Posts by Jai Ganesh

Jai Ganesh · This is Cool

Hovercraft

Gist

Hovercraft are used for rescue, commercial, military and paramilitary applications to transport, save and protect lives across the world's most challenging environments.

Hovercraft are actually more like planes than boats or cars, although they are more at home moving across water than flying down the runway at Birmingham! Hovercrafts use the same 'lift' physics that an aeroplane uses to fly, although you'll never really get that far off the ground to find out.

The highest recorded speed by a hovercraft is 137.4 km/h (85.38 mph), by Bob Windt (USA) at the 1995 World Hovercraft Championships on the Rio Douro River, Peso de Regua, Portugal.

Summary

A hovercraft (pl.: also hovercraft), also known as an air-cushion vehicle or ACV, is an amphibious craft capable of travelling over land, water, mud, ice, and various other surfaces.

Hovercraft use blowers to produce a large volume of air below the hull, or air cushion, that is slightly above atmospheric pressure. The pressure difference between the higher-pressure air below the hull and lower pressure ambient air above it produces lift, which causes the hull to float above the running surface. For stability reasons, the air is typically blown through slots or holes around the outside of a disk- or oval-shaped platform, giving most hovercraft a characteristic rounded-rectangle shape.

The first practical design for hovercraft was derived from a British invention in the 1950s. They are now used throughout the world as specialised transports in disaster relief, coastguard, military and survey applications, as well as for sport or passenger service. Very large versions have been used to transport hundreds of people and vehicles across the English Channel, whilst others have military applications used to transport tanks, soldiers and large equipment in hostile environments and terrain. Decline in public demand meant that as of 2025, only two year-round public hovercraft service in the world are still in operation: Hovertravel, which serves between the Isle of Wight and Southsea in the UK, and Oita Hovercraft resumed services in Oita, Japan in July 2025.

Although now a generic term for the type of craft, the name Hovercraft itself was a trademark owned by Saunders-Roe (later British Hovercraft Corporation (BHC), then Westland), hence other manufacturers' use of alternative names to describe the vehicles.

Details

One part boat, one part airplane, and one part helicopter a hovercraft is a vehicle that traps a cushion of air underneath itself and then floats along on top of it. The air cushion holds it high above waves and land obstructions, making the craft superbly amphibious (equally capable of traveling on land or water or gliding smoothly from one to the other). That's why military hovercraft, designed for swift beach landings, are often called LCACs (Landing Craft Air Cushion).

Hovercraft come in all shapes and sizes, from one-person fun machines and small beach rescue craft to giant passenger ferries capable of carrying over 400 passengers and 50 cars. Where boats are slowed by hulls that drag deep in the water, hovercraft ride fully clear, which means they use less fuel and can reach blistering speeds of up to 145kph (90mph). From ice and water to mud and sand, from floodplains and river deltas to mangrove swamps and frozen glaciers, the great advantage of a hovercraft is that it can glide with ease to places ordinary boats struggle to reach, and land people safely even where there are no harbors or landing stages.

In practice, hovercraft have four broad applications: large commercial hovercraft are mostly used as high-speed people and car ferries; slightly smaller military LCACs are used as tried-and-tested beach landing craft; smaller niche craft are used for things like oil and gas prospecting, inshore search and rescue, and scientific surveys; and small, one-person recreational craft are often raced round courses like flying go-karts!

How does a hovercraft work?

At first sight, you might think a hovercraft works in much the same way as a helicopter: it throws air down underneath itself and then simply rides along on top. But where a helicopter balances its own weight (the force of gravity pulling it down) with a massive down-draft of air (pushing it back up again), a hovercraft works in a much more subtle way that allows it to use far less air, far more efficiently, so getting by with a much smaller engine and considerably less fuel.

The basic mechanism of a hovercraft is very simple: there's an engine (diesel or gasoline) that powers both a large central fan, pointing downward, and one or more other fans pointing backward. The central fan creates the lift that holds the craft above the waves; the other fans propel the craft backward, forward, or to the side. A rubber skirt (with or without fingers) traps a cushion of air under the craft. Side-wall hovercraft have only partial skirts: with solid sides and a skirt only at the front and back, they can be powered by quieter propellers or water-jet engines, making them quieter.

Other important parts

What else do you need to make a hovercraft? A downward-pointing fan can only blow air underneath, so hovercraft typically have one or more propeller fans on top of the hull, pointing backward to propel them forward. Usually, there's a rudder positioned just behind each fan to swivel the air it produces and steer the hovercraft in the appropriate direction. An alternative method of steering is to divert some of the down-draft from the fan through air nozzles that point horizontally—and the very first hovercraft prototype, SR.N1, effectively worked this way. Although hovercraft usually have separate fans (to create the cushion) and propellers (to drive them along), the same engines typically drive both, using gearboxes and transmissions to turn the engine's power through ninety degrees. Bigger hovercraft like the US military LCACs typically use several very hefty engines, such as powerful gas turbines. Then there's the hull itself. Most large hovercraft are built from light, rustproof, and highly durable aluminum, though hobby craft are often molded from tough composite materials such as fiber glass. Finally, you need a math to keep your pilot safe and sound—and some cargo space (either enclosed, for passengers and cars, or a large "open well" deck for carrying military cargo).

Advantages and disadvantages

Hovercraft can launch and land anywhere, travel over almost any kind of surface, race along at high speeds, and efficiently carry large numbers of passengers and equipment or hefty military cargos. They compare favorably with all kinds of rival vehicles. Since they produce an air cushion more efficiently than a helicopter, they're cheaper to operate, simpler, and easier to maintain (safer too). Where boats waste energy dragging through water and waves, a hovercraft riding smoothly on top creates little in the way of either drag or wake, so it's generally more efficient (and less disruptive to the marine environment than a propeller-driven ship).

But if hovercraft are so wonderful, why aren't they used everywhere? They're expensive initially and, though cheaper than helicopters, considerably more costly to maintain than ships and boats of similar cargo capacity (because they're essentially aircraft, not boats, and mechanically more complex). Although hovercraft successfully carried tens of millions of people between Britain and France for just over 30 years, they eventually stopped operating following the opening of the Channel Tunnel and the arrival of low-cost ferry ships and fast, wave-piercing catamarans. Hovercraft are also fairly tricky to pilot: more like helicopters, in this respect, than simple-to-operate boats. They're very noisy too, which can be a problem both for passengers and people living near the ports where they operate, and is certainly a drawback for "covert" military operations.

Additional Information:

Objective

Investigate how different amounts of air in the hovercraft's balloon affect how long the hovercraft can hover.

Introduction

A hovercraft is a vehicle that glides over a smooth surface by hovering upon an air cushion. Because of this, a hovercraft is also called an Air-Cushion Vehicle, or ACV. How is the air cushion made? The hovercraft creates vents or currents of slow-moving, low-pressure air that are pushed downward against the surface below the hovercraft. Modern ACVs often have propellers on top that create the air currents. These currents are pushed beneath the vehicle with the use of fans. Surrounding the base of the ACV is a flexible skirt, also called the curtain, which traps the air currents, keeping them underneath the hovercraft. These trapped air currents can create an air cushion on any smooth surface, land or water! Since a hovercraft can travel upon the surface of water, it is also called an amphibious vehicle.

How does the air cushion beneath the hovercraft allow the vehicle to glide to freely? The key to the ease of movement is reducing friction. A simple way to think of friction is to think about how things rub together. It is easier to rollerblade on a smooth sidewalk than a gravel path because the sidewalk has less friction. The wheels of the rollerblade do not rub as much against the sidewalk as they do all the pieces of gravel on the path. Similarly, the air cushion beneath the hovercraft greatly reduces the friction of the vehicle, allowing it to glide freely upon the land or water below.

In this aerodynamics and hydrodynamics science project, you will build your own mini hovercraft using a CD or DVD, pop-top lid from a plastic drinking bottle, and a balloon. The balloon will create the air currents the hovercraft needs to work. These air currents will travel through the pop-top lid and go beneath the hovercraft. You will fill the balloon up with different amounts of air to test if more air will cause the hovercraft to travel for longer periods of time. A balloon blown up with a lot of air will provide a large volume of air, and a balloon blown up with less air will provide a smaller volume of air.

Hovercrafts.jpg.webp

Jai Ganesh · This is Cool

2486) Automative Industry

Gist

An automobile engine is defined as a mechanical system that generates power through the combustion of fuel, producing heat energy that must be effectively dissipated to prevent overheating, typically using coolants and radiators for heat transfer.

"Automative" refers to processes, systems, or mechanisms that are automated or self-acting, often relating to machinery that operates without direct human intervention. It is distinct from "automotive" (related to motor vehicles), though they share similar roots in mechanics. The term is sometimes used to describe robotic or AI-driven automation.

Summary

Automotive industry is all those companies and activities involved in the manufacture of motor vehicles, including most components, such as engines and bodies, but excluding tires, batteries, and fuel. The industry’s principal products are passenger automobiles and light trucks, including pickups, vans, and sport utility vehicles. Commercial vehicles (i.e., delivery trucks and large transport trucks, often called semis), though important to the industry, are secondary. The design of modern automotive vehicles is discussed in the articles automobile, truck, bus, and motorcycle; automotive engines are described in gasoline engine and diesel engine.

The modern industry

The modern automotive industry is huge. In the United States it is the largest single manufacturing enterprise in terms of total value of products, value added by manufacture, and number of wage earners employed. One of every six American businesses is dependent on the manufacture, distribution, servicing, or use of motor vehicles; sales and receipts of automotive firms represent more than one-fifth of the country’s wholesale business and more than one-fourth of its retail trade. For other countries these proportions are somewhat smaller, but Japan, South Korea, and the countries of western Europe have been rapidly approaching the level in the United States.

Consolidation

The trend toward consolidation in the industry has already been traced. In each of the major producing countries the output of motor vehicles is in the hands of a few very large firms, and small independent producers have virtually disappeared. The fundamental cause of this trend is mass production, which requires a heavy investment in equipment and tooling and is therefore feasible only for a large organization. Once the technique is instituted, the resulting economies of scale give the large firm a commanding advantage, provided of course that the market can absorb the number of vehicles that must be built to justify the investment. Although the precise numbers required are difficult to determine, the best calculations, considering both the assembly operation and the stamping of body panels, place the optimum output at between 200,000 and 400,000 cars per year for a single plant. Increasingly stringent and costly regulations aimed at correcting environmental damage due to the rising number of vehicles on the road also have been a factor in the move toward consolidation.

The structural organization of these giant enterprises, despite individual variation, resembles the pattern first adopted by General Motors in the 1920s. There is a central organization with an executive committee responsible for overall policy and planning. The operating divisions are semiautonomous, each reporting directly to the central authority but responsible for its own internal management. In some situations the operating divisions even compete with each other. The Ford Motor Company was consciously reorganized on the GM pattern after World War II; other American automotive firms have similar structures.

In addition, the largest producers decentralize their manufacturing operations by means of regional assembly plants. These permit the central factory to ship frames and components rather than complete automobiles to the areas served by the assembly plants, effecting substantial savings in transportation costs. This system was developed for the Ford company in 1911.

Some alteration of that principle took place in the 1980s and ’90s as Japanese firms built new plants around the world and American and European manufacturers adopted, to varying degrees, the Japanese “just-in-time” inventory method. Rather than stockpiling a large number of parts at the assembly plant or shipping all the parts from central locations, automakers have yielded the manufacture of many noncritical components (such as seats and wheel assemblies) to independent suppliers to make the pieces at small facilities close to the assembly plants. The components are often assembled into larger groups of parts or modules (a complete instrument panel, for example) and sent to the assembly plant in the exact sequence and at the exact time needed.

Diversity of products

The automotive industry’s immense resources in production facilities and technical and managerial skills have been devoted predominantly to the building of motor vehicles, but there has been a consistent and strong incentive to extend into related products and occasionally into operations whose relationship to automobiles is remote. The Ford Motor Company, for example, once manufactured tractors and made the famous Ford Trimotor all-metal transport airplane in the late 1920s and early ’30s. GM manufactured refrigerators and diesel-powered railway locomotives. By the end of the 20th century, however, Ford and GM had divested themselves of most of their nonautomotive operations and had spun off the majority of their automotive component-making divisions into separate stock companies—Delphi Automotive Systems in the case of General Motors and Visteon Automotive in the case of Ford.

In Europe, but to a lesser extent, automakers also divested noncore operations, while depressed economic conditions in Japan forced auto companies there to begin divorcing themselves from nonautomotive and components companies in which they had long held interests. By the late 1990s the trend was toward more international consolidation of core automotive operations.

New car development

The process of putting a new car on the market has become largely standardized. If a completely new model is contemplated, the first step is a market survey. Since there may be an interval of five years between this survey and the appearance of the new car in the dealers’ showrooms, there is a distinct element of risk, as illustrated by the Ford Motor Company’s Edsel of the late 1950s. (Market research had indicated a demand for a car in a relatively high price range, but, by the time the Edsel appeared, both public taste and economic conditions had changed.) Conferences then follow for engineers, stylists, and executives to agree on the basic design. The next stage is a mock-up of the car, on which revisions and refinements can be worked out.

Because of the increasingly competitive and international nature of the industry, manufacturers have employed various means to shorten the time from conception to production to less than three years in many cases. This has been done at GM, for example, by incorporating vehicle engineers, designers, manufacturing engineers, and marketing managers into a single team responsible for the design, engineering, and marketing launch of the new model. Automakers also involve component manufacturers in the design process to eliminate costly time-consuming reengineering later. Often the component maker is given full responsibility for the design and engineering of a part as well as for its manufacture.

Manufacturing processes

The bulk of the world’s new cars come from the moving assembly line introduced by Ford, but the process is much more refined and elaborated today. The first requisite of this process is an accurately controlled flow of materials into the assembly plants. No company can afford either the money or the space to stockpile the parts and components needed for any extended period of production. Interruption or confusion in the flow of materials quickly stops production. Ford envisioned an organization in which no item was ever at rest from the time the raw material was extracted until the vehicle was completed—a dream that has not yet been realized.

The need for careful control over the flow of materials is an incentive for automobile firms to manufacture their own components, sometimes directly but more often through subsidiaries. Yet complete integration does not exist, nor is it desirable. Tires, batteries, and dashboard instruments are generally procured from outside sources. In addition, and for the same reasons, the largest companies support outside suppliers even for items of in-house manufacture. First, it may be more economical to buy externally than to provide additional internal facilities for the purpose. Second, the supplier firm may have special equipment and capability. Third, the outside supplier provides a check on the costs of the in-house operation. American companies rely more than others on independent suppliers.

Production of a new model also calls for elaborate tooling, and the larger the output, the more highly specialized the tools in which the manufacturer is willing to invest. For example, it is expensive to install a stamping press exclusively to make a single body panel for a single model, but, if the model run reaches several hundred thousand, the cost is amply justified.

The assembly process itself has a quite uniform pattern throughout the world. As a rule, there are two main assembly lines, body and chassis. On the first the body panels are welded together, the doors and windows are installed, and the body is painted and trimmed (with upholstery, interior hardware, and wiring). On the second line the frame has the springs, wheels, steering gear, and power train (engine, transmission, drive shaft, and differential) installed, plus the brakes and exhaust system. The two lines merge at the point at which the car is finished except for minor items and necessary testing and inspection. A variation on this process is “unitized” construction, whereby the body and frame are assembled as a unit. In this system the undercarriage still goes down the chassis line for the power train, front suspension, and rear axle, to be supported on pedestals until they are joined to the unitized body structure. Most passenger vehicles today are manufactured by the unitized method, and most trucks and commercial vehicles still employ a separate frame.

Assembly lines have been elaborately refined by automatic control systems, transfer machines, computer-guided welding robots, and other automated equipment, which have replaced many manual operations when volume is high. Austin Motors in Britain pioneered with its automatic transfer machines in 1950. The first large-scale automated installation in the United States was a Ford Motor Company engine plant that went into production in 1951. A universal form of automatic control has used computers to schedule assembly operations so that a variety of styles can be programmed along the same assembly line. Customers can be offered wide choices in body styles, wheel patterns, and colour combinations.

Sales and service organization

Mass production implies mass consumption, which in turn requires an elaborate distributive organization to sell the cars and to develop confidence among customers that adequate service will be available. In the early days of the industry, cars were sold directly from the factory or through independent dealers, who might handle several different makes. Many bicycle manufacturers simply used their existing sales outlets when they added horseless carriages to their line. When sales in large quantities became the objective, however, more elaborate and better organized techniques of distribution became essential.

In the United States the restricted franchise dealership became the uniform and almost exclusive method of selling new cars. In this system, dealers may sell only the particular make of new car specified in their franchise, must accept a quota of cars specified by the manufacturer, and must pay cash on delivery. In return the dealers receive some guarantee of sales territory and may be assisted in various ways by the manufacturer—financing or aid in advertising, for example. Contracts also specify that dealers must maintain service facilities according to standards approved by the manufacturer.

Seemingly weighted in favour of the manufacturer, the system has been subjected to periodic dealer complaints, producing state legislation and a federal statute in 1956 to protect dealers from arbitrary actions by manufacturers. Yet dealers have never been united in these attitudes, and no effective substitute for the restricted franchise has yet been found. On the contrary, it is becoming the general practice in other parts of the world where large-scale markets for motor vehicles have developed.

Attempts by automakers in the 1990s to move away from the traditional franchised dealer network to direct selling via the Internet met strong resistance in the United States. American dealers enlisted the help of state governments in enacting prohibitions of this practice (and in blocking attempts by automakers to own dealers through subsidiary corporations). In markets outside the United States, principally in Europe and South America, manufacturers sell directly to consumers via the Internet in limited quantities.

The market in used cars is an important part of the distribution system for motor vehicles in all countries with a substantial motor vehicle industry because it affects the sale and styling of new cars. The institution of the annual model was adopted in the United States during the 1920s to promote new-car sales in the face of used-car competition. The new model must have enough changes in styling or engineering to persuade prospective buyers that it is indeed an improvement. At the same time, it must not be so radically different from its predecessors as to give the buyer doubts about its resale potential.

Like all machinery, motor vehicles wear out. Some become scrap metal to feed steel furnaces; some go to wrecking yards where usable parts are salvaged. Throughout the world, however, the disposal of discarded motor vehicles has become a problem without a completely satisfactory solution. In many areas, landscapes are disfigured by abandoned wrecks or unsightly automobile graveyards. Spurred by European legislation requiring automakers to take back all of their end-of-life-cycle vehicles beginning in 2007, manufacturers worldwide have begun engineering new products with the complete recycling of components in mind. At the same time, they have used more and different recycled material in new vehicles. For example, old bumper covers have been recycled into fender liners or battery trays for new cars.

Details

There are a wide variety of propulsion systems available or potentially available for automobiles and other vehicles. Options included internal combustion engines fueled by petrol, diesel, propane, or natural gas; hybrid vehicles, plug-in hybrids, fuel cell vehicles fueled by hydrogen and all electric cars. Fueled vehicles seem to have the advantage due to the limited range and high cost of batteries. Some options required construction of a network of fueling or charging stations. With no compelling advantage for any particular option, car makers pursued parallel development tracks using a variety of options. Reducing the weight of vehicles was one strategy being employed.

Recent developments

The use of high-technology (such as electronic engine control units) in advanced designs resulting from substantial investments in development research by European countries and Japan seemed to give an advantage to them over Chinese automakers and parts suppliers who, as of 2013, had low development budgets and lacked capacity to produce parts for high-tech engine and power train designs.

Characteristics

The chief characteristic of an automotive engine (compared to a stationary engine or a marine engine) is a high power-to-weight ratio. This is achieved by using a high rotational speed. However, automotive engines are sometimes modified for marine use, forming a marine automobile engine.

History

In the early years, steam engines and electric motors were tried, but with limited success. In the 20th century, the internal combustion engine (ICE), became dominant. In 2015, the internal combustion engine remains the most widely used but a resurgence of electricity seems likely because of increasing concern about ICE engine exhaust gas emissions.

As of 2017, the majority of the cars in the United States are gasoline powered. In the early 1900s, the internal combustion engines faced competition from steam engines and electric motors. The internal combustion engines of the time were powered by gasoline. Internal combustion engines function with the concept of a piston being pushed by the pressure of a certain explosion. This explosion is burning the hydrocarbon within the cylinder of an engine. Out of all the cars manufactured during the time, only around one fourth are actually considered internal combustion. Within the next couple of years, the internal combustion engine came out to become the most popular automotive engine. Sometime within the 19th century, Rudolf Diesel invented a new form of internal combustion power, using a concept of injecting liquid fuel into air heated solely by compression. This is the predecessor to the modern diesel engine used in automobiles, but more specifically, heavy duty vehicles such as semi-trucks.

Engine types:

Internal combustion engines

Petrol engines quickly became the choice of manufacturers and consumers alike. Despite the rough start, noisy and dirty engine, and the difficult gear shifting, new technologies such as the production line and the advancement of the engine allowed the standard production of the gas automobiles. This is the start, from the invention of the gas automobile in 1876, to the beginning of mass production in the 1890s. Henry Ford's Model T drove down the price of cars to a more affordable price. At the same time, Charles Kettering invented an electric starter, allowing the engine to be started without the need for a mechanical hand crank. The abundance of fuel propelled gas automobiles to be highly capable and affordable. The demand of gasoline rose from 3 billion barrels in 1919 to around 15 billion in 1929.

An internal combustion engine is powered by the expansion of gas which is created by the combustion of hydrocarbon gases fuels. To elaborate, an internal combustion used the heat of a combustion created by the injected hydrocarbon fuel to create mechanical motion. At the time of the early 1900s, wood alcohol was a popular fuel for French and German automobiles, but as governments imposed large taxes on the production, the price of wood alcohol rose above that of gasoline. Gasoline engines became popular as a result of this, as internal combustion engines were commonly known as gasoline engines. Although gasoline engines became popular, they were not particularly desirable due to the dangers of fuel leaks that may cause explosions. Therefore, many inventors attempted to create a kerosene burning engine as a result. This was not a successful venture applying it for automotive usage. There are many different types of fuels for internal combustion engines. These include diesel, gasoline, and ethanol.

Steam engines

The steam engine was invented in the late 1700s, and the primary method of powering engines and soon, locomotives. One of the most popular steam automobiles was the “Stanley Steamer,” offering low pollution, power, and speed. The downside of these steam automobiles is the unreliability, complexity, and the frequent accidents that occurred with them. The startup time for a steam car may take up to 45 minutes, defeating the purpose of faster transportation. By the time the steam automobile was improved, the complexity of manufacturing relative to the gas automobiles made steam automobiles unprofitable.

A steam engine is a device which transforms heat into mechanical motion. This is provided with the usage of boilers, which create steam by boiling water. In the early 1900s, Abner Doble introduced a steam-powered car in the United States which had capabilities that could potentially overpower Ford's Model T in efficiency. Steam has been known to have very efficient fuel economy with a high power source. That is why half the world was powered by steam for almost the entirety of the 19th century and almost half the 20th century. The main drawback of the steam engine in automobiles was that operators were required to have full knowledge of boilers and steam engines before operating, as it was detrimental to the engine itself if the operator neglected it.

Electric motors

Electric vehicles seemed to be the most viable option, similar to the steam automobiles. They were first invented in the early 1800s, and became a viable option of transportation around 1890, when William Morrison created the first electric car that traveled 14 miles per hour. The electric cars offered low pollution and a soundless ride, unlike their gasoline counterparts. The greatest downside of electric cars was the range. The typical electric car could reach around 20 miles before requiring a recharge. Manufacturers could not increase the number of batteries, due to the bulkiness of the batteries at the time. Without an incentive to purchase the electric automobiles, gas automobiles were the most viable option at the time.

Electric cars use batteries to store electricity which is used to power electric motors. The battery delivers the power to the motor, which is either Alternating Current (AC) or Direct Current (DC). The difference between AC and DC motors is the sort of system that is required to run it in an electric vehicle. An AC motor is generally cheaper but the components required to run it in an electric vehicle such as the controller and inverter makes it more expensive than the DC motor. A unique feature of electric vehicles compared to its gasoline counterparts, the electric vehicle is more simple than the gasoline vehicle. The electric vehicle bypasses the gasoline car components such as the crankshaft which allows it to generate power much faster than gasoline. Because of the faster transfer of power, the electric vehicle is able to accelerate faster than gasoline cars.

In the 1970s, the electric vehicle made its reappearance because of the 1973 OPEC Oil Embargo. Previously, the abundant gasoline had become the prime source of fuel for vehicles. But after the shortage, manufacturers began looking towards electric vehicles again. Despite the improved technology from the 1800s, the electric vehicles faced similar technological flaws such as limited mileage and speed. They could only travel up to 45 miles per hour and had a range of approximately 40 miles.

Jai Ganesh · Dark Discussions at Cafe Infinity

2424) Arthur Kornberg

Gist:

Work

The substances known as DNA and RNA bear organisms' genetic code and also determine their vital processes. Arthur Kornberg took an interest in the way DNA and RNA are formed, and which enzymes steer this process. Enzymes are substances that speed up chemical processes inside organisms' cells without being consumed. By studying bacteria, Kornberg succeeded in isolating DNA polymerase in 1956–an enzyme that is active in the formation of DNA. Using a DNA molecule as a blueprint, the enzyme builds a copy of the DNA molecule from nucleotides, which are the building blocks of DNA.

Summary

Arthur Kornberg (born March 3, 1918, Brooklyn, N.Y., U.S.—died Oct. 26, 2007, Stanford, Calif.) was an American biochemist and physician who received (with Severo Ochoa) the 1959 Nobel Prize for Physiology or Medicine for discovering the means by which deoxyribonucleic acid (DNA) molecules are duplicated in the bacterial cell, as well as the means for reconstructing this duplication process in the test tube.

At the U.S. National Institutes of Health, Bethesda, Md. (1942–53), Kornberg directed research on enzymes and intermediary metabolism. He also helped discover the chemical reactions in the cell that result in the construction of flavine adenine dinucleotide (FAD) and diphosphopyridine nucleotide (DPN), coenzymes that are important hydrogen-carrying intermediaries in biological oxidations and reductions.

Appointed professor and director of the microbiology department at Washington University, St. Louis, Mo. (1953–59), he continued to study the way in which living organisms manufacture nucleotides, which consist of a nitrogen-containing organic base linked to a five-carbon sugar ring—ribose or deoxyribose—linked to a phosphate group. Nucleotides are the building blocks for the giant nucleic acids DNA and RNA (ribonucleic acid, which is essential to the construction of cell proteins according to the specifications dictated by the “message” contained in DNA).

This research led Kornberg directly to the problem of how nucleotides are strung together (polymerized) to form DNA molecules. Adding nucleotides “labeled” with radioactive isotopes to extracts prepared from cultures of the common intestinal bacterium Escherichia coli, he found (1956) evidence of an enzyme-catalyzed polymerization reaction. He isolated and purified an enzyme (now known as DNA polymerase) that—in combination with certain nucleotide building blocks—could produce precise replicas of short DNA molecules (known as primers) in a test tube.

Kornberg became a professor of biochemistry at Stanford University, Palo Alto, Calif., in 1959. From 1959 to 1969 he was department chairman. His writings include Enzymatic Synthesis of DNA (1961). Kornberg’s son Roger D. Kornberg won the 2006 Nobel Prize for Chemistry. They became the sixth father-son tandem to win Nobel Prizes.

Details

Arthur Kornberg (March 3, 1918 – October 26, 2007) was an American biochemist who won the Nobel Prize in Physiology or Medicine in 1959 for the discovery of "the mechanisms in the biological synthesis of ribonucleic acid and deoxyribonucleic acid" together with Spanish biochemist and physician Severo Ochoa of New York University. He was also awarded the Paul-Lewis Award in Enzyme Chemistry from the American Chemical Society in 1951, an L.H.D. degree from Yeshiva University in 1962, and the National Medal of Science in 1979. In 1991, Kornberg received the Golden Plate Award of the American Academy of Achievement and the Gairdner Foundation Award in 1995.

Kornberg's primary research interests were in biochemistry, especially enzyme chemistry, deoxyribonucleic acid synthesis (DNA replication) and studying the nucleic acids which control heredity in animals, plants, bacteria and viruses.

Early life and education

Born in New York City, Kornberg was the son of Jewish parents Joseph and Lena (née Katz) Kornberg, who emigrated to New York from Austrian Galicia (now part of Poland) in 1900 before they were married. His paternal grandfather had changed the family name from Queller (also spelled Kweller) to avoid the draft by taking on the identity of someone who had already completed military service. Joseph married Lena in 1904. Joseph worked as a sewing machine operator in the sweat shops of the Lower East Side, Manhattan for almost 30 years, and when his health failed, opened a small hardware store in Brooklyn, where Arthur assisted customers at the age of nine. Joseph spoke at least six languages although he had no formal education.

Arthur Kornberg was educated first at Abraham Lincoln High School and then at City College of New York. He received a B.S. in 1937, followed by a Doctor of Medicine at the University of Rochester in 1941. Kornberg had a mildly elevated level of bilirubin in his blood— jaundice due to a hereditary genetic condition known as Gilbert's syndrome—and, while at medical school, he took a survey of fellow students to discover how common the condition was. The results were published in Kornberg's first research paper in 1942.

Kornberg's internship was at Strong Memorial Hospital in Rochester, New York, in 1941–1942. After completing his medical training, he joined the armed services as a lieutenant in the United States Coast Guard, serving as a ship's doctor in 1942 in the Caribbean. Rolla Dyer, the Director of National Institutes of Health, had noticed his paper and invited him to join the research team at the Nutrition Laboratory of the NIH. From 1942 to 1945, Kornberg's work was the feeding of specialized diets to rats to discover new vitamins.

Research and career

The feeding of rats was boring work, and Kornberg became fascinated by enzymes. He transferred to Dr Severo Ochoa's laboratory at New York University in 1946, and took summer courses at Columbia University to fill out the gaps in his knowledge of organic and physical chemistry while learning the techniques of enzyme purification at work. He became Chief of the Enzyme and Metabolism Section at NIH from 1947–1953, working on understanding of ATP production from NAD and NADP. This led to his work on how DNA is built up from simpler molecules.

While working at NIH, he also researched at Washington University in St. Louis (in the lab of Carl Ferdinand Cori and Gerty Cori in 1947), and the University of California, Berkeley (in the lab of Horace Barker in 1951).

In 1953 he became professor and head of the department of microbiology, Washington University in St. Louis, until 1959. Here he continued experimenting with the enzymes which created DNA. In 1956 he isolated the first DNA polymerizing enzyme, now known as DNA polymerase I. This got him elected to the United States National Academy of Sciences in 1957 and won him the Nobel prize in 1959.

In 1960, he was elected to the American Philosophical Society, received a LL.D. again from City College and a D.Sc. at the University of Rochester in 1962. He became professor and executive head of the department of biochemistry, Stanford University, in 1959. In an interview in 1997, Arthur Kornberg (referring to Josh Lederberg) said: "Lederberg really wanted to join my department. I knew him; he's a genius, but he'd be unable to focus and to operate within a small family group like ours, and so, I was instrumental in establishing a department of genetics [at Stanford] of which he would be chairman."

Kornberg's mother died of gas gangrene from a spore infection after a routine gall bladder operation in 1939. This started his lifelong fascination with spores, and he devoted some of his research efforts to understanding them while at Washington University. From 1962 to 1970, in the midst of his work on DNA synthesis, Kornberg devoted half his research effort to determining how DNA is stored in the spore, what replication mechanisms are included, and how the spore generates a new cell. This was an unfashionable but complex area of science, and although some progress was made, eventually Kornberg abandoned this research.

The Arthur Kornberg Medical Research Building at the University of Rochester Medical Center was named in his honor in 1999.

Until his death, Kornberg maintained an active research laboratory at Stanford and regularly published scientific journal articles. For several years the focus of his research was the metabolism of inorganic polyphosphate.

The "Kornberg school" of biochemistry refers to Arthur Kornberg's many graduate students and post-doctoral fellows, i.e., his intellectual children, and the trainees of his trainees, i.e., his intellectual grandchildren. Kornberg's intellectual children include I. Robert Lehman, Charles C. Richardson, Randy Schekman, William T. Wickner, James Rothman, Arturo Falaschi and Ken-ichi Arai.

Jai Ganesh · Dark Discussions at Cafe Infinity

Combination Quotes - III

1. I want every version of a woman and a man to be possible. I want women and men to be able to be full-time parents or full-time working people or any combination of the two. - Natalie Portman

2. To us, the value of a work lies in its newness: the invention of new forms, or a novel combination of old forms, the discovery of unknown worlds or the exploration of unfamiliar areas in worlds already discovered - revelations, surprises. - Octavio Paz

3. Looking beautiful isn't just about what you apply on your face. It's the little things you do that matter. A combination of a good diet, exercise, healthy habits, discipline, dancing etc. is what my beauty routine consists of. Also, I have no bad habits; I don't drink or smoke. All these contribute to me being fit and looking good. - Madhuri Dixit

4. I have a flexible body, thanks to the combination exercise routine I follow. But I'm fairly lazy when it comes to working out my legs and back. - Shriya Saran

5. It's an interesting combination: Having a great fear of being alone, and having a desperate need for solitude and the solitary experience. That's always been a tug of war for me. - Jodie Foster

6. For me a good body is a combination of peaceful mind, positive energy and physical exercise. - Shriya Saran

7. Books are mute as far as sound is concerned. It follows that reading aloud is a combination of two distinct operations, of two 'languages.' It is something far more complex than speaking and reading taken separately by themselves. - Maria Montessori

8. Nature teaches us that tens of billions of light years may have passed, and life in all of its expressions has always been subjected to an incredible combination of matter and radiation. - Fidel Castro.

Jai Ganesh · Jokes

Q: What do you call sad coffee?
A: Despresso.
* * *
Q: Why can Starbucks get away with charging outrageous prices for coffee?
A: Because they have Italian titles for everything!
* * *
Q: What kind of coffee was served on the Titanic?
A: Sanka.
* * *
Q: Why do I not like hot drinks?
A: It's just not my cup of tea.
* * *
Q: What do Chocolate, men, and coffee have in common?
A: They are all better rich!
* * *

Jai Ganesh · Science HQ

Fetoscope/Fetoscopy

Gist

A fetoscope, also known as a fetal stethoscope or Pinard horn, is a simple, non-electronic instrument used in prenatal care to listen to a baby's heartbeat by amplifying sounds through the mother's abdomen, typically after 18-20 weeks of gestation. It's a cone-shaped device, often made of metal or plastic, that allows midwives and doctors to monitor fetal well-being without ultrasound, providing a traditional, cost-effective method for assessing the fetus.

The fetoscope allows healthcare providers, especially midwives, to monitor the heartbeat of a fetus and assess the baby's health and development. A fetal heartbeat is a vital sign that helps to detect potential issues (especially genetic conditions) early on.

Summary

A fetoscopy is a procedure that allows your healthcare team to see the inside of your uterus during pregnancy. It helps treat certain genetic conditions in a developing fetus.

Fetoscopy is a procedure during pregnancy that lets your pregnancy care provider see the fetus developing inside your uterus. Providers use it to evaluate and treat congenital disorders (diseases you’re born with). It involves inserting a thin, fiber-optic tube (endoscope or fetoscope) into your uterus through a tiny incision in your abdomen. It has a small camera on the end so your provider can see inside your uterus and amniotic sac (the sac that holds the fetus in your uterus). The fetoscope is hollow, so your provider can insert surgical tools through it, allowing them to treat certain fetal conditions or obtain samples of tissue (biopsy). In some cases, the fetoscope is inserted through your cervix instead of through your abdomen.

When is a fetoscopy done?

Fetoscopy is performed in the second or third trimester of pregnancy to treat fetal conditions or collect biopsies.

Some of the most common conditions treated with fetoscopy are:

* Twin-to-twin transfusion syndrome

Twin-to-twin transfusion syndrome is a rare, potentially life-threatening condition that occurs when identical twins aren't getting an equal share of blood while in the uterus. Your surgeon uses a fetoscope to better visualize your placenta and the blood vessels causing the condition. Then, they place a laser through the fetoscope that they use to close off the blood vessels causing uneven blood flow. This procedure is called fetoscopic laser photocoagulation.

* Amniotic band syndrome

Amniotic band syndrome occurs when the fetus gets tangled up in bands of tissue from the amniotic sac. It can restrict blood flow or cause amputation of limbs or organs. A fetoscope allows your surgeon to insert a laser device that cuts and releases the bands of tissue around the fetus.

* Congenital diaphragmatic hernia (CDH)

CDH occurs when the fetus has a hole in its diaphragm, which causes its abdominal organs to shift upward, putting pressure on the lungs. This prevents its lungs from growing properly. Surgeons use fetoscopy to insert a balloon in the fetus's airway to promote lung growth. The balloon is removed several weeks later. This procedure is called fetoscopic endoluminal tracheal occlusion (FETO).

There are other conditions fetoscopy may be used for, like treatment of placental tumors, spina bifida and other congenital diseases.

Details:

What is a Fetoscope, and Why do Midwives Use it?

A fetoscope is a medical instrument that allows healthcare providers to listen to the fetal heartbeat. Unlike a standard stethoscope, a fetoscope is designed to pick up the sounds of a baby’s heartbeat through the mother’s abdomen. It is essential to prenatal care, especially in environments prioritizing low-intervention, natural childbirth approaches, like Birthways Family Birth Center.

The Purpose of a Fetoscope

The fetoscope allows healthcare providers, especially midwives, to monitor the heartbeat of a fetus and assess the baby’s health and development. A fetal heartbeat is a vital sign that helps to detect potential issues (especially genetic conditions) early on. This monitoring is crucial throughout pregnancy, especially as the due date approaches.

Difference Between a Doppler and a Fetoscope

A fetoscope and a Doppler device detect a fetal heartbeat, but they differ in several ways:

* Technology: A Doppler uses ultrasound waves to detect the movement of the baby’s heart and translate it into sound. On the other hand, a fetoscope relies on the practitioner’s ability to manually detect and listen to the fetal heartbeat without electronic amplification.
* Sound Quality: The sound detected through a Doppler is electronically amplified to make it louder and clearer. The fetoscope provides a more natural sound but may require more skill to handle.
* Safety: The Doppler uses ultrasound waves and introduces a small amount of energy into the body. However, it is generally considered safe. A fetoscope, however, is entirely noninvasive and doesn’t involve any ultrasound or electronic waves, making it a safe option for both mother and baby.

When Can You Use it?

A fetoscope is typically used to detect a fetal heartbeat starting around 18 to 20 weeks of pregnancy. However, it requires skill and patience, as the heartbeat may not always be easy to locate, especially in early pregnancy.

Using a fetoscope is generally more effective in the later stages of pregnancy when the baby is larger and the heartbeat is stronger.

Is it Safe?

Yes, a fetoscope is entirely safe during all stages of pregnancy. It’s a non-invasive tool that does not emit radiation, ultrasound, or electronic waves. Sometimes, a fetoscope may not detect the fetal heartbeat. But this is not a concern as long as the baby is moving.

Why Do Midwives Use Them?

Midwives often prefer fetoscopes because of their safety, simplicity, and effectiveness. It aligns with the midwifery philosophy of providing natural, low-intervention care. A fetoscope creates a calm and natural environment for the mother and the baby.

To sum up, the fetoscope is a valuable tool in prenatal care. It offers a safe, effective, and natural way to monitor the baby’s health throughout pregnancy. You can learn more about fetoscopes on our YouTube channel.

Additional Information

Fetoscopy is an endoscopic procedure during pregnancy to allow surgical access to the fetus, the amniotic cavity, the umbilical cord, and the fetal side of the placenta. A small (3–4 mm) incision is made in the abdomen, and an endoscope is inserted through the abdominal wall and uterus into the amniotic cavity. Fetoscopy allows for medical interventions such as a biopsy (tissue sample) or a laser occlusion of abnormal blood vessels (such as chorioangioma) or the treatment of spina bifida.

Fetoscopy is usually performed in the second or third trimester of pregnancy. The procedure can place the fetus at increased risk of adverse outcomes, including fetal loss or preterm delivery, so the risks and benefits must be carefully weighed in order to protect the health of the mother and fetus(es). The procedure is typically performed in an operating room by an obstetrician-gynecologist.

Non-surgical fetoscopes

Fetoscopy is a surgical procedure which may involve the use of a fibreoptic device called a fetoscope. Some confusion may arise from the use of specialized forms of stethoscopes, including Pinard horns and Doppler wands, to audibly monitor fetal heart rate (FHR). These audio diagnostic tools are also called "fetoscopes" but are not related to visual fetoscopy.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#10729. What does the term in Biology Fertilisation or Fertilization mean?

#10730. What does the term in Biology Fetus or Foetus mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#5925. What does the noun plaintiff (Law) mean?

#5926. What does the noun placenta mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#2559. What does the medical term Aneurysm mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#9844.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#6338.

Jai Ganesh · Exercises

Hi,

2695.

Jai Ganesh · This is Cool

2485) Seychelles

Gist

Seychelles is considered a rich country in Africa, often ranking highest in GDP per capita on the continent due to its strong tourism and fisheries-based economy, leading to high-income status with good social programs, though some inequality exists, note WorldAtlas, Global Finance Magazine, Seychelles News Agency, ISS African Futures, U.S. Department of State (.gov), and YouTube.

Summary

Seychelles, officially the Republic of Seychelles (French: République des Seychelles; Seychellois Creole: Repiblik Sesel), is an island country and archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, Victoria, is 1,500 kilometres (800 nautical miles) east of mainland Africa. Nearby island countries and territories include the Maldives, Comoros, Madagascar, Mauritius, and the French overseas departments of Mayotte and Réunion to the south; and the Chagos Archipelago to the east. Seychelles is the smallest country in Africa as well as the least populated sovereign African country, with an estimated population of 100,600 in 2022.

The Seychelles archipelago was uninhabited prior to sustained external contact. Although Arab and Swahili sailors likely knew of the islands earlier through Indian Ocean trade routes, there is no evidence of permanent settlement before European involvement.

The islands were first recorded by Europeans in the 16th century, but were not settled until the 18th century, when France formally claimed them. During the period of French colonization, enslaved Africans—many of whom had already been captured through existing African, Arab slave trade, and Indian Ocean slave trade networks—were brought to the islands for plantation labor.

It faced competing French and British interests until it came under full British control in the early 19th century. After Britain assumed control in the early 19th century, slavery was abolished and later replaced in part by indentured laborers from India. Since proclaiming independence from the United Kingdom in 1976, it has developed from a largely agricultural society to a market-based diversified economy, characterized by service, public sector, and tourism activities. From 1976 to 2015, nominal GDP grew nearly 700%, and purchasing power parity nearly 1600%. Since the late 2010s, the government has taken steps to encourage foreign investment.

As of the early 21st century, Seychelles has the highest nominal per capita GDP and the highest Human Development Index ranking of any African country. According to the 2024 V-Dem Democracy indices, Seychelles is the 43rd-ranked electoral democracy worldwide, the 1st-ranked liberal democracy in Africa, and the 2nd-ranked electoral democracy on the continent.

Seychellois culture and society is an eclectic mix of French, British, Indian and African influences, with infusions of Chinese elements. The country is a member of the United Nations, the African Union, the Southern African Development Community, and the Commonwealth of Nations.

Details:

Ethnic groups, languages, and religion

The original French colonists on the previously uninhabited islands, along with their black slaves, were joined in the 19th century by deportees from France. Asians from China, India, and Malaya (Peninsular Malaysia) arrived later in smaller numbers. Widespread intermarriage has resulted in a population of mixed descent.

Creole, also called Seselwa, is the mother tongue of most Seychellois. Under the constitution, Creole, English, and French are recognized as national languages.

More than three-fourths of the population are Roman Catholics. There are also Anglicans, Christians of other denominations, Hindus, and Muslims.

Settlement patterns and demographic trends

More than four-fifths of the population lives on Mahé, many in the capital city, Victoria. The birth and death rates, as well as the annual population growth rate, are below the global average. Some one-fifth of the population is younger than age 15, and an additional one-sixth is under age 30. Life expectancy for both men and women is significantly higher than the global average.

Economy

Seychelles has a mixed developing economy that is heavily dependent upon the service sector in general and the tourism industry in particular. Despite continued visible trade deficits, the economy has experienced steady growth. The gross domestic product (GDP) is growing more rapidly than the population. The gross national income (GNI) per capita is significantly higher than those found in most nearby continental African countries.

Agriculture, forestry, and fishing

Agriculture accounts for only a fraction of the GDP and employs an equally modest proportion of the workforce. Arable land is limited and the soil is generally poor—and the country remains dependent upon imported foodstuffs—but copra (from coconuts), cinnamon bark, vanilla, tea, limes, and essential oils are exported. Seychelles has a modern fishing industry that supplies both domestic and foreign markets; canned tuna is a particularly important product. The extraction of guano for export is also an established economic activity.

Manufacturing, finance, and trade

The country’s growing manufacturing sector—which has expanded to account for almost one-sixth of the total GDP—is composed largely of food-processing plants; production of alcoholic beverages and of soft drinks is particularly significant. Animal feed, paint, and other goods are also produced.

Seychelles’ sizable trade deficit is offset by income from the tourism industry and from aid and investment. Although the country’s relative prosperity has not made it a preferred aid recipient, it does receive assistance from the World Bank, the European Union, the African Development Bank, and a variety of contributing countries, and aid obtained per capita is relatively high. The Central Bank of Seychelles, located in Victoria, issues the official currency, the Seychelles rupee.

Seychelles’ main imports are petroleum products, machinery, and foodstuffs. Canned tuna, copra, frozen fish, and cinnamon are the most important exports, together with the reexport of petroleum products. Significant trade partners include France, the United Kingdom, the United Arab Emirates, and Italy.

Services

The service sector accounts for nearly four-fifths of the GDP and employs the largest proportion of the workforce, almost three-fourths of all laborers. After the opening of an international airport on Mahé in 1971, the tourism industry grew rapidly, and at the beginning of the 21st century it provided almost one-fourth of the total GDP. Each year Seychelles draws thousands of tourists, many attracted by the islands’ magnificent venues for scuba diving, surfing, windsurfing, fishing, swimming, and sunbathing. The warm southeasterly trade winds offer ideal conditions for sailing, and the waters around Mahé and the other islands are afloat with small boats.

Transportation and telecommunications

The majority of Seychelles’ roadways are paved, most of which are on the islands of Mahé and Praslin; there are no railroads. Ferry services operate between the islands—for example, linking Victoria with destinations that include Praslin and La Digue. Air service is centered on Seychelles International Airport, located near Victoria on Mahé, and the smaller airports and airstrips found on several islands. Seychelles has air connections with a number of foreign cities and direct flights to major centers that include London, Paris, Frankfurt, Rome, and Bangkok. Scheduled domestic flights, provided by Air Seychelles, chiefly offer service between Mahé and Praslin, although chartered flights elsewhere are also available. The tsunami that reached Seychelles in 2004 damaged portions of the transportation infrastructure, including the road linking Victoria with the international airport.

Telecommunications infrastructure in Seychelles is quite developed. The country has a high rate of cellular telephone use—among the highest in sub-Saharan Africa—and, at the beginning of the 21st century, the use of personal computers in Seychelles was several times the average for the region.

Jai Ganesh · Dark Discussions at Cafe Infinity

2423) Jaroslav Heyrovský

Gist:

Work

Chemical and electrical phenomena are often associated, as in the case of redox reactions, when electrons are emitted and absorbed. In 1922 Jaroslav Heyrovsky discovered a method for analyzing the occurrence and content of various substances in solutions using electrical measurements. The solution is analyzed with two electrodes, one of which is a dropping mercury electrode. At a voltage specific for different substances, redox reactions cause the current to rapidly increase to a level dependent on the concentration of the substance.

Summary

Jaroslav Heyrovský (born December 20, 1890, Prague, Bohemia, Austro-Hungarian Empire [now in Czech Republic]—died March 27, 1967, Prague, Czechoslovakia) was a Czech chemist who received the Nobel Prize for Chemistry in 1959 for his discovery and development of polarography.

Educated at the Charles University (Universita Karlova) of Prague and at University College, London, Heyrovský worked in London under Sir William Ramsay and F.G. Donnan. After holding several posts at the Charles University, he became professor and director of the department of physical chemistry (1926–54), and he was director of the Polarography Institute at the Czechoslovak Academy of Sciences (1950, 1952–63).

The work that eventually led to the discovery of polarography was begun in London at Donnan’s suggestion. Polarography is an instrumental method of chemical analysis used for qualitative and quantitative determinations of reducible or oxidizable substances. Heyrovský’s instrument measures the current that flows when a predetermined potential is applied to two electrodes immersed in the solution to be analyzed. Within 10 years of the demonstration of the first polarograph (1924) the method was in common use. Heyrovský’s monograph Polarographie appeared in 1941.

Details

Jaroslav Heyrovský (20 December 1890 – 27 March 1967) was a Czech chemist and inventor who received the Nobel Prize in Chemistry in 1959 for his invention of polarography.

Life and work

Jaroslav Heyrovský was born in Prague on 20 December 1890, the fifth child of Leopold Heyrovský, Professor of Roman Law at the Charles University in Prague, and his wife Clara, née Hanl von Kirchtreu. He obtained his early education at secondary school until 1909 when he began his study of chemistry, physics, and mathematics at the Charles University in Prague. From 1910 to 1914 he continued his studies at University College London, under Professors Sir William Ramsay, W. C. McC. Lewis, and F. G. Donnan, taking his B.Sc. degree in 1913. He was particularly interested in working with Professor Donnan, on electrochemistry.

During the First World War Heyrovský worked in a military hospital as a dispensing chemist and radiologist, which enabled him to continue his studies and to take his Ph.D. degree in Prague in 1918 and D.Sc. in London in 1921.

Heyrovský started his university career as assistant to Professor B. Brauner in the Institute of Analytical Chemistry of the Charles University, Prague; he was promoted to Associate Professor in 1922 and in 1926 he became the university's first professor of physical chemistry.

Heyrovský's invention of the polarographic method dates from 1922 and he concentrated his whole further scientific activity on the development of this new branch of electrochemistry. He formed a school of Czech polarographers in the university, and was himself in the forefront of polarographic research. In 1950 Heyrovský was appointed as the Director of the newly established Polarographic Institute, which was incorporated into the Czechoslovak Academy of Sciences in 1952.

In 1926 Professor Heyrovský married Marie (Mary) Koranová, and the couple had two children, a daughter, Jitka, and a son, Michael.

Jaroslav Heyrovský died on 27 March 1967. He was interred in the Vyšehrad cemetery in Prague.

Honors, awards, legacy

Many universities and seats of learning honored Heyrovský. He was elected Fellow of University College, London, in 1927, and received honorary doctorates from the Technical University, Dresden in 1955, the University of Warsaw in 1956, the University Aix-Marseille in 1959, and the University of Paris in 1960. He was granted honorary membership in the American Academy of Arts and Sciences in 1933; in the Hungarian Academy of Sciences in 1955; the Indian Academy of Sciences, Bangalore, in 1955; the Polish Academy of Sciences, Warsaw, in 1962; was elected Corresponding Member of the German Academy of Sciences, Berlin, in 1955; member of the German Academy of Natural Scientists, Leopoldina (Halle-Saale) in 1956; Foreign Member of the Royal Danish Academy of Sciences, Copenhagen, in 1962; Vice-President of the International Union of Physics from 1951 to 1957; President and first honorary member of the Polarographic Society, London; honorary member of the Polarographic Society of Japan; honorary member of the Chemical Societies of Czechoslovakia, Austria, Poland, England and India. In 1965, Heyrovský was elected a Foreign Member of the Royal Society (ForMemRS) in 1965.

In Czechoslovakia Heyrovský was awarded the State Prize, First Grade, in 1951, and in 1955 the Order of the Czechoslovak Republic.

Heyrovský lectured on polarography in the United States in 1933, the USSR in 1934, England in 1946, Sweden in 1947, the People's Republic of China in 1958, and in U.A.R. (Egypt) in 1960 and 1961.

The crater Heyrovský on the Moon is named in his honour.

Jai Ganesh · This is Cool

Calyx

Gist

What Is a Calyx? In flowering plants (also called angiosperms), the part of the flower that surrounds the growing bud, often found at the base of the bloom, is called the calyx. The calyx is composed of one or more leaf-like structures called sepals.

Are sepals called calyx?

Collectively, the sepals are called the calyx (plural: calyces), the outermost whorl of parts that form a flower. The word calyx was adopted from the Latin calyx, not to be confused with calix 'cup, goblet'.

Summary

Calyx is the usually green outer whorl of a flower consisting of separate or fused sepals. The calyx serves primarily to protect the developing flower bud and, in some cases, to support the flower once it has bloomed. In some species, the calyx persists even when the fruit matures, as seen in persimmon, eggplant, strawberry, and tomato. Given that it is not directly involved in reproduction, the calyx is considered an accessory part of the flower.

There are commonly four distinct whorls of flower parts: (1) an outer calyx consisting of sepals; (2) the corolla, within the calyx and consisting of petals; (3) the male androecium, comprising the pollen-bearing stamens; and (4) the female gynoecium, at the center and consisting of the pistils, which hold ovules and one or more ovaries. A flower’s calyx and corolla (e.g., all the sepals and petals together) form the perianth, which serves to protect the reproductive organs and attract pollinators. The arrangement of floral organs, including the calyx, is typically in concentric whorls, with the sepals forming the outermost layer, though not every flower has every whorl. The numbers and arrangements of flower parts—including the number and degree of fusion of the sepals of the calyx—are key characteristics botanists use to identify flowering plant species.

The calyx exhibits a wide range of morphological diversity across different angiosperm species. In some flowers, the sepals are free and distinct, a condition known as aposepalous or polysepalous. In other species, the sepals are fused together, forming a tubular structure with lobes or teeth at the end, a condition referred to as synsepalous. The number of sepals in a calyx often corresponds to the number of petals, either directly (e.g., five sepals and five petals) or in multiples (e.g., four sepals and eight petals). In some species, the sepals are brightly colored and function as petals—for example, Clematis and Bougainvillea. In others, the petals and sepals are both present but are similar in color and appearance, as in the tulip tree (Liriodendron tulipifera) and Easter lily (Lilium longiflorum); in such cases, they are known as tepals.

Details

A sepal is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom. Collectively, the sepals are called the calyx.

Description

Sepals are usually green. The term tepal is usually applied when the parts of the perianth are difficult to distinguish, e.g. the petals and sepals share the same color or the petals are absent and the sepals are colorful. When the undifferentiated tepals resemble petals, they are referred to as "petaloid", as in petaloid monocots, orders of monocots with brightly colored tepals. Since they include Liliales, an alternative name is lilioid monocots. Examples of plants in which the term tepal is appropriate include genera such as Aloe and Tulipa. In contrast, genera such as Rosa and Phaseolus have well-distinguished sepals and petals.[citation needed]

The number of sepals in a flower is its merosity. Flower merosity is indicative of a plant's classification. The merosity of a eudicot flower is typically four or five. The merosity of a monocot or palaeodicot flower is three, or a multiple of three.

The development and form of the sepals vary considerably among flowering plants. They may be free (polysepalous) or fused together (gamosepalous). Often, the sepals are much reduced, appearing somewhat awn-like, or as scales, teeth, or ridges. Most often such structures protrude until the fruit is mature and falls off.

Examples of flowers with much-reduced perianths are found among the grasses.

In some flowers, the sepals are fused towards the base, forming a calyx tube (as in the families Lythraceae and Fabaceae). In other families (e.g. Rosaceae and Myrtaceae), a hypanthium includes the bases of sepals, petals, and the attachment points of the stamens.

Mechanical cues may be responsible for sepal growth and there is a strong evidence suggesting that microtubules are present and determine the tensile strength and direction of growth at a molecular level.

Morphology

Morphologically, both sepals and petals are modified leaves. The calyx (the sepals) and the corolla (the petals) are the outer sterile whorls of the flower, which together form the perianth. In some plants, such as Aristolochia, the calyx is the primary whorl, forming a flower up to 50 cm (20 in) wide, with one sepal growing to a slender ribbon with a length of up to 4 m (13 ft) in Aristolochia grandiflora, the largest of all calyces.

Function

Sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom.

Similarly to ordinary leaves, sepals are capable of performing photosynthesis. However, photosynthesis in sepals occurs at a slower rate than in ordinary leaves due to sepals having a lower stomatal density which limits the spaces for gas exchange.

After flowering, most plants have no more use for the calyx, which withers or becomes vestigial, although in a few plants such as Lodoicea and Solanum melongena (aubergine, brinjal) the calyx grows along with the fruit, possibly to protect the attachment point. Some plants retain a thorny calyx, either dried or live, as protection for the fruit or seeds. Examples include species of Acaena, some of the Solanaceae (for example the tomatillo Physalis philadelphica), and the water caltrop, Trapa natans. In some species, the calyx not only persists after flowering but instead of withering, begins to grow until it forms a bladder-like enclosure around the fruit. This is an effective protection against some kinds of birds and insects, for example in Hibiscus trionum and in Physalis species. In some other plants, the calyx grows into an accessory fruit.

Additional Information:

Calyx Meaning

The outermost whorl of the flower is referred to as the calyx. Sepals are the functional units of the calyx, meaning that the calyx is a collection of sepals. The sepals are mostly green in colour and protect the inner structures of the flower from breakage, mechanical injury and desiccation. It supports the other internal structures of flowers such as the corolla, gynoecium and androecium. Corolla is the collection of petals, androecium is the male reproductive whorl and gynoecium is the female reproductive whorl of the flower.

The calyx is found just below the corolla. In some plants, the calyx and corolla are indistinguishable and are termed as perianth. Once the flower has bloomed, the calyx goes on to support the development of fruit. Sometimes, an additional whorl is found externally to the calyx that consists of a whorl of bracts that arise by the union of sepal appendages.

Forms of Calyx

* Polysepalous: When the calyx consists of sepals that are free from each other, it is referred to as polysepalous. E.g., Rose, Cassia
* Gamosepalous: When the sepals are fused in the calyx, it is referred to as gamosepalous. E.g., Datura
* Caducous: When the sepals of a flower wither or drop off, it is referred to as caducous. E.g., Poppy
* Petalloid: In petalloid conditions, the sepals of the flowers are coloured. E.g., Delphinium
* Persistent: In this form, the sepals do not wither and are persistent even in the fruits. E.g., Brinjal.

Functions of Calyx in Plants

The calyx serves several essential functions in the life cycle of a plant. These are:

* Protection: Primarily, the calyx is a protective covering for the developing flower bud, shielding it from physical damage, desiccation, and predation.
* Support: The calyx also provides structural support to the flower, holding its various components in place as it grows and develops. This support is crucial, especially in windy conditions, as it prevents the flower from dislodging or damaging.
* Regulation of Pollination: The sepals of the calyx can also play a role in attracting pollinators to the flower. In some plant species, the sepals' color, shape, and texture may aid in pollinator attraction, ultimately facilitating the transfer of pollen and ensuring successful fertilization, like in Petalloid Calyx.
* Water Regulation: The calyx also helps regulate the uptake and retention of water within the flower bud. The calyx prevents excessive water loss through transpiration and maintains optimal flower hydration.

The different types of calyx are:

* Polysepalous Calyx: This type of Calyx has sepals that are free and separate from each other. Polysepalous calyx examples are found in flowers like Hibiscus and Camellia, where individual sepals encircle the base of the flower, forming a protective shield around the developing bud.
* Gamosepalous Calyx: The sepals in this type are fused or united, forming a single structure. The Petunia is a classic example of a plant having a gamosepalous calyx.
* Caducous Calyx: Caducous Calyx is a calyx where the sepals eventually wither or fall off after the flower blooms. This can be seen in trees like the Maple, where the calyx serves its protective purpose during the bud's development and sheds away once the flower matures.
* Petalloid Calyx: Here, the sepals transform remarkably, adopting colors akin to petals. This phenomenon can be seen in plants like the Poinsettia, where the calyx protects and contributes to the flower's reproductive success by attracting pollinators like bright-colored petals.
* Persistent Calyx: The sepals remain even after the flower has bloomed. Instead of withering away, they stay attached to the developing fruit, offering continued support and protection. A notable example of this can be found in the Tomato plant, where the calyx persists even as the fruit ripens.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#10727. What does the term in Biology Fitness mean?

#10728. What does the term in Biology Fitness landscape mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#5923. What does the adjective musty mean?

#5924. What does the noun mutation mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#2558. What does the medical term Funiculus (neuroanatomy) mean?

Jai Ganesh · Science HQ

Laser Surgery

Gist

Laser surgery uses highly focused, intense light beams to treat, remove, or alter tissue with high precision, often serving as a minimally invasive alternative to traditional surgery. It commonly cuts, vaporizes, or coagulates tissue in various fields, including ophthalmology (LASIK), dermatology (skin lesions), and general surgery. Key benefits include faster recovery, reduced blood loss, and improved precision (LASIK: LASIK stands for Laser-Assisted In Situ Keratomileusis and is a procedure that permanently changes the shape of the cornea, the clear covering of the front of the eye, using an excimer laser.)

What is the laser surgery used for?

To help prevent blood loss by sealing small blood vessels. Refractive eye surgery. Dental procedures. To treat some skin conditions, including to remove warts, moles, tattoos, birthmarks, acne, scars, wrinkles, and unwanted hair.

Summary

Laser surgery is a type of surgery that uses special light beams instead of instruments for surgical procedures. LASER stands for "Light Amplification by the Stimulated Emission of Radiation." Lasers were first developed in 1960.

Newer laser modifications continue to have a large impact on medical and surgical practices. A large part of their impact has been seen in the treatment of various skin lesion and diseases.

What types of surgeries use lasers?

There are many indications for the use of lasers in surgery. The following are some of the more common indications:

* To remove tumors
* To help prevent blood loss by sealing small blood vessels
* To seal lymph vessels to help decrease swelling and decrease the spread of tumor cells
* To treat some skin conditions, including to remove or improve warts, moles, tattoos, birthmarks, scars, and wrinkles

How are lasers used during cancer surgery?

Laser surgery is a type of surgery that uses special light beams instead of instruments, such as scapels, to perform surgical procedures. There are several different types of lasers, each with characteristics that perform specific functions during surgery. Laser light can be delivered either continuously or intermittently and can be used with fiber optics to treat areas of the body that are often difficult to access. The following are some of the different types of laser used for cancer treatment:

* Carbon dioxide (CO2) lasers: Carbon dioxide (CO2) lasers can remove a very thin layer of tissue from the surface of the skin without removing deeper layers. The CO2 laser may be used to remove skin cancers and some precancerous cells.

* Neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers: Neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers can penetrate deeper into tissue and can cause blood to clot quickly. The laser light can be carried through optical fibers to reach less accessible internal parts of the body. For example, the Nd:YAG laser can be used to treat throat cancer.

* Laser-induced interstitial thermotherapy (LITT): Laser-induced interstitial thermotherapy (LITT) uses lasers to heat certain areas of the body. The lasers are directed to areas between organs (interstitial areas) that are near a tumor. The heat from the laser increases the temperature of the tumor, thereby shrinking, damaging, or destroying the cancer cells.

* Argon lasers: Argon lasers pass only through superficial layers of tissue such as skin. Photodynamic therapy (PDT) uses argon laser light to activate chemicals in the cancer cells.

Details

Laser surgery is a type of surgery that cuts tissue using a laser in contrast to using a scalpel.

Soft-tissue laser surgery is used in a variety of applications in humans (general surgery, neurosurgery, ENT, dentistry, orthodontics, and oral and maxillofacial surgery) as well as veterinary surgical fields. The primary uses of lasers in soft tissue surgery are to cut, ablate, vaporize, and coagulate. There are several different laser wavelengths used in soft tissue surgery. Different laser wavelengths and device settings (such as pulse duration and power) produce different effects on the tissue. Some commonly used lasers types in soft tissue surgery include erbium, diode, and CO2. Erbium lasers are excellent cutters, but provide minimal hemostasis. Diode lasers (hot tip) provide excellent hemostasis, but are slow cutters. CO2 lasers are both efficient at cutting and coagulating. Laser surgery is commonly used on the eye. Techniques used include LASIK, which is used to correct near and far-sightedness in vision, and photorefractive keratectomy, a procedure which permanently reshapes the cornea using an excimer laser to remove a small amount of the human tissue.

Effects

* Photochemical effect: clinically referred to as photodynamic therapy. Photosensitizer (photophrin II) is administered which is taken up by the tumor tissue and later irradiated by laser light resulting in highly toxic substances with resultant necrosis of the tumor. Photodynamic therapy is used in palliation of oesophageal and bronchial carcinoma and ablation of mucosal cancers of Gastrointestinal tract and urinary bladder.
* Photoablative effect: Used in eye surgeries like refractive surgery, band keratoplasty, and endartectomy of peripheral blood vessels.
* Photothermal effect: this property is used for endoscopic control of bleeding e.g. Bleeding peptic ulcers, oesophageal varices
* Photomechanical effect: used in intraluminal lithotripsy

Equipment

Surgical laser systems, sometimes called "laser scalpels", are differentiated not only by the wavelength, but also by the light delivery system: flexible fiber or articulated arm, as well as by other factors. Types of surgical lasers include carbon dioxide, argon, Nd:YAG laser, and potassium titanyl phosphate. CO2 lasers were the dominant soft-tissue surgical lasers as of 2010. (Nd:YAG (neodymium-doped yttrium aluminium garnet; Nd:Y3Al5O12) is a crystal that is used as a lasing medium for solid-state lasers.)

Applications:

Dermatology and plastic surgery

A range of lasers such as erbium, dye, Q switch lasers, and CO2 are used to treat various skin conditions including scars, vascular and pigmented lesions, and for photorejuvenation. The laser surgery for dermatology often bypasses the skin surface. The principle of laser surgery for dermatologic problems is based on SPTL (selective photothermolysis). The laser beam penetrates the skin until it encounters chromophore which absorbs the laser beam. After absorption of the laser beam, heat is generated to induce coagulation, necrosis of the targeted tissue, this results in the removal of unwanted tissue by laser surgery.

Laser resurfacing is a technique in which covalent bonds of a material are dissolved by a laser, a technique invented by aesthetic plastic surgeon Thomas L. Roberts, III using CO2 lasers in the 1990s.

Lasers are also used for laser-assisted lipectomy.

Eye surgery

Various types of laser surgery are used to treat refractive error. LASIK, in which a knife is used to cut a flap in the cornea, and a laser is used to reshape the layers underneath, is used to treat refractive error. IntraLASIK is a variant in which the flap is also cut with a laser. In photorefractive keratectomy (PRK, LASEK), the cornea is reshaped without first cutting a flap. In laser thermal keratoplasty, a ring of concentric burns is made in the cornea, which causes its surface to steepen, allowing better near vision. ReLEx SMILE is the latest advancement in laser vision correction technology. In SMILE surgery, ZEISS VisuMax femtosecond laser is used to make a small incision and to create a pre-calculated mini lens tissue (or lenticule) inside the cornea.

Lasers are also used to treat non-refractive conditions, such as phototherapeutic keratectomy (PTK) in which opacities and surface irregularities are removed from the cornea and laser coagulation in which a laser is used to cauterize blood vessels in the eye, to treat various conditions. Lasers can be used to repair tears in the retina.

Endovascular surgery

Laser endarterectomy is a technique in which an entire atheromatous plaque in the artery is excised. Other applications include laser assisted angioplasties and laser-assisted vascular anastomosis.

Foot and ankle surgery

Lasers are used to treat several disorders in foot and ankle surgery. They are used to remove benign and malignant tumors, treat bunions, debride ulcers and burns, excise epidermal nevi, blue rubber bleb nevi, and keloids, and the removal of hypertrophic scars and tattoos.

A carbon dioxide laser (CO2) is used in surgery to treat onychocryptosis (ingrown nails), onychauxis (club nails), onychogryposis (rams horn nail), and onychomycosis (fungus nail).

Gastro-intestinal tract

1) Peptic ulcer disease and oesophageal varices - Laser photoablation is done.
2) Coagulation of vascular malformations of stomach, duodenum, and colon.
3) Lasers can be effectively used to treat early gastric cancers provided they are less than 4 cm and without lymph node involvement. Lasers are also used in treating oral submucous fibrosis.
4) Palliative laser therapy is given in advanced oesophageal cancers with obstruction of lumen. Recanalisation of the lumen is done which allows the patient to resume a soft diet and maintain hydration.
5) Ablative laser therapy is used in advanced colorectal cancers to relieve obstruction and to control bleeding.
6) Laser surgery used in hemorrhoidectomy, and is a relatively popular and non-invasive method of hemorrhoid removal.
7) Laser-assisted liver resections have been done using carbon dioxide and Nd:YAG lasers.
8) The ablation of liver tumors can be achieved by selective photovaporization of the tumor.
9) Endoscopic laser lithotripsy is a safer modality compared to electrohydraulic lithotripsy.

Oral and dental surgery

The CO2 laser is used in oral and dental surgery for virtually all soft-tissue procedures, such as gingivectomies, vestibuloplasties, frenectomies, and operculectomies. The CO2 10,600 nm wavelength is safe around implants as it is reflected by titanium, and thus has been gaining popularity in the field of periodontology. The laser may also be effective in treating peri-implantitis.

Spine surgery

Laser spine surgery first began seeing clinical use in the 1980s and was primarily used within discectomy to treat lumbar disc disease under the notion that heating a bulging disc vaporized enough tissue to relieve pressure on the nerves and help alleviate pain.

Since that time, laser spine surgery has become one of the most marketed forms of minimally invasive spine surgery, despite the fact that it has never been studied in a controlled clinical trial to determine its effectiveness apart from disc decompression. Evidence-based data surrounding the use of lasers in spine surgery is limited and its safety and efficacy were poorly understood as of 2017.

Thoracic surgery

In thoracic surgery, surgical laser applications are most often used to remove pulmonary metastases and tumors of different primary localizations. Other areas of application are surgical sectioning of the parenchyma, anatomic segmental resections, removal of tumors from the thoracic wall and abrasion of the pleura parietalis. Since the introduction of surgical lasers, the amount of potentially surgically resectable pulmonary nodules has significantly increased. Compared to laser surgery, other conventional surgical methods such as segmental or wedge resections with surgical stapling will normally lead to a bigger loss of lung tissue, especially in patients with multiple pulmonary nodules methods.

Other advantages of laser surgery compared to conventional methods are that it leads to an improved postoperative lung function and that it gives the additional possibility to histologically analyze the removed material which would otherwise be destroyed through radiation or heat.

Hard tissues

Lasers are used to cut or ablate bones and teeth in dentistry.

Other surgery

The CO2 laser is also used in gynecology, genitourinary, general surgery, otorhinolaryngology, orthopedic, and neurosurgery.

Additional Information:

What is laser surgery?

Laser surgery is a type of surgery that uses special light beams instead of instruments for surgical procedures.

How does a laser work?

The functioning of a laser goes back to Albert Einstein's theory of stimulated emission of radiation. It also includes other theories that help explain local tissue damage. As the light beam hits the skin, the skin may either reflect the light away, scatter the light, absorb the light, or let the light pass right through the different layers of the skin.

Certain parts of the skin called chromophores absorb the light. When these chromophores absorb the light, physical, mechanical, chemical, or temperature changes may occur in the tissue.

There are many different types of lasers. They include the carbon dioxide laser, the YAG (neodymium, or yttrium aluminum garnet) laser, and the argon laser. Each one works differently and may be used for different treatment options. Laser light can be delivered either continuously or intermittently. The wavelength of the laser determines the target within the skin and the effect it may have.

What types of surgeries use lasers?

There are many reasons to use lasers in surgery. The following are some of the more common reasons:

* To shrink or destroy tumors
* To help prevent blood loss by sealing small blood vessels
* Refractive eye surgery
* Dental procedures
* To treat some skin conditions, including to remove warts, moles, tattoos, birthmarks, acne, scars, wrinkles, and unwanted hair.

image?url=https%3A%2F%2Fbed.apexhospitals.com%2Fuploads%2Flaser_surgery_8f769b34a8.png&w=1200&q=75

Jai Ganesh · Dark Discussions at Cafe Infinity

Combination Quotes - II

1. Art imitates life and, sometimes, life imitates art. It's a weird combination of elements. - Bruce Willis

2. There is a certain combination of anarchy and discipline in the way I work. - Robert De Niro

3. I am a combination of being an introvert and an extrovert - I am cordial, I connect, I can chat with people and then I like to be in my own space. - Bhumika Chawla

4. Music is so abstract; it is a combination of words and melody. - Shankar Mahadevan

5. Ideas rose in clouds; I felt them collide until pairs interlocked, so to speak, making a stable combination. - Henri Poincare

6. I think the combination of graduate education in a field like Computer Science and the opportunity to apply this in a work environment like Microsoft is what drove me. The impact these opportunities create can lead to work that has broad, worldwide impact. - Satya Nadella

7. We talk about this concept of openness and transparency as the high-level ideal that we're moving towards at Facebook. The way that we get there is by empowering people to share and connect. The combination of those two things leads the world to become more open. - Mark Zuckerberg

8. It's always a combination of physics and poetry that I find inspiring. It's hard to wrap your head around things like the Hubble scope. - Tom Hanks.

Jai Ganesh · Jokes

Q: Why are men are like coffee?
A: The best ones are rich, hot, and can keep you up all night!
* * *
Q: What do you call a cow who's just given birth?
A: De-calf-inated!
* * *
Q: Why are all Jewish men required to make a good cup of coffee?
A: Because according to the Torah He Brews!
* * *
Q: Why is a bad cup of coffee the end of a marriage?
A: Because it's GROUNDS for divorce!
* * *
Q: What is best Beatles song?
A: Latte Be!
* * *

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#9843.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#6337..

Jai Ganesh · Exercises

Hi,

2694.

Jai Ganesh · This is Cool

Corolla

Gist

A corolla is the collection of a flower's petals, often brightly colored to attract pollinators, forming the second whorl inside the sepals and surrounding the reproductive organs (stamens and pistils) to help with pollination and protect them. It comes from the Latin word for "wreath" or "crown" and can vary greatly in shape (bell, funnel, tubular) and fusion (fused or free) across different plants.

The corolla is the name given to the collective rings of petals around a flower and its reproductive organs. The corolla functions in aiding the reproduction process known as pollination. Pollination is when pollen is transferred between flowers resulting in fertilization.

Summary

Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the corolla. Petals are usually surrounded by an outer whorl of modified leaves called sepals, that collectively form the calyx and lie just beneath the corolla. The calyx and the corolla together make up the perianth, the non-reproductive portion of a flower. When the petals and sepals of a flower are difficult to distinguish, they are collectively called tepals. Examples of plants in which the term tepal is appropriate include genera such as Aloe and Tulipa. Conversely, genera such as Rosa and Phaseolus have well-distinguished sepals and petals. When the undifferentiated tepals resemble petals, they are referred to as "petaloid", as in petaloid monocots, orders of monocots with brightly coloured tepals. Since they include Liliales, an alternative name is lilioid monocots.

Although petals are usually the most conspicuous parts of animal-pollinated flowers, wind-pollinated species, such as the grasses, either have very small petals or lack them entirely (apetalous).

Corolla

The collection of all petals in a flower is referred to as the corolla. The role of the corolla in plant evolution has been studied extensively since Charles Darwin postulated a theory of the origin of elongated corollae and corolla tubes.

A corolla of separate petals, without fusion of individual segments, is apopetalous. If the petals are free from one another in the corolla, the plant is polypetalous or choripetalous; while if the petals are at least partially fused, it is gamopetalous or sympetalous. In the case of fused tepals, the term is syntepalous. Fused petals may form a tube, which is then known as a 'corolla tube'.

Details

A petal, in flowering plants, is a sterile floral part that usually functions as a visually conspicuous element of a flower. Petals are modified leaves and are often brightly colored or white to attract specific pollinators to the flower. Petals often come in multiples of three in monocots or in multiples of four or five in eudicots. Many horticultural flowers, such as roses and peonies, have been bred to have multiple layers of petals, resulting in showy, textured blooms.

Many flowers have two sets of sterile appendages, the petals and the sepals, that are attached below the fertile parts of the flower, the stamens and the pistils. All of the petals of a flower are collectively called the corolla, while all the sepals form the calyx. The calyx and the corolla together are referred to as the perianth. Like petals, sepals are modified leaves, but they are often green and somewhat rugged; they serve to protect and enclose the flower bud. Petals, by contrast, are often thinner and more delicate than sepals and come in a myriad of colors. In some flowers, such as many lilies and orchids, the petals and sepals are nearly indistinguishable in appearance; such undifferentiated structures are known as tepals.

The “petals” of certain members of the aster family (Asteraceae), such as those of daisies and sunflowers, are actually each individual flowers on a composite head. In more than half the members of the family, these ray flowers form in the outermost row or rows of the composite head and have a modified, mainly flat and elongate corolla that resembles an individual petal of most other flowers.

Additional Information:

Parts of a Flower

Plants are primarily divided into flowering and non-flowering classes based on whether they have flowers. A flower, a defining feature of flowering plants, is essentially an extension of the shoot used for reproduction.

The four primary components of most flowers are sepals, petals, stamens, and carpels. The female component of the flower is the carpels, while the male component is the stamens. Most flowers are hermaphrodites, meaning they have both male and female components. Others may be male or female and contain one of the two parts.

* Peduncle: The flower’s stalk is known as a peduncle.
* Receptacle: This is the area of the flower where the stalk is attached. It is tiny and is located at the centre of the flower’s base.
* Petals: This layer is located right above the sepal layer. The collection of petals is known as the corolla. Since their primary function is to draw pollinators, such as insects, butterflies, and other creatures, to the flower, they are often brightly coloured.
* Sepals: At the base of the petals, they are tiny, leaf-like components. They constitute the top whorl of the flower. Sepals are collectively referred to as the calyx. The primary purpose of the calyx and its sepals is to safeguard the flower before blooming (in the bud phase).
* Stamens: They are the male components of a flower. The androecium is a collection of many stamens. They are structurally separated into two parts:
* Filament: The extended, slender portion that connects the anther to the flower is called a filament.
* Anthers: The stamen’s head is where the pollen is produced, which is then transmitted to the pistil or other female sections of the same or different flower to induce fertilisation.
* Pistil: This constitutes the female components of a flower. The pistil consists of four parts: Style, Stigma, Ovary, and Ovules. The gynoecium is the term for a collection of pistils.

Corolla of Flower

What do you see when you first look at a flowering plant? Is it the flower, the stem, or the leaves? The brightly coloured petals of the flower are the most prominent part of most flowering plants. The corolla is the collective term for the arrangement of petals of flowers, which are frequently placed in a circle around the flower’s centre.

Most flowers include sepals, or little leaf-like structures, on the outside of the corolla that surround the petals before the flower develops. Most flowers have three more circles of structures added to the corolla that make up the entire flower. The first circle of structures inside the corolla is made up of many stamens and other male reproductive elements. The female reproductive part, known as the pistil, is located in a circle at the centre of the flower.

In this article, we will learn the corolla’s meaning, features, variations, and significant functions.

Meaning of Corolla

In plants, the term “corolla” refers to a collection of petals that strongly displays colour and encircles the stamen and carpel, the reproductive organs of a flower. Therefore, corolla or petals refers to the second whorl of a flower, which is internal to the calyx. Corollas can also be gamopetalous (fused) and polypetalous (free), just like the calyx.

Plants have a wide range of corolla shapes and colours. Corolla might be wheel-shaped, bell-shaped, tubular, or styled like a funnel. These corollas draw insects to the flower, and while at the flower, these insects participate in pollination.

Features of Corolla of Flower

* The important function of petals is to keep the vital flower components in their younger state.
* Due to the presence of specific pigments such as water-soluble anthocyanin, anthoxanthin, carotenoids, etc., corolla typically has a vibrant colour.
* The essential oil gives the petals their fragrance.
* Additionally, the petals have organs called nectaries that produce sugar-rich nectar to attract insects.
* Sepaloid has petals that are pale or green in colour. Examples are the Polyalthia and Annona species.
* The petals can occasionally be thicker while often being thin.
* The petal structure consists of two parts: the claw and the limb.
* The claw is the thin, stalk-like basal portion of a petal. All clawless bracts are sessile.
* A limb is the enlarged apex of the petals.
* Petals can have regular or irregular sizes and shapes.
* The corolla can have bilateral or radial symmetry.
* The edges of a petal might be whole, serrated, split, etc., much like a leaf lamina.

Functions of Corolla

Corolla performs three functional activities:

1. Pollination: The flower petals have a vibrant appearance and an aromatic fragrance that attracts everyone’s attention. Bees, birds, and other pollinating creatures thus aid in the fertilisation of flowers.

2. Storage: To draw pollinators, petals serve as storage for sugar-rich nectar.

3. Protection: The male (stamen) and female (carpel) reproductive elements of the flower, which are involved in fertilising the flower to generate fruits, are protected by the whorl of petals.

Conclusion

Thus, the group of petals collectively known as corolla is the most appealing feature of a flower due to its vibrant colours and fragrance. Although it does not directly participate in pollination, it indirectly can attract or deter specific pollinators.

Math Is Fun Forum

#1 This is Cool » Hovercraft » Yesterday 19:43:21

#2 Re: This is Cool » Miscellany » Yesterday 17:39:48

#3 Re: Dark Discussions at Cafe Infinity » crème de la crème » Yesterday 17:04:25

#4 Dark Discussions at Cafe Infinity » Combination Quotes - III » Yesterday 16:48:56

#5 Jokes » Coffee Jokes - II » Yesterday 16:26:19

#6 Science HQ » Fetoscope/Fetoscopy » Yesterday 16:14:51

#7 Re: Jai Ganesh's Puzzles » General Quiz » Yesterday 15:38:12

#8 Re: Jai Ganesh's Puzzles » English language puzzles » Yesterday 15:27:21

#9 Re: Jai Ganesh's Puzzles » Doc, Doc! » Yesterday 15:07:46

#10 Re: Jai Ganesh's Puzzles » 10 second questions » Yesterday 14:54:09

#11 Re: Jai Ganesh's Puzzles » Oral puzzles » Yesterday 14:46:31

#12 Re: Exercises » Compute the solution: » Yesterday 14:33:37

#13 Re: This is Cool » Miscellany » 2026-02-03 18:43:44

#14 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2026-02-03 18:06:46

#15 This is Cool » Calyx » 2026-02-03 17:49:51

#16 Re: Jai Ganesh's Puzzles » General Quiz » 2026-02-03 17:17:51

#17 Re: Jai Ganesh's Puzzles » English language puzzles » 2026-02-03 17:05:24

#18 Re: Jai Ganesh's Puzzles » Doc, Doc! » 2026-02-03 16:55:43

#19 Science HQ » Laser Surgery » 2026-02-03 16:47:31

#20 Dark Discussions at Cafe Infinity » Combination Quotes - II » 2026-02-03 15:49:00

#21 Jokes » Coffee Jokes - I » 2026-02-03 15:32:25

#22 Re: Jai Ganesh's Puzzles » 10 second questions » 2026-02-03 14:51:33

#23 Re: Jai Ganesh's Puzzles » Oral puzzles » 2026-02-03 14:42:46

#24 Re: Exercises » Compute the solution: » 2026-02-03 14:34:16

#25 This is Cool » Corolla » 2026-02-02 22:00:32

Board footer