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If conditional exercises
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Zero conditional if exercise
Create me a multiple choice test questions with 4 options on the following topic:Consumer Education for Different Audience 1. Children and Youth: - Focus: Building foundational knowledge about basic consumer concepts, making safe choices, understanding money and value, and recognizing scams and unsafe situations. 2. Teens and Young Adults: - Focus: Building financial literacy, responsible debt management, understanding contracts and agreements, responsible technology use, online safety, and consumer rights. 3. Working Adults and Families: - Focus: Managing budgets, making informed purchasing decisions, understanding credit and debt, finding consumer protection resources, and navigating complex financial products (mortgages, insurance, investments). 4. Seniors: - Focus: Protecting themselves from scams and fraud, understanding common consumer issues like telemarketing, identity theft, and online scams, managing medications and healthcare costs, and accessing community resources. 5. Special Populations: - Focus: Adapting consumer education programs to the specific needs of people with disabilities, immigrants, refugees, and other marginalized communities. 6. Business and Industry:- Focus: Understanding ethical marketing practices, complying with consumer protection laws, and providing clear and accurate information to consumers. 7. Policymakers and Regulators: - Focus: Understanding consumer needs, developing effective consumer protection laws, enforcing regulations, and ensuring a fair and competitive marketplace. Adapting consumer education programs for children, teens, and seniors requires tailoring content and delivery methods to their unique needs and learning styles. Children (Ages 5-12): - Understanding the concept of money: Teaching children about saving, spending, and the value of money. - Developing basic budgeting skills: Helping children learn to make choices about how to spend their allowance or pocket money. EFFECTIVE STRATEGIES âąFocus on basic concepts: Introduce core concepts like saving, spending, and budgeting in a fun and engaging way. Use simple language and relatable examples. âąReal-life scenarios: Use age-appropriate scenarios to illustrate financial concepts, like buying toys or snacks. âąParental involvement: Encourage parent participation and provide resources to help them reinforce lessons at home. Teens (Ages 13-18): - Building budgeting and financial planning skills: Teaching teens how to manage their money, set financial goals, and plan for the future. - Navigating the digital marketplace: Equipping teens with the knowledge and skills to make safe and informed online purchases, understand digital marketing, and protect themselves from scams. EFFECTIVE STRATEGIES âą Practical skills: Focus on skills relevant to teens, like managing money for social activities, saving for college, and understanding credit cards. âą Digital literacy: Address the growing influence of online shopping, social media advertising, and financial scams. âą Real-world applications: Connect financial concepts to real-life decisions teens make, like choosing a part-time job or making purchases online. Seniors (Ages 65+) - Managing retirement savings and healthcare costs: Providing information and resources on retirement planning, Medicare and Medicaid, and other healthcare options. - Navigating the digital world: Offering technology training and resources to help seniors access online services and information safely and securely. EFFECTIVE STRATEGIES âą Addressing specific concerns: Focus on topics relevant to senior citizens, like retirement planning, managing healthcare expenses, and avoiding scams. âą Clear and concise communication: Use simple language and visual aids to ensure easy understanding. âą Social interaction: Create opportunities for seniors to share experiences and learn from each other. Teaching Financial Literacy in school and Communities In Schools: Curriculum Integration: Financial literacy concepts can be seamlessly integrated into existing subjects, making learning more relevant and engaging. - Math: Budgeting exercises, calculating interest rates, analyzing financial data, and understanding compound interest are all natural applications of math skills. - Social Studies: Exploring the history of money, financial institutions, economic systems, and the impact of financial decisions on society provide valuable context. - Economics: Discussions about supply and demand, inflation, investment, and the role of consumers in the economy enhance financial literacy. Dedicated Courses: Offering elective courses or workshops specifically focused on personal finance provides deeper dives into crucial topics. - Personal Finance: Cover budgeting, saving, investing, credit, debt management, and insurance. - Entrepreneurship: Introduce concepts like business planning, marketing, financial forecasting, and managing cash flow. In Communities: Community Centers and Libraries: Workshops, seminars, and classes tailored to adults and families provide accessible learning opportunities. - Financial Planning: Cover budgeting, retirement planning, debt management, and estate planning. - Homeownership: Provide guidance on buying, selling, and maintaining a home. - Consumer Protection: Educate individuals about their rights and how to avoid scams. Partnerships with Financial Institutions: Collaborations with banks, credit unions, and financial advisors offer valuable resources, workshops, and financial literacy programs. Consumer Education for Low-Income and Vulnerable Populations Low-income refers to individuals or households with limited financial resources, typically below a certain threshold. Low-income individuals may face challenges like: 1. Limited education and job opportunities 2. Poor living conditions and housing 3. Food insecurity and malnutrition Causes of low income: 1. Unemployment or underemployment 2. Low-paying jobs or minimum wage 3. Limited education or skills 4. Single parenthood or large family size Vulnerable population'' is a term that is used to describe a group of people who possess some sort of disadvantage. elderly people, people with low incomes, homeless people, people in prison, migrant workers, pregnant women, Family Consumer Education: Managing Household Finances and Resources Financial literacy is the ability to understand and manage personal finances effectively. 1. Debt Debt is money you spend that isnât yours. If you borrow money from the bank, use a credit card, or take out a short-term loan, or a payday loan, you are accumulating debt. Good debt is considered money borrowed for things that are absolutely necessary for making a life e.g. a house and for advancing your money-making potential e.g. an education. Bad debt is considered borrowing money or using a credit card to pay for things you donât need, such as expensive clothes, hi-tech electronics, eating out at restaurants, going on holidays, etc. 2. Saving Saving is an essential part of financial wellness, a secure present, and a happy future. 3. Budgeting Budgeting is the life skill of planning and managing your money. By understanding exactly where your money goes every month, you are empowered to create an actionable plan by which you can spend less, by curtailing those unnecessary expenses and saving more for the things you need and want. 4. Investing Investing is all about creating and growing the wealth you need to enjoy a financially secure and happy future. Itâs about putting your money into something that will make you a profit over time, such as property, retirement funds, and unit trusts Integrating Consumer Education into the Home Economics Curriculum. Integrating consumer education into the home economics curriculum can provide students with essential skills for making informed choices about their personal finances, food, clothing, and overall well-being. Here are some strategies and ideas for effectively incorporating consumer education: Financial Literacy Budgeting: Teach students how to create and manage a personal budget, including setting financial goals, tracking expenses, and understanding savings. Saving and Investment: Cover the basics of saving, including different saving accounts, and introduce concepts related to investing. Food and Nutrition Food Label Literacy: Engage students in learning how to read and interpret food labels, including nutrition facts and ingredient lists. Grocery Shopping Skills: Teach students how to compare product costs, understand unit pricing, and make healthy, budget-friendly choices while shopping. Clothing and Textile Education Consumer Choices in Clothing:Discuss factors influencing clothing purchases, such as quality, price, and sustainability. Fashion and Trends: Analyze the impact of marketing and advertising on consumer behavior regarding clothing. Sustainable Purchasing Eco-Friendly Choices: Raise awareness about environmentally friendly products and the importance of sustainability in consumer choices. Project-Based Learning - Assign real-life projects where students must apply their knowledge, such as creating a meal plan within a budget, planning a shopping list based on nutrient needs, or evaluating the cost-effectiveness of different products. Technology Integration - Use technology to teach students about online shopping, price comparison websites, and apps that aid budgeting and financial planning. Collaborative Learning Opportunities - Organize team projects where students work together to solve consumer-related problems, emphasizing teamwork and communication skills. Assessment and Reflection - Incorporate assessments that allow students to reflect on what they have learned about consumer education and how they can apply these skills in their daily lives.
Personality development means developing positive characteristics among individuals. Positive characteristics of an individual include: ï¶ Obedience â Learn how to follow family as well as school regulations and decisions made for your own good. If young children like Something to read: Home Economics and Livelihood Education 7 Seibo College 5 you, can learn how to obey your elders then there will always be peaceful and happy relationship around. ï¶ CourtesyBeing courteous means to be respectful. Polite behavior must be something you must observe anywhere, every time. ï¶ Cleanliness and Orderliness â It means practicing good health and good grooming habits everyday. ï¶ Understanding â To be in anotherâs shoes is to be in the same place as what others are experiencing through life. One must be very careful about what others may feel so be tactful and develop sensitivity towards their needs. ï¶ Friendly â It is necessary that growing child like you to possess a good attitude in dealing with others. Develop a fine character and talk in such a manner that others will realize what admirable qualities you do possess. Home Economics and Livelihood Education 7 Seibo College 6 Becoming friendly means getting along well with each other. As you grow up, it is important to be able to meet and be acquainted other people. Sometimes. you will meet people who for some reason wonât like you. Understanding otherâs feeling and emotion will make it possible to become the kind of person whom most people enjoy being with. It will help you become good natured and considerate to others. The following are guidelines for you to follow in order to develop your positive characteristics. ï¶ be sensitive of otherâs need. ï¶ be genuinely concern with others. ï¶ be thoughtful and pleasant. ï¶ listen when others are talking. ï¶ make them feel important. More effective way of being likeable can be summed up by the Golden Rule which says âDo unto others as you would have others do unto youâ Do you want to be treated kindly? Then, follow the golden rule so that your relationship with others will be at its best. Your personality is influenced by many factors; however the most influential are heredity and environment. What is heredity? Heredity is the transmission of physical and mental traits from parents to offspring. The table below will identify your inherited traits and abilities: Home Economics and Livelihood Education 7 Seibo College 7 Here are some inherited physical features and traits from your mother and father. Physical Features Intelligence and mental ability Personal disposition - blood type - power to think - manner of thinking - body structure - power to learn - manner of feeling - color of skin/eyes - power to understand - manner of acting - color and texture of hair - power to do something What is environment? Home Economics and Livelihood Education 7 Seibo College 8 Your environment provides you with experiences, conditions, and influences that mold your personality. These are the people around you, your school, community, as well as the things that surround you that affect your personality. The people who will most likely affect your personality ,are your friends or peers, their manner of thinking and behaving will be sooner or later, the same as your manner and behavior as well. The things you use everyday like your personal computer, cell phone will also have an impact on your personality. Always remember to be yourself and do not pretend to be somebody you are not. Act according to your age and do not copy the identity of other person. Otherwise, you may become an individual that you and other person may not like. Understand yourself and do something to improve your personality. It is always necessary to practice good health habits as follows: ï¶ eat the right kind of food. ï¶ have a regular exercise. ï¶ have enough sleep and rest. Observe good grooming habits as well: ï¶ maintain cleanliness and neatness. ï¶ wear appropriate clothes. ï¶ observe good posture. Home Economics and Livelihood Education 7 Seibo College 9 If you understand our lesson well, you can now proceed to the next activities But if you have any questions, you can ask your le
Make a multiple choice quiz for my year 8 science students based on the science in this transcript from a video: 3°C 0:04 It can be the difference between snow and sleet 0:08 Wearing a jacket or not 0:11 In your day-to-day life, it may not seem significant 0:15 But 3°C of global warming would be catastrophic 0:20 Heatwaves, droughts, extreme precipitation, even fire 0:25 3°C of warming is really disastrous 0:28 The scary thing is, the world is well on its way there 0:32 Since the industrial revolution, the Earth has warmed between 1.1°C and 1.3°C 0:40 This is a problem that babies you pass in the street will have to live with 0:46 Children born today... 0:47 ...are up to seven times more likely to face extreme weather than their grandparents 0:52 If global temperatures do rise by 3°C... 0:55 ...what would their world look like? Climate change is already having devastating effects 1:03 Rising sea levels 1:05 Desertification 1:07 Hollywood has always enjoyed imagining the end of the world 1:11 While blockbusters like this are clearly fiction... 1:14 ...this film will show the scenario we all face... 1:17 ...unless more drastic measures are taken to stop burning fossil fuels 1:30 In some parts of the world the effects of inaction are already clear 1:35 The slums of Bangladeshâs capital are filling up with climate migrants 1:41 Minara comes from Bhola District, an area in southern Bangladesh 1:46 There, like many other parts of the country... 1:49 ...rivers swollen by heavier rain and melting Himalayan glaciers... 1:53 ...are washing away peopleâs homes 1:56 Many, like her, have lost everything 2:00 Our home in Bhola had endless amounts of land 2:03 There was lots of space for farming, we had a spacious house 2:08 There were different types of fruits, vegetation and trees growing at home 2:12 We used to eat the fruit from our own trees 2:18 I canât eat them now because they don't exist anymore 2:21 Since the river flooded for the third time, I had to flee to Dhaka 2:26 Life was much better back home 2:29 It was unbearable to live through, truly intolerable 2:33 We didnât have the time to save anything at all 2:38 1.1°C to 1.3°C of global warming has already transformed Minaraâs life 2:45 Itâs one of the reasons why so many migrants like her... 2:47 ...are moving to the city each year... 2:50 ...nearly 400,000 according to the last estimate 2:53 And climate models show there could be much worse to come How climate modelling works 3:02 Climate scientist Joeri Rogelj... 3:04 ...has spent the last ten years modelling future climate scenarios... 3:08 ...for the United Nations 3:10 The models we use to carry out this exercise... 3:13 ...really represent the state of the art... 3:15 ...of our current knowledge of climate change and where we are heading 3:19 Joeriâs projections use data collected by hundreds of scientists around the world 3:26 Here this is the 3°C level... 3:28 ...and so there is at least a one-in-four chance that under current policies... 3:32 ...we would hit 3°C by the end of the century 3:36 This is just one of the scenarios Joeri looks at 3:40 Another one imagines that all policy promises are kept 3:44 The most optimistic assumes that all promises have been kept... 3:47 ...and net-zero targets are met 3:50 Where our best estimate ends up around 2°C at the end of the century... 3:54 ...there is still a one-in-20 chance that we end up with 3°C instead 3:59 One would not be entering a plane if there is a one-in-20 chance... 4:03 ...that the plane will crash Nowhere is safe from global warming 4:07 A rise of 3°C would affect everyone 4:10 Even wealthy cities in rich countries wouldnât be immune to the consequences 4:15 European capitals like Paris and Berlin... 4:18 ...would bake under more extreme heatwaves 4:22 Frequent storm-surges in New York could turn parts of the city desolate 4:27 In many ways, cities magnify, intensify climate events 4:33 Cities are hotter than the places around them... 4:36 ...they tend to be more vulnerable to flooding 4:39 And you can get a really bad event in a city in a way that you canât in the countryside 4:46 And because of their denser populations... 4:49 ...disasters in a city affect far more people 4:52 Some cities might be badly prepared for the changes coming 4:56 But they have the means to adapt 4:59 Cities tend to be wealthier than surrounding places 5:03 They have a lot of amenities 5:05 A city that has taken seriously the risks of a 3°C world... 5:08 âŠwouldnât necessarily be a worse place to be in a 3°C world 5:12 But a city that hasnât prepared for these sort of eventualities... 5:16 ...that might be a really nasty place The impact of prolonged droughts 5:20 So far, many developed cities have got off lightly... 5:24 ...but some rural parts of the world are suffering disproportionately 5:29 Smallholdersâsmall-scale farmersâare particularly vulnerable to climate change 5:35 And there are over 600 million around the world 5:38 Smallholders with farms under two hectares... 5:40 ...produce around a third of the global food supply 5:46 Central Americaâs âDry Corridorâ... 5:48 ...supports a mix of smallholdings and medium-sized farms 5:53 Sandwiched between the Pacific Ocean and the Caribbean Sea... 5:56 ...the area is prone to droughts 6:08 Israel RamĂrez Rivera is a smallholder in Guatemala 6:12 Here, climate change is making the dry seasons longer, and more severe 6:18 This is the biggest ear of maize that this plot could deliver 6:23 He depends on his crops of corn and beans 6:26 But theyâre getting harder to grow 6:30 The surrounding mountains... 6:32 ...used to provide us with native food... 6:38 ...and now that isnât an option anymore... 6:41 ...due to climate change and its effects 6:46 Nearly two-thirds of the smallholders in the Dry Corridor now live in poverty 6:52 The impact of all of this for us... 6:59 ...malnutrition among children 7:03 Weâve lost a few 7:07 For my crops especially, the midsummer heat is harder than before 7:16 The plant dries up and canât provide us... 7:19 ...with the necessary food provision 7:24 Severe droughts in Central America... 7:26 ...are now four times more likely than they were last century 7:30 Many families from here have gone to the States 7:37 The economic despair and debts... 7:44 ...have pushed many people from this community to do this journey 7:53 Migration from Guatemala to the United States has quadrupled since 1990 7:59 Not all of this has been due to climate change 8:02 But longer droughts would force even more to move 8:05 In a 3°C world, annual rainfall in this region... 8:09 ...could drop by up to 14% 8:12 At 3°C, over a quarter of the worldâs population... 8:16 ...could endure extreme droughts for at least a month of the year 8:19 Northern Africa could see droughts that last for years at a time Rising sea levels, storm surges and flooding 8:24 But for some, too much water will be the problem 8:29 10% of the worldâs population lives on a coastline... 8:32 ...thatâs less than 10 metres above sea level 8:35 For these coastal inhabitants, a 3°C world would spell disaster 8:40 By 2100, global sea levels could have climbed by half a metre from 2005 levels 8:46 Low-lying cities like Lagos would be especially vulnerable... 8:49 ...with up to up to a third of the population displaced 8:54 And in Fiji, rising waters are already upending lives 9:04 You can see the graveyard there, itâs all under water now... 9:08 ...due to this rising sea level and climate change 9:15 The village of Togoru in Fiji is being swallowed by the sea 9:19 Barney Dunn, the village headman, has seen over half the village disappear 9:24 Relativesâ houses have been abandoned, and family graves are now under water 9:29 We have been asked by the government to relocate... 9:32 ...but no one wants to relocate... 9:34 ...because we have our great-great-grandparents down there in the sea 9:39 This is the place weâve been brought up in 9:41 ...itâs not easy to leave 9:44 Past attempts to build a seawall havenât worked 9:48 But Barney sees building a new one as the villageâs only hope 9:52 If they do that, maybe we can save whatever is left 9:56 But if we donât have the seawall, then it will be keep eroding and time will come... 10:01 ...maybe in ten,15 years, Togoru will be all eroded 10:05 Rising seas also mean storms cause more floods 10:11 And many more countries could suffer 10:14 The Philippines and Myanmar are just two countries... 10:17 ...that will also see an increase in storm surges in a 3°C world 10:21 To escape, many will move⊠10:24 âŠoften, to urban areas Extreme heat and wet-bulb temperatures 10:27 Half the worldâs population already lives in cities... 10:31 ...almost a third in slums 10:36 For them, a 3°C world could be deadly 10:40 Minara has moved to Dhaka to escape the impact of climate change 10:44 But life could get even worse for her 10:47 Iâm struggling a lot nowadays 10:49 The heat during the day is unbearable 10:52 Even late at night it doesnât cool down 10:57 The heat is getting more intense every day 10:59 I mean, itâs going to get much worse 11:03 I can barely survive it now, how will I live through it in the future? 11:08 Dhaka is getting hotter 11:11 In the last 20 years the average daytime temperature... 11:13 ...has crept up by nearly half a degree 11:17 Days that approach 40°C are now being reported 11:20 And high so-called wet-bulb temperatures are on the rise 11:26 A wet-bulb temperature is a measure of heat and humidity 11:30 Humans cool themselves by sweating⊠11:32 But in these conditions, when relative humidity is near 100%... 11:36 ...sweat doesnât evaporate well 11:38 So people canât cool down⊠11:41 ...even if given unlimited shade and water 11:45 At a high wet-bulb temperature, the body canât lose heat... 11:49 ...and so it gets hotter and hotter... 11:51 ...and the body is designed to work at a given temperature 11:53 And if it gets too hot inside, you will die 11:58 The human limit for wet-bulb temperatures is 35°C... 12:02 ...around skin temperature 12:04 Dhaka will have a much higher chance... 12:05 ...of reaching dangerous wet-bulb temperatures... 12:07 ...if global warming reaches 3°C 12:12 You canât really adapt to that 12:14 You have to get out. If the temperature is so high that you canât work... 12:20 ...canât do hard manual labour outside for significant parts of the year... 12:25 ...then many places will become functionally no longer part of the economy 12:33 Jacobabad in Pakistan, and Ras al Khaimah, in the United Arab Emirates... 12:37 ...have already recorded deadly wet-bulb temperatures 12:40 More of the tropics and the Persian Gulf... 12:43 ...as well as parts of Mexico and the south-eastern United States... 12:47 ...could all get to this threshold by the end of the century 12:50 Climate modelling might show us the weather Increased migration and conflict 12:52 But it doesnât show us its other effects on society 12:56 Established migration patterns could change 12:59 Climate disasters may exacerbate reasons people cross borders 13:03 Within countries, more people will move to cities 13:07 In a 3°C world, tens of millions of people a year... 13:10 ...could be displaced by disasters made worse by climate change 13:15 When people are displaced by climate... 13:18 âŠthey may well go to cities... 13:19 ...because cities are the places that attract people from the countryside already 13:25 A lot of people who can get to the developed world... 13:28 ...not least because the developed world tends to be less hot, will give that a go 13:35 As migration around the world increases... 13:38 ...there could be more competition for fewer resources 13:42 Waterâalready a highly contested resourceâwill be a focal point 13:47 Turkeyâs new Ilisu dam has reduced the flow of water into Iraq 13:53 China lays claim to rivers vital to India and Pakistan 13:57 The prospect of a water-conflict makes people very uneasy 14:03 How national tensions would exacerbate those sorts of reactions... 14:08 ...in a 3°C world... 14:09 ...is the sort of thing that no one should really want to find out 14:14 I think youâd have to be incredibly sanguine... 14:16 ...not to think that the sort of climate extremes that we talk about... 14:19 ...in a 3°C world wouldnât lead some places... 14:22 ...to the brink of societal collapse 14:25 Those lucky enough to escape unrest... Adaptation and mitigation are crucial 14:28 ...would still have to adapt to a radically different world 14:32 People can adapt to climate change in all sorts of ways, one of the most obvious ones... 14:37 ...is air conditioning 14:39 But other ways to adapt at a local or regional level... 14:42 ...I mean, one of the most obvious is diversifying agriculture 14:47 There are physical things you can do, like seawalls 14:52 The fact that people can adapt and that adaptation will reduce suffering... 14:57 ...doesnât mean that it will eliminate suffering 15:00 Suffering is built into this whole process of heating up the planet 15:06 Adaptation will only get the world so far 15:09 The best way to deal with a 3°C world... 15:12 ...is not to go to a 3°C world 15:14 And thatâs why increasing efforts on mitigation are important 15:17 Itâs why working towards negative emissions... 15:20 ...that could bring down the temperature after it peaks are important 15:25 Once you get to a 3°C world, you are in real bad global trouble 15:33 The scale of change needed... 15:35 ...and the slow progress of governments so far... 15:38 ...means 3°C of warming is uncomfortably likely unless more is done 15:44 Despite existing pledges, greenhouse-gas emissions... 15:48 ...are still set to rise by 16% from 2010 levels by 2030 15:54 The need to act has never been clearer 15:57 Thereâs still time to reduce emissions, so that a 3°C world remains fiction... 16:02 ...rather than becoming fact
Ions Ions are charged substances that have formed through the gain or loss of electrons. Cations form from the loss of electrons and have a positive charge while anions form through the gain of electrons and have a negative charge. Cation Formation Cations are the positive ions formed by the loss of one or more electrons. The most commonly formed cations of the representative elements are those that involve the loss of all of the valence electrons. Consider the alkali metal sodium (Na) . It has one valence electron in the n=3 energy level. Upon losing that electron, the sodiu ion now has an octet of electrons from the second energy level and a charge of 1+ . The electron arrangement of the sodium ion is now the same as that of the noble gas neon. Consider a similar process with magnesium and aluminum. In this case, the magnesium atom loses its two valence electrons in order to achieve the same arrangement as the noble gas neon and a charge of 2+ . The aluminum atom loses its three valence electrons to have the same electron arrangement as neon and a charge of 3+ . For representative elements under typical conditions, three electrons is usually the maximum number that will be los. Representative elements will not lose electrons beyond their valence because they would have to "break" the octet of the previous energy level which provides stability to the ion. Anions Anions are the negative ions formed from the gain of one or more electrons. When nonmetal atoms gain elections, they often do so until their outermost principal energy level achieves an octet. For fluorine, which has an electron arrangement of (2, 7), it only needs to gain one electron to have the same electron arrangement as neon. Forming an octet (eight electrons in the outer shell) provides stability to the atom. Fluorine will gain one electron and have a charge of 1â . The electron arrangement of the fluoride ion (2, 8) will also change to reflect the gain of an electron. Oxygen has an electron arrangement of (2, 6) and needs to gain two electrons to fill the n=2 energy level and achieve an octet of electrons in the outermost shell. The oxide ion will have a charge of 2â as a result of gaining two electrons. Under typical conditions, three electrons is the maximum that will be gained in the formation of anions. Subatomic Particles in an Ion Since ions form from the gain or loss of electrons, we can also look at the number of subatomic particles (protons, neutrons, and electrons) found in an ion. Remember that the number of protons determines the identity of the element and will not change in a chemical process. Example 2.5.1 How many protons, neutrons, and electrons in a single oxide (O2â) ion? Solution Oxygen has the atomic number 8 so both the atom and the ion will have 8 protons. The average atomic mass of oxygen is 16. Therefore, there will be 8 neutrons (atomic massâatomic number=neutrons) . A neutral oxygen atom would have 8 electrons. However, the anion has gained two electrons so O2â has 10 electrons. We can also use information about the subatomic particles to determine the identity of an ion. Example 2.5.2 An ion with a 2+ charge has 18 electrons. Determine the identity of the ion. Solution If an ion has a 2+ charge then it must have lost electrons to form the cation. If the ion has 18 electrons and the atom lost 2 to form the ion, then the neutral atom contained 20 electrons. Since it was neutral, it must also have had 20 protons. Therefore the element is calcium. Polyatomic Ions A polyatomic ion is an ion composed of two or more atoms that have a charge as a group (poly = many). The ammonium ion (see figure below) consists of one nitrogen atom and four hydrogen atoms. Together, they comprise a single ion with a 1+ charge and a formula of NH+4 . The hydroxide ion (see figure below) contains one hydrogen atom and one oxygen atom with an overall charge of 1â . The carbonate ion (see figure below) consists of one carbon atom and three oxygen atoms and carries an overall charge of 2â . The formula of the carbonate ion is CO2â3 . The atoms of a polyatomic ion are tightly bonded together and so the entire ion behaves as a single unit. The figures below show several examples. Soult Screenshot 2-2-1.png Figure 2.5.1 : The ammonium ion (NH+4) is a nitrogen atom (blue) bonded to four hydrogen atoms (white). Soult Screenshot 2-2-2.png Figure 2.5.2 : The hydroxide ion (OHâ) is an oxygen atom (red) bonded to a hydrogen atom. Soult Screenshot 2-2-3.png Figure 2.5.3 : The carbonate ion (CO2â3) is a carbon atom (black) bonded to three oxygen atoms. The table below lists a number of polyatomic ions by name and by structure. The heading for each column indicates the charge on the polyatomic ions in that group. Note that the vast majority of the ions listed are anions - there are very few polyatomic cations. 1â 2â 3â 1+ Table 2.5.1 : Common Polyatomic Ions acetate, CH3COOâ carbonate, CO2â3 arsenate, AsO3â3 ammonium, NH+4 bromate, BrOâ3 chromate, CrO2â4 phosphite, PO3â3 chlorate, ClOâ3 dichromate, Cr2O2â7 phosphate, PO3â4 chlorite, ClOâ2 hydrogen phosphate, HPO2â4 cyanide, CNâ oxalate, C2O2â4 dihydrogen phosphate, H2POâ4 peroxide, O2â2 hydrogen carbonate, HCOâ3 silicate, SiO2â3 hydrogen sulfate, HSOâ4 sulfate, SO2â4 hydrogen sulfide, HSâ sulfite, SO2â3 hydroxide, OHâ hypochlorite, ClOâ nitrate, NOâ3 nitrite, NOâ2 perchlorate, ClOâ4 permanganate, MnOâ4 The vast majority of polyatomic ions are anions, many of which end in -ate or -ite. Notice that in some cases such as nitrate (NOâ3) and nitrite (NOâ2) , there are multiple anions that consist of the same two elements. In these cases, the difference between the ions is the number of oxygen atoms present, while the overall charge is the same. As a class, these are called oxyanions. When there are two oxyanions for a particular element, the one with the greater number of oxygen atoms gets the -ate suffix, while the one with the fewer number of oxygen atoms gets the -ite suffix. The four oxyanions of chlorine are shown below, which also includes the use of the prefixes hypo- and per-. ClOâ , hypochlorite ClOâ2 , chlorite ClOâ3 , chlorate ClOâ4 , perchlorate Not your usual ion Soult Screenshot 2-2-4.png "Drink you milk. It's good for your bones." We're told this from early childhood, and with good reason. Milk contains a good supply of calcium, part of the structure of bone. However, there are two other ionic components of hydroxyapatite, the mineral component. Phosphate ion and hydroxide ion make up the remainder of the inorganic material in bone. News You Can Use Bone is a very complex structure. It is composed of protein (mainly collagen), hydroxyapatite (a calcium-phosphate-hydroxide mixture), some other minerals, and contains 10 - 20% water. The calcium/phosphate ratios are not stoichiometric, but vary somewhat from one portion of bone to the next. Bones are very strong but will break under enough stress. Regular exercise and proper nutrition help to increase bone strength. Watch a video about bone structure at http://www.youtube.com/watch?v=d9owEvYdouk Nitrate is an anion with a complex bonding structure. Major sources for this ion in drinking water are runoff from fertilizer, septic tank leakage, sewage, and natural deposits. High concentrations of nitrates represent a significant health hazard, especially to infants. The nitrate in the body is converted to nitrite, which then binds to hemoglobin. This binding decreases the ability of hemoglobin to transport oxygen, thus depriving the cells of the O2 needed for proper functioning. Cyanide production is widespread throughout nature. Forest fires will produce significant amounts of cyanide. Many plants contain cyanide, and it is produced by a number of bacteria, algae, and fungi. Cyanide is used industrially in metal finishing, iron and steel mills, and in organic synthesis processes. This material is also an important component for the refining of precious metals. Formation of a complex between cyanide and gold allows extraction of this metal from a mixture.
Fed. 51: To the People of the State of New York: TO WHAT expedient, then, shall we finally resort, for maintaining in practice the necessary partition of power among the several departments, as laid down in the Constitution? The only answer that can be given is, that as all these exterior provisions are found to be inadequate, the defect must be supplied, by so contriving the interior structure of the government as that its several constituent parts may, by their mutual relations, be the means of keeping each other in their proper places. Without presuming to undertake a full development of this important idea, I will hazard a few general observations, which may perhaps place it in a clearer light, and enable us to form a more correct judgment of the principles and structure of the government planned by the convention. In order to lay a due foundation for that separate and distinct exercise of the different powers of government, which to a certain extent is admitted on all hands to be essential to the preservation of liberty, it is evident that each department should have a will of its own; and consequently should be so constituted that the members of each should have as little agency as possible in the appointment of the members of the others. Were this principle rigorously adhered to, it would require that all the appointments for the supreme executive, legislative, and judiciary magistracies should be drawn from the same fountain of authority, the people, through channels having no communication whatever with one another. Perhaps such a plan of constructing the several departments would be less difficult in practice than it may in contemplation appear. Some difficulties, however, and some additional expense would attend the execution of it. Some deviations, therefore, from the principle must be admitted. In the constitution of the judiciary department in particular, it might be inexpedient to insist rigorously on the principle: first, because peculiar qualifications being essential in the members, the primary consideration ought to be to select that mode of choice which best secures these qualifications; secondly, because the permanent tenure by which the appointments are held in that department, must soon destroy all sense of dependence on the authority conferring them. It is equally evident, that the members of each department should be as little dependent as possible on those of the others, for the emoluments annexed to their offices. Were the executive magistrate, or the judges, not independent of the legislature in this particular, their independence in every other would be merely nominal. But the great security against a gradual concentration of the several powers in the same department, consists in giving to those who administer each department the necessary constitutional means and personal motives to resist encroachments of the others. The provision for defense must in this, as in all other cases, be made commensurate to the danger of attack. Ambition must be made to counteract ambition. The interest of the man must be connected with the constitutional rights of the place. It may be a reflection on human nature, that such devices should be necessary to control the abuses of government. But what is government itself, but the greatest of all reflections on human nature? If men were angels, no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary. In framing a government which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed; and in the next place oblige it to control itself. A dependence on the people is, no doubt, the primary control on the government; but experience has taught mankind the necessity of auxiliary precautions. This policy of supplying, by opposite and rival interests, the defect of better motives, might be traced through the whole system of human affairs, private as well as public. We see it particularly displayed in all the subordinate distributions of power, where the constant aim is to divide and arrange the several offices in such a manner as that each may be a check on the other that the private interest of every individual may be a sentinel over the public rights. These inventions of prudence cannot be less requisite in the distribution of the supreme powers of the State. But it is not possible to give to each department an equal power of self-defense. In republican government, the legislative authority necessarily predominates. The remedy for this inconveniency is to divide the legislature into different branches; and to render them, by different modes of election and different principles of action, as little connected with each other as the nature of their common functions and their common dependence on the society will admit. It may even be necessary to guard against dangerous encroachments by still further precautions. As the weight of the legislative authority requires that it should be thus divided, the weakness of the executive may require, on the other hand, that it should be fortified. An absolute negative on the legislature appears, at first view, to be the natural defense with which the executive magistrate should be armed. But perhaps it would be neither altogether safe nor alone sufficient. On ordinary occasions it might not be exerted with the requisite firmness, and on extraordinary occasions it might be perfidiously abused. May not this defect of an absolute negative be supplied by some qualified connection between this weaker department and the weaker branch of the stronger department, by which the latter may be led to support the constitutional rights of the former, without being too much detached from the rights of its own department? If the principles on which these observations are founded be just, as I persuade myself they are, and they be applied as a criterion to the several State constitutions, and to the federal Constitution it will be found that if the latter does not perfectly correspond with them, the former are infinitely less able to bear such a test. There are, moreover, two considerations particularly applicable to the federal system of America, which place that system in a very interesting point of view. First. In a single republic, all the power surrendered by the people is submitted to the administration of a single government; and the usurpations are guarded against by a division of the government into distinct and separate departments. In the compound republic of America, the power surrendered by the people is first divided between two distinct governments, and then the portion allotted to each subdivided among distinct and separate departments. Hence a double security arises to the rights of the people. The different governments will control each other, at the same time that each will be controlled by itself. Second. It is of great importance in a republic not only to guard the society against the oppression of its rulers, but to guard one part of the society against the injustice of the other part. Different interests necessarily exist in different classes of citizens. If a majority be united by a common interest, the rights of the minority will be insecure. There are but two methods of providing against this evil: the one by creating a will in the community independent of the majority that is, of the society itself; the other, by comprehending in the society so many separate descriptions of citizens as will render an unjust combination of a majority of the whole very improbable, if not impracticable. The first method prevails in all governments possessing an hereditary or self-appointed authority. This, at best, is but a precarious security; because a power independent of the society may as well espouse the unjust views of the major, as the rightful interests of the minor party, and may possibly be turned against both parties. The second method will be exemplified in the federal republic of the United States. Whilst all authority in it will be derived from and dependent on the society, the society itself will be broken into so many parts, interests, and classes of citizens, that the rights of individuals, or of the minority, will be in little danger from interested combinations of the majority. In a free government the security for civil rights must be the same as that for religious rights. It consists in the one case in the multiplicity of interests, and in the other in the multiplicity of sects. The degree of security in both cases will depend on the number of interests and sects; and this may be presumed to depend on the extent of country and number of people comprehended under the same government. This view of the subject must particularly recommend a proper federal system to all the sincere and considerate friends of republican government, since it shows that in exact proportion as the territory of the Union may be formed into more circumscribed Confederacies, or States oppressive combinations of a majority will be facilitated: the best security, under the republican forms, for the rights of every class of citizens, will be diminished: and consequently the stability and independence of some member of the government, the only other security, must be proportionately increased. Justice is the end of government. It is the end of civil society. It ever has been and ever will be pursued until it be obtained, or until liberty be lost in the pursuit. In a society under the forms of which the stronger faction can readily unite and oppress the weaker, anarchy may as truly be said to reign as in a state of nature, where the weaker individual is not secured against the violence of the stronger; and as, in the latter state, even the stronger individuals are prompted, by the uncertainty of their condition, to submit to a government which may protect the weak as well as themselves; so, in the former state, will the more powerful factions or parties be gradnally induced, by a like motive, to wish for a government which will protect all parties, the weaker as well as the more powerful. It can be little doubted that if the State of Rhode Island was separated from the Confederacy and left to itself, the insecurity of rights under the popular form of government within such narrow limits would be displayed by such reiterated oppressions of factious majorities that some power altogether independent of the people would soon be called for by the voice of the very factions whose misrule had proved the necessity of it. In the extended republic of the United States, and among the great variety of interests, parties, and sects which it embraces, a coalition of a majority of the whole society could seldom take place on any other principles than those of justice and the general good; whilst there being thus less danger to a minor from the will of a major party, there must be less pretext, also, to provide for the security of the former, by introducing into the government a will not dependent on the latter, or, in other words, a will independent of the society itself. It is no less certain than it is important, notwithstanding the contrary opinions which have been entertained, that the larger the society, provided it lie within a practical sphere, the more duly capable it will be of self-government. And happily for the REPUBLICAN CAUSE, the practicable sphere may be carried to a very great extent, by a judicious modification and mixture of the FEDERAL PRINCIPLE. PUBLIUS.
Long Call Option Trading Strategy: Learn the Basics LONG CALL SUMMARY Purchasing a call option is a bullish strategy that gives the buyer the right, but not the obligation, to buy 100 shares of the underlying asset at a specified strike price on or before the expiration date. This strategy is typically employed when an investor believes that the price of the underlying asset will increase in the future. The value of a call option is influenced by several factors, including the underlying asset's price, the strike price, the time to expiration, and implied volatility. As the price of the underlying asset increases and approaches or breaches the long call's strike price, the option's value will appreciate. This is because the option holder has the right to buy the underlying asset at a lower price than the current market price, resulting in a potential profit. Out-of-the-money (OTM) calls have a strike price that is higher than the current market price of the underlying asset. These options are typically cheaper than in-the-money (ITM) calls, which have a strike price lower than the current market price. ITM calls have intrinsic value, which is the difference between the strike price and the current market price, and extrinsic value, which is the additional premium paid for the option's time value. Extrinsic value decays over time as the option approaches expiration, and this can cause the option to lose value, especially if the underlying asset does not move towards the strike price. LONG CALL OPTION Purchasing a call option grants you the privilege, but not the responsibility, to buy 100 shares of the underlying asset at the specified strike price on or before the expiration date. This option grants you the flexibility to capitalize on potential price increases of the underlying asset. The value of a call option is positively correlated with the price of the underlying asset. As the price of the stock or ETF rises and approaches your strike price, the value of your call option increases. This is because the difference between the market price and the strike price widens, giving you a greater potential profit. This characteristic makes call options suitable for bullish strategies where investors anticipate price increases. Conversely, the value of a call option diminishes when the price of the underlying asset drops or remains constant. Time decay, which refers to the gradual loss of an option's value as its expiration date approaches, also contributes to the depreciation of call options. Over time, the intrinsic value of the option, which represents the difference between the strike price and the underlying asset's market price, decreases as the option nears expiration. Additionally, if the price of the underlying asset remains below the strike price, the option may expire worthless, resulting in a total loss of the premium paid. Understanding these dynamics is crucial when trading call options. It allows you to make informed decisions about when to enter and exit positions, taking into account factors such as the underlying asset's price movements, time decay, and market sentiment. Buying call options can provide an alternative strategy to gain long exposure to a stock's price movement without the need for purchasing shares directly. This approach, known as a long call position, offers the potential advantage of lower capital outlay compared to buying shares outright. However, it's crucial to understand the concept of time decay, which significantly impacts the value of long call options. Time decay refers to the gradual decrease in the value of an option as time passes. This phenomenon occurs due to two primary factors: theta and vega. Theta measures the rate at which an option's value decays over time, while vega measures the sensitivity of an option's price to changes in implied volatility. As the expiration date of the call option approaches, both theta and vega work together to erode the option's value. Consequently, to offset the impact of time decay, the underlying stock price must rise at a greater velocity towards the call option's strike price. This is because the intrinsic value of a call option, which represents the difference between the strike price and the underlying stock's current market price, increases as the stock price moves higher. Another important consideration when evaluating call options is the distinction between out-of-the-money (OTM) and in-the-money (ITM) calls. OTM calls have a strike price higher than the current market price of the underlying stock, while ITM calls have a strike price lower than the current market price. OTM calls are typically less expensive than ITM calls because their value is composed entirely of extrinsic value. Extrinsic value refers to the portion of an option's price that is not attributable to its intrinsic value. ITM calls, on the other hand, have both intrinsic and extrinsic value, resulting in a higher cost per contract. As time relentlessly marches forward, the value of call options undergoes a transformation. The extrinsic value, which represents the premium paid for the potential of future price movements, steadily diminishes as expiration approaches. This decay is universal, affecting all call options regardless of their initial strike price or distance from the underlying asset's current price. However, amidst this gradual erosion of extrinsic value, ITM (in-the-money) call options stand as an exception. These options retain their intrinsic value at expiration, which is the difference between the strike price and the underlying asset's price. This characteristic sets ITM call options apart from their OTM (out-of-the-money) counterparts, whose extrinsic value decays entirely to zero near or at expiration. The distinction between ITM and OTM call options underscores the significance of carefully considering both the time frame and strike price when making investment decisions. Traders seeking to maximize their potential gains through call options must be mindful of the impending decay of extrinsic value as expiration draws near. For long ITM call options, the ideal scenario is for the underlying asset to exhibit a significant upward movement. Such a price increase would enhance the intrinsic value of the option, making it worth more at expiration than the initial purchase price. This scenario holds true for OTM call options as well, as they require the underlying asset to move ITM at expiration to possess any value. Prior to expiration, both OTM and ITM call options have the potential to gain a combination of extrinsic and intrinsic value if the stock exhibits a rapid upward trajectory. This dynamic underscores the importance of monitoring market conditions and adjusting investment strategies accordingly. Understanding the Interplay of Time, Strike Price, and Option Value in Call Option Trading: In the realm of call option trading, comprehending the intricate interplay between time, strike price, and option value is paramount to success. These three factors collectively shape the dynamics of call option contracts, allowing traders to make informed decisions and capitalize on market opportunities. Time (Days to Expiration): Time, measured in days until expiration, is a crucial element in call option trading. As expiration approaches, the value of a call option is directly influenced by the time premium. The closer an option gets to expiration, the less time value it holds. This time decay accelerates in the final days leading up to expiration. Therefore, traders must carefully consider the time factor when selecting their expiration dates. Strike Price: The strike price represents the predetermined price at which the underlying asset can be bought (in the case of a call option) or sold (in the case of a put option). When choosing a strike price, traders must assess the current market price of the underlying asset and make an educated guess about its future direction. ITM (In-the-Money) call options are those with a strike price below the current market price, while OTM (Out-of-the-Money) call options have a strike price above the current market price. Option Value: Option value refers to the premium paid by the buyer of an option contract to the seller. This premium comprises two components: intrinsic value and time value. Intrinsic value is the difference between the strike price and the underlying asset's current market price. Time value, as mentioned earlier, is the premium paid for the remaining time until expiration. Auto-Exercise and Expiration Scenarios: Auto-Exercise: Long call options that expire ITM by $0.01 or more will be automatically exercised. This means that the buyer of the call option has the right to purchase the underlying asset at the strike price. If the investor holds only a long call, this will result in 100 long shares per contract purchased at the call option's strike price. On the other hand, investors holding the corresponding short shares will cover or buy shares at the call option's strike price. Expiration Worthless: Any long call options that expire OTM will expire worthless. In this scenario, the investor loses the entire premium paid for the contract, resulting in a maximum loss. Understanding these concepts is instrumental in developing effective call option trading strategies. By carefully considering the interplay between time, strike price, and option value, traders can position themselves to make profitable trades and minimize potential losses. PROFIT & LOSS DIAGRAM OF A LONG OTM CALL A long OTM call option can be profitable if the current market value of the option exceeds the price paid to purchase it. This can occur in two main scenarios: Stock Price Surpasses Strike Price: If the underlying asset's price rises above the strike price of the call option by more than the premium paid for the option, the call option becomes profitable. This is because the intrinsic value of the call option (the difference between the strike price and the underlying asset's price) becomes positive, and the call option can be exercised to purchase the underlying asset at a price below the market price. OTM Call Moves Closer to Underlying Asset Price: Even if the underlying asset's price does not reach the strike price, a long OTM call can still be profitable if the option's price increases. This can happen when there is a quick rally in the underlying asset's price, causing the call option's price to increase as well, even if the strike price is not reached. This is because the time value of the call option increases as the expiration date approaches, and the call option becomes more likely to be in the money. However, it's important to note that long OTM call options can also result in losses if the underlying asset's price does not surpass the breakeven point. The breakeven point is the price at which the call option's intrinsic value becomes equal to the purchase price of the option. If the underlying asset's price remains below the breakeven point until expiration, the call option will expire worthless, and the investor will lose the entire amount paid for the option. The maximum profit potential of a long OTM call option indeed has no theoretical limit, as a stock's price can theoretically rise indefinitely. This means that if the underlying stock price increases significantly, the call option holder can potentially reap substantial profits by exercising the option and buying the stock at the predetermined strike price. On the downside, the maximum loss on a long call option is limited to the premium paid for the option. This premium represents the total amount invested in the option contract and acts as a protective barrier against further losses. If the stock price declines or stays below the strike price at expiration, the option will expire worthless, and the investor will lose the entire premium paid. The flattened red loss zone in the diagram illustrates this limited loss potential. This zone represents the range of stock prices below the strike price at expiration where the option holder will lose money. The loss amount decreases as the stock price approaches the strike price and becomes zero when the stock price equals the strike price. Beyond the strike price, the option holder starts to make a profit. It's important to note that while the maximum profit potential is theoretically unlimited, it is highly unlikely for a stock price to rise dramatically within the short timeframe of an OTM option's expiration period. Therefore, while the potential rewards can be significant, the probability of achieving them is relatively low. PROFIT & LOSS DIAGRAM OF A LONG ITM CALL ITM (In-the-Money) options have a unique characteristic where the price of their intrinsic value directly correlates with the underlying asset's price. This means that for every one point movement in the underlying asset's price, the ITM option's intrinsic value moves by the same amount. While purchasing an ITM option provides immediate intrinsic value, it does not guarantee profitability upon execution. Similar to buying an OTM (Out-of-the-Money) call option, the purchase price of an ITM call must increase for it to be profitable. This requires the stock price to move further above the call strike price. This relationship is visually represented in the diagram, where the red and green zones converge on the x-axis. The maximum potential loss on a long call option is limited to the debit paid for the option, which is represented by the flattened red area in the diagram. This means that the most an investor can lose on a long call is the premium paid for the option, regardless of how far the underlying asset's price moves below the strike price. Understanding the price dynamics and potential risks associated with ITM options is crucial for traders and investors. While ITM options offer immediate intrinsic value, careful analysis and consideration of market conditions are necessary to determine their potential profitability. EXAMPLE OF A LONG OTM CALL OPTION XYZ currently trading @ $45 Buy to Open +1 XYZ 50-strike call @ $4 debit Cost: $4 debit ($400 total, ($4 x 100 shares)) Time Decay Affect Works against the optionâs value Max Profit Theoretically unlimited Max Loss Debit paid per contract ($400) Breakeven Price (at expiration) Strike price + debit paid ($54) Account Type Required Cash, Margin, and IRA EXAMPLE OF A LONG ITM CALL OPTION XYZ currently trading @ $45 Buy to Open +1 XYZ 40-strike call @ $7 debit ($5 intrinsic value + $2 extrinsic value) Cost: $7 debit ($700 total) Time Decay Affect Works against the optionâs value Max Profit Theoretically unlimited Max Loss Debit paid per contract ($700) Breakeven Price (at expiration) Strike price + debit paid ($47) Account Type Required Cash, Margin, and IRA
Received: 26 November 2019 Revised: 10 January 2020 Accepted: 19 January 2020 DOI: 10.1111/obr.13005 PEDIATRICS/PHYSIOLOGY Adipokines: A gear shift in puberty DesirĂ©e Nieuwenhuis | NatĂ lia Pujol-Gualdo Amanda J. Kiliaan Department of Anatomy, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Preclinical Imaging Center PRIME, Nijmegen, The Netherlands Correspondence Amanda J. Kiliaan, PhD, Associate Professor, Department of Anatomy, Donders Institute for Brain, Cognition, and Behaviour, Preclinical Imaging Center PRIME, Radboud university medical center, 6500 HB Nijmegen, Geert Grooteplein 21N 6525 EZ Nijmegen, The Netherlands. Email: amanda.kiliaan@radboudumc.nl Funding information Europees Fonds voor Regionale Ontwikkeling (EFRO), Grant/Award Number: BriteN 2016 1 | INTRODUCTION The prevalence of obesity in adolescents and children is increasing in | Ilse A.C. Arnoldussen | Summary In this review, we discuss the role of adipokines in the onset of puberty in children with obesity during adrenarche and gonadarche and provide a clear and detailed overview of the biological processes of two major players, leptin and adiponectin. Adipokines, especially leptin and adiponectin, seem to induce an early onset of puberty in girls and boys with obesity by affecting the hypothalamic-pituitary- gonadal (HPG) axis. Moreover, adipokines and their receptors are expressed in the gonads, suggesting a role in sexual maturation and reproduction. All in all, adipokines may be a clue in understanding mechanisms underlying the onset of puberty in child- hood obesity and puberty onset variability. KEYWORDS adipokines, obesity, puberty 1,2 the age of 5 years were overweight or were with obesity in 2016, and 3 Obesity is defined by an excessive accumulation of white adipose tissue (WAT), and it is often indicated by a body mass index (BMI) 4 above 30. Two main types of adipose tissue were described: WAT and brown adipose tissue (BAT), which differ in morphology and func- 5-7 Ilse A.C. Arnoldussen and Amanda J. Kiliaan contributed equally to this work. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2020 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity Federation Obesity Reviews. 2020;21:e13005. wileyonlinelibrary.com/journal/obr 1 of 10 https://doi.org/10.1111/obr.13005 alarming rates. Specifically, worldwide, 41 million children below this number is expected to increase to 70 million in 2025. obesity is associated with various severe health complications, includ- ing increased risk of diabetes mellitus type 2, hypertension, heart dis- eases, and disturbances in sex hormone levels. 5,6 and mitochondria and plays a role in thermogenesis. Adipocytes in tion. BAT consists of adipocytes containing multiple lipid droplets WAT contain only a few mitochondria and a single lipid droplet. Adipose tissue has several functions including the storage of energy, thermogenesis, and the production and secretion of adipokines Generally, two physiological processes, adrenarche and gonadarche, 11,24 Childhood 5,7,8 a key role in puberty onset. Puberty is known as a period through which the body changes physically, being a physiological process resulting in the maturation of children, i.e. they develop sexual characteristics and obtain reproduc- 9,11 Adipokines are involved in a number of physiological processes including blood pressure, metabo- lism, glucose, and vascular homeostasis and may play amongst others 8-10 (hormones, cytokines, and peptides). tive functions. between obesity and puberty,2,12-23 the biological mechanisms under- lying obesity and puberty onset remain unclear. Hereafter, we review in detail the role of adipokines in the onset of puberty in childhood obesity. Although many studies have shown associations 2 | INITIATION OF PUBERTY PHYSIOLOGICAL PROCESSES IN THE interact to regulate the onset of puberty. During adrenarche, the adrenal cortex secretes steroid hormones (including 2 of 10 NIEUWENHUIS ET AL. androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, and cortisol), insulin-like growth factor, and growth hormone, which contribute to the pubertal insights on new genetic loci (e.g. melanocortin-4 receptor, mitochon- drial carrier 2, and mitogen-activated protein kinase 13) and on sev- eral pathways that regulate the timing of puberty; however, it partly 34 9,24,25 Both adrenarche and gonadarche are involved in the development growth spurt, body odor, skin oiliness, and skeletal maturation. explains puberty timing variation. Thereby, defining the role of 25 adipokines is of importance in elucidating the variability in puberty as the expression of adipokines is sex-specific and is altered with body composition, adiposity, and during growth spurts. Moreover, adipokines and their receptors are expressed in gonads and several brain regions suggesting involvement in the onset of puberty and sex- ual maturation. Lastly, adipokines interfere in processes regulating timing and duration of puberty, for instance in the HPA and HPG axes which are both key players during adrenarche and gonadarche. Involvement of adipokines in the onset of puberty and specifically in individuals with obesity will be further reviewed in the next 2,24 3 | Puberty onset in girls is assessed using different markers, such as thelarche (breast development), menarche (the start of of pubic hair. pituitary-gonadal (HPG) axis is activated,2,26 and several hormones have been identified to participate in the activation of the HPG axis During gonadarche (Figure 1), the hypothalamic- 2,27 Kisspeptin, neurokinin B, and dynorphin are released by specialized including kisspeptin, neurokinin B, dynorphin, leptin, and ghrelin. 28 key regulator of the pulsatile secretion of gonadotropin releasing neurons, the KNDy neurons in the hypothalamus. Kisspeptin is a 29,30 B stimulates, and dynorphin inhibits the release of kisspeptin, which hormone (GnRH) from the hypothalamus. In addition, neurokinin implies that both coordinate a pulsatile release of kisspeptin. 31 Sub- sections. sequently, the activated HPG axis induces the pituitary gland to secrete luteinising hormone (LH) and follicle stimulating hormone (FSH). As a result, gametogenesis occurs, and the gonads will release sex hormones. Consequently, secondary sex characteristics develop including breast development in girls and an increased testicular vol- 2,26,32 is possibly due to differences in levels of body fat, hypothalamic-pitui- THE ONSET OF PUBERTY IN GIRLS ume in boys. The age at puberty onset varies greatly among individuals, which 19 35 menstruation), and pubic hair development. 33 genome-wide association studies have provided important new tary-adrenal (HPA) axis activity, and genetic background. Recent The average age of However, this age differs between cultures and ethnicities, and since 1980, age at menarche is girls at start of menarche is 12.4 years. 36 significantly decreasing. 36-39 F I G U R E 1 Hormonal regulation in the initiation of puberty in boys and girls. The secretion of kisspeptin, neurokinin B, and dynorphin from KNDy neurons initiate the release of gonadotropin releasing hormone (GnRH) from the hypothalamus. This activates the pituitary gland to produce and secrete luteinising hormone (LH) and follicle stimulating hormone (FSH), which in turn stimulate the gonads to produce estrogen and testosterone in girls and boys, respectively 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License NIEUWENHUIS ET AL. 3 of 10 T A B L E 1 Summary of included studies Authors Year Country Study Design Primary Outcome Sex Sample Size (n) Age (y) Data Collection Lian et al21 2019 China Cross-sectional Puberty starts earlier in Chinese Han girls with obesity compared with Chinese Han girls with normal weight. Girls 2996 9-19 2012 and 2013 Biro et al12 Lazzeri et al20 2018 USA 2018 Italy Longitudinal Cross-sectional Body mass index had a greater effect on age at menarche than did race and ethnicity. Girls 946 6-16 2004-2014 Li et al23 2018 China Longitudinal For both, boys and girls, a higher BMI (ie, overweight and obese) is associated with earlier onset of puberty Girls Girls Boys Girls 542 Deng et al22 Flom et al15 2017 China Cross-sectional Increased BMI is associated with early timing spermarche and menarche. Boys Girls Girls 1278258 9-15 2005-2012 He et al24 Holmgren et al17 2017 China 2017 Sweden Cross-sectional Longitudinal Onset of puberty is not related to obesity in boys. Boys Boys Girls Girls 782 7-17 972 929 5839 Kelly et al19 2017 UK 2016 Brazil 2016 USA Longitudinal prospective cohort Higher BMI in girls is associated with the onset of menstruation at an earlier age. 11 10-18 11-17 Barcellos Gemelli et al25 Cross-sectional Longitudinal Excess weight is associated with early age of menarche. Girls 727 2014 2003-2009 Glass et al16 Lee et al26 In girls, but not in boys, greater adiposity is associated with the earlier onset of puberty. Boys Girls 135 Cabrera et al27 Leonibus et al14 2014 USA 2013 Italy Cross-sectional Longitudinal Thelarche occurred earlier than recently reported, while age of menarche remained unchanged. Girls 610 3-17.9 2007 2005-2012 Currie et al13 2012 Europe, USA, Canada Cross-sectional Overweight/obesity during childhood predicts the early onset of puberty in girls. Girls 20410 11, 13, 15 2005-2006 2017 USA Prospective birth cohort Overweight/obese status at the age of 7 ye was associated with increased risk of early menarche 788 From birth to menarche occurred Pregnancies 1959-1966 2016 USA Cross-sectional Boys with overweight enter puberty earlier compared with boys with normal weight or obesity, while puberty starts later in boys with obesity compared with boys with normal weight and overweight. Boys 3872 6-16 2005-2010 Overweight during childhood shows a relation with the early onset of puberty in girls. 6535 4259 695 11 15 5.8-12.2 2009/2010 2013/2014 2014-2017 Higher BMI during childhood is associated with early puberty. 2008 and 2009 2000-2002 Obesity during childhood is related to the earlier onset of puberty. Boys Girls 84 123 71 (Continues) 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 4 of 10 NIEUWENHUIS ET AL. 3.1 | Fat storage For the initiation of puberty, the timing of stimulation and/or inhibi- tion of different hormones is important, and additionally, a certain amount and distribution of body fat is needed in order to start menar- che, which emphasizes the importance of body fat. From an evolution- ary point of view, body fat increases in mammalian females during puberty onset, and it highlights the need to guarantee a healthy preg- 40 women with anorexia nervosa. particularly body fat localized predominantly on the gluteofemoral fat depots, is profoundly associated with start of menarche, more than nancy, offspring, and maternal survival. fat, sex-hormones, and neuroendocrine alterations can evolve in men- strual dysfunction, for instance, in women with severe obesity or in 41-43 44-46 to gluteofemoral fat depots suggesting that leptin may convey infor- amount of total body fat. mation on body fat distribution to the hypothalamus during puberty. An improper level of body Importantly, body fat distribution, Blood leptin levels are strongly related 45 3.2 | HPG axis The HPG axis is activated by the release of kisspeptin resulting in the release of GnRH from the hypothalamus, and LH and FSH from the pituitary gland. In girls, FSH is involved in the development of the folli- cles in the ovaries, and it promotes the secretion of estrogen. LH stim- ulates the production of androgen hormones and induces ovulation 48 9,47 the release of kisspeptin and neurokinin B, and kisspeptin thereby (Figure 1). The secretion of estrogen has an inhibitory effect on inhibits the GnRH release from the hypothalamus. pattern of GnRH is important for the regulation of the menstrual cycle. This roughly 28-day-cycle comprises several phases, including the follicular phase and luteal phase. During the follicular phase, increasing levels of FSH stimulate the maturation of follicles and the production of estrogen from the ovaries. This in turn inhibits the release of FSH from the pituitary gland. A high level of estrogen will induce the production of LH by the pituitary gland, resulting in ovula- tion. The matured follicle secretes progesterone thereby inhibiting the release of GnRH. When the corpus luteum is demolished, there is less 48 3.3 | Adipokines According to results from studies reported in Table 1, girls with obe- sity enter puberty earlier compared with girls with normal higher leptin concentrations inhibit the intake of food and increases inhibition of GnRH. As a consequence, the cycle will start again. whole process, starting from the activated HPG axis, results in the development of the secondary sex characteristics in girls including 9,47 thelarche and menarche. 13,14,16-23,49-51 weight. these girls might be found in the secretion of adipokines. For instance, leptin is positively associated with the amount of body fat. Generally, energy expenditure. 9,52-54 An explanation for the early onset of puberty in The expression This TABLE 1 (Continued) Authors Year Country Study Design Primary Outcome Sample Sex Size (n) Age (y) Data Collection Herman-Giddens et al28 2012 USA Cross-sectional Observed mean ages of beginning genital and pubic hair growth and early testicular volumes were earlier than in past studies, depending on the characteristic and race/ethnicity. Boys 4131 6-16 2005-2010 Sorensen et al29 Aksglaede et al30 2010 2009 Denmark Denmark Cross-sectional/longitudinal Longitudinal Puberty onset at earlier ages was associated with an increased BMI in boys. Boys 1528 5.8-19.9 1991-1993/2006-2008 1930-1969 Juul et al31 Ribeiro et al32 2007 2006 Denmark Portugal Retrospective cohort Cross-sectional Higher BMI is associated with early voice break. 11-15 10-15 1990-1999 Kaplowitz et al18 Abbreviation: BMI, body mass USA Cross-sectional The early onset of puberty in Caucasian girls is likely related to an increased BMI. 5-12 1992-1993 2001 index. The higher BMI in boys and girls at 7 y of age, the earlier they enter puberty. Boys 21 612 Girls 135 223 Boys 463 Boys 382 Girls 437 Girls 10 750 Early sexual maturation in boys and girls is associated with overweight. 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License NIEUWENHUIS ET AL. 5 of 10 Leptin may possibly play a role in adrenarche as its plasma level increases with higher levels of body fat and as it can modulate both girls. 33 ing adrenarche. In coherence, in children with obesity, the androgen These findings suggested that lower reproductive status was associated with higher total adiponectin concentrations and that a higher reproductive status was related to higher HMW adiponectin the HPA and HPG axes. These axes are functionally integrated dur- DHEAS was positively associated with leptin levels. Nevertheless, concentrations in girls. In addition, individuals with obesity often another study showed that enhanced adrenal androgen secretion in girls with premature adrenarche was not explained by leptin or BMI 55 ated with androgen levels in girls ; however, it was not related to levels. and IL-6. TNF-α alters, and IL-6 inhibits the expression of 56 8 In addition, the adipokine adiponectin was negatively associ- 57 differences of adiponectin seem to develop during the progression of 56 adiponectin (Figure 2). Thereby, a low level of total adiponectin and/or high levels of inflammatory cytokines in individuals with obe- sity can promote the onset of puberty. Many more adipokines are secreted by WAT including omentin, 52,65-67 9,36,62,68 adrenarche in girls with Prader-Willi syndrome. Interestingly, sex puberty. adrenarche; however, both are not required factors. Thus, leptin and adiponectin might be able to influence In gonadarche, leptin can stimulate the secretion of kisspeptin, and subsequently activation of the HPG axis, which eventually increases the expression of estrogen and androstenedione in the ova- 58 2,60 65-67 The expression of these ries (Figure 2). Ob gene in WAT, resulting in the synthesis and secretion of leptin. Thus, high levels of leptin promote onset of puberty in girls via secre- tion of kisspeptin, and estrogen stimulates leptin secretion addition- ally. Moreover, adiponectin can affect the HPG axis due to the expression of adiponectin receptors in the hypothalamus, pituitary In return, estrogen stimulates the expression of the 59 gland, and gonads. onset as it inhibits the secretion of kisspeptin and GnRH in the hypo- thalamus and the release of GH and LH in the pituitary gland, and 2,60-62 52,60 63 girls with central precocious puberty (CPP). Moreover, total adiponectin had negative correlations with progression of puberty in girls (defined by Tanner stages), whereas HMW adiponectin had FIGURE 2 Adipokinesaffectingthe initiation of puberty in girls. Leptin stimulates the release of kisspeptin in KNDy neurons, which activates the hypothalamus to produce gonadotropin releasing hormone (GnRH). In response to the release of GnRH, the pituitary gland secretes follicle stimulating hormone (FSH) and luteinising hormone (LH), which stimulates the ovaries to release estrogen resulting in the formation of secondary sex characteristics in girls. Estrogen stimulates the production of leptin. Adiponectin inhibits GnRH release resulting in reduced levels of GnRH and thereby a delayed onset of puberty. TNF- α and IL-6 inhibit the production of adiponectin and therefore stimulate the onset of puberty In detail, adiponectin is a regulator of puberty thereby inhibiting the onset of puberty (Figure 2). with obesity often have low levels of adiponectin. et al. showed that total adiponectin was significantly lower, whereas high molecular weight (HMW) adiponectin was significantly higher in ment. 55 63 develop a chronic low-grade inflammatory state, which can be indi- cated by a high level of circulating inflammatory cytokines like TNF-α 64 Individuals Sitticharoon positive associations with LH levels and the progression of puberty in 63 visfatin, resistin, and chemerin. and visfatin are expressed in the ovaries. adipokines in the ovaries suggests a role within the reproductive sys- tem; however, the exact biological processes have to be examined. Thus, specifically leptin, adiponectin, and inflammatory cytokines pro- duced by WAT could be permissive key players during an early onset of puberty in girls with obesity. As an exception, HMW adiponectin seems to have a stimulatory effect on peripheral repro- ductive function as HMW is not able to cross the blood brain 63 barrier. 4 | Markers that are used to assess puberty onset in boys are THE ONSET OF PUBERTY IN BOYS spermarche, voice break, testicular volume, and pubic hair develop- 35 spermarche develop in the early stages of puberty onset, voice In women, omentin, chemerin, While pubic hair development, larger testicular volume, and 69 testicular volume increases, which occurs at an average age of break usually appears in later stages of puberty. Generally, first 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 6 of 10 NIEUWENHUIS ET AL. 11.9 years, followed by the development of pubic hair at 12.2 years of average, and lastly, boys experience spermarche around an aver- 55 related with leptin levels. Thereby, leptin plausibly has a minor impact in adrenarche in boys. Since leptin receptors are found in the hypothalamus, pituitary gland, and testes, they might be involved in the onset of puberty by affecting the HPG axis during gonadarche. Leptin stimulates the release of kisspeptin and GnRH, and as a consequence, it accelerates the onset of puberty (Table 1, Figure 3). In contrast, adiponectin inhibits the secretion of GnRH, GH, LH, and FSH therewith delaying the onset of puberty. However, adiponectin levels are generally lower in men compared with women and even lower in men with obe- age age of 13.4 years. 70 4.1 | Fat storage Many aspects of the reproductive physiology are energetically demanding,71 and therefore, an adequate energy level is necessary. In boys, a dynamic change in body composition occurs around the age of 10 to 13 years, in which they gain approximately 40% of sity. culating inflammatory cytokines. levels can stimulate the HPG axis and therewith an early onset of puberty in boys. Nevertheless, leptin can inhibit the production of tes- 72 mostly consisting of lean mass, which causes exhaustion of most of fat. Subsequently, a growth spurt follows in which they gain tissue 72 in boys, an adequate amount of body fat is important in the onset of their body fat. These alterations in amount of body fat indicate that 4.2 | Puberty in boys is initiated by the release of kisspeptin. As mentioned before, this activates the HPG axis, resulting in the release of GnRH from the hypothalamus, and consequently the release of LH and FSH 9,74 puberty. tosterone from the testes, to estrogen (Figure 3). of the development of secondary sex characteristics in boys. Additionally, leptin can affect fertility in men as it can modulate the nutritional support of spermatogenesis, and moreover, dysfunction of spermatogenesis is associated with an increased leptin level and 73 58 2,60-62 HPG axis from the pituitary gland (Figure 1). and LH stimulates the secretion of testosterone from the testes, which inhibits the release of kisspeptin from the KNDy neurons and 9,48 in men, the release of kisspeptin is more consistent, causing a con- 29,48 subsequently GnRH from the hypothalamus. receptors expressed on KNDy neurons. In humans, KNDy neurons Contrarily to women, LH-induced testosterone levels lead to the stant release of LH. development of secondary sex characteristics in boys. differences between sexes in kisspeptin release are related to a sex- specific and sex steroid-dependent kisspeptin system as estrogen and progesterone modulate kisspeptin activity through the sex-steroid 48 in the infundibular nucleus are involved in negative and positive sex- 48 tal exposure to sex steroids and result in sex-specific differences in steroid feedbacks. kisspeptin release. These sexual dimorphisms are induced by perina- 75,76 4.3 | Adipokines The association between obesity and puberty onset in boys is rather controversial compared with findings in girls. Most studies reported an early onset of puberty in boys associated with increased ate adipose tissue from actual breast tissue. stages are more difficult to assess than female stages as boys lack a more determined marker such as menarche. Thirdly, puberty onset can be indicated by the activation of the HPG axis, and the presence of these secondary sex characteristics is the result of hormonal 2 14,17,22,23,50,51,77,78 BMI, 20,49 all while others reported no associations at Current markers used 79 16,80 or a delayed onset of puberty (Table 1). The presence of excessive adipose tissue can be involved in puberty onset in boys as the secretion of adipokines can modulate both adrenarche and gonadarche. Leptin can affect adrenarche by modulating both the HPG and HPA axes,33 and moreover, androgen levels were positively 55 nal androgen secretion in boys with premature adrenarche was not associated with plasma leptin levels. Nevertheless, enhanced adre- 9 In more detail, 61,62 adiponectin, and individuals with obesity often have high levels of cir- Moreover, inflammatory cytokines, TNF-α, and IL-6, inhibit expression of the leptin receptor in the testis. FSH induces spermatogenesis, too. function and role still have to be examined. 64 High leptin and low adiponectin and fat tissue can convert testosterone Both processes might result in the delay 29,61,79 81,82 In men, other adipokines like chemerin are found in the gonads 65 Thus, particularly high leptin and low adiponectin levels stimulate the HPG axis and thereby accelerate the onset of puberty in boys. Additionally, leptin can dysregulate the development of secondary sex characteristics and spermatogenesis by affecting testosterone levels and nutritional sup- port of spermatogenesis. 5 | LIMITATIONS AND FUTURE RESEARCH DIRECTIONS Even though multiple epidemiological studies have shown the link between puberty onset and obesity, there are some important limita- tions. Firstly, determining both the onset and stage of puberty is rather difficult. For instance, assessing the stage of breast develop- ment in girls with obesity is complicated as clinicians should differenti- 2 changes in response to the activated HPG axis. to determine the onset of puberty refer to secondary sex characteris- tics, such as testicular volume in boys and breast development in girls. A more accurate measurement of puberty onset would be to combine secondary sex characteristics with plasma or serum hormone level measurements such as LH, FSH, adipokines, e.g. leptin. Thereby, differences in puberty measurements could explain variations in the age of puberty onset between boys and girls within different Thereby, resistin is expressed in the testes of rats, but its exact 83 Secondly, male pubertal 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License NIEUWENHUIS ET AL. 7 of 10 FIGURE 3 Adipokines affecting the initiation of puberty in boys. Leptin activates kisspeptin secretion in KNDy neurons, this activates the production of gonadotropin releasing hormone (GnRH) from the hypothalamus. GnRH stimulates the pituitary gland to secrete follicle stimulating hormone (FSH) and luteinising hormone (LH), activating the production of testosterone from the testes allowing the development of secondary sex characteristics. Leptin also inhibits the production of testosterone, which may cause a delayed onset of puberty. Adiponectin inhibits GnRH release. Low levels of adiponectin, as a result of TNF-α and IL-6 expression, lead to a reduced inhibition of GnRH. In response to GnRH release, the pituitary gland will secrete FSH and LH, and the testes will produce testosterone resulting in the development of secondary sex characteristics in boys countries, and In addition, the inclusion of a of puberty. ferent time points is complicated, as subjects examined several decades ago presented pronounced differences concerning lifestyle patterns such as nutrition and exercise habits. Lastly, obesity or over- weight is often determined by BMI, a classification based on weight and height measurements. Additionally, it is important that all studies studies or across continents, ethnicities proper age range (8-16 years) is important when assessing the onset (Figure 4). 12-15,17,20-23,49,77-79,84,85 30,47 Furthermore, comparison between studies from dif- 86 Specifically in children, BMI is often dependent on age and growth use the same anthropometric standards and sex-specific cut-offs. 13,14,16-23,49-51,77-80 fat and would represent a more accurate measurement in its regard. Based on this review, several suggestions can be made for further research. Firstly, the roles of adipokines like resistin, chemerin, visfatin, and omentin in puberty onset, fertility, and sexual maturation should be examined in detail. Secondly, future research examining the onset of puberty should combine indicators of puberty onset (e.g. breast development or testicular volume) with plasma or serum hor- mone measurements such as LH, FSH, sex-steroids, adipokines (e.g. spurts. ment in case of growth spurts. distribution of body fat should be taken into account in determining puberty and obesity in children. For instance, the body adiposity index (BAI), which was introduced in 2011 by Bergman et al.,87 uses hip cir- cumference and height in order to estimate the percentage of body 87 Thereby, BMI is a less accurate measure- F I G U R E 4 87,88 Therefore, both percentage and Average age of puberty onset in Europe, China, and the United States according to several studies from Table 1. Age of puberty onset ranges from 8.47 to 13.33 years in girls and from 8.63 leptin), and body fat distribution (e.g. BAI,87 waist-hip ratio's and/or dual-energy X-ray absorptiometry (DXA)2). Additionally, defining con- sistent and general measurements of puberty in both boys and girls, combined with a proper age range (8-16 years), would facilitate the comparisons between different studies and their results. 12-15, 17, 20-23, 25-29, 31 to 13.7 years in boys. included if average age of markers used to assess puberty was not reported. Pink: girls. Blue: boys Studies (Table 1) were not 39, 56 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 8 of 10 NIEUWENHUIS ET AL. 6 | CONCLUSION In conclusion, epidemiological data regarding obesity and puberty onset in girls show similar outcomes as adiposity results in the early onset of puberty in girls. The majority of the studies examining boys with obesity indicate an early onset of puberty, while not all reported an earlier onset of puberty. In detail, high leptin, TNF-α, and IL-6 levels combined with low adiponectin levels stimulate the activation of the HPG axis in girls and boys with obesity, and 5, 45, 50, 51 REFERENCES 1. Kumar S, Kelly AS. Review of childhood obesity: from epidemiology, etiology, and comorbidities to clinical assessment and treatment. May- o Clin Proc. 2017;92(2):251-265. 2. Reinehr T, Roth CL. Is there a causal relationship between obesity and puberty? The Lancet Child & adolescent health. 2019;3(1):44-54. 3. WorldHealthOrganization. Facts and figures on childhood obesity. 2017. 4. Guglielmi V, Sbraccia P. Obesity phenotypes: depot-differences in adipose tissue and their clinical implications. Eat Weight Disord. 2018; 23(1):3-14. 5. Gomez-Hernandez A, Beneit N, Diaz-Castroverde S. Escribano O. 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FUNDING INFORMATION This research was funded by Europees Fonds voor Regionale Ontwikkeling (EFRO), project BriteN 2016. ORCID Ilse A.C. Arnoldussen Amanda J. Kiliaan https://orcid.org/0000-0002-7395-5284 https://orcid.org/0000-0002-2158-6210 13, 14, 16-26, 29-32 Furthermore, several receptors Nevertheless, We conclude Search strategy We searched PubMed for articles published before Novem- ber 15th, 2019 using relevant keywords, including âonset of puberty and adiposity/obesityâ, âonset of pubertyâ, âchildren with obesityâ, âadipose tissueâ, âchildhood obesityâ, âadiposityâ, âobesityâ, âadipokine(s)â, âHPG axisâ, âadipokines ovary/ova- riesâ, or âadipokines testesâ, either alone or in combination. 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Obesity Reviews. 2020;21:e13005. https://doi.org/ 10.1111/obr.13005 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are gover