods in Pittsburgh showed that participants more typically conveyed negative health changes and reduced resources. Additionally, one study examined qualitative data from 14 cities in Europe and North America and commonly noticed that gentrification negatively affects the health of historically marginalised communities. These include threats to housing and monetary protection, socio-cultural expulsion, loss of services and conveniences, and raised chances of criminal behaviour and compromised public security. This can be equally observed during green gentrification, where longtime historically marginalised inhabitants feel excluded from green or natural spaces, and are less likely to use them compared to newer residents. To mitigate these negative impacts of gentrification, inclusive urban renewal guidelines should be drafted that consider vulnerable populations to boost health benefits through physical and social improvements. The first step would be to provide residents with enough information and establish trust between them and the local authorities because any inequality in providing social options dramatically affects people’s health-related behaviours. Intriguingly, gentrification has been shown to increase the opportunity for exposure to tick-borne pathogens by populations staying in place, displacement within urban areas, and suburban removal. This increases tick-borne disease risk, which poses a health hazard to impacted residents ( Figure 2 ). As for mental health, research has indicated that residing in gentrified areas is linked to greater levels of anxiety and depression in older adults and children. Additionally, one study found young people encountered spatial disconnection and affective exclusion due to gentrification and felt disoriented by the quickness of transition. Therefore, all of these problems associated with gentrification reveal that it can harm public health and well-being, aggravating disparities and creating feelings of isolation and aloneness in impacted communities. Conclusion Gentrification is a complicated and controversial approach that has noteworthy consequences for the health of neighbourhoods. Its advantages include enhanced infrastructure and boosted economic prospects, potentially leading to fairer access to healthcare services and improved health outcomes for residents. However, gentrification often leads to removal and the loss of affordable housing, which can harm the health of vulnerable populations. Therefore, it is vital for policymakers and stakeholders to carefully evaluate the likely health effects of gentrification and enforce alleviation strategies to safeguard the well-being of all citizens (see Table 1 ). Written by Sam Jarada Related article: A perspective on well-being REFERENCES WHO. Health and Well-Being. Who.int . 2015. Available from: https://www.who.int/data/gho/data/major-themes/health-and-well-being Sartorius N. The meanings of health and its promotion. Croatian Medical Journal. 2006;47(4):662–4. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2080455/ Krahn GL, Robinson A, Murray AJ, Havercamp SM, Havercamp S, Andridge R, et al. It’s time to Reconsider How We Define Health: Perspective from disability and chronic condition. Disability and Health Journal. 2021 Jun;14(4):101129. Available from: https://www.sciencedirect.com/science/article/pii/S1936657421000753 Svalastog AL, Donev D, Jahren Kristoffersen N, Gajović S. Concepts and Definitions of Health and health-related Values in the Knowledge Landscapes of the Digital Society. Croatian Medical Journal. 2017 Dec;58(6):431–5. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5778676/ Foryś I. Gentrification on the Example of Suburban Parts of the Szczecin Urban Agglomeration. remav. 2013 Sep 1;21(3):5–14. Uribe-Toril J, Ruiz-Real J, de Pablo Valenciano J. Gentrification as an Emerging Source of Environmental Research. Sustainability. 2018 Dec 19;10(12):4847. Schnake-Mahl AS, Jahn JL, Subramanian SV, Waters MC, Arcaya M. Gentrification, Neighborhood Change, and Population Health: a Systematic Review. Journal of Urban Health. 2020 Jan 14;97(1):1–25. Project Gallery The chemistry of an atomic bomb | Scientia News Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link The chemistry of an atomic bomb Julius Oppenheimer Julius Robert Oppenheimer, often credited with leading the development of the atomic bomb, played a significant role in its creation in the early 1940s. However, it is essential to recognize the collaborative effort of many scientists, engineers, and researchers who contributed to the project. The history and chemistry of the atomic bomb are indeed fascinating, shedding light on the scientific advancements that made it possible. The destructive power of an atomic bomb stems from the rapid release of energy resulting from the splitting, or fission, of fissile atomic nuclei in its core. Isotopes such as uranium-235 and plutonium-239 are selected for their ability to undergo fission readily and sustain a self-sustaining chain reaction, leading to the release of an immense amount of energy. The critical mass of fissionable material required for detonation ensures that the neutrons produced during fission have a high probability of impacting other nuclei and initiating a chain reaction. To facilitate a controlled release of energy, neutron moderation plays a crucial role in the functioning of an atomic bomb. Neutrons emitted during fission have high velocities, making them less likely to be absorbed by other fissile material. However, by employing a moderator material such as heavy water (deuterium oxide) or graphite, these high-speed neutrons can be slowed down. Slowing down the neutrons increases the likelihood of their absorption by fissile material, enhancing the efficiency of the chain reaction and the release of energy. The sheer magnitude of the energy released by atomic bombs is staggering. For example, one kilogram (2.2 pounds) of uranium-235 can undergo complete fission, producing an amount of energy equivalent to that released by 17,000 tons (17 kilotons) of TNT. This tremendous release of energy underscores the immense destructive potential of atomic weapons. It is essential to note that the development of the atomic bomb represents a confluence of scientific knowledge and technological advancements, with nuclear chemistry serving as a foundational principle. The understanding of nuclear fission, the critical mass requirement, and the implosion design were key factors in the creation of the atomic bomb. Exploring the chemistry behind this devastating weapon not only provides insights into the destructive capabilities of atomic energy but also emphasises the responsibility that accompanies its use. In conclusion, while Oppenheimer's contributions to the development of the atomic bomb are significant, it is crucial to acknowledge the collective effort that led to its creation. The chemistry behind atomic bombs, from the selection of fissile isotopes to neutron moderation, plays a pivotal role in harnessing the destructive power of nuclear fission. Understanding the chemistry of atomic weapons highlights the remarkable scientific achievements and reinforces the need for responsible use of atomic energy. By Navnidhi Sharma Project Gallery View All Forum Posts (19) Quizzes #3 In Questions & Answers · 15 February 2023 Form of energy which is due to an object/ particle's motion? A. Kinetic energy B. Gravitational potential energy C. Potential energy D. Thermal energy 0 1 16 Quizzes #5 In Questions & Answers · 4 March 2023 0 1 22 Forum rules In General Discussion · 13 December 2022 We want everyone to get the most out of this community, so we ask that you please read and follow these guidelines: Respect each other Keep posts relevant to the forum topic No spamming 1 0 6 View All

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