Choline is an organic compound. It is the precursor molecule (~building block) for the neurotransmitter acetylcholine. Acetylcholine is involved in many functions including memory and muscle control.
Some animals cannot produce choline, but must have it in their diet to stay healthy. Humans make a small amount of choline in the liver. In the United States, choline is recommended as an essential nutrient after research showed that humans need to get it. They need to have choline in their diet or take a supplementation for proper health. Possible benefits include reducing the risk of neural tube defects and fatty liver disease. It has also been found that intake of choline during pregnancy can have long-term beneficial effects on memory for the child.
Choline is usually grouped with the Vitamin B complex. It is a vitamin that is needed by the human body. Adults should take between 425 and 550 milligrams of it daily. Choline is used by the body in the walls of cells and as a neurotransmitter. It also helps to prevent heart disease. There are claims that it helps reduce body fat, but this has not been proven.
Choline was discovered by Andreas Strecker in 1864. In 1998 choline was classified as an needed nutrient by the Food and Nutrition Board of the Institute of Medicine (USA).
Sources of Choline are egg yolks, soy and cooked beef, chicken, veal and turkey (bird) livers. Many foods contain small amounts of choline, even iceberg lettuce.
La Borinqueña
La Borinqueña is the national anthem of Puerto Rico. The current official music and words were made up in 1903 and have been taught in schools and accepted by the public. The music was officially made the national anthem by the government in 1952, and the words in 1977. The title refers to the Taíno (Native American) name for the island of Puerto Rico, "Boriken" or "Borinquen".
Boy (album)
Boy was Irish rock group U2's first album, from the year 1980.
Before this album came a single, a song that is played on its own, called "I Will Follow". It became popular and was played on college radio stations and made people know who U2 were. "I Will Follow" was thought of as a Christian song. This was because most of the members of U2 were Christians. None of the band members has said that that is true. This album is somewhat about Bono's life as a child, and his mother's death when he was 14.
At first, the producer of band Joy Division, Martin Hannett, was supposed to produce (help record) the album, but he was sad about the suicide of Ian Curtis, so he did not help record the album. It was produced by Steve Lillywhite, and recorded in a Dublin studio called Windmill Lane Studios. Some songs were written in the studio, like "An Cat Dubh" and "The Ocean". Some other songs had already been written, and U2 were performing them often, like the songs "Stories for Boys", Out of Control", and "Twilight". The Edge, U2's guitarist, recorded all of the songs using his Gibson Explorer guitar and his Fender Stratocaster guitar.
"Boy" reached #63 on the Billboard album charts, a list of the most popular albums in the U.S., and was not on the popularity charts in the United Kingdom. The song "I Will Follow" reached #20 on a popularity chart called the Mainstream rock charts. People said that their live shows were too predictable and that Bono, the singer, used too much echo in his singing, but their playing showed that they could play very well. People also said that Bono was a "charismatic and passionate" singer, meaning that he sang very emotionally and that people could connect to him. "Boy" is the only U2 album that every song has been played live, including all of the b-sides (songs that are extra songs on a single). On the list of the 500 greatest albums of all time, made by the rock magazine Rolling Stone, "Boy" was 417th on the list.
The boy on the cover of the album is a boy named Peter Rowen. He is the brother of Bono's friend Guggi, and he is a famous Irish photographer. He has been on other U2 album covers, including "Three" and "War". The person who took the picture has made other U2 covers, too. In case that the band could be blamed for pedophilia, they changed the cover to a stretched picture of the four band members.
All of the songs were written by U2, and all of the lyrics were written by Bono.
There were two singles released from this album. They were "I Will Follow" and "A Day Without Me". The album that came before "Boy" was called "Three". On very early copies of "Boy", there is a 30-second instrumental piece that is am early version of "Fire", which was on a later album called "October".
Ergastic substance
An ergastic substance is a non-protoplasm material that one can find in cells. These are usually products of metabolism.
Ergastic substances include crystals, oil drops, gums, tannins, resins and other compounds. Some of these substances help the organism function, keep up cell structure, or are just stored food material such as oil or fat. During the life of a cell, they can appear and disappear. Ergastic substances may appear in the protoplasm, in vacuoles, or in the cell wall.
Ergastic substances are usually absent in tissue with dividing cells, such as meristem tissue in plants. Plant cells often store noxious substances in leaf cells as a kind of defence against herbivory. In animals storing noxious substances is done as defence against predation. Storing venom for use in biting or stings is common in some groups of animals.
In general, if animals need quantity of a liquid substance they produce it with special cells in a gland, and send the product to where it is needed or stored.
Adenine
Adenine is one of the nucleobase or basic molecules which form DNA and RNA. They are usually called Nitrogenous bases in genetics.
In DNA, adenine sticks to thymine with two hydrogen bonds to help in making the nucleic acid structures stronger. In RNA, which is used in the cytoplasm for protein synthesis, adenine sticks to uracil.
Adenine was sometimes called Vitamin B, but no longer. However, two B vitamins, niacin and riboflavin, bind with adenine to form the essential cofactors NAD and FAD respectively.
Adenine when bonded to ribose forms adenosine, part of molecules such as adenosine triphosphate.
Some think that, at the origin of life on Earth, the first adenine was formed by the polymerization (joining) of five hydrogen cyanide (HCN) molecules. This is not generally accepted.
888
Year 888 (DCCCLXXXVIII) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar.
Trial and error
Trial and error is a primitive method of solving problems. It is characterised by repeated, varied attempts which are continued until success, or until the agent stops trying. It is an unsystematic method, which does not employ insight, theory or organised methodology.
According to W.H. Thorpe, the term was devised by C. Lloyd Morgan after trying out similar phrases "trial and failure" and "trial and practice". Under Morgan's canon, animal behaviour should be explained in the simplest possible way. Where behaviour seems to imply higher mental processes, it might be explained by trial and error learning. An example is the skilful way in which his terrier Tony opened the garden gate, easily misunderstood as an insightful act by someone seeing the final behaviour. Lloyd Morgan, however, had watched and recorded the series of approximations by which the dog had gradually learned the response, and could demonstrate that no insight was required to explain it.
Edward Thorndike showed how to manage a trial and error experiment in the laboratory. In his famous experiment, a cat was placed in a series of puzzle boxes in order to study the law of effect in learning. He plotted learning curves which recorded the timing for each trial. Thorndike's key observation was that learning was promoted by positive results, which was later refined and extended by B.F. Skinner's operant conditioning.
Harris Scarfe