Posts by Jai Ganesh

Jai Ganesh · This is Cool

Mosquito

Gist

Mosquitoes are attracted to the carbon dioxide (CO2) we exhale, body heat, and specific skin odors like lactic acid, ammonia, and carboxylic acids, often from skin bacteria, with factors like dark clothing, Type O blood, alcohol, and scented products also playing a role, while they find standing water for breeding. They use these cues, detected by antennae, to find hosts for blood meals (females) and breeding sites.

The mosquito is the world's deadliest animal. Spreading diseases like dengue, West Nile, Zika, chikungunya, malaria, and lymphatic filariasis, the mosquito kills more people than any other creature in the world.

Summary

Mosquitoes are one of the most intensely studied creatures on the planet. Their role in disease transmission and nuisance biting makes them worthy of such attention. There are over 3,500 species of mosquito on Earth and they are found on every continent except Antarctica. Yet, from this great diversity, only a small handful can carry the pathogens that cause disease and it is these species which have been studied most intensely. For the purposes of public health, this substantial body of research has helped us to understand mosquito-borne disease transmission and informed the development of mosquito- and disease-control methods. But parallel to this, a fascinating and complex biology has been revealed, showing the mosquito’s incredible and unusual behavioural, anatomical and physiological traits. This chapter will explore some of the unique aspects of mosquito biology and ecology, drawn from the ever-growing body of research on the most medically important species, and highlight the sophisticated adaptations of mosquitoes to their ecological niche.

Details

A mosquito, (family Culicidae), is any of approximately 3,500 species of familiar insects, some of which are important in public health because of the bloodsucking habits of the females. Mosquitoes are known to transmit serious diseases, including yellow fever, Zika fever, malaria, filariasis, chikungunya fever, and dengue, though less than 10 percent of all mosquito species are vectors of human disease. Ecologically, mosquitoes serve as an important food source for countless animals and play an integral role in local food webs. In natural bodies of standing water, mosquito eggs and larvae make up a substantial portion of the biomass in many places, providing food not only for fishes but also for turtles, amphibians, and even the larvae of other insects, such as dragonflies. In terrestrial environments, mosquitoes are a major food source for bats, birds, lizards, frogs, spiders, and predatory insects, and also serve as pollinators.

Mosquitoes are found in nearly every part of the world. They thrive in warm, humid environments and are especially abundant in tropical and subtropical regions, though some species inhabit temperate zones and survive cold seasons by overwintering in the egg or adult stage. In 2025, following record-breaking spring heat, mosquitoes (a male and two female of the species Culiseta annulata) were detected in the mountains of Iceland for the first time. If the population there survives the winter and becomes established, Antarctica would become the last remaining mosquito-free land mass on Earth. Mosquitoes are expected to benefit from anthropogenic climate change, as rising global temperatures, milder winters, and increasingly frequent heat waves, storms, and floods expand suitable habitats and create more standing water for breeding. A number of species, including several important vectors of disease, have already encroached into novel areas in higher latitudes and altitudes.

Physical features and behavior

The slender elongated body of the adult is covered with scales, as are the veins of the wings. Mosquitoes are also characterized by long fragile-looking legs and elongated piercing mouthparts. The feathery antennae of the male are generally bushier than those of the female. The males, and sometimes the females, feed on nectar and other plant juices and are known pollinators. In most species, however, the females require the proteins obtained from a blood meal in order to mature their eggs. Different species of mosquitoes show preferences and, in many cases, narrow restrictions as to host animals. The females of Uranotaenia sapphirina, for example, specialize on earthworms and leeches, while those of a related species, Uranotaenia lowii, feast only on the blood of frogs and toads. Mammals, birds, and reptiles are common hosts for many mosquitoes.

The eggs are laid on the surface of water and hatch into aquatic larvae, or wrigglers, which swim with a jerking, wriggling movement. In most species, larvae feed on algae and organic debris, although a few are predatory and may even feed on other mosquitoes. Unlike most insects, mosquitoes in the pupal stage, called tumblers, are active and free-swimming. The pupae breathe by means of tubes on the thorax. The adults mate soon after emerging from their pupal cases. The duration of the life cycle varies greatly, depending on the species.

Mosquitoes are apparently attracted to host animals by moisture, lactic acid, carbon dioxide, body heat, and movement. The mosquito’s hum results from the high frequency of its wingbeats, and the female’s wingbeat frequency may serve as a means of sex recognition.

Major genera and species

There are three important mosquito genera that cause disease in humans.

Aedes mosquitoes

The genus Aedes carries the pathogens that cause yellow fever, dengue, Zika fever, chikungunya fever, and encephalitis. Like Culex, it holds its body parallel to the resting surface, with the proboscis bent down. The wings are uniformly colored. Aedes may be distinguished from Culex by its silver thorax with white markings and posterior spiracular bristles. The tip of the female’s abdomen is pointed and has protruding cerci. Aedes usually lays eggs in floodwater, rain pools, or salt marshes. The eggs are capable of withstanding long periods of dryness. The short, stout larvae have a breathing tube containing a pair of tufts, and the larvae hang head down at a 45° angle from the water surface. The life cycle may be as short as 10 days or, in cool weather, as long as several months.

A. aegypti, the important carrier of the virus responsible for yellow fever and other diseases, has white bands on its legs and spots on its abdomen and thorax. This domestic species breeds in almost any kind of container, from flower pots to discarded car-tire casings. The Asian tiger mosquito (A. albopictus) is another serious disease vector that has spread from its native Asia to the Americas.

The eastern salt marsh mosquito (A. sollicitans), the black salt marsh mosquito (A. taeniorhynchus), and the summer salt marsh mosquito (A. dorsalis) are important mosquitoes in coastal marsh areas that experience daily or occasional flooding with brackish or salt water. They are prolific breeders, strong fliers, and irritants to animals, including humans.

Anopheles mosquitoes

Anopheles, the only known carrier of malaria, also transmits filariasis and encephalitis. Anopheles mosquitoes are easily recognized from their resting position, in which the proboscis, head, and body are held in a straight line with one another but at an angle to the surface. The spotted coloring on the wings results from colored scales. Egg laying usually occurs in water containing heavy vegetation. The female deposits her eggs singly on the water surface. Anopheles larvae lie parallel to the water surface and breathe through posterior spiracular plates on the abdomen instead of through a tube, as do most other mosquito larvae. The life cycle is from 18 days to several weeks.

Culex mosquitoes

The genus Culex is a carrier of viral encephalitis and, in tropical and subtropical climates, of filariasis. It holds its body parallel to the resting surface and its proboscis is bent downward relative to the surface. The wings, with scales on the veins and the margin, are uniform in color. The tip of the female’s abdomen is blunt and has retracted cerci (sensory appendages). Egg laying may occur on almost any body of fresh water, including standing polluted water. The eggs, which float on the water, are joined in masses of 100 or more. The long and slender Culex larvae have breathing tubes that contain hair tufts. They hang head downward at an angle of 45° from the water surface. The life cycle, usually 10 to 14 days, may be longer in cold weather.

The northern house mosquito (C. pipiens) is the most abundant species in northern regions, while the southern house mosquito (C. quinquefasciatus) is abundant in southern regions, namely the tropics and subtropics.

Mosquito control

Because mosquitoes are such prolific carriers of infectious diseases, preventing them from feeding on humans is considered to be a key global health strategy. The likelihood of disease transmission can be reduced through the use of mosquito repellent, long clothing that covers the arms and legs, screens in open doors and windows, and insecticide-treated mosquito bed nets. Mosquito populations can be controlled in part through the elimination of sources of standing water, which provide ideal breeding sites for mosquitoes. A surface film of oil can be applied to standing water to clog the breathing tubes of wrigglers, which may also be killed by larvicides. Biological control using larvivorous fish, such as the mosquitofish (Gambusia affinis) is an option for some bodies of water. At times, insecticides are used to destroy adult mosquitoes indoors.

Aerial and truck-spraying applications of insecticides are commonly used in urban areas. Such applications are often done in the early evening to reduce the impact on pollinators, and ideally, they consist of insecticides that leave minimal residual effects, though regulations vary widely across the globe. Even in developed countries, commercial yard treatments are often less regulated than municipal applications and are frequently overused by the public. Nontarget fly species and many beneficial insects, including bees, are often killed with broad or persistent insecticide treatments. Naled, pyrethrins, pyrethroids, and other common insecticides used for mosquito control can make their way into waterways and harm aquatic invertebrates, affecting food webs far beyond the application site. Using mosquito insecticides in adverse weather conditions can exacerbate their negative environmental impacts.

Researchers have investigated the possibility of manipulating mosquito populations to prevent the production of viable mosquito offspring, thereby reducing the number of mosquitoes. Researchers have also identified ways in which male mosquitoes may be genetically engineered to transmit a gene to their offspring that causes the offspring to die before becoming sexually mature. Scientists have found that female mosquitoes are less attracted to humans when exposed to small compounds related to the neurotransmitter molecule neuropeptide Y. These compounds could be emitted via dispensers in areas where mosquitoes are abundant, helping to deter them from biting humans.

Additional Information

Many mosquitoes, such as Culex quinquefasciatus, lay their eggs on the surface of fresh or stagnant water. The water may be in tin cans, barrels, horse troughs, ornamental ponds, swimming pools, puddles, creeks, ditches, catch basins or marshy areas. Mosquitoes prefer water sheltered from the wind by grass and weeds.

Culex mosquitoes usually lay their eggs at night over a period of time sticking them together to form a raft of from 100 to 300 eggs. A raft of eggs looks like a speck of soot floating on the water and is about 1/4 inch long and 1/8 inch wide. A female mosquito may lay a raft of eggs every third night during its life span.

Anopheles and many other mosquitoes lay their eggs singly on the water surface. Aedes and Ochlerotatus mosquitoes lay their eggs singly, usually on damp soil. Aedes and Ochlerotatus eggs are more resistant to drying out (some require complete drying out before the eggs will hatch) and hatch only when flooded with water (salt water high tides, irrigated pastures, treeholes flooded by rains, flooded stream bottoms). Anopheles, Culex and Mansonia eggs are susceptible to drying out during extended droughts.

Tiny mosquito larvae (1st instar) emerge from the eggs within 24 - 48 hours almost in unison.

Mosquito Larva

Mosquito larvae, commonly called "wigglers," live in water from 4 to 14 days depending on water temperature.

Larvae of almost all species must come to the surface at frequent intervals to obtain oxygen through a breathing tube called a siphon. Larvae of Coquillettidia and Mansonia possess modified siphons that allow them to pierce the stems of emergent vegetation in water and draw their oxygen from the plant in this process. Larvae are constantly feeding since maturation requires a huge amount of energy and food. They hang with their heads down and the brushes by their mouths filtering anything small enough to be eaten toward their mouths to nourish the growing larvae. They feed on algae, plankton, fungi and bacteria and other microorganisms. They breath at the water surface with the breathing tube up breaking the water surface tension. The larvae of a few mosquito species are cannibalistic, feeding on larvae of other mosquitoes: Toxorhynchites and some Psorophora, the largest mosquitoes known, are predators of other mosquito larvae sharing their habitat. Their larvae are much larger than other mosquito larvae.

During growth, the larva molts (sheds its skin) four times. The stages between molts are called instars. At the 4th instar, the usual larva reaches a length of almost 1/2 inch and toward the end of this instar ceases feeding. When the 4th instar larva molts, it becomes a pupa.

Mosquito Pupa

Mosquito pupae, commonly called "tumblers," live in water from 1 to 4 days, depending upon species and temperature.

The pupa is lighter than water and therefore floats at the surface. It takes oxygen through two breathing tubes called "trumpets." The pupa does not eat, but it is not an inactive stage. When disturbed, it dives in a jerking, tumbling motion toward protection and then floats back to the surface.

The metamorphosis of the mosquito into an adult is completed within the pupal case. The pupal case thus serves as a factory wherein the mosquito makes an adult out of a larva. The adult mosquito splits the pupal case and emerges to the surface of the water where it rests until its body dries and hardens.

Mosquito Adult

Only female mosquitoes require a blood meal and bite animals - warm or cold blooded - and birds. Stimuli that influence biting (blood feeding) include a combination of carbon dioxide, temperature, moisture, smell, color and movement. Male mosquitoes do not bite, but feed on the nectar of flowers or other suitable sugar source. Acquiring a blood meal (protein) is essential for egg production, but mostly both male and female mosquitoes are nectar feeders for their nutrition. Female Toxorhynchites actually can't obtain a bloodmeal and are restricted to a nectar diet. Of those female mosquitoes capable of blood feeding, human blood meals are seldom first or second choices. Horses, cattle, smaller mammals and/or birds are preferred.

Aedes and Ochlerotatus mosquitoes are painful and persistent biters.

They search for a blood meal early in the morning, at dusk (crepuscular feeders) and into the evening. Some are diurnal (daytime biters) especially on cloudy days and in shaded areas. They usually do not enter dwellings, and they prefer to bite mammals like humans. Aedes and Ochlerotatus mosquitoes are strong fliers and are known to fly many miles from their larval development sites.

Culex mosquitoes are painful and persistent biters also but prefer to attack at dusk and after dark. They readily enter dwellings for blood meals. Domestic and wild birds usually are preferred over man, cows, and horses. Culex nigripalpus is known to transmit St. Louis encephalitis to man in Florida. Culex mosquitoes are generally weak fliers and do not move far from home, although they have been known to fly up to two miles, Culex usually live only a few weeks during the warm summer months. Those females that emerge in late summer search for sheltered areas where they "hibernate" until spring. Warm weather brings them out again in search of water on which to lay their eggs.

Culiseta mosquitoes are moderately aggressive biters, attacking in the evening hours or in the shade during the day. Psorophora, Coquillettidia and Mansonia mosquitoes are becoming more pestiferous as an ever-expanding human population invades their natural habitats. Anopheles mosquitoes are persistent biters and are the only mosquitoes which transmit malaria to man.

Jai Ganesh · Science HQ

Nebulizer

Gist

A nebulizer is a medical device used to turn liquid medicine into a fine mist, allowing it to be easily inhaled deep into the lungs to treat respiratory conditions like asthma, COPD, cystic fibrosis, and bronchiectasis. It's especially helpful for people who have trouble using standard inhalers, delivering medication directly to the airways through a mouthpiece or mask over several minutes.

(COPD: Chronic Obstructive Pulmonary Disease)

According to the American College of Allergy, Asthma, and Immunology (ACAAI), nebulizers are often recommended for treating respiratory illnesses such as asthma, bronchitis, and chronic obstructive pulmonary disease (COPD), all of which may include chronic coughing as a symptom.

Summary:

What is a nebulizer?

A nebulizer changes liquid medicine into fine droplets (in aerosol or mist form) that are inhaled through a mouthpiece or mask. Nebulizers can be used to deliver many types of medicines. The medicines and moisture help control breathing problems like wheezing and help loosen lung secretions.

A nebulizer might be used instead of other inhalers. A nebulizer is powered by an air compressor that plugs into an electrical outlet.

What supplies do you need to use the nebulizer?

You will need the following supplies:

* Hand-held nebulizer.
* Air compressor.
* Mouthpiece or face mask.

Where should you use the nebulizer?

Use the nebulizer in a well-lighted area. Select a comfortable place in your home where you can take your treatment without being interrupted. Sit in a comfortable, straight-backed chair when taking your treatment.

Treatment procedure

* Place the compressor on a sturdy surface that will support its weight, such as a table or desk. Plug the compressor's cord into a properly grounded (three-pronged) outlet.
* Wash your hands with soap and water and dry completely with a clean towel.
* Become familiar with the nebulizer parts.
* Place your medication in the nebulizer cup.
* Attach the top portion of the nebulizer cup, and connect the mouthpiece or face mask to the cup.
* Connect the tubing to the nebulizer and compressor.
* Turn on the compressor with the on/off switch. Once you turn on the compressor, you should see a light mist.
* Sit up straight on a comfortable chair.
* Using a mouthpiece is preferred. When using a mouthpiece, place the mouthpiece between your teeth and seal your lips around it.
* If you are using a mask, position it comfortably and securely on your face.
* Breathe normally through your mouth. If possible, every fifth breath, take a slow deep breath and hold this breath for 2 to 3 seconds before breathing out. This allows the medication to settle into the airways.
* Continue the treatment until the medication is gone (about 5 to 15 minutes). Use all of the medicine unless you are directed otherwise by your doctor.
* If you become dizzy, slow your breathing or rest briefly. Some medicine may make you feel "jittery" or "shaky." This is not uncommon, but if these symptoms continue to bother you, inform your healthcare provider.
* Turn off the compressor.
* Wash your hands with warm water and soap. Dry them with a clean towel.

Care of nebulizer

Cleaning and disinfecting your equipment is simple, yet very important. After each treatment, rinse the nebulizer cup with warm water. Shake off excess water and let it air dry.

At the end of each day, the nebulizer cup, mask, or mouthpiece should be washed in warm, soapy water using a mild detergent. Rinse thoroughly, and allow to air dry. Note: There is no need to clean the tubing that connects the nebulizer to the air compressor.

Disinfect your nebulizer once per week or more frequently as directed. After washing your equipment, disinfect the nebulizer with one of the following methods.

Disposable nebulizers should use one of these cold disinfecting methods:

* Soak in 70% isopropyl alcohol for 5 minutes.
* Soak in 3% hydrogen peroxide for 30 minutes.
* Soak in a one-part white vinegar to 3-part water solution for 30 minutes.
* After any of these cold disinfecting techniques, rinse well and air dry.

Non-disposable nebulizers may be disinfected as described above. They may also be disinfected by any of the following heat disinfecting methods:

* Boil for 5 minutes.
* Microwave in a bowl of water for 5 minutes.
* Put in the dishwasher at 158 degrees Fahrenheit for 30 minutes.
* Use an electric steam sterilizer (baby bottle sterilizer).

Medicine storage

Store all of your medicines in a cool, dry place, and follow the manufacturer’s recommendations.

Check your medicines often. Make sure they have not changed color or formed crystals. If you notice any changes in the appearance of your medicines, throw them away.

Compressor care

* Make sure that your unit is unplugged before you clean it. Keep your air compressor clean by wiping it with a clean damp cloth as needed.
* Do not put the air compressor on the floor during your treatments or while storing.
* Check the air compressor’s filter as directed. Replace or clean or clean the filter according to the directions from your equipment supplier.
* Always have an extra nebulizer cup and mask or mouthpiece.
* You can obtain all of the equipment for your nebulizer therapy through your equipment supplier.

Details

In medicine, a nebulizer (American English) or nebuliser (English) is a drug delivery device used to administer medication in the form of a mist inhaled into the lungs. Nebulizers are commonly used for the treatment of asthma, cystic fibrosis, COPD and other respiratory diseases or disorders. They use oxygen, compressed air or ultrasonic power to break up solutions and suspensions into small aerosol droplets that are inhaled from the mouthpiece of the device. An aerosol is a mixture of gas and solid or liquid particles.

Medical uses:

Guidelines

Various asthma guidelines, such as the Global Initiative for Asthma Guidelines [GINA], the British Guidelines on the management of Asthma, The Canadian Pediatric Asthma Consensus Guidelines, and United States Guidelines for Diagnosis and Treatment of Asthma each recommend metered dose inhalers in place of nebulizer-delivered therapies. The European Respiratory Society acknowledge that although nebulizers are used in hospitals and at home they suggest much of this use may not be evidence-based.

Effectiveness

Recent evidence shows that nebulizers are no more effective than metered-dose inhalers (MDIs) with spacers. An MDI with a spacer may offer advantages to children who have acute asthma. Those findings refer specifically to the treatment of asthma and not to the efficacy of nebulisers generally, as for COPD for example. For COPD, especially when assessing exacerbations or lung attacks, there is no evidence to indicate that MDI (with a spacer) delivered medicine is more effective than administration of the same medicine with a nebulizer.

The European Respiratory Society highlighted a risk relating to droplet size reproducibility caused by selling nebulizer devices separately from nebulized solution. They found this practice could vary droplet size 10-fold or more by changing from an inefficient nebulizer system to a highly efficient one. Two advantages attributed to nebulizers, compared to MDIs with spacers (inhalers), are their ability to deliver larger dosages at a faster rate, especially in acute asthma; however, recent data suggests actual lung deposition rates are the same. In addition, another trial found that an MDI (with spacer) had a lower required dose for clinical result compared to a nebulizer.

Beyond use in chronic lung disease, nebulizers may also be used to treat acute issues like the inhalation of toxic substances. One such example is the treatment of inhalation of toxic hydrofluoric acid (HF) vapors. Calcium gluconate is a first-line treatment for HF exposure to the skin. By using a nebulizer, calcium gluconate is delivered to the lungs as an aerosol to counteract the toxicity of inhaled HF vapors.

Aerosol deposition

The lung deposition characteristics and efficacy of an aerosol depend largely on the particle or droplet size. Generally, the smaller the particle the greater its chance of peripheral penetration and retention. However, for very fine particles below 0.5 μm in diameter there is a chance of avoiding deposition altogether and being exhaled. In 1966 the Task Group on Lung Dynamics, concerned mainly with the hazards of inhalation of environmental toxins, proposed a model for deposition of particles in the lung. This suggested that particles of more than 10 μm in diameter are most likely to deposit in the mouth and throat, for those of 5–10 μm diameter a transition from mouth to airway deposition occurs, and particles smaller than 5 μm in diameter deposit more frequently in the lower airways and are appropriate for pharmaceutical aerosols. Nebulizing processes have been modeled using computational fluid dynamics.

Additional Information

There are different types of medicines and delivery devices to treat COPD. A nebulizer is a device that turns the liquid medicine into a mist which is then inhaled through a mouthpiece or a mask. Sometimes asthma medication is given through a nebulizer as well, so this information can benefit people living with asthma too. With COPD, or any chronic lung disease, taking your medicine correctly is a major part in successfully managing the disease.

Learning how to use your nebulizer and clean it properly is important so that your medications are most effective. These videos offer a step-by-step guide to cleaning and using medications correctly.

How to Use a Nebulizer

Many people with chronic lung diseases such as COPD or asthma use a nebulizer to take their medication in the form of a mist that is inhaled into the lungs.

Nebulizers are often recommended for patients who have a hard time using inhalers because of health issues, or patients who are unable to inhale deeply enough for other devices.

A nebulizer has five basic parts A medicine cup, a top piece or cap to attach to a mask or mouthpiece to the medicine cup.

With your healthcare provider, you can decide which type works best for you. thin plastic tubing connects the mouthpiece to the machine and an air machine called a compressor, which can be plugged into an electrical socket for indoor use, a car adapter for when you are on the go, or battery-operated for portable use while not at home.

With clean hands, take the medicine as prescribed by your healthcare provider, and pour it into the medicine cup. Attach the top piece to the medicine cup, and then the mouthpiece or mask. Connect the tubing from the compressor to the medicine cup.

Put the mask over your face, or put the mouthpiece in your mouth between your teeth, and close your lips tightly around it. Turn on your compressor. Hold the nebulizer in an upright position to prevent spilling and to ensure the medication is correctly distributed.

Take normal regular breaths in through your mouth so that the medicine can go deep into your lungs. Continue until all of the medicine is gone from the cup. For more demonstration videos and information on cleaning and caring for your nebulizer, visit the American Lung Association's website at Lung.org/nebulizer.

How to Clean a Nebulizer

Many people with chronic lung diseases such as COPD or asthma use a nebulizer to take their medication in the form of a mist that is inhaled into the lungs.

Cleaning your nebulizer is important to prevent the spread of germs and keep you from getting sick. It will also keep your device working properly. It is recommended to wash the parts of your nebulizer after each use, including the mouthpiece or mask, top piece, and medicine cup.

To start, take the nebulizer apart by removing the tubing and setting it aside.

The tubing should never be placed under water. Remove the mouthpiece or mask, and medicine cup from the top piece, and place them all into the top shelf of the dishwasher.

Or wash the medicine cup, top piece, and mouthpiece or mask, in warm soapy water, and rinse. Shake off the excess water and let the pieces air-dry in a cool, dry place until the next use.

Your nebulizer will also need a thorough cleaning once a week. Soak the mouthpiece or mask, top piece, and medicine cup in a white vinegar and water solution for 30 minutes, or as recommended by your device manufacturer.

After 30 minutes, rinse and air-dry in a cool, dry place.

Clean the surface of the compressor and the outside of the tubing with a soapy cloth or disinfectant wipe.

The compressor and the tubing should never be submerged in water.

And remember, most compressors have an air filter that will need to be replaced every six months, or as recommended by your manufacturer.

Jai Ganesh · Dark Discussions at Cafe Infinity

2410) Francis Crick

Gist:

Work

In 1944, Oswald Avery proved that DNA is the bearer of organisms' genetic code. Further explanation was provided when Francis Crick and James Watson determined the structure of the DNA molecule in 1953. This structure–a long double helix–contains a long row of pairs of four different nitrogen bases, which allow the molecule to function like a code. The molecule's structure also explains how it is able to copy itself. The nitrogen bases always pair in the same constellations, so that if a molecule is split, its halves can be supplemented so that they form copies of the original molecule.

Summary

Francis Harry Compton Crick (8 June 1916 – 28 July 2004) was an English molecular biologist, biophysicist, and neuroscientist. He, James Watson, Rosalind Franklin, and Maurice Wilkins played crucial roles in deciphering the helical structure of the DNA molecule.

Crick and Watson's paper in Nature in 1953 laid the groundwork for understanding DNA structure and functions. Together with Maurice Wilkins, they were jointly awarded the 1962 Nobel Prize in Physiology or Medicine "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material".

Crick was an important theoretical molecular biologist and played a crucial role in research related to revealing the helical structure of DNA. He is widely known for the use of the term "central dogma" to summarise the idea that once information is transferred from nucleic acids (DNA or RNA) to proteins, it cannot flow back to nucleic acids. In other words, the final step in the flow of information from nucleic acids to proteins is irreversible.

During the remainder of his career, Crick held the post of J.W. Kieckhefer Distinguished Research Professor at the Salk Institute for Biological Studies in La Jolla, California. His later research centred on theoretical neurobiology and attempts to advance the scientific study of human consciousness. Crick remained in this post until his death in 2004; "he was editing a manuscript on his death bed, a scientist until the bitter end" according to Christof Koch.

Details

Francis Crick (born June 8, 1916, Northampton, Northamptonshire, England—died July 28, 2004, San Diego, California, U.S.) was a British biophysicist, who, with James Watson and Maurice Wilkins, received the 1962 Nobel Prize for Physiology or Medicine for their determination of the molecular structure of deoxyribonucleic acid (DNA), the chemical substance ultimately responsible for hereditary control of life functions. This accomplishment became a cornerstone of genetics and was widely regarded as one of the most important discoveries of 20th-century biology.

During World War II, Crick interrupted his education to work as a physicist in the development of magnetic mines for use in naval warfare, but afterward he turned to biology at the Strangeways Research Laboratory, University of Cambridge (1947). Interested in pioneering efforts to determine the three-dimensional structures of large molecules found in living organisms, he transferred to the university’s Medical Research Council Unit at the Cavendish Laboratories in 1949.

In 1951, when the American biologist James Watson arrived at the laboratory, it was known that the mysterious nucleic acids, especially DNA, played a central role in the hereditary determination of the structure and function of each cell. Watson convinced Crick that knowledge of DNA’s three-dimensional structure would make its hereditary role apparent. Using the X-ray diffraction studies of DNA done by Wilkins and X-ray diffraction pictures produced by Rosalind Franklin, Watson and Crick were able to construct a molecular model consistent with the known physical and chemical properties of DNA. The model consisted of two intertwined helical (spiral) strands of sugar-phosphate, bridged horizontally by flat organic bases. Watson and Crick theorized that if the strands were separated, each would serve as a template (pattern) for the formation, from small molecules in the cell, of a new sister strand identical to its former partner. This copying process explained replication of the gene and, eventually, the chromosome, known to occur in dividing cells. Their model also indicated that the sequence of bases along the DNA molecule spells some kind of code “read” by a cellular mechanism that translates it into the specific proteins responsible for a cell’s particular structure and function.

By 1961 Crick had evidence to show that each group of three bases (a codon) on a single DNA strand designates the position of a specific amino acid on the backbone of a protein molecule. He also helped to determine which codons code for each of the 20 amino acids normally found in protein and thus helped clarify the way in which the cell eventually uses the DNA “message” to build proteins. From 1977 until his death, Crick held the position of distinguished professor at the Salk Institute for Biological Studies in San Diego, California, where he conducted research on the neurological basis of consciousness. His book Of Molecules and Men (1966) discusses the implications of the revolution in molecular biology. What Mad Pursuit: A Personal View of Scientific Discovery was published in 1988. In 1991 Crick received the Order of Merit.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#5895. What does the noun lavender mean?

#5896. What does the adjective lavish mean?

Jai Ganesh · This is Cool

2470) Atlas Mountains

Gist

The Atlas Mountains are a major North African range spanning Morocco, Algeria, and Tunisia, forming a natural barrier between the Mediterranean/Atlantic coasts and the Sahara Desert, with the highest peak, Toubkal (4,167m), in Morocco, and are home to indigenous Berber populations and unique ecosystems. This extensive system is divided into several sub-ranges, like the High Atlas, Middle Atlas, and Anti-Atlas, known for their rugged terrain, traditional villages, and biodiversity.

The Atlas Mountains also have a diverse ecosystem and support a variety of flora and fauna. The lower slopes are covered in oak and cedar forests, while higher elevations feature alpine meadows. There are over 150 flower species, some 50 of which are endemic.

Summary

The Atlas Mountains are a mountain range in northwest Africa. They extend about 2,400 km (1,500 miles) through Morocco, Algeria, and Tunisia. The highest peak is Toubkal, with an elevation of 4,167 metres (13,671 ft) in southwestern Morocco. The second highest mountain is the M'Goun of 4071 meters. The southwestern part is called "Anti-Atlas".

The Atlas ranges separate the Mediterranean and Atlantic coastlines from the Sahara Desert. Most of the people living in the Atlas Mountains are part of Berber tribes in Morocco and in Algeria.

The mountains are named after the ancient Greek Titan, Atlas.

Details

The Atlas Mountains are a mountain range in the Maghreb in North Africa. They separate the Sahara Desert from the Mediterranean Sea and the Atlantic Ocean; the mountain range stretches around 2,500 km (1,600 mi) through Morocco, Algeria and Tunisia. The mountains are associated with the Titan Atlas. The range's highest peak is Toubkal, in central Morocco, with an elevation of 4,167 metres (13,671 ft). The Atlas Mountains are primarily inhabited by Berber populations.

The terms for 'mountain' are Adrar and adras in some Berber languages, and these terms are believed to be cognates of the toponym Atlas. The mountains are home to a number of animals and plants which are mostly found within Africa but some of which can be found in Europe. Many of these species are endangered and a few are already extinct. The weather is generally cool but summers are sunny, and the average temperature there is 25 °C.

Geology

The basement rock of most of Africa was formed during the Precambrian supereon and is much older than the Atlas Mountains lying on the continent. The Atlas was formed during three subsequent phases of Earth's geology.

The first tectonic deformation phase involves only the Anti-Atlas, which was formed in the Paleozoic Era (~300 million years ago) as the result of continental collisions. North America, Europe and Africa were connected millions of years ago.

The Anti-Atlas Mountains are believed to have originally been formed as part of the Alleghenian orogeny. These mountains were formed when Africa and America collided and were once a chain rivaling today's Himalayas. Today, the remains of this chain can be seen in the Fall Line region in the Eastern United States. Some remnants can also be found in the later formed Appalachians in North America.

A second phase took place during the Mesozoic Era (before ~66 My). It consisted of a widespread extension of the Earth's crust that rifted and separated the continents mentioned above. This extension was responsible for the formation of many thick intracontinental sedimentary basins including the present Atlas. Most of the rocks forming the surface of the present High Atlas were deposited under the ocean at that time.

In the Paleogene and Neogene Periods (~66 million to ~1.8 million years ago), the mountain chains that today constitute the Atlas were uplifted, as the land masses of Europe and Africa collided at the southern end of the Iberian Peninsula. Such convergent tectonic boundaries occur where two plates slide towards each other forming a subduction zone (if one plate moves underneath the other), and/or a continental collision (when the two plates contain continental crust). In the case of the Africa-Europe collision, it is clear that tectonic convergence is partially responsible for the formation of the High Atlas, as well as for the closure of the Strait of Gibraltar and the formation of the Alps and the Pyrenees.

However, there is a lack of evidence for the nature of the subduction in the Atlas region, or for the thickening of the Earth's crust generally associated with continental collisions. One of the most striking features of the Atlas to geologists is the relatively small amount of crustal thickening and tectonic shortening despite the important altitude of the mountain range. Recent studies suggest that deep processes rooted in the Earth's mantle may have contributed to the uplift of the High and Middle Atlas.

Natural resources

The Atlas are rich in natural resources. There are deposits of iron ore, lead ore, copper, silver, mercury, rock salt, phosphate, marble, anthracite coal and natural gas among other resources.

Additional Information

Atlas Mountains, series of mountain ranges in northwestern Africa, running generally southwest to northeast to form the geologic backbone of the countries of the Maghrib (the western region of the Arab world)—Morocco, Algeria, and Tunisia. They extend for more than 1,200 miles (2,000 kilometres), from the Moroccan port of Agadir in the southwest, to the Tunisian capital of Tunis in the northeast. Their thick rim rises to form a high sill separating the Mediterranean basin to the north from the Sahara to the south, thus constituting a barrier that hinders, without completely preventing, communication between the two regions. Across the mountains filter both air masses and human migrations. It is, however, only in the east–west direction that the Atlas Mountains facilitate movement. These are the conditions that create at the same time both the individuality and the homogeneity of the Atlas countries. Although the Saharan region is more likely to be described as the archetypal North African habitat, it is the well-watered mountains north of this vast desert that provide the foundation for the livelihood of most of the peoples of North Africa and a striking green or white background for many North African towns.

Physical features:

Physiography

The Atlas mountain system takes the shape of an extended oblong, enclosing within its ranges a vast complex of plains and plateaus.

The northern section is formed by the Tell Atlas, which receives enough rainfall to bear fine forests. From west to east several massifs (mountainous masses) occur. The first of these is Er-Rif, which forms a half-moon-shaped arc in Morocco between Ceuta and Melilla; its crest line exceeds 5,000 feet (1,500 metres) above sea level at several points, reaching 8,058 feet at Mount Tidirhine. East of the gap formed by the Moulouya River the Algerian ranges begin, among which the rugged bastion of the Ouarsenis Massif (which reaches a height of 6,512 feet), the Great Kabylie, which reaches 7,572 feet at the peak of Lalla Khedidja, and the mountains of Kroumirie in Tunisia are all prominent.

The southern section, which is subject to desert influences, is appropriately called the Saharan Atlas. It includes in the centre a palisade formed by shorter ranges, such as the Ksour and Ouled-Naïl mountains, grouped into massifs between two mighty ranges—the Moroccan High Atlas to the west and the Aurès Mountains to the east. The High Atlas culminates in Mount Toubkal at 13,665 feet (4,165 metres), the highest point in the Atlas Mountains, which is surrounded by high snowcapped peaks; the Aurès Mountains are formed of long parallel folds, which reach a height of 7,638 feet at Mount Chelia.

The Tell Atlas and the Saharan Atlas merge in the west into the long folds of the Middle Atlas and in the east join together in the Tébessa and Medjerda mountains.

Geology

If the relief of the Atlas region is relatively simple, its geology is complex. In essence, the two Atlases comprise two different structural regions.

The Tell Atlas originally arose out of a basin filled with sediment, which was dominated to the north by a marginal rim, of which the massifs of Tizi Ouzou, Collo, and Edough are the remnants. Its elevation took place during a lengthy mountain-building process that was marked by upheavals in the Paleogene and Neogene periods (i.e., about 65 to 2.6 million years ago); over the cluster of folds that were uplifted from the rift valley were spread sheets of flysch (deposits of sandstones and clays), which were carried down from the north over the top of the marginal rim. Thus the Tell Atlas represents an example of a young folded mountain range still in the process of formation, as is shown by the earth tremors to which it is subject.

To the south the Saharan Atlas belongs to another structural grouping, that of the vast plateaus of the African continent, which form part of the ancient base rock largely covered by sediments deposited by shallow seas and by alluvial deposits. The Saharan Atlas is the result either of the mighty folding of the substructure that raised up fragments of the base rock—such as the horst (uplifted block of the Earth’s crust), which constitutes the Moroccan High Atlas—or else of the crumpling into folds of the Earth’s crust during the Jurassic Period (about 200 to 145 million years ago) and the Cretaceous Period (about 145 to 65 million years ago).

Drainage

The seasonal character of the rains, which fall in torrents, determines the characteristics of drainage in the Atlas: the runoff feeds streams that are of great erosive capacity and that have cut their way down through the thickness of accumulated layers of sediment to form deep narrow gorges difficult to cross. The pre-Roman fortress of Cirta (now called Constantine) in Algeria stands on a rock sculptured out by one such stream, the winding Rhumel River.

The great Maghribian wadis (French: oueds; channels of watercourses that are dry except during periods of rain) issue from the Atlas ranges. Among the more perennial rivers are the Moulouya, which rises from the Middle Atlas, and the Chelif, which rises from the Amour Mountains. Destructive of the soils of their headstreams, they deposit their loads of silt at the foot of the mountain ranges or else leave a long line of conical deposits locally known as dirs (“hills”).

Soils

Good soil is sparse at higher altitudes in the Atlas region. Most often nothing is to be found but bare rock, debris, and fallen materials incessantly renewed by landslides. Two materials predominate—limestone, which forms ledges that are half-buried in rough debris, and marls (chalky clays) cut by erosion into a maze of ravines and crumbling gullies. The rarer sandstones favour forest growth. The best soils are the alluvia found on the terraced slopes and on the valley bottoms.

Climate of the Atlas Mountains

The Atlas Mountains are the meeting place of two different kinds of air masses—the humid and cold polar air masses that come from the north and the hot and dry tropical air masses that move up from the south. To the influences of altitude and latitude must be added that of aspect or exposure.

Rain is more plentiful in the Tell Atlas than in the Saharan Atlas, and more so to the northeast than to the southwest: the highest rainfall is recorded east of the Tell Atlas. ʿAyn ad-Darāhim in the Kroumirie mountains receives 60 inches (1,524 millimetres) a year; nowhere in the Anti-Atlas Mountains, south of the High Atlas, is the total more than 17 inches a year. In a single massif the slopes with a northern exposure receive more rainfall than those with a southern exposure.

With increased altitude the temperature drops rapidly; despite the proximity of the sea, the coastal massifs are cold regions. At 6,575 feet the summits of Mount Babor in the Little Kabylie region are covered with snow for four or five months, while the Moroccan High Atlas retains its snows until the height of summer. Winter in the Atlas is hard, imposing severe conditions upon the inhabitants.

Plant and animal life

Erosion of the soils in the Atlas region is aggravated by the sparseness of the vegetation covering the landscape; only about 39,000 square miles (101,000 square kilometres) of land are forested. On Er-Rif and the Kabylie and Kroumirie ranges, which experience some rainfall, moist forests of cork oaks cover an undergrowth of arbutus (cane apple) and heather shrub, and carpets of rockroses and lavender are found. When the total annual rainfall is less than about 30 inches and limestone is present, green oak and arborvitae (a species of pine tree) cover the soil, forming light, dry forests with a thin and bushy undergrowth. Stands of cedar predominate at higher altitudes. On the dry summits of the Saharan Atlas the vegetation is reduced to scattered stands of green oak and juniper trees.

The clearance of land for agriculture has reduced the forest cover in the Atlas ranges; animal life in the mountains is also in retreat. There remain only a few jackals, some tribes of monkeys (Barbary apes) at higher elevations, and occasional herds of wild boars in the oak woods.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#10699. What does the term in Geography Continental divide mean?

#10700. What does the term in Geography Continental shelf mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#2544. What does the medical term Myotonic dystrophy mean?

Jai Ganesh · Science HQ

Chemotherapy

Gist

Chemotherapy (often called "chemo") is a type of cancer treatment that uses powerful anti-cancer drugs to destroy fast-growing cells in the body. The goal can be to cure the cancer, control its growth, or ease symptoms.

Chemotherapy itself isn't usually painful during administration (pills, IVs), but the process can cause discomfort from needle sticks, and the drugs often lead to painful side effects like mouth sores, nerve pain (neuropathy), headaches, and body aches, which are manageable with medications and support. Pain levels vary greatly, but reporting any discomfort to your medical team is key, as they can offer relief through anti-nausea meds, pain relievers, or other strategies like acupuncture and massage.

Summary

Chemotherapy is the treatment of diseases by chemical compounds. Chemotherapeutic drugs were originally those employed against infectious microbes, but the term has been broadened to include anticancer and other drugs.

Until the end of the 19th century, most drugs were derived either from minerals or from plants. The researches of Louis Pasteur in France and Robert Koch in Germany laid the foundations of bacteriology. It was Paul Ehrlich, however, who made the greatest contribution to the science (chemotherapy) he named. The problem facing medical scientists was to produce a disinfectant that would destroy parasites within a living animal without serious damage to the host.

William H. Perkin, in England, made the first aniline dye (1856) as a result of abortive attempts to synthesize quinine, the sole antimalarial drug available at that time. About 30 years later, Ehrlich found that a synthetic dye, methylene blue, has antimalarial properties. He had been led to this by a study of the specific staining of organs of an animal or of a parasite following the injection of a synthetic dye. From these studies there emerged (1901–04) Ehrlich’s well-known “side-chain” theory, in which he sought for the first time to correlate the chemical structure of a synthetic drug with its biological effects. In 1903 Ehrlich invented a dye, trypan red, which was the first drug to show activity against trypanosomal infections in mice. Ehrlich’s greatest triumph, however, was the discovery (1910) of the organic math drug Salvarsan, which proved to be effective in the treatment of syphilis. The discovery of other chemotherapeutic agents followed, including mepacrine, proguanil, and chloroquine.

The discovery of Prontosil in the early 1930s proved that antibacterial agents could be developed. Prontosil was the forerunner of the sulfonamide drugs, which came to be widely used for the treatment of bacterial infections in humans and domestic animals.

The discovery of penicillin by Sir Alexander Fleming in 1928, and its practical development by Sir Howard Florey and Ernst Chain, marked another important advance in bacterial chemotherapy. Penicillin, which did not become widely used until World War II, was the first of the so-called antibiotics, and it was followed by other important antibiotics such as streptomycin, the tetracyclines, and the macrolides.

Antibiotics, whether they are produced by living organisms (usually fungi or bacteria) or artificially synthesized, have transformed the modern management of diseases caused by bacteria and most other microorganisms. Paradoxically, the more widely they are used, the greater the likelihood that drug-resistant bacteria will emerge. Bacteria may develop resistance to drugs in several ways: mutation changes in genetic composition; transduction, whereby resistance is transferred from a resistant to a nonresistant strain; transformation, in which a bacterial cell takes from its environment the genes from a resistant form to acquire resistance; and conjugation, in which the organism acquires resistance by cell-to-cell contact.

Another comparative failure of chemotherapy is the lack of drugs to combat viruses (although viral infections can be controlled through prophylactic measures).

Drug modes of action vary. For example, some may act on the bacterial wall, others affect cell membranes, some modify the molecular mechanism for duplication, some change the nucleic acid metabolism, and others change the intermediary metabolism of two interacting organisms.

Cancer chemotherapy is an increasingly important aspect of drug treatment. Alkylating agents (that work by impairing cell division) and antimetabolites (that interfere with enzymes and thus block vital cell processes) are used cytotoxically to attack malignant cells. Steroid hormones are used in the treatment of breast and prostate cancers, and corticosteroids are used to treat leukemia and lymphatic cancers. The periwinkle plant derivatives vincristine and vinblastine have been used effectively in treating Hodgkin’s disease and leukemia.

The alkylating agents and antimetabolites have serious drawbacks. As they cannot distinguish between healthy and malignant cells, these drugs also interfere with actively multiplying noncancerous cells. They also reduce the body’s resistance to infection. Work is being done on tumour-specific agents that attack only cancer cells.

Another area where chemotherapy has had a major, albeit controversial, impact is mental illness. Severe depression, anxiety, and schizophrenia are now treated with various drugs.

Concomitant with the successes of drug therapy has come increasing concern about attendant dangers. Stringent controls are operated by such regulatory agencies as the Food and Drug Administration in the United States and the Committee on Safety of Medicines in the United Kingdom. These bodies ensure the safety of pharmaceuticals before they are placed on the market and monitor any side effects thereafter. Public demands for “watchdog” agencies were triggered in large part by the 1962 Thalidomide tragedy, when thousands of severely deformed children were born to users of that insufficiently tested drug.

Details

Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) in a standard regimen. Chemotherapy may be given with a curative intent (which almost always involves combinations of drugs), or it may aim only to prolong life or to reduce symptoms (palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called medical oncology.

The term chemotherapy now means the non-specific use of intracellular poisons to inhibit mitosis (cell division) or to induce DNA damage (so that DNA repair can augment chemotherapy). This meaning excludes the more-selective agents that block extracellular signals (signal transduction). Therapies with specific molecular or genetic targets, which inhibit growth-promoting signals from classic endocrine hormones (primarily estrogens for breast cancer and androgens for prostate cancer), are now called hormonal therapies. Other inhibitions of growth-signals, such as those associated with receptor tyrosine kinases, are targeted therapy.

The use of drugs (whether chemotherapy, hormonal therapy, or targeted therapy) is systemic therapy for cancer: they are introduced into the blood stream (the system) and therefore can treat cancer anywhere in the body. Systemic therapy is often used with other, local therapy (treatments that work only where they are applied), such as radiation, surgery, and hyperthermia.

Traditional chemotherapeutic agents are cytotoxic by means of interfering with cell division (mitosis) but cancer cells vary widely in their susceptibility to these agents. To a large extent, chemotherapy can be thought of as a way to damage or stress cells, which may then lead to cell death if apoptosis is initiated. Many of the side effects of chemotherapy can be traced to damage to normal cells that divide rapidly and are thus sensitive to anti-mitotic drugs: cells in the bone marrow, digestive tract and hair follicles. This results in the most common side-effects of chemotherapy: myelosuppression (decreased production of blood cells, hence that also immunosuppression), mucositis (inflammation of the lining of the digestive tract), and alopecia (hair loss). Because of the effect on immune cells (especially lymphocytes), chemotherapy drugs often find use in a host of diseases that result from harmful overactivity of the immune system against self (so-called autoimmunity). These include rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, vasculitis and many others.

Additional Information

Chemotherapy (chemo) is one of the most common treatments for cancer. Learning about how it works and what to expect can help you prepare for treatment and make informed decisions about your care.

What is chemotherapy?

Chemotherapy is a treatment that uses medicines to destroy cancer cells. There are many different types of chemo. They don’t all work exactly the same way, so different types of chemo might be used for different types of cancer. Most are given as an infusion into a vein (IV), but some are given as an injection, taken as pills, or applied to the skin.

What is the goal of chemo?

If your doctor has recommended chemo, it’s important to understand the goal of treatment. This can depend on your type of cancer, its stage (size and location), and how far it has spread. Chemo can have 3 possible treatment goals:

* To cure the cancer (curative intent)
* To control the cancer
* To ease symptoms (palliative intent)

How is chemo different from other cancer treatments?

Chemo is a systemic treatment. It travels through the bloodstream to reach all parts of your body. It can kill cancer cells that have spread (metastasized) to parts of the body far away from the original (primary) tumor or cancer cells in blood cancers, such as leukemia, that have spread throughout the body. This makes chemo different from local treatments like surgery and radiation, which only affect one part of the body.

How does chemotherapy work?

Understanding how chemotherapy works can help you know what to expect during treatment.

Chemotherapy interrupts the cell cycle

Chemotherapy works by affecting cells when they are growing and dividing to make new cells. During this process (called the cell cycle), cells:

* Grow in size
* Make copies of their genetic material (DNA)
* Divide to form new cells

Some cells, such as skin cells, are fast growing, meaning they move through this process quickly. Other cells, such as muscle cells, complete it more slowly. Cancer cells tend to be faster growing, moving through the cell cycle very quickly.

Different types of chemo target cells at different phases of the cell cycle. This is why certain chemo drugs work better for different types of cancer cells, and sometimes different combinations of chemo work better together. Understanding how chemo works also helps doctors plan how often each chemo should be given, and how those doses should be timed.

Chemo affects normal cells, too

Chemo interrupts the cell cycles of normal cells, too – especially cells that grow faster, like hair or skin cells. This is why chemo often causes certain side effects, like hair loss.

The good news is that most normal cells will recover from chemo. Chemo is a useful cancer treatment because cancer cells are abnormal (mutated) and less able to recover from its effects.

To work best, chemo treatments must be at just the right dose to kill the cancer cells while sparing as many normal cells as possible.

Are all medicines used to treat cancer called chemo?

Not all cancer medicines are chemotherapy. Other medicines and biological treatments may be used alone or with chemo or other treatments. They work differently and often have different side effects.

* Targeted therapy: These find and attack specific proteins or receptors that some cancer cells have, without affecting most normal cells.
* Hormone therapy: These block or lower hormones that help some cancers (like breast, prostate, and endometrial (uterine) cancers) grow. They either stop the body from making the hormone or block the cancer cells from using it.
* Immunotherapy: These help a person's immune system recognize and attack certain types of cancer cells.

Although these treatments can be very effective, they are more specialized than traditional chemo. They might only work on certain types of cancer, often based on specific traits of the cancer cells. And because many of them are newer, less is known about their long-term side effects. Sometimes they are used only when chemo isn’t working or is no longer effective.

What is it like to get chemo?

Most people get chemo as infusions at a clinic or hospital. But some types of chemo can be taken by mouth or applied to the skin at home. Each type has its own routine, side effects, and safety steps. Learn what it’s like to get each type of chemo and how to stay safe during treatment.

Jai Ganesh · Dark Discussions at Cafe Infinity

Collectively Quotes

1. I never did anything alone. Whatever was accomplished in this country was accomplished collectively. - Golda Meir

2. And I believe we should strengthen unions which have formed the bedrock of a strong middle class. It should be easier to bargain collectively. That's not only fair, it makes workers more productive, it strengthens our economy. - Hillary Clinton

3. An economically peaceful and prosperous Sri Lanka is the dream of youth of the nation. My message for the youth is to collectively work for an inclusively developed Sri Lanka. - A. P. J. Abdul Kalam

4. I even get inspired by movies that aren't very good, because there's always something good in movies that are collectively thought of as a failure. There's good in everything, I find. - Steven Spielberg

5. I have a lot of wonderful people in my life - probably five, collectively - who I can tell everything to. - Selena Gomez

6. Isolated decisions, however well-founded they might seem to the individual, and national go-it-alone moves must belong to the past. They should not be the 21st-century method of choice, particularly because the consequences of the European community's actions must often be carried collectively. - Helmut Kohl

7. Cancer treatment is very expensive, and the process is painful and long. This is something that we have to collectively think about, on how to make it affordable. - Manisha Koirala.

Jai Ganesh · Jokes

Q: What Welsh cheese must you always eat with caution?
A: Caerphilly.
* * *
Q: What do you call a cheese that is an alcoholic?
A: Livarot.
* * *
Q: What is a lions favourite cheese?
A: Roar-quefort.
* * *
Q: What did the piece of Cheddar say to the ghost?
A: I'm Lac-ghost intolerant.
* * *
Q: Why did the one legged clown leave the cheese circus?
A: Because he couldn't get his stilton.
* * *

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#9828.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#6322.

Jai Ganesh · Exercises

Hi,

2679.

Jai Ganesh · Dark Discussions at Cafe Infinity

2409) John Kendrew

Gist:

Work

When X-rays pass through a crystalline structure, the patterns formed can be captured as photographic images, which are then used to determine the crystal's structure. During the 1930s, this method was used to map increasingly large and complex molecules. In 1957, John Kendrew became the first person to successfully determine the atomic structure of a protein. He had unlocked the structure of myoglobin, an oxygen-storing protein found in muscle cells.

Summary

Sir John Cowdery Kendrew (born March 24, 1917, Oxford, Oxfordshire, England—died August 23, 1997, Cambridge, Cambridgeshire) was a British biochemist who determined the three-dimensional structure of the muscle protein myoglobin, which stores oxygen in muscle cells. For his achievement he shared the Nobel Prize for Chemistry with Max Ferdinand Perutz in 1962.

Kendrew was educated at Trinity College, Cambridge, receiving his Ph.D. there in 1949. In 1946–47 he and Perutz founded the Medical Research Council Unit for Molecular Biology at Cambridge. They used the technique of X-ray crystallography to study the structures of proteins, with Perutz studying hemoglobin and Kendrew trying to determine the structure of the somewhat simpler molecule of myoglobin. By 1960, with the use of special diffraction techniques and the help of computers to analyze the X-ray data, Kendrew was able to devise a three-dimensional model of the arrangement of the amino acid units in the myoglobin molecule, which was the first time this had been accomplished for any protein.

A fellow of Peterhouse College, Cambridge, from 1947 to 1975, Kendrew was also deputy chairman of the Medical Research Council Unit and, from 1971, chairman of the Defence Scientific Advisory Council. He was knighted in 1974 and became president of St. John’s College, Oxford, in 1981.

Details

Sir John Cowdery Kendrew, (24 March 1917 – 23 August 1997) was an English biochemist, crystallographer, and science administrator. Kendrew shared the 1962 Nobel Prize in Chemistry with Max Perutz, for their work at the Cavendish Laboratory to investigate the structure of haem-containing proteins.

Education and early life

Kendrew was born in Oxford, son of Wilfrid George Kendrew, reader in climatology in the University of Oxford, and Evelyn May Graham Sandburg, art historian. After preparatory school at the Dragon School in Oxford, he was educated at Clifton College in Bristol, 1930–1936. He attended Trinity College, Cambridge in 1936, as a Major Scholar, graduating in chemistry in 1939. He spent the early months of World War II doing research on reaction kinetics, and then became a member of the Air Ministry Research Establishment, working on radar. In 1940 he became engaged in operational research at the Royal Air Force headquarters; commissioned a squadron leader on 17 September 1941, he was appointed an honorary wing commander on 8 June 1944, and relinquished his commission on 5 June 1945. He was awarded his PhD after the war in 1949.

Research and career

During the war years, he became increasingly interested in biochemical problems, and decided to work on the structure of proteins.

Crystallography

In 1945 he approached Max Perutz in the Cavendish Laboratory in Cambridge. Joseph Barcroft, a respiratory physiologist, suggested he might make a comparative protein crystallographic study of adult and foetal sheep haemoglobin, and he started that work.

In 1947 he became a Fellow of Peterhouse; and the Medical Research Council (MRC) agreed to create a research unit for the study of the molecular structure of biological systems, under the direction of Sir Lawrence Bragg. In 1954 he became a Reader at the Davy-Faraday Laboratory of the Royal Institution in London.

Crystal structure of myoglobin

Kendrew shared the 1962 Nobel Prize for chemistry with Max Perutz for determining the first atomic structures of proteins using X-ray crystallography. Their work was done at what is now the MRC Laboratory of Molecular Biology in Cambridge. Kendrew determined the structure of the protein myoglobin, which stores oxygen in muscle cells.

In 1947 the MRC agreed to make a research unit for the Study of the Molecular Structure of Biological Systems. The original studies were on the structure of sheep haemoglobin, but when this work had progressed as far as was possible using the resources then available, Kendrew embarked on the study of myoglobin, a molecule only a quarter the size of the haemoglobin molecule. His initial source of raw material was horse heart, but the crystals thus obtained were too small for X-ray analysis. Kendrew realized that the oxygen-conserving tissue of diving mammals could offer a better prospect, and a chance encounter led to his acquiring a large chunk of whale meat from Peru. Whale myoglobin did give large crystals with clean X-ray diffraction patterns. However, the problem still remained insurmountable, until in 1953 Max Perutz discovered that the phase problem in analysis of the diffraction patterns could be solved by multiple isomorphous replacement — comparison of patterns from several crystals; one from the native protein, and others that had been soaked in solutions of heavy metals and had metal ions introduced in different well-defined positions. An electron density map at 6 angstrom (0.6 nanometre) resolution was obtained by 1957, and by 1959 an atomic model could be built at 2 angstrom (0.2 nm) resolution.

Later career

In 1963, Kendrew became one of the founders of the European Molecular Biology Organization; he also founded the Journal of Molecular Biology and was for many years its editor-in-chief. He became Fellow of the American Society of Biological Chemists in 1967 and honorary member of the International Academy of Science, Munich. In 1974, he succeeded in persuading governments to establish the European Molecular Biology Laboratory (EMBL) in Heidelberg and became its first director. He was knighted in 1974. From 1974 to 1979, he was a Trustee of the British Museum, and from 1974 to 1988 he was successively Secretary General, Vice-President, and President of the International Council of Scientific Unions.

After his retirement from EMBL, Kendrew became President of St John's College at the University of Oxford, a post he held from 1981 to 1987. In his will, he designated his bequest to St John's College for studentships in science and in music, for students from developing countries. The Kendrew Quadrangle at St John's College in Oxford, officially opened on 16 October 2010, is named after him.

Kendrew was married to the former Elizabeth Jarvie (née Gorvin) from 1948 to 1956. Their marriage ended in divorce. Kendrew was subsequently partners with the artist Ruth Harris. He had no surviving children.

A biography of Kendrew, entitled A Place in History: The Biography of John C. Kendrew, by Paul M. Wassarman was published by Oxford University Press in 2020.

Jai Ganesh · Dark Discussions at Cafe Infinity

26) Marin Mersenne

Marin Mersenne, OM (also known as Marinus Mersennus or le Père Mersenne; French: [maʁɛ̃ mɛʁsɛn]; 8 September 1588 – 1 September 1648) was a French polymath whose works touched a wide variety of fields. He is perhaps best known today among mathematicians for Mersenne prime numbers, those written in the form

for some integer n. He also developed Mersenne's laws, which describe the harmonics of a vibrating string (such as may be found on guitars and pianos), and his seminal work on music theory, Harmonie universelle, for which he is referred to as the "father of acoustics".

Mersenne, an ordained Catholic priest, had many contacts in the scientific world and has been called "the center of the world of science and mathematics during the first half of the 1600s" and, because of his ability to make connections between people and ideas, "the post-box of Europe". He was also a member of the ascetical Minim religious order and wrote and lectured on theology and philosophy.

Jai Ganesh · This is Cool

Watch or Wrist watch

Gist

A wristwatch is worn around the wrist, attached by a watch strap or another type of bracelet, including metal bands or leather straps. A pocket watch is carried in a pocket, often attached to a chain.

The "best" watch depends on your needs: Quartz for accuracy & low cost, Automatic for craftsmanship & tradition, and Smartwatches for tech; choose styles like Field (rugged), Dress (formal), or Chronograph (multi-function) based on lifestyle, ensuring it fits your wrist and reflects your personality. There's no single best, but rather the best for you, balancing convenience, style, and purpose.

Summary

A watch is a timepiece carried or worn by a person. It is designed to maintain a consistent movement despite the motions caused by the person's activities. A wristwatch is worn around the wrist, attached by a watch strap or another type of bracelet, including metal bands or leather straps. A pocket watch is carried in a pocket, often attached to a chain. A stopwatch is a type of watch that measures intervals of time.

During most of their history, beginning in the 16th century, watches were mechanical devices, driven by clockwork, powered by winding a mainspring, and keeping time with an oscillating balance wheel. These are known as mechanical watches. In the 1960s the electronic quartz watch was invented, powered by a battery and keeping time with a vibrating quartz crystal. By the 1980s it had taken over most of the watch market, in what became known as the quartz revolution (or the quartz crisis in Switzerland, whose renowned watch industry it decimated). In the 2010s, smartwatches emerged, small wrist-worn computers with touchscreens and with functions that go far beyond timekeeping.

Modern watches often display the day, date, month, and year. Mechanical watches may have extra features ("complications") such as moon-phase displays and different types of tourbillon. Quartz watches often include timers, chronographs, and alarm functions. Smartwatches and more complicated electronic watches may even incorporate calculators, GPS and Bluetooth technology or have heart-rate monitoring capabilities, and some use radio clock technology to regularly correct the time.

Most watches used mainly for timekeeping have quartz movements. But expensive collectible watches, valued more for their elaborate craftsmanship, aesthetic appeal, and glamorous design than for timekeeping, often have traditional mechanical movements, despite being less accurate and more expensive than their electronic counterparts. As of 2019, the most expensive watch ever sold at auction was the Patek Philippe Grandmaster Chime for US$31.2 million.

Details

A watch is a portable timepiece that has a movement driven either by spring or by electricity and that is designed to be worn or carried in the pocket.

Mechanical watches

The first watches appeared shortly after 1500, early examples being made by Peter Henlein, a locksmith in Nürnberg, Ger. The escapement used in the early watches was the same as that used in the early clocks, the verge. Early watches were made notably in Germany and at Blois in France, among other countries, and were generally carried in the hand or worn on a chain around the neck. They usually had only one hand for the hours.

The mainspring, the element that drives the watch, consists of a flat spring-steel band stressed in bending or coiling; when the watch, or other spring-driven mechanism, is wound, the curvature of the spring is increased, and energy is thus stored. This energy is transmitted to the oscillating section of the watch (called the balance) by the wheeltrain and escapement, the motion of the balance itself controlling the release of the escapement and consequently the timing of the watch. A friction drive permits the hand to be set.

One of the main defects of the early watches was the variation in the torque exerted by the mainspring; that is, the force of the mainspring was greater when fully wound than when it was almost run down. Since the timekeeping of a watch fitted with a verge escapement was greatly influenced by the force driving it, this problem was quite serious. Solution of the problem was advanced almost as soon as the mainspring was invented (about 1450) by the application of the fusee, a cone-shaped, grooved pulley used together with a barrel containing the mainspring. With this arrangement, the mainspring was made to rotate a barrel in which it was housed; a length of catgut, later replaced by a chain, was wound on it, the other end being coiled around the fusee. When the mainspring was fully wound, the gut or chain pulled on the smallest radius of the cone-shaped fusee; as the mainspring ran down, the leverage was progressively increased as the gut or chain pulled on a larger radius. With correct proportioning of mainspring and fusee radii, an almost constant torque was maintained as the mainspring unwound.

The going barrel, in which the mainspring barrel drives the wheeltrain directly, is fitted to all modern mechanical watches and has superseded the fusee. With better quality mainsprings, torque variations have been reduced to a minimum, and with a properly adjusted balance and balance spring, good timekeeping is ensured.

Up to about 1580, the mechanisms of German watches were made almost wholly of iron; about this time, brass was introduced.

In the earliest watches a plain wheel, known as the balance, was used to control the rate of going of the mechanism. It was subjected to no consistent restoring force; consequently, its period of oscillation and, hence, the rate of the timekeeper were dependent on the driving force. This explains the great importance of the fusee.

Controlling the oscillations of a balance with a spring was an important step in the history of timekeeping. English physicist Robert Hooke designed a watch with a balance spring in the late 1650s; there appears to be no evidence, however, that the spring was in the form of a spiral, a crucial element that would become widely employed. Dutch scientist Christiaan Huygens was probably the first to design (1674–75) a watch with a spiral balance spring. The balance spring is a delicate ribbon of steel or other suitable spring material, generally wound into a spiral form. The inner end is pinned into a collet (a small collar), which fits friction-tight on the balance staff, while the outer end is held in a stud fixed to the movement. This spring acts on the balance as gravity does on the pendulum. If the balance is displaced to one side, the spring is wound and energy stored in it; this energy is then restored to the balance, causing it to swing nearly the same distance to the other side if the balance is released.

If there were no frictional losses (e.g., air friction, internal friction in the spring material, and friction at the pivots), the balance would swing precisely the same distance to the other side and continue to oscillate indefinitely; because of these losses, however, the oscillations in practice die away. It is the energy stored in the mainspring and fed to the balance through the wheel train and escapement that maintains the oscillations.

The performance of the modern watch depends on the uniformity of the period of oscillation of the balance—i.e., the regularity of its movement. The balance takes the form of a wheel with a heavy rim, while the spring coupled to it provides the restoring torque. The balance possesses inertia, dependent on its mass and configuration. The spring should ideally provide a restoring force directly proportional to the displacement from its unstressed or zero position.

The balance is mounted on a staff with pivots, and, in watches of good quality, these run in jewels. Two jewels are used at each end of the balance staff, one pierced to provide a bearing, the other a flat end stone providing axial location by bearing against the domed end of the pivot. Frictional effects at the pivots influence the performance of the watch in various positions—for example, lying and hanging.

The balance and spring can be brought to time, or “regulated,” by varying either the restoring couple provided by the spring or the moment of inertia of the balance. In the first case (by far the more common), this is generally effected by providing a pair of curb pins mounted on a movable regulator index that lengthen or shorten the balance spring as needed.

In the second instance, screws are provided at opposite points on the rim of the balance; these screws are friction-tight in their holes and thus can be moved in or out so as to adjust the inertia of the balance. In “free-sprung” watches no regulator index is provided, and the only adjusters are the screws on the balance rim.

Many modern mechanical watches use a lever escapement, invented in England about 1755 by Thomas Mudge, that leaves the balance free to oscillate, coupling to it only while delivering the impulse, taken from the mainspring via the wheel train and while being unlocked by the balance. It was developed into its modern form with the club-tooth escape wheel at the beginning of the 19th century but was not universally adopted until the early 20th century. In good-quality watches the club-tooth escape wheel is made of hardened steel, with the acting surfaces ground and polished. An improved form of the lever escapement is characterized by a double-roller safety action in which the intersection between the guard pin and roller, which takes place underneath the roller, is much deeper than in early single-roller watches; thus, any friction caused by jolts encountered in wear causes less constraint on the balance and less endangerment of the timekeeping properties of the watch. By far the most important watch escapement today is the lever escapement; it is used in its jeweled form in watches of moderate to excellent quality, and it is used with steel pallet pins and a simplified fork-and-roller action in cheaper watches (known as pin-pallet watches).

In the wheel train of a modern watch, it is necessary to achieve a step-up ratio of approximately 1 to 4,000 between barrel and escape wheel. This involves four pairs of gears, the ratio per pair commonly being between 6 to 1 and 10 to 1. Because of space considerations, the pinions must have a low number of leaves (teeth), commonly 6 to 12. This entails a number of special gearing problems, aggravated by the fineness of the pitch. Any error in centre distance, form, or concentricity is therefore proportionately more important than in larger gear trains.

The first patent covering the application of jewels in watches was taken out in London in 1704; diamonds and sapphires were used. Synthetic jewels made from fused powdered alumina (aluminum oxide) are now commonly used. Watch jewels are given a very high polish; a uniform outside diameter for the jewel bearings is highly important, because they are pressed into accurately sized holes smaller than the jewels themselves and held there by friction.

The first patent on the self-winding pocket watch was taken out in London in 1780. An English invention patented in 1924, the self-winding wristwatch by Louis Recordon, contains a swinging weight pivoted at the centre of the movement, coupled to the barrel arbor through reduction wheels and gears. A more modern self-winding watch is fitted with a weight or rotor swinging 360 degrees and winding in both directions.

Electric-powered and electronic watches

Electric-powered watches use one of three drive systems: (1) the galvanometer drive, consisting of the conventional balance-hairspring oscillator, kept in motion by the magnetic interaction of a coil and a permanent magnet, (2) the induction drive, in which an electromagnet attracts a balance containing soft magnetic material, or (3) the resonance drive, in which a tiny tuning fork (about 25 mm [1 inch] in length), driven electrically, provides the motive power. Both galvanometer and induction drive types use a mechanical contact, actuated by the balance motion, to provide properly timed electric-drive pulses. Each oscillation of the balance operates a time-indicating gear train by advancing a toothed wheel one tooth. First produced in 1953, the resonance drive type, properly called an electronic watch, is inherently more accurate since it operates at a frequency higher than that customarily used with balance-type watches, and the tuning fork is a fairly stable source of frequency. The higher frequency requires the replacement of a mechanical contact by a transistor. The minute and rapid motion of the tuning fork moves forward an extremely fine-toothed ratchet wheel. There is very little friction in the electronic watch; only tiny amounts of oil are needed. When the battery is too weak to operate the tuning fork, the watch simply stops, without deterioration. Miniature high-energy-density batteries are used as power sources in all three types.

The progressive miniaturization of electronic components in the late 20th century made possible the development of all-electronic watches, in which the necessary transistors, resistors, capacitors, and other elements were all on one or several miniature integrated circuits, or chips. The complex circuitry of such watches enabled them to perform a variety of timekeeping functions and also made possible digital readouts of the time in place of the traditional second, minute, and hour hands.

Additional Information

A wristwatch is a small, portable timepiece worn on the wrist, attached by a strap or bracelet, designed to keep consistent time despite a person's movements. Functioning as both a practical tool for telling time and a fashion accessory, wristwatches range from traditional mechanical or quartz models to modern smartwatches with advanced digital capabilities like fitness tracking and smartphone connectivity.

Wearing a watch offers benefits beyond just telling time, including improved time management, self-expression through style, a break from phone distractions, increased confidence, and the potential for sentimental value as a keepsake or heirloom, while also acting as a functional tool for fitness or notifications, especially with smartwatches.

Jai Ganesh · This is Cool

2469) Hibiscus

Gist

Hibiscus refers to a large genus of flowering plants known for their large, showy, trumpet-shaped flowers in vibrant colors, used ornamentally and for teas, dyes, and traditional medicine, particularly Hibiscus sabdariffa (Roselle), valued for its edible calyxes with potential blood pressure-lowering and antioxidant properties, though it needs warmth and sun to thrive.

Summary

Hibiscus, (genus Hibiscus), genus of numerous species of herbs, shrubs, and trees in the mallow family (Malvaceae) that are native to warm temperate and tropical regions. Several are cultivated as ornamentals for their showy flowers, and a number are useful as fibre plants.

Physical description

The leaves are often lobed and may be smooth or covered in trichomes (plant hairs). The flowers can be borne singly or in clusters, and the flowers of many species last only a single day. An epicalyx (whorl of leaflike bracts that surrounds the sepals) is particularly common, and the stamens are typically fused into a tube. Members of the genus characteristically have spiny pollen, and their fruits are capsules.

Major species

The tropical Chinese hibiscus, or China rose (Hibiscus rosa-sinensis), which may reach a height of 4.5 metres (15 feet), rarely exceeds 2 metres (6.5 feet) in cultivation. It is grown for its large somewhat bell-shaped blossoms. Cultivated varieties have red, white, yellow, or orange flowers. The East African hibiscus (H. schizopetalus), a drooping shrub with deeply lobed red petals, is often grown in hanging baskets indoors.

Other members of the genus Hibiscus include the fibre plants mahoe (H. tiliaceus), kenaf (H. cannabinus), and roselle (H. sabdariffa), rose of Sharon (H. syriacus), and many flowering plants known by the common name mallow.

Details

Hibiscus is a genus of flowering plants in the mallow family, Malvaceae. The genus is quite large, comprising several hundred species that are native to warm temperate, subtropical and tropical regions throughout the world. Member species are renowned for their large, showy flowers and those species are commonly known simply as "hibiscus", or less widely known as rose mallow. The genus includes both annual and perennial herbaceous plants, as well as woody shrubs and small trees.

Several species are widely cultivated as ornamental plants, notably Hibiscus syriacus and Hibiscus × rosa-sinensis.

Description

The leaves are alternate, ovate to lanceolate, often with a toothed or lobed margin (dentate). The flowers are large and conspicuous. They are trumpet-shaped, with five or more petals, colour from white to pink, red, blue, orange, peach, yellow or purple, and from 4–18 cm broad.

Flower colour in certain species, such as H. mutabilis and H. tiliaceus, changes with age. The fruit is a dry five-lobed capsule, containing several seeds in each lobe, which are released when the capsule dehisces (splits open) at maturity. It is of red and white colours. It is an example of complete flowers.

Species

The yellow hibiscus is the state flower of Hawaii, although the most commonly seen hibiscus in the state is Hibiscus × rosa-sinensis.

In temperate zones, probably the most commonly grown ornamental species is Hibiscus syriacus, the common garden hibiscus, also known in some areas as the "rose of Althea" or "rose of Sharon" (but not to be confused with the unrelated Hypericum calycinum, also called "rose of Sharon"). In tropical and subtropical areas, the Chinese hibiscus (H. × rosa-sinensis), with its many showy hybrids, is the most popular hibiscus.

Uses:

Landscaping

Many species are grown for their showy flowers or used as landscape shrubs, and are used to attract butterflies, bees, and hummingbirds.

Hibiscus is a very hardy, versatile plant and in tropical conditions it can enhance the beauty of any garden. Being versatile it adapts itself easily to balcony gardens in crammed urban spaces and can be easily grown in pots as a creeper or even in hanging pots. It is a perennial and flowers throughout the year. As it comes in a variety of colors, it's a plant which can add vibrancy to any garden.

The only infestation that gardeners need to be vigilant about is mealybugs. Mealybug infestations are easy to spot as they are clearly visible as a distinct white cottony infestation on buds, leaves or even stems.

Paper

One species of Hibiscus, known as kenaf (Hibiscus cannabinus), is extensively used in paper-making.

Rope and construction

The inner bark of the sea hibiscus (Hibiscus tiliaceus), also called 'hau', is used in Polynesia for making rope, and the wood for making canoe floats. The ropes on the missionary ship Messenger of Peace were made of fibres from hibiscus trees.

Beverage

The tea made of the calyces of Hibiscus sabdariffa is known by many names in many countries around the world and is served both hot and cold. The beverage is well known for its red colour, tartness and unique flavour. Additionally, it is highly nutritious because of its vitamin C content.

It is known as bissap in West Africa, "Gul e Khatmi" in Urdu & Persian, agua de jamaica in Mexico and Central America (the flower being flor de jamaica) and Orhul in India. Some refer to it as roselle, a common name for the hibiscus flower. In Jamaica, Trinidad and many other islands in the Caribbean, the drink is known as sorrel (Hibiscus sabdariffa; not to be confused with Rumex acetosa, a species sharing the common name sorrel). In Ghana, the drink is known as sobolo.

In Egypt and Sudan, hibiscus tea is known as karkadé, and is served as both a hot and a cold drink.

Food

Dried hibiscus is edible, and it is often a delicacy in Mexico. It can also be candied and used as a garnish, usually for desserts. Contrary to popular assumptions that the flowers or petals are what is being eaten, it is the calyces.

The roselle (Hibiscus sabdariffa) is used as a vegetable. The species Hibiscus suratensis Linn synonymous with Hibiscus aculeatus G. Don is noted in Visayas in the Philippines as being a souring ingredient for almost all local vegetables and menus. Known as labog in the Visayan area (or labuag/sapinit in Tagalog), the species is an ingredient in cooking native chicken soup.

Hibiscus species are used as food plants by the larvae of some lepidopteran species, including Chionodes hibiscella, Hypercompe hambletoni, the nutmeg moth, and the turnip moth.

Folk medicine

Hibiscus × rosa-sinensis is described as having a number of medical uses in Indian Ayurveda.

Symbolism and culture

The red hibiscus is the flower of the Hindu goddess Kali, and appears frequently in depictions of her in the art of Bengal, India, often with the goddess and the flower merging in form. The hibiscus is used as an offering to Kali and the god Ganesha in Hindu worship.

In the Philippines, the gumamela (the local name for hibiscus) is used by children as part of a bubble-making pastime. The flowers and leaves are crushed until the sticky juices come out. Hollow papaya stalks are then dipped into this and used as straws for blowing bubbles. Together with soap, hibiscus juices produce more bubbles. It is also called "Tarukanga" in Waray, particularly in Eastern Samar province.

The hibiscus flower is traditionally worn by Pacific island women, and is a known shared custom that if the flower is worn behind the left ear, the woman is married or has a boyfriend. If the flower is worn on the right, she is single or openly available for a relationship. The pink hibiscus flower has its origins in Asia and the Pacific Islands, where it has served as a symbol of beauty, femininity, and young love. It is commonly associated with the Hawaiian culture and the Aloha spirit, which celebrates love, happiness, and peace.

A stylized image of the hibiscus flower was used as a logo of Air Polynésie.

Nigerian author Chimamanda Ngozi Adichie named her first novel Purple Hibiscus after the delicate flower.

The bark of the hibiscus contains strong bast fibres that can be obtained by letting the stripped bark set in the sea to let the organic material rot away.

A coastal area in Auckland, New Zealand is known as the Hibiscus Coast, named after the non-native flower due to its associations with beach and holiday atmospheres.

As a national and state symbol

The hibiscus is a national symbol of Haiti, and the national flower of nations including the Solomon Islands and Niue. Hibiscus syriacus is the national flower of South Korea, and Hibiscus × rosa-sinensis is the national flower of Malaysia. Hibiscus brackenridgei is the state flower of Hawaii.

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Jai Ganesh · Dark Discussions at Cafe Infinity

Collective Quotes - I

1. Really, the only thing that makes sense is to strive for greater collective enlightenment. - Elon Musk

2. The press should be not only a collective propagandist and a collective agitator, but also a collective organizer of the masses. - Vladimir Lenin

3. Duty is not collective; it is personal. - Calvin Coolidge

4. Collective fear stimulates herd instinct, and tends to produce ferocity toward those who are not regarded as members of the herd. - Bertrand Russell

5. You have many years ahead of you to create the dreams that we can't even imagine dreaming. You have done more for the collective unconscious of this planet than you will ever know. - Steven Spielberg

6. Money is our madness, our vast collective madness. - D. H. Lawrence

7. I don't believe in collective guilt, but I do believe in collective responsibility. - Audrey Hepburn

8. In America, it was decided to attempt the production of atomic bombs with an effort that would constitute a large part of the collective American war effort. In Germany, an effort one thousandth the scale of the American was applied to the problem of producing atomic energy that would drive engines. - Werner Heisenberg.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#2543. What does the medical term Vertical banded gastroplasty surgery mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#5893. What does the noun counterattack mean?

#5894. What does the adjective counterclockwise mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#10697. What does the term in Geography Continent mean?

#10698. What does the term in Geography Continental climate mean?

Jai Ganesh · Jokes

Q: What group of cheese has been known to fly?
A: Curds of prey!
* * *
Q: What is the name of the country near Iraq that is made entirely of cheese?
A: Curd-istan.
* * *
Q: What does a lady in a mall do with a cheesey credit card?
A: Go on a shopping brie.
* * *
Q: What cheese surrounds a medieval castle?
A: Moatzeralla.
* * *
Q: What cheese should you use to hide a horse?
A: Mascarpone.
* * *

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#9827.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#6321.

Jai Ganesh · Exercises

Hi,

2678.

Math Is Fun Forum

#1 This is Cool » Mosquito » Yesterday 21:08:21

#2 Science HQ » Nebulizer » Yesterday 20:36:52

#3 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2026-01-05 22:50:02

#4 Re: Jai Ganesh's Puzzles » English language puzzles » 2026-01-05 20:49:32

#5 Re: This is Cool » Miscellany » 2026-01-05 18:40:45

#6 Re: Jai Ganesh's Puzzles » General Quiz » 2026-01-05 18:09:34

#7 Re: Jai Ganesh's Puzzles » Doc, Doc! » 2026-01-05 17:58:14

#8 Science HQ » Chemotherapy » 2026-01-05 17:41:09

#9 Dark Discussions at Cafe Infinity » Collectively Quotes » 2026-01-05 17:09:35

#10 Jokes » Cheese Jokes - IV » 2026-01-05 16:29:39

#11 Re: Jai Ganesh's Puzzles » 10 second questions » 2026-01-05 16:10:48

#12 Re: Jai Ganesh's Puzzles » Oral puzzles » 2026-01-05 15:57:02

#13 Re: Exercises » Compute the solution: » 2026-01-05 15:26:39

#14 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2026-01-04 22:12:34

#15 Re: Dark Discussions at Cafe Infinity » Greatest Mathematicians from 1 CE ... » 2026-01-04 21:54:23

#16 This is Cool » Watch or Wrist watch » 2026-01-04 20:46:56

#17 Re: This is Cool » Miscellany » 2026-01-04 17:20:22

#18 Dark Discussions at Cafe Infinity » Collective Quotes » 2026-01-04 16:28:57

#19 Re: Jai Ganesh's Puzzles » Doc, Doc! » 2026-01-04 15:58:28

#20 Re: Jai Ganesh's Puzzles » English language puzzles » 2026-01-04 15:44:57

#21 Re: Jai Ganesh's Puzzles » General Quiz » 2026-01-04 15:35:29

#22 Jokes » Cheese Jokes - III » 2026-01-04 15:14:57

#23 Re: Jai Ganesh's Puzzles » 10 second questions » 2026-01-04 14:48:49

#24 Re: Jai Ganesh's Puzzles » Oral puzzles » 2026-01-04 14:31:47

#25 Re: Exercises » Compute the solution: » 2026-01-04 13:56:58

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