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#1 Science HQ » Convex Mirror » Today 16:51:08
- Jai Ganesh
- Replies: 0
Convex Mirror
Gist
A convex mirror is a spherical mirror with a reflecting surface that bulges outwards, causing it to diverge light rays and provide a wider field of view, making it ideal for rearview mirrors and security surveillance where it forms upright, virtual, and diminished (smaller) images.
Convex mirrors are used as rear-view mirrors in vehicles because they provide a wider field of view. This helps drivers see more traffic and reduces blind spots, improving safety on roads. Key reasons include: Forming erect, virtual, and diminished images.
Summary
Convex Mirror is a curved mirror where the reflective surface bulges out toward the light source. This bulging-out surface reflects light outwards and is not used to focus light. These mirrors form a virtual image as the focal point (F), and the centre of curvature (2F) are imaginary points in the mirror that cannot be reached. This results in the formation of images that cannot be projected on a screen as the image is inside the mirror. The image looks smaller than the object from a distance but gets larger as the object gets closer to the mirror.
Uses of Convex Mirror
* Convex mirrors are often used in buildings’ hallways, including stores, schools, hospitals, hotels and apartment buildings.
* They are used in driveways, roads, and alleys to provide safety to all the bikers and motorists at curves and turns and other places where there is a lack of visibility.
* They are also used in some automated teller machines as a handy security feature that allows users to see what is happening behind them.
* They are used in the passenger side mirror on a car, and somewhere it is labelled as “ objects in mirror are closer than they appear” to warn the driver.
Details
A convex mirror or diverging mirror is a curved mirror in which the reflective surface bulges towards the light source. Convex mirrors reflect light outwards, therefore they are not used to focus light. Such mirrors always form a virtual image, since the focal point (F) and the centre of curvature (2F) are both imaginary points "inside" the mirror, that cannot be reached. As a result, images formed by these mirrors cannot be projected on a screen, since the image is inside the mirror. The image is smaller than the object, but gets larger as the object approaches the mirror.
A collimated (parallel) beam of light diverges (spreads out) after reflection from a convex mirror, since the normal to the surface differs at each spot on the mirror.
Uses
The passenger-side mirror on a car is typically a convex mirror. In some countries, these are labeled with the safety warning "Objects in mirror are closer than they appear", to warn the driver of the convex mirror's distorting effects on distance perception. Convex mirrors are preferred in vehicles because they give an upright (not inverted), though diminished (smaller), image and because they provide a wider field of view as they are curved outwards.
These mirrors are often found in the hallways of various buildings (commonly known as "hallway safety mirrors"), including hospitals, hotels, schools, stores, and apartment buildings. They are usually mounted on a wall or ceiling where hallways intersect each other, or where they make sharp turns. They are useful for people to look at any obstruction they will face on the next hallway or after the next turn. They are also used on roads, driveways, and alleys to provide safety for road users where there is a lack of visibility, especially at curves and turns.
Convex mirrors are used in some automated teller machines as a simple and handy security feature, allowing the users to see what is happening behind them. Similar devices are sold to be attached to ordinary computer monitors. Convex mirrors make everything seem smaller but cover a larger area of surveillance.
Round convex mirrors called Oeil de Sorcière (French for "sorcerer's eye") were a popular luxury item from the 15th century onwards, shown in many depictions of interiors from that time. With 15th century technology, it was easier to make a regular curved mirror (from blown glass) than a perfectly flat one. They were also known as "bankers' eyes" because their wide field of vision was useful for security. Famous examples in art include the Arnolfini Portrait by Jan van Eyck and the left wing of the Werl Altarpiece by Robert Campin.
Image
The image on a convex mirror is always virtual (rays haven't actually passed through the image; their extensions do, like in a regular mirror), diminished (smaller), and upright (not inverted). As the object gets closer to the mirror, the image gets larger, until approximately the size of the object, when it touches the mirror. As the object moves away, the image diminishes in size and gets gradually closer to the focus, until it is reduced to a point in the focus when the object is at an infinite distance. These features make convex mirrors very useful: since everything appears smaller in the mirror, they cover a wider field of view than a normal plane mirror, so useful for looking at cars behind a driver's car on a road, watching a wider area for surveillance, etc.
Additional Information:
Introduction
A mirror is a smooth surface that shows images of the objects near it. Most mirrors are a sheet of glass with a shiny metallic coating on the back.
Reflection
The appearance of an image in a mirror is called a reflection. Reflection happens when light hits a surface. If the light cannot pass through the surface, it bounces off, or reflects. Most surfaces absorb some light and reflect some light. Mirrors, however, reflect almost all the light that hits them. The metallic coating on the back causes the reflection.
When you stand in front of a mirror, your body reflects patterns of light to the mirror. Those patterns of light bounce off the mirror and go back to your eyes. Your brain then interprets, or reads, the patterns of light as an image of yourself in the mirror.
Types of Mirrors
Most mirrors are flat. They are called plane mirrors. Images in a plane mirror are reversed. For example, if you raise your right hand while looking in a mirror, you will appear to raise your left hand. People use plane mirrors to check their appearance.
Other mirrors are curved. Convex mirrors curve outward, like a dome. They make objects appear reversed and smaller than their actual size. Concave mirrors curve inward, like a bowl. At a distance, they make objects appear upside down. Nearby, however, objects appear right side up and larger than their actual size.
How Mirrors Are Made
Mirrors are made in factories with special machinery. First, a sheet of glass is polished smooth and cleaned. Next, the back of the glass is covered with a thin layer of silver, aluminum, or another metal. Then the metal is covered with copper, varnish, or paint to protect it from scratches.
#2 Dark Discussions at Cafe Infinity » Come Quotes - VII » Today 16:08:24
- Jai Ganesh
- Replies: 0
Come Quotes - VII
1. Many people take no care of their money till they come nearly to the end of it, and others do just the same with their time. - Johann Wolfgang von Goethe
2. The vegetable life does not content itself with casting from the flower or the tree a single seed, but it fills the air and earth with a prodigality of seeds, that, if thousands perish, thousands may plant themselves, that hundreds may come up, that tens may live to maturity; that, at least one may replace the parent. - Ralph Waldo Emerson
3. If you come to fame not understanding who you are, it will define who you are. - Oprah Winfrey
4. Belief is a wise wager. Granted that faith cannot be proved, what harm will come to you if you gamble on its truth and it proves false? If you gain, you gain all; if you lose, you lose nothing. Wager, then, without hesitation, that He exists. - Blaise Pascal
5. Our greatness has always come from people who expect nothing and take nothing for granted - folks who work hard for what they have, then reach back and help others after them. - Michelle Obama
6. Peace is not a relationship of nations. It is a condition of mind brought about by a serenity of soul. Peace is not merely the absence of war. It is also a state of mind. Lasting peace can come only to peaceful people. - Jawaharlal Nehru
7. Trust has to be earned, and should come only after the passage of time. - Arthur Ashe
8. Living Life Tomorrow's fate, though thou be wise, Thou canst not tell nor yet surmise; Pass, therefore, not today in vain, For it will never come again. - Omar Khayyam.
#3 Jokes » Grapefruit Jokes - II » Today 15:49:27
- Jai Ganesh
- Replies: 0
Q: Why did the grapefruit fail his driving test?
A: It kept peeling out.
* * *
Q: Why did the grapefruit go to the doctor?
A: It wasn't peeling well.
* * *
Q: Did you hear about the spring training games that used fruits instead of baseballs?
A: They called it the "Grapefruit League".
* * *
Q: Why did the fruit bat eat the orange?
A: Because it had appeal.
* * *
Q: Why did the man lose his job at the grapefruit juice factory?
A: He couldn't concentrate!
* * *
#4 Re: Jai Ganesh's Puzzles » General Quiz » Today 15:42:26
Hi,
#10755. What does the term in Biology Genetic variation mean?
#10756. What does the term in Biology Genetics mean?
#5 Re: Jai Ganesh's Puzzles » English language puzzles » Today 15:24:19
Hi,
#5951. What does the verb descale mean?
#5952. What does the noun deserter mean?
#6 Re: Jai Ganesh's Puzzles » Doc, Doc! » Today 15:12:39
Hi,
#2572. What does the medical term Goblet cell mean?
#7 Re: Jai Ganesh's Puzzles » Oral puzzles » Today 14:49:07
Hi,
#6351.
#8 Re: Jai Ganesh's Puzzles » 10 second questions » Today 14:40:05
Hi,
#9857.
#9 Re: Exercises » Compute the solution: » Today 14:27:21
Hi,
2712.
#10 Re: Dark Discussions at Cafe Infinity » crème de la crème » Yesterday 18:52:59
2436) Daniel Bovet
Gist:
Work
Hormones and signal substances are chemical materials that convey signals governing different parts of the body. These substances include histamines, which are involved in allergic reactions, and it can be difficult to moderate their effects. Daniel Bovet looked for substances that block histamines, and in 1937 he found the first antihistamine, which later led to other antihistamine formulations to relieve allergies. Bovet also produced additional substances that block signal substances in other ways and have a numbing effect, among other things.
Summary
Daniel Bovet (born March 23, 1907, Neuchâtel, Switz.—died April 8, 1992, Rome, Italy) was a Swiss-born Italian pharmacologist who received the 1957 Nobel Prize for Physiology or Medicine for his discoveries of certain chemotherapeutic agents—namely, sulfa drugs, antihistamines, and muscle relaxants.
Bovet studied at the University of Geneva, graduating with a doctorate in science in 1929. That same year, he went on to the Pasteur Institute in Paris and became head of the therapeutic chemistry laboratory there in 1939. In 1937 Bovet discovered the first antihistamine substance, which (in counteracting the effect of histamine) is effective in treating allergic reactions. This discovery led to development of the first antihistamine drug for humans in 1942, and in 1944 one of Bovet’s own discoveries, pyrilamine, was produced as a drug.
In 1947 Bovet was invited to establish a laboratory of chemotherapeutics at the Superior Institute of Health in Rome, and eventually he took Italian citizenship. There he turned his attention to curare, a drug used to relax muscles during surgery. Because the drug was expensive and somewhat unpredictable in its effects, a low-cost dependable synthetic alternative was desired. Bovet produced hundreds of synthetic alternatives, of which gallamine and succinylcholine came into widespread use.
In 1964 Bovet became professor of pharmacology at the University of Sassari, on the Italian island of Sardinia. He served as the head of the psychobiology and psychopharmacology laboratory of the National Research Council (Rome) from 1969 until 1971, when he became professor of psychobiology at the University of Rome (1971–82).
Details
Daniel Bovet (23 March 1907 – 8 April 1992) was a Swiss-born Italian pharmacologist who won the 1957 Nobel Prize in Physiology or Medicine for his discovery of drugs that block the actions of specific neurotransmitters. He is best known for his discovery in 1937 of antihistamines, which block the neurotransmitter histamine and are used in allergy medication. His other research included work on chemotherapy, sulfa drugs, the sympathetic nervous system, the pharmacology of curare, and other neuropharmacological interests.
In 1965, Bovet led a study team which concluded that smoking of tobacco cigarettes increased users' intelligence. He told The New York Times that the object was not to "create geniuses, but only [to] put the less-endowed individual in a position to reach a satisfactory mental and intellectual development".
Bovet was born in Fleurier, Switzerland. He was a native Esperanto speaker. He graduated from the University of Geneva in 1927 and received his doctorate in 1929. Between 1929 and 1947, he worked at the Pasteur Institute in Paris. He then moved to the Istituto Superiore di Sanità (Superior Institute of Health) in Rome in 1947. Two years later, in 1949, Bovet was awarded the Cameron Prize for Therapeutics of the University of Edinburgh. In 1964, he became a professor in at the University of Sassari in Italy. From 1969 to 1971, he was the head of the Psychobiology and Psychopharmacology Laboratory of the National Research Council, in Rome, before stepping down to become a professor at the University of Rome La Sapienza. He retired in 1982.
#11 Re: This is Cool » Miscellany » Yesterday 18:14:06
2498) Food Chain
Gist
A food chain is a linear sequence illustrating how energy and nutrients transfer between organisms in an ecosystem, starting from producers and moving through various consumers to decomposers. It typically begins with plants (producers) capturing sunlight, followed by herbivores (primary consumers), carnivores (secondary/tertiary consumers), and finally decomposers.
A food chain is a linear sequence showing how energy and nutrients move through an ecosystem when one organism eats another, starting with producers (like plants) and moving up through consumers (herbivores, carnivores, omnivores) to decomposers, illustrating dependence for survival. Arrows in a food chain represent the flow of energy, pointing from the organism being eaten to the organism that eats it (e.g., Grass → Grasshopper → Frog).
Summary
A food chain outlines who eats whom. A food web is all of the food chains in an ecosystem. Each organism in an ecosystem occupies a specific trophic level or position in the food chain or web. Producers, who make their own food using photosynthesis or chemosynthesis, make up the bottom of the trophic pyramid. Primary consumers, mostly herbivores, exist at the next level, and secondary and tertiary consumers, omnivores and carnivores, follow. At the top of the system are the apex predators: animals who have no predators other than humans.
Details
A food chain is a linear network of links in a food web, often beginning with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as earthworms and woodlice), or decomposer (such as fungi or bacteria). A food web is distinct from a food chain. A food chain illustrates the associations between organisms according to the energy sources they consume in trophic levels, and the most common way to quantify them is in length: the number of links between a trophic consumer and the base of the chain.
Studies of food chains are essential to many biological studies.
Stability of the food chain is crucial for survival of most species. Removing even one component from the food chain could result in extinction or significant decreases in a species' probability of surviving. Many food chains and food webs contain a keystone species, a species that could directly affect the food chain and has a significant impact on the environment. The absence of a keystone species could destroy the balance of the entire food chain.
The efficiency of a food chain depends on the energy first consumed by the primary producers. This energy then moves through the trophic levels.
History
Food chains were first discussed by al-Jahiz, a 10th century Arab philosopher. The modern concepts of food chains and food webs were introduced by Charles Elton.
Food chain versus food web
A food chain differs from a food web as a food chain follows a direct linear pathway of consumption and energy transfer. Natural interconnections between food chains make a food web, which are non-linear and depict interconnecting pathways of consumption and energy transfer.
Trophic levels
Food chain models typically predict that communities are controlled by predators at the top and plants (autotrophs or producers) at the bottom.
Thus, the foundation of the food chain typically consists of primary producers. Primary producers, or autotrophs, utilize energy derived from either sunlight or inorganic chemical compounds to create complex organic compounds, such as starch, for energy. Because the sun's light is necessary for photosynthesis, most life could not exist if the sun disappeared. Even so, it has recently been discovered that there are some forms of life, chemotrophs, that appear to gain all their metabolic energy from chemosynthesis driven by hydrothermal vents, thus showing that some life may not require solar energy to thrive. Chemosynthetic bacteria and archaea use hydrogen sulfide and methane from hydrothermal vents and cold seeps as an energy source (just as plants use sunlight) to produce carbohydrates; they form the base of the food chain in regions with little to no sunlight. Regardless of where the energy is obtained, a species that produces its own energy lies at the base of the food chain model, and is a critically important part of an ecosystem.
Higher trophic levels cannot produce their own energy and so must consume producers or other life that itself consumes producers. In the higher trophic levels lies consumers (secondary consumers, tertiary consumers, etc.). Consumers are organisms that eat other organisms. All organisms in a food chain, except the first organism, are consumers. Secondary consumers eat and obtain energy from primary consumers, tertiary consumers eat and obtain energy from secondary consumers, etc.
At the highest trophic level is typically an apex predator, a consumer with no natural predators in the food chain model.
When any trophic level dies, detritivores and decomposers consume their organic material for energy and expel nutrients into the environment in their waste. Decomposers and detritivores break down the organic compounds into simple nutrients that are returned to the soil. These are the simple nutrients that plants require to create organic compounds. It is estimated that there are more than 100,000 different decomposers in existence.
Models of trophic levels also often model energy transfer between trophic levels. Primary consumers get energy from the producer and pass it to the secondary and tertiary consumers.
Studies
Food chains are vital in ecotoxicology studies, which trace the pathways and biomagnification of environmental contaminants. It is also necessary to consider interactions amongst different trophic levels to predict community dynamics; food chains are often the base level for theory development of trophic levels and community/ecosystem investigations.
Additional Information
Food chain, in ecology, is the sequence of transfers of matter and energy in the form of food from organism to organism. Food chains intertwine locally into a food web because most organisms consume more than one type of animal or plant. Plants, which convert solar energy to food by photosynthesis, are the primary food source. In a predator chain, a plant-eating animal is eaten by a flesh-eating animal. In a parasite chain, a smaller organism consumes part of a larger host and may itself be parasitized by even smaller organisms. In a saprophytic chain, microorganisms live on dead organic matter.
Because energy, in the form of heat, is lost at each step, or trophic level, chains do not normally encompass more than four or five trophic levels. People can increase the total food supply by cutting out one step in the food chain: instead of consuming animals that eat cereal grains, the people themselves consume the grains. Because the food chain is made shorter, the total amount of energy available to the final consumers is increased.
#12 This is Cool » Balanced Diet » Yesterday 17:44:35
- Jai Ganesh
- Replies: 0
Balanced Diet
Gist
A balanced diet provides the essential nutrients—carbohydrates, proteins, fats, vitamins, minerals, fiber, and water—needed for optimal bodily function, growth, and disease prevention. It generally consists of 50-60% carbohydrates (whole grains), 10-15% protein, 20-30% healthy fats, and high intake of fruits and vegetables. A simple, effective method is the "plate method": half vegetables/fruits, one-quarter protein, and one-quarter whole grains.
A healthy diet is essential for good health and nutrition. It protects you against many chronic noncommunicable diseases, such as heart disease, diabetes and cancer. Eating a variety of foods and consuming less salt, sugars and saturated and industrially-produced trans-fats, are essential for healthy diet.
What is a balanced diet?
This means eating a wide variety of foods in the right proportions, and consuming the right amount of food and drink to achieve and maintain a healthy body weight.
Summary
A balanced diet is essential for a healthy body, but given all the different opinions and trends around food, figuring out what constitutes a healthy diet can be confusing. One source says to cut carbs, another says to eat more fat, but a balanced diet isn't just about following strict rules or cutting out foods you enjoy; it's about including a variety of foods in the right amounts to give your body the nutrients it needs to function well. It supports everything from your energy levels and digestion to immunity and overall health. This blog will demystify what constitutes a balanced diet, explore its numerous benefits beyond just physical health, and provide practical sample meal plans that you can easily adapt to your personal preferences and lifestyle.
What is a Balanced Diet?
A balanced diet isn’t defined by one specific food or meal — it’s about the overall pattern of your eating habits over time. It means getting the right proportion of macronutrients (carbohydrates, proteins, and fats) along with essential micronutrients (vitamins and minerals) through a varied and consistent diet.
To put it into perspective:
* Around 50–60% of your daily energy should ideally come from carbohydrates (preferably whole grains and fibre-rich sources).
* 10–15% should come from protein (from both animal and plant sources).
* 20–30% from fats (focusing on unsaturated fats and limiting trans fats and excess saturated fats).
But numbers aside, a practical way to visualise a balanced meal is the “plate method”: half your plate should contain vegetables and fruits, one-quarter should have whole grains, and the remaining quarter should include a protein source. Adding a small serving of healthy fat — such as nuts, seeds, or a dash of oil — rounds it out.
Water, too, is an often-overlooked part of a balanced diet. Staying hydrated supports digestion, metabolism, and even appetite regulation.
A balanced diet isn’t about rigid rules — it’s flexible, adaptable, and can look different for each person depending on their age, activity level, health status, and cultural food preferences.
What are the Components of a Balanced Diet?
A balanced diet is made up of several key components, each serving a vital function to keep your body healthy and operating at its best. Here's a more detailed look at the main nutrients and their roles:
1. Carbohydrates
Carbohydrates are the body's primary source of energy. They fuel your muscles, brain, and organs, and are particularly important during physical activity. Carbohydrates are found in both simple and complex forms:
Simple carbohydrates: These are sugars found in fruits, dairy, and processed foods (like sweets and sugary drinks). While they provide quick energy, it’s best to limit refined sugars.
Complex carbohydrates: These come from whole grains, legumes, and starchy vegetables (like sweet potatoes). They are broken down more slowly, providing sustained energy and supporting digestive health due to their fibre content.
2. Proteins
Proteins are essential for growth, muscle repair, and immune function. They help in the production of enzymes, hormones, and other vital body chemicals. Proteins are made up of amino acids, some of which must be obtained from food. High-quality protein sources include:
Animal-based: Chicken, fish, eggs, and dairy.
Plant-based: Lentils, beans, chickpeas, tofu, quinoa, and seeds. Proteins also help keep you full longer, making them a great part of weight management.
3. Fats
Fats are crucial for maintaining healthy cell membranes, producing hormones, and absorbing fat-soluble vitamins (A, D, E, and K). While fats are often viewed negatively, healthy fats are essential for overall health:
Unsaturated fats: Found in avocados, olive oil, nuts, seeds, and fatty fish (such as salmon and mackerel), these fats support heart health and help reduce inflammation.
Saturated fats: Present in animal products (like butter and cheese) and some plant oils (like coconut oil), these should be consumed in moderation.
Trans fats: These artificial fats are found in processed and fried foods and should be avoided as they contribute to poor heart health.
4. Vitamins and Minerals
Vitamins and minerals are micronutrients that regulate processes in the body, from immunity and energy production to bone health and wound healing. They don't provide energy but are essential for a variety of functions:
Vitamins: Different vitamins play various roles in maintaining health. For example, Vitamin C (found in citrus fruits) helps boost immunity, while Vitamin A (found in carrots and leafy greens) supports vision and skin health.
Minerals: Key minerals like calcium (for bones and teeth), iron (for oxygen transport in blood), and magnesium (for muscle function) are found in foods such as dairy, leafy greens, meats, and legumes.
5. Fibre
Fibre is an essential part of a healthy diet, particularly for digestive health. It helps regulate bowel movements, prevents constipation, and can reduce the risk of chronic diseases like heart disease and type 2 diabetes. Fibre is found in:
Soluble fibre: Found in oats, apples, beans, and peas, this type helps lower cholesterol and regulate blood sugar levels.
Insoluble fibre: Found in whole grains, vegetables, and nuts, this type helps with bowel regularity and digestive health
6. Water
Water is often overlooked but is a critical component of a balanced diet. It makes up about 60% of your body and is involved in nearly every bodily function, including temperature regulation, digestion, and nutrient transport. Staying well-hydrated is essential for maintaining energy, supporting brain function, and keeping your skin healthy. Aim to drink at least 8 glasses of water a day, or more if you're physically active.
Why Is a Balanced Diet Important?
A balanced diet is crucial for maintaining optimal health and supporting the body’s daily functions. It provides essential nutrients that help the body perform key tasks, from boosting energy levels to supporting immune function. Without the proper mix of carbohydrates, proteins, fats, vitamins, and minerals, the body cannot function efficiently, leading to fatigue, illness, and long-term health issues. By prioritising a balanced diet, you can reduce the risk of chronic diseases, improve mental and physical well-being, and ensure the body has everything it needs to thrive.
Details
Generally, a healthy diet consists of many fresh fruits and vegetables and limits processed foods. But ask your doctor or a dietitian for advice on making more specific dietary changes to improve your health.
What is a balanced diet?
A balanced diet gives your body the nutrients it needs to function correctly. To get the nutrition you need, most of your daily calories should come from:
* fresh fruits
* fresh vegetables
* whole grains
* legumes
* nuts
* lean proteins
About calories
The number of calories in a food refers to the amount of energy stored in that food. Your body uses calories from food for walking, thinking, breathing, and other important functions.
The average person needs about 2,000 calories every day to maintain their weight, but the amount will depend on their age, sex, and physical activity level.
Males tend to need more calories than females, and people who exercise need more calories than people who don’t.
The source of your daily calories are also important. Foods that provide mainly calories and very little nutrition are known as “empty calories.”
Examples of foods that provide empty calories include:
* cakes, cookies, and donuts
* processed meats
* energy drinks and sodas
* fruit drinks with added sugar
* ice cream
* chips and fries
* pizza
* sodas
However, it’s not only the type of food but the ingredients that make it nutritious.
A homemade pizza with a wholemeal base and plenty of fresh veggies on top may be a healthy choice. In contrast, premade pizzas and other highly processed foods often contain empty calories.
To maintain good health, limit your consumption of empty calories and instead try to get your calories from foods that are rich in other nutrients.
Get some tips for curbing cravings of less nutritious foods.
Calories are a measure of energy that foods supply. The number of calories you need will depend on your sex, age, and activity level.
Why a balanced diet is important
A balanced diet supplies the nutrients your body needs to work effectively. Without balanced nutrition, your body is more prone to disease, infection, fatigue, and low performance.
Children who don’t get enough healthy foods may face growth and developmental problems, poor academic performance, and frequent infections.
They can also develop unhealthy eating habits that may persist into adulthood.
Without exercise, they’ll also have a higher risk of obesity and various diseases that make up metabolic syndrome, such as type 2 diabetes and high blood pressure.
According to the Center for Science in the Public Interest, 4 of the top 10 leading causes of death in the United States are directly linked to diet.
These are:
* heart disease
* cancer
* stroke
* type 2 diabetes
Your body needs nutrients to stay healthy, and food supplies essential nutrients that stop us from getting sick.
What to eat for a balanced diet
A healthy, balanced diet will usually include the following nutrients:
* vitamins, minerals, and antioxidants
* carbohydrates, including starches and fiber
* protein
* healthy fats
A balanced diet will include a variety of foods from the following groups:
* fruits
* vegetables
* grains
* dairy
* protein foods
Examples of protein foods include meat, eggs, fish, beans, nuts, and legumes.
People who follow a vegan diet will focus entirely on plant-based foods. They won’t eat meat, fish, or dairy, but their diet will include other items that provide similar nutrients.
Tofu and beans, for example, are plant-based sources of protein. Some people are intolerant of dairy but can still build a balanced diet by choosing a variety of nutrient-rich replacements.
Foods to avoid
Foods to avoid or limit on a healthy diet include:
* highly processed foods
* refined grains
* added sugar and salt
* red and processed meat
* alcohol
* trans fats
What’s healthy for one person may not be suitable for another.
Whole wheat flour can be a healthy ingredient for many people but isn’t suitable for those with a gluten intolerance, for example.
Fruits
Fruits are nutritious, they make a tasty snack or dessert, and they can satisfy a sweet tooth.
Local fruits that are in season are fresher and provide more nutrients than imported fruits.
Fruits are high in sugar, but this sugar is natural. Unlike candies and many sweet desserts, fruits also provide fiber and other nutrients. This means they’re less likely to cause a sugar spike and they’ll boost the body’s supply of essential vitamins, minerals, and antioxidants.
If you have diabetes, your doctor or dietitian can advise you on which fruits to choose, how much to eat, and when.
Vegetables
Vegetables are a key source of essential vitamins, minerals, and antioxidants. Eat a variety of vegetables with different colors for a full range of nutrients.
Dark, leafy greens are an excellent source of many nutrients. They include:
* spinach
* kale
* green beans
* broccoli
* collard greens
* Swiss chard
Local, seasonal vegetables are often reasonable in price and easy to prepare. Use them in the following ways:
* as a side dish
* roasted in a tray with a splash of olive oil
* as the base in soups, stews, and pasta dishes
* as a salad
* in purées
* in juices and smoothies
Grains
Refined white flour is featured in many breads and baked goods, but it has limited nutritional value. This is because much of the goodness is in the hull of the grain, or outer shell, and the center, or “wheat germ,” which manufacturers remove during processing.
Whole grain products include the entire grain, including the hull and germ. They provide additional vitamins, minerals, and fiber. Many people also find that whole grains add flavor and texture to a dish.
Try switching from white breads, pastas, and rice to whole grain options.
Proteins
Meats and beans are primary sources of protein, which is essential for wound healing and muscle maintenance and development, among other functions.
Additional Information
A healthy diet is a diet that maintains or improves overall health. A healthful diet provides the body with essential nutrition: water, macronutrients such as protein, micronutrients such as vitamins, and adequate fibre and food energy.
A healthy diet may contain fruits, vegetables, and whole grains, and may include little to no ultra-processed foods or sweetened beverages. The requirements for a healthy diet can be met from a variety of plant-based and animal-based foods, although additional sources of vitamin B12 are needed for those following a vegan diet. Various nutrition guides are published by medical and governmental institutions to educate individuals on what they should be eating to be healthy. Not only advertising may drive preferences towards unhealthy foods. To reverse this trend, consumers should be informed, motivated and empowered to choose healthy diets. Nutrition facts labels are also mandatory in some countries to allow consumers to choose between foods based on the components relevant to health.
It was estimated that 40% of the world population in 2023 could not afford a healthy diet. This is often a political issue. The Food and Agriculture Organization and the World Health Organization have formulatedfour core principles of what constitutes healthy diets. According to these two organizations, health diets are:
* Adequate, as they meet, without exceeding, our body's energy and essential nutrient requirements in support of all the many body functions.
* Diverse, as they include various nutritious foods within and across food groups to help secure the sufficient nutrients needed by our bodies.
* Balanced, as they include energy from the three primary sources (protein, fats, and carbohydrates) in a balanced way and foster healthy weight, growth and activity, and to prevent disease.
* Moderate, as they include only small quantities (or none) of foods that may have a negative impact on health, such as highly salty and sugary foods.
#13 Science HQ » Hypermetropia » Yesterday 16:47:08
- Jai Ganesh
- Replies: 0
Hypermetropia
Gist
Hypermetropia, or farsightedness, is a common refractive error where distant objects are clear, but near objects appear blurry because light focuses behind the retina. It is caused by a short eyeball or flat cornea, often hereditary. Symptoms include eye strain, headaches, and reading difficulty. Treatment includes convex lenses (glasses/contacts) or refractive surgery.
Hypermetropia (or farsightedness/hyperopia) is a common vision condition where distant objects are seen clearly, but nearby objects appear blurry because light focuses behind the retina instead of on it, often due to the eyeball being too short or the cornea having too little curvature. This condition is corrected with convex lenses (glasses or contacts) that help converge light onto the retina, restoring clear vision, especially for close work.
Summary
Far-sightedness, also known as long-sightedness, hypermetropia, and hyperopia, is a condition of the eye where distant objects are seen clearly but near objects appear blurred. This blur is due to incoming light being focused behind, instead of on, the retina due to insufficient accommodation by the lens. Minor hypermetropia in young patients is usually corrected by their accommodation, without any defects in vision. But, due to this accommodative effort for distant vision, people may complain of eye strain during prolonged reading. If the hypermetropia is high, there will be defective vision for both distance and near. People may also experience accommodative dysfunction, binocular dysfunction, amblyopia, and strabismus. Newborns are almost invariably hypermetropic, but it gradually decreases as the newborn gets older.
There are many causes for this condition. It may occur when the axial length of eyeball is too short or if the lens or cornea is flatter than normal. Changes in refractive index of lens, alterations in position of the lens or absence of lens are the other main causes. Risk factors include a family history of the condition, diabetes, certain medications, and tumors around the eye. It is a type of refractive error. Diagnosis is based on an eye exam.
Management can occur with eyeglasses, contact lenses, or refractive corneal surgeries. Glasses are easiest while contact lenses can provide a wider field of vision. Surgery works by changing the shape of the cornea. Far-sightedness primarily affects young children, with rates of 8% at 6 years old and 1% at 15 years old. It then becomes more common again after the age of 40, known as presbyopia, affecting about half of people. The best treatment option to correct hypermetropia due to aphakia is IOL implantation. (IOL: Intraocular lens).
Other common types of refractive errors are near-sightedness, astigmatism, and presbyopia.
Details
Hypermetropia, also called hyperopia, is a common condition that can also be hereditary. If you suspect you have hypermetropia, it is not something that should cause you great worry. You can visit one of our optometrists in our stores to learn more about your treatment options. If you are farsighted, glasses or contact lenses provide a straightforward solution.
Light rays enter your eye through the cornea – the front part of your eye. Then, the light goes through the pupil to the eye lens. The light rays are redirected by the cornea and the lens, so that they land exactly on the retina.
When a person is farsighted, the light that enters the eye falls behind their retina, resulting in blurred vision when viewing objects nearby.
There are two different hypermetropia (hyperopia) causes:
Axial hypermetropia
The distance between the front of your eye (cornea) and the back of your eye (retina) is too small, causing the light rays to fall behind the retina.
Refractive hypermetropia
The cornea or eye lens is too flat, so the light rays do not ‘break’ enough, causing the light to fall behind the retina.
Hypermetropia symptoms
People with hypermetropia can usually see objects in the distance clearly, but struggle as they get closer to an object. Depending on how high the refractive error is, even an object a few metres away may appear blurred.
Risk factors for hypermetropia can include a family history of the condition, certain medicines and diabetes.
Symptoms of hypermetropia include eye strain, blurry vision and headaches, with eye strain often being the first and most noticeable symptom. Some people with hypermetropia can experience difficulty with depth perception, or seeing with both eyes, and some children may experience double vision as a result of trying to focus. Sometimes symptoms can include squinting or eye-watering.
Some of the first signs in children may be complaining about not being able to read textbooks in school, having difficulty drawing or putting beads on a string, having tired eyes when looking at a screen, or possibly learning difficulties.
Hypermetropia treatment: what are your options?
For some people it may be a relief to learn what has been causing their headaches and eye strain, and that there are several effective treatment options available.
Hypermetropia, or long-sightedness, is caused by the light rays falling behind the retina, causing nearby objects to appear blurred or unfocused. this condition can be present from birth, but more commonly, it occurs later in life. Many people can correct their vision themselves, by squinting or adjusting their eye muscles. this is called accommodation. Accommodation may make your vision clear, but you may still experience symptoms relating to hypermetropia, such as eye strain and headaches.
When looking at hypermetropia treatments, there are various options. Your optometrist can explain to you about hypermetropia causes, symptoms and treatment, and can advise you which treatment will be best for you, based on your lifestyle, budget and overall health.
Here are some hypermetropia treatment options:
Glasses
One of the most common forms of hypermetropia treatment is glasses. After an eye examination the optometrist will give you your prescription. The dioptres are the numbers used to measure the power of the refractive error. With hypermetropia the dioptres are positive. A plus lens will redirect the light rays so that they fall exactly on the retina, allowing you to see clearly.
The benefits of glasses are that they are a quick solution, with no downtime for recovery, and that they are easy to adjust, as your prescription naturally changes over time. For most people, adapting to wearing glasses is just a matter of wearing them for a few days.
Contacts
For some people, contact lenses are a good option for hypermetropia treatment, especially if they experience high levels of farsightedness. The main benefits of contact lenses are that they can be worn during sports and that they are virtually invisible. There are several options when it comes to contact lenses. Based on your ocular health and your personal preferences, an optometrist will give you advice tailored to your needs. Some examples of different contact lenses are daily disposable or reusable lenses. The latter can be worn for either two weeks or a month (depending on the type), but require daily cleaning of the lenses.
Contact lenses can also be worn by children, depending on their age and maturity. It is important for contact lens wearers to always have at least one pair of glasses.
Laser surgery for hypermetropia treatment
Another optional treatment is laser surgery although it is not a hypermetropia cure. As with any procedure, recovery times vary, and it may not be suitable for everyone. Common types of laser surgery include PRK, LASIK and LASEK, all of which can be effective for long-sightedness.
Additional Information
Hypermetropia (long-sightedness) is a common eye condition where nearby objects appear blurred, but your vision is clearer when looking at things further away.
If you feel your eyes are often tired and you have problems focusing on objects close to your eyes, you may have hypermetropia.
Causes
Your eye is like a camera. It focuses light on the back of your eye (on a place called the retina), which provides you with clear vision. Long-sight is caused by light not being correctly focused, with light travelling behind the retina.
* One cause may be that your eyeballs are shorter than usual. This means that the retina is closer to the pupil, causing light to travel past the retina. A normal eye is usually around 23mm in length, so an eye that is hypermetropic will be shorter than 23mm.
* Alternatively you can also have hypermetropia if your cornea is flat. The cornea should be curved to direct light onto the retina.
Both of these factors cause long-sightedness, as they cause light to travel past the retina. This results in blurry vision, and can affect your daily life.
Hypermetropia in children.
Hypermetropia is usually genetic. Babies and young children may suffer from hypermetropia, but this should eventually correct itself. This happens as the eyeballs lengthen as they grow. However, a lazy eye may develop as a result. This is because the eye with the weakest vision is ignored by the brain, and does not learn the correct way to see. If this is not corrected in young children, there is a risk that the weaker eye will never see as well as the other eye.
Treatments for hypermetropia
If you think you may be longsighted, let your optician know. They will be able to diagnose this in an eye examination and provide you with a prescription if you need one.
If you have been diagnosed with hypermetropia by an optician, there are three solutions:
Glasses
If you have long-sighted vision, it can be corrected by wearing plus powered lenses. This helps focus light entering the eye on the correct area of the retina, making your vision clearer.
Contact Lenses
Contact lenses are another alternative, although you will still need a pair of glasses as backup in case you are unable to wear your lenses. Again, they will be plus powered to refract the light to the retina. The prescription is likely to differ from a glasses prescription. There are different types of contact lenses available, including daily or monthly disposables. Talk to your optician about the best option to suit your lifestyle.
Laser Surgery
Laser surgery provides the opportunity to correct your vision. Although it corrects existing visual impairments, it does not prevent further changes to eyesight afterwards.
FAQs About Hypermetropia:
Can children outgrow hypermetropia?
Yes, many children are born farsighted and gradually develop normal vision as their eyes grow, but regular check-ups are necessary.
Is hypermetropia hereditary?
Genetics can play a role, but environmental factors also contribute.
Can hypermetropia cause headaches?
Yes, eye strain from focusing efforts often leads to headaches, especially after close work.
Does hypermetropia worsen with age?
In some cases, it can worsen, especially if presbyopia develops.
Can hypermetropia be cured?
While it cannot be “cured,” it can be effectively managed with glasses, contact lenses, or surgery.
Conclusion
Hypermetropia is a common and manageable eye condition that affects the ability to see nearby objects clearly. Recognizing the symptoms early and seeking professional diagnosis can prevent discomfort and improve quality of life. Whether through corrective lenses or surgical options, effective treatments exist to restore clear vision and reduce eye strain.
Regular eye examinations and adopting good eye care habits are essential steps toward maintaining healthy vision. If you experience blurred near vision, headaches, or eye fatigue, consult an eye care specialist to discuss appropriate evaluation and treatment.
#14 Dark Discussions at Cafe Infinity » Come Quotes - VI » Yesterday 16:02:30
- Jai Ganesh
- Replies: 0
Come Quotes - VI
1. You and I come by road or rail, but economists travel on infrastructure. - Margaret Thatcher
2. Come forth into the light of things, let nature be your teacher. - William Wordsworth
3. In our obscurity - in all this vastness - there is no hint that help will come from elsewhere to save us from ourselves. It is up to us. - Carl Sagan
4. A lot of legends, a lot of people, have come before me. But this is my time. - Usain Bolt
5. The golden moments in the stream of life rush past us, and we see nothing but sand; the angels come to visit us, and we only know them when they are gone. - George Eliot
6. Diplomacy is listening to what the other guy needs. Preserving your own position, but listening to the other guy. You have to develop relationships with other people so when the tough times come, you can work together. - Colin Powell
7. Everyone likes flattery; and when you come to Royalty you should lay it on with a trowel. - Benjamin Disraeli
8. We are born weak, we need strength; helpless, we need aid; foolish, we need reason. All that we lack at birth, all that we need when we come to man's estate, is the gift of education. - Jean-Jacques Rousseau.
#15 Re: Jai Ganesh's Puzzles » General Quiz » Yesterday 15:44:18
Hi,
#10753. What does the term in Biology Genetic code mean?
#10754. What does the term in Biology Genetic drift mean?
#16 Re: Jai Ganesh's Puzzles » English language puzzles » Yesterday 15:28:53
Hi,
#5949. What does the noun gore mean?
#5950. What does the adjective gorgeous mean?
#17 Re: Jai Ganesh's Puzzles » Doc, Doc! » Yesterday 15:07:38
Hi,
#2571. What does the medical term Chondrolaryngoplasty mean?
#18 Jokes » Grapefruit Jokes - I » Yesterday 14:36:11
- Jai Ganesh
- Replies: 0
Q: Why did the grapefruit stop rolling down the hill?
A: It ran out of juice.
* * *
Q: Why did the grapefruit go out with a prune?
A: Because she couldn't find a date.
* * *
Q: Why do grapefruits wear suntan lotion?
A: Because they peel.
* * *
Q: What did grapefruit say to lemon?
A: Nothing stupid, grapefruits don't talk.
* * *
Q: What does a grapefruit tree drink?
A: Root beer.
* * *
#19 Re: Jai Ganesh's Puzzles » 10 second questions » Yesterday 14:26:40
Hi,
#9856.
#20 Re: Jai Ganesh's Puzzles » Oral puzzles » Yesterday 14:14:18
Hi,
6350.
#21 Re: Exercises » Compute the solution: » Yesterday 14:02:08
Hi,
2711.
#22 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2026-02-15 19:48:51
2435) Alec Todd
Gist:
Work
The substances known as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are found in nearly all cells in almost all organisms. The building blocks of DNA and RNA consist of nucleotides. In turn, these consist of what scientists call a nitrogen base, a sugar molecule, and one or more phosphate groups. Around 1940, Alexander Todd began to examine the composition of nucleotides more closely. Using chemical methods, Todd split nucleotides apart and compared their parts with substances that had been constructed from known components in a way that was already understood.
Summary
Alexander Robertus Todd, Baron Todd (born Oct. 2, 1907, Glasgow, Scot.—died Jan. 10, 1997, Cambridge, Eng.) was a British biochemist whose research on the structure and synthesis of nucleotides, nucleosides, and nucleotide coenzymes gained him the 1957 Nobel Prize for Chemistry.
After receiving doctorates from the universities of Frankfurt am Main (1931) and Oxford (1933), Todd held posts with the Lister Institute of Preventive Medicine, London, and the University of London before becoming professor of organic chemistry at the University of Manchester (1938–44) and then at Cambridge (1944–71), where he was also master of Christ’s College (1963–78). He was named chancellor of the University of Strathclyde in 1975 and was visiting professor at Hatfield Polytechnic (1978–86).
While at Manchester he began work on nucleosides, compounds that form the structural units of nucleic acids (DNA and RNA). In 1949 he synthesized a related substance, adenosine triphosphate (ATP), which is vital to energy utilization in living organisms. He synthesized two other important compounds, flavin adenine dinucleotide (FAD) in 1949 and uridine triphosphate in 1954. In 1955 he elucidated the structure of vitamin B12.
Todd also worked on the structure and synthesis of vitamin B1, vitamin E, and alkaloid substances found in marijuana and hashish. He studied other alkaloids as well, plant and insect pigments, and mold products, including penicillin. He served as chairman (1952–64) of the British government’s advisory committee on scientific policy, and in 1975 he was elected president of the Royal Society. Knighted in 1954, he was created a life peer in 1962 and made a member of the Royal Order of Merit in 1977.
Details
Alexander Robertus Todd, Baron Todd (2 October 1907 – 10 January 1997) was a British biochemist whose research on the structure and synthesis of nucleotides, nucleosides, and nucleotide coenzymes gained him the Nobel Prize for Chemistry in 1957.
Early life and education
Todd was born at Cathcart in outer Glasgow, the elder son of Alexander Todd, a clerk with the Glasgow Subway, and his wife, Jane Lowry.
He attended Allan Glen's School and graduated from the University of Glasgow with a bachelor's degree (BSc) in 1928. He received a doctorate (Dr Phil.nat.) from Goethe University Frankfurt in 1931 for his thesis on the chemistry of the bile acids.
Todd was awarded an 1851 Research Fellowship from the Royal Commission for the Exhibition of 1851, and, after studying at Oriel College, Oxford, he received another doctorate (DPhil) in 1933.
Career
Todd held posts with the Lister Institute, the University of Edinburgh (staff, 1934–1936) and the University of London, where he was appointed Reader in biochemistry.
In 1938, Alexander Todd spent six months as a visiting professor at California Institute of Technology, eventually declining an offer of faculty position.
Todd became the Sir Samuel Hall Chair of Chemistry and director of the Chemical Laboratories of the University of Manchester in 1938, where he began working on nucleosides, compounds that form the structural units of nucleic acids (DNA and RNA). At 31, he was the youngest professor of chemistry since Frankland. He was elected to membership of the Manchester Literary and Philosophical Society in 1938.
In 1944, he was appointed to the 1702 Chair of Chemistry in the University of Cambridge, which he held until his retirement in 1971. In 1949, he synthesised adenosine triphosphate (ATP) and flavin adenine dinucleotide (FAD). Todd served as a visiting professor at the University of Chicago in Autumn 1948 and University of Sydney in 1950.
By 1951, Todd and collaborators at Cambridge had determined by biochemical methods how the backbone of DNA is structured via the successive linking of carbon atoms 3 and 5 of the sugar to phosphates. This helped corroborate Francis Crick and James_Watson's X-ray structural work published in 1953.
In 1955, he helped elucidate the structure of vitamin B12, although the final formula and definite structure was determined by Dorothy Hodgkin and her team, and later worked on the structure and synthesis of vitamin B1 and vitamin E, the anthocyanins (the pigments of flowers and fruits) from insects (aphids, beetles) and studied alkaloids found in cannabis. He served as chairman of the Government of the United Kingdom's advisory committee on scientific policy from 1952 to 1964.
He is credited as the first person to synthesize H4-CBD and H2-CBD from Cannabidiol by hydrogenation as early as 1940.
He received the 1957 Nobel Prize in Chemistry "for his work on nucleotides and nucleotide co-enzymes."
Elected a Fellow of Christ's College, Cambridge in 1944, he served as Master from 1963 to 1978. Lord Todd became the first Chancellor of the new University of Strathclyde in 1965, and a visiting professor at Hatfield Polytechnic (1978–1986). Among his many honours, including over 40 honorary degrees, he was elected a Fellow of the Royal Society in 1942, a member of the United States National Academy of Sciences in 1955, a member of the American Academy of Arts and Sciences in 1957, and the American Philosophical Society in 1965. President of the Royal Society from 1975 to 1980, The Queen awarded him the Order of Merit in 1977.
In 1981, Todd became a founding member of the World Cultural Council.
Personal life and death
In 1937, Todd married Alison Sarah Dale (d. 1987), daughter of Nobel Prize winner Henry Hallett Dale, who like Todd, served as President of the Royal Society of London. They had a son and two daughters:
* Dr the Hon Alexander Henry Todd (b. 1939), educated at Oriel College, Oxford, Master Salters' Company (1999/2000), m. 1stly 1967 (div 1981) Joan Margaret Koester, m. 2ndly Patricia Mary Harvey Jones, daughter of Brigadier Alan Harvey Jones CBE TD, of Somerford Booths, Cheshire;
* The Hon Helen Jean Todd (b. 1941), m. 1963 Philip Edgar Brown, and has two sons and a daughter;
* The Hon Hilary Alison Todd (b. 1946).
Todd died in Cambridge on 10 January 1997 at the age of 89 following a heart attack.
#23 Re: Jai Ganesh's Puzzles » General Quiz » 2026-02-15 19:27:43
Hi,
#10751. What does the term in Biology Gene mean?
#10752. What does the term in Biology Gene pool mean?
#24 Re: Jai Ganesh's Puzzles » English language puzzles » 2026-02-15 19:06:38
Hi,
#5947. What does the noun imbecile mean?
#5948. What does the verb (used with object) imbibe mean?
#25 Re: Jai Ganesh's Puzzles » Doc, Doc! » 2026-02-15 18:55:12
Hi,
#2570. What does the medical term Chondrodermatitis nodularis chronica helicis mean?