open-index/open-wikipedia-markdown huggingface dataset:
Sahel

]]

The **Sahel** is a narrow belt of land in North Africa. It is a strip of land about 5500 kilometers long and 450 kilometres wide.  It lies at the southern edge of the Sahara Desert 

The Sahel has a tropical semi-arid climate. It is between the dry desert land to the north and the forest areas to the south. The temperature is high throughout the year. There is little rainfall in the Sahel (between 100 and 150&nbsp;mm and 600mm). It comes during summer months and may be unreliable. It may be very dry in some years, especially if a large area of low pressure, which brings rain, is not carried North over the Sahel by strong winds.

Sahel is the Arabic word for 'edge' or 'shore'.

The Sahel is facing a big problem, desertification.
The distribution of rainfall in the Sahel region is uneven. The rainfall in the region has been below average since 1970. Source needed The Sahel is becoming drier on the whole. The problem of drought affects most of the countries in the Sahel. As a result, crops and animals die. There is no vegetation to protect the soil, which is then removed by flash floods and strong wind. This leads to soil erosion. Finally, the desert spreads towards the surrounding areas.

With better medical services, the birth rate increases and the death rate decreases in the Sahel. As a result, the population in the Sahel is growing. To meet the ever-increasing demand for firewood, a lot of trees have been cut down. More land has become barren. This is called deforestation.

Furthermore, people farm intensively in order to grow more crops, the soil becomes infertile with a lack of nutrients. If this process continues for a long time, no crops can be grown. This is called overcultivation.

People keep animals for food due to the lack of good soil, the animals will have to eat grass and etc. But as the animals eat the grass, they also dug up the soil. As people keep too many animals, the demand for grass is too great. Soil erosion is caused while the animals keep digging the soil up as they eat, and the wind and rain blow away the soil. This process is called overgrazing.

## References
Bread

**Bread** is a type of baked food. It is mainly made from dough, which is made mainly from flour and water. Usually, salt and yeast are added. Bread is often baked in an oven. It can be bought all over the world.

Bread can be toasted or used to make sandwiches. Bread can be made into many different foods, like pizza. There are many different kinds of bread. 

The two main types of bread are:
# Leavened bread is made by adding yeast or other leavening agents to the dough. The yeast produces gas that makes the dough lighter. Leavened bread can be made into larger loaves baked in an oven. This is the main type of bread eaten in Europe, America, and many parts of Asia.
# Unleavened flatbread is baked from a dough of water and flour, with no yeast. It is baked in flat rounds like tortilla or chapati. This type of bread cannot be made thick as it would be too dense to eat. Unleavened bread is eaten throughout Greece, Africa, parts of Asia, and as the Central America such as Pitta bread or tortilla. Baking can be done on a metal plate or hot stone, or in an oven.

The color and taste of the bread depending on the kind of flour used and the style of baking. Flour made from the whole grain gives darker bread. Flour made just from the polished wheat grain gives a very white bread. Rye and barley flour give darker types of bread. The type of flour also changes how long the bread can be kept before going bad. Some strains of wheat are resistant to fungus, but may not produce bread as tasty as a weaker strain.

## Religious breads 
Christianity and Judaism have rules about the use of bread in their religions. Unleavened bread (matzo) is eaten by Jews during the Passover. The Catholic celebration of the Eucharist uses unleavened wafers.

Orthodox churches forbid the use of unleavened bread for the Eucharist (Old Testament) and permit leavened bread only as a symbol of the New. This was one of the three points of contention that brought about the schism between Eastern and Western churches in 1054.

## Types of bread 
*Bagel
*Baguette
*Croissant
*Injera
*Khachapuri
*Lavash
*Markouk in Egypt and the Levant
*Matzo in all Kosher communities
*Naan
*North American biscuit
*Pita
*Pizza dough
*Pretzel
*Rice bread
*Roti
*Rye bread (Includes Pumpernickel)
*Scone
*Sprouted bread
*Tortilla
*White Bread
*Wholemeal bread

Bread is an important part of life in many countries because so many people eat it. In many cultures, bread is so important that it is part of religious rituals. 

Cake is made in a similar way to bread but sugar, fat, and milk are added to the dough and often more ingredients.

## References
Japanese

**Japanese** might mean:

*Anything related to Japan
*Japanese language
*Japanese people
*Japanese cuisine
Marco Polo

**Marco Polo** was born in 1254 and died on January 8, 1324. He was an Italian trader and explorer. He was one of the first Europeans to explore Central Asia and East Asia. Many other explorers, including Christopher Columbus, looked up to him. He spoke four languages.

Marco Polo was known for the book, *Travels of Marco Polo,* where he talked about Asia.

## Early life 
Marco Polo was born in Venice, one of the most successful trading cities. Polo's mother died when he was very young and he was raised by his aunt and uncle. His father and uncle returned from their Silk Road travels when Marco was about 15 years old. Two years later, the three of them started their journey to Cathay (China). His family were well-known merchants, not explorers. He learned about writing, reading, and arithmetic, and how to do business.

## Travels 
Polo went on a 24-year trip to China with his father and uncle during the Mongol Dynasty. He left Venice at the age of 17 on a boat that went through the Mediterranean Sea, to Acre, and later to Tabriz and Kerman. Then he travelled across Asia getting as far as Beijing. On the way there he went over mountains and through deserts, across scorching hot lands and places where the cold was unbearable. Arriving in Cathay at age 21, he served in Kublai Khan's court for 17 years. He left the Far East and returned to Venice by sea. There was sickness on board and 600 passengers and crew died. Nevertheless, Marco Polo survived the journey. Polo returned to Venice with treasures like ivory, jade, jewels, porcelain and silk.

Some scholars believe that while Marco Polo did go to China, they doubt that he went to all of the other places described in his book.

## *"Travels of Marco Polo"* 
Soon after Polo returned from his journeys he fought in a war against Genoa, got captured and put in prison. When he was in prison, he became friendly with a fellow prisoner, Rusticello, who was a writer of romances and novels. He told the writer about all his adventures, which became a book called *The Travels of Marco Polo*. The published version was written by Rustichello da Pisa, based on what Polo had told him. It became famous throughout Europe. In the book he said that Kublai Khan's wealthy new empire had a postal system. He also talked about the Chinese people. China used paper money that was made from mulberry bark.

## References
Herpes zoster

**Herpes zoster** (also known as **shingles** or **zona**) is a disease in humans. The same virus that causes chickenpox also causes shingles. The symptoms are pain and a  with blisters. The shingles vaccine reduces the risk of shingles. Antivirus medicine can reduce the seriousness and duration of shingles if started within 3 days of the rash.

## General information 
Shingles is a viral disease produced by the varicella zoster virus (VZV), the same virus that causes chicken pox. Its symptoms include pain and a blistering rash that occurs along the nerves that contain dormant virus. You can not catch shingles. However, you can catch chicken pox through direct contact with someone who has shingles, by touching the area of the rash. Most people who get shingles are old. It sometimes infects younger people, or people with a weakened immune system.  may trigger shingles. The disease starts with tingling, itchiness, or pain on an infected person's skin. After a few days, the disease causes a blistering rash. This rash may be on the trunk or face. The rash grows into small blisters filled with fluid. These blisters dry out and crust over for several days. The rash causes anything from mild itching to extreme pain. The rash stays in one region of the body.

The shingles virus is contagious from person to person only by direct contact. For this reason, persons with shingles are advised to limit contact with those who are not immune to chicken pox, those with increased risk are young children and pregnant women. Contracting chickenpox when one is pregnant can be dangerous to the unborn child.

If people have had chickenpox, they cannot get chickenpox from someone else again. However, it is thought that contact with a shingles patient may trigger a person's own dormant chickenpox virus to become shingles.

## Treatment 
Doctors recommend antiviral drugs, steroids, antidepressants, anticonvulsants, and topical agents to treat shingles. The antiviral drugs acyclovir, valacyclovir, and famcyclovir can reduce the severity of shingles.

## Prognosis 
Shingles can be very painful and itchy. It is not very dangerous to healthy people, and it usually ends without major problems. The rash and pain last 3 to 5 weeks. Sometimes, serious problems like temporary, partial facial paralysis, ear damage, or
encephalitis may occur. Persons with shingles on the upper half of the face need immediate medical attention: the virus may cause serious damage to the eyes. Most people who have shingles have only one attack of the disease in their lifetime. However, people with AIDS, cancer or weak immune systems may have multiple attacks.

## References 
## Other websites 
* NIH Facts About Shingles 
* NINDS Shingles Information Page
Alexander Graham Bell

**Alexander Graham Bell** (March 3, 1847 – August 2, 1922) was a Scottish-born British-Canadian-American teacher, scientist, and inventor. He was the founder of the Bell Telephone Company. In 1876, Bell was the first inventor to patent the telephone, and he helped start the Bell Telephone Company with others in July 1877. In his writings he explained ways of teaching people who were deaf and Mute. It also showed how these people could learn to speak words by watching their lips and reading what other people were saying.

## Education
Alexander Graham Bell went to the Royal High School of Edinburgh. He graduated at the age of fifteen. At the age of sixteen, he got a job as a student and teacher of elocution and music in Weston House Academy, at Elgin in Morayshire. He spent the next year at the University of Edinburgh. While still in Scotland, he became more interested in the science of sound (acoustics). He hoped to help his deaf mother. From 1866 to 1867, he was a teacher at Somersetshire College in Bath, Somerset.

## Career
In 1870 when he was 23 years old, he moved with his family to Canada where they settled at Brantford, Ontario. where he wrote that the deaf could be taught to read lips and speak (known as oralism).  This would make it possible to integrate them with the wider society. Bell has been criticised by members of the Deaf community for supporting ideas that could cause the closure of dozens of deaf schools, and what some consider eugenicist ideas. Bell did not support a ban on deaf people marrying each other, an idea articulated by the National Association of the Deaf (United States). Although, in his memoir *Memoir upon the Formation of a Deaf Variety of the Human Race*, Bell observed that if deaf people tended to marry other deaf people, this could result in the emergence of a "deaf race".  Ultimately, in 1880, the Second International Congress on Education of the Deaf passed a resolution preferring the teaching of oral communication rather than signing in schools.

## References
## Other websites 
*
* Bell Homestead, National Historic Site
* Alexander Graham Bell Association for the Deaf and Hard of Hearing
Heinrich Rudolf Hertz

**Heinrich Rudolf Hertz** (22 February 1857 – 1 January 1894) was a German physicist.

He died from blood poisoning in 1894.

## References
## Other websites
1621

## Events 
* February 9 – Gregory XV is elected pope.
* February 17 – Miles Standish is appointed as first commander of Plymouth Colony.
* March 16 – Samoset, a Wampanoag, visits the settlers of Plymouth Colony and greets them, "Welcome, Englishmen! My name is Samoset."
* March 22 – The Pilgrims of Plymouth Colony sign a peace treaty with Massasoit of the Wampanoags.
* April 5 – The *Mayflower* sets sail from Plymouth on a return trip to Great Britain.
* The Swedish city of Gothenburg is founded by Gustavus Adolphus
* Riga falls under rule of Sweden
* Willebrord Snell discovers the laws of refraction.
1822

## Events 
* André-Marie Ampère discovered the attraction between current-carrying wires.
* The law of electric current and magnetic field was developed.
* The Sunday Times newspaper is first published in the United Kingdom.
## Births 
* February 25 &ndash; Princess Charlotte of Cambridge, British royal (died 1916)
* April 27 &ndash; Ulysses S. Grant, eighteenth President of the United States (d. 1885)
* October 4 &ndash; Rutherford B. Hayes, nineteenth President of the United States (d. 1893)
* December 27 &ndash; Louis Pasteur, French scientist (died 1895)
1824

## Events 
* Heat was discovered to be transferred from hot to cold objects.
* Royal Society for the Prevention of Cruelty to Animals founded.
* Brauerei C & A Veltins brewery founded
* Thomas Jefferson University founded
1827

## Events 
* People see individual particles of water move.

## Births 
* February 5 – Peter Lalor, leader of miners rebellion at Eureka Stockade, Ballarat, Australia

## Deaths 
* March 26 – Ludwig van Beethoven

## New Books 
* *Book of Songs*  (poetry) – Heinrich Heine
* *Herzog Theodor von Gotland* (play) – Christian Dietrich Grabbe
* *Hope Leslie* – Catharine Maria Sedgwick
* *Intrigue* – Henrietta Rouviere Mosse
* *I Promessi sposi* (*The Betrothed*) – Alessandro Manzoni
* *The Lettre de Cachet* – Catherine Gore
* ''The O'Briens and The O'Flaherties* – Sydney Owenson
* *The Prairie* – James Fenimore Cooper
* *The Red Rover* – James Fenimore Cooper
* *The Reign of Terror* – Catherine Gore
* *The Wolf of Badenoch'' – Sir Thomas Dick Lauder
1850

## Events 
* The speed of light in water was observed to be slower than that in air.

## Books 
* *The Scarlet Letter* by Nathaniel Hawthorne

## Births 
* January 21 – Paul Vinzenz Busch, ringmaster (d. 1927)
* January 27 – Samuel Gompers, English-born labor leader (d. 1924)
* January 27 – Edward J. Smith, Captain of the Titanic (d. 1912)
* May 1 – Prince Arthur of the United Kingdom (d. 1942)
* May 8 – Ross Barnes, baseball player (d. 1915)
* May 12 –  Henry Cabot Lodge, U.S. statesman (d. 1924)
* May 21 – Giuseppe Mercalli, Italian volcanologist (d. 1914)
* July 12 – Otto Schoetensack, German anthropologist (d. 1912)
* September 2 – Albert Spalding, baseball player and sporting goods manufacturer (d. 1915)
* November 13 – Robert Louis Stevenson, Scottish writer (d. 1894)
* December 9 – Emma Abbott, American opera singer (d. 1891)
* December 21 – Zdenek Fibich, Czech composer (d. 1900)

## Deaths 
* July 2 – Robert Peel
* July 9 - Zachary Taylor, 65, twelfth President of the United States, cholera (b. 1784)
Deep house

**Deep house** is a type of house music. It has influences from disco music and jazz music. The BPM of deep house is usually 100 - 128.
1687

## Events 
* March 19 – The men under explorer Robert Cavelier de La Salle murder him while searching for the mouth of the Mississippi River.
* April 4 – King James II of England issues the Declaration of Indulgence, suspending laws against Catholics and non-conformists.
* May 6 – Emperor Higashiyama succeeds Emperor Reigen on the throne of Japan.
* July 5 –  Isaac Newton's three laws of motion (*Philosophiae Naturalis Principia Mathematica*) is published.
* August 12 – Battle of Mohács, fight between Sultan Mehmed IV's Ottoman Turks and Emperor Leopold I's Austrian Habsburgs' forces commanded by Charles of Lorraine.
* September 28 – The Parthenon explodes, while being used as a gunpowder store.
* December 31 – The first Huguenots set sail from France to the Cape of Good Hope.

### Undated 
* Change of emperor of the Ottoman Empire from Mehmed IV (1648-1687) to Suleiman II (1687-1691).

## Births 
* January 27 – Johann Balthasar Neumann, German architect (died 1753)
* March 7 – Jean Lebeuf, French historian (died. 1760)
* June 24 – Johann Albrecht Bengel, German scholar (died 1757)
* September 7 – Durastante Natalucci, Italian historian (died 1772)
* October 4 – Robert Simson, Scottish mathematician (died 1768)
* October 21 – Nicolaus I Bernoulli, Swiss mathematician (died 1759)
* November 7 – William Stukeley, English archaeologist (died 1765)
* December 5 – Francesco Geminiani, Italian violinist and composer (died 1762)
* December 26 – Johann Georg Pisendel, German musician (died 1755)
* *date unknown* Shahzada Assadullah Khan Abdali, Persian Governor of Herat (died 1720)

## Deaths 
* January 13 – Jean Claude, French Protestant clergyman (born 1619)
* January 28 – Johannes Hevelius, astronomer (born 1611)
* March 19 – René-Robert Cavelier, Sieur de La Salle, French explorer (born 1643)
* March 22 – Jean-Baptiste Lully, French composer (born 1632)
* March 28 – Constantijn Huygens, Dutch poet and composer (born 1596)
* April 12 – Ambrose Dixon, Virginia Colony pioneer (born c.1628)
* April 16 – George Villiers, 2nd Duke of Buckingham, English statesman (born 1628)
* September 1 – Henry More, English philosopher (born 1614)
* September 12 – John Alden, Mayflower pilgrim (born c.1599)
* September 28 – Francis Turretin, Swiss theologian (born 1623)
* October 13 – Geminiano Montanari, Italian astronomer (born 1633)
* October 21 – Edmund Waller, English poet (born 1606)
* November 14 – Nell Gwyn, English mistress of Charles II of England (born 1650)
* December 16 – Sir William Petty, English philosopher (born 1623)
1815

## Events 
* Fresnel developed the theory of light diffraction.
* Napoleon loses the Battle of Waterloo and is sent to Saint Helena.

## Births 
*January 10 – John A. Macdonald, first Prime Minister of Canada (d. 1891)
*February 15 – Constantin von Tischendorf, German Biblical scholar (d. 1874)
*April 1 – Otto von Bismarck, German statesman (d. 1898)
* April 1 – Edward Clark, Governor of Texas (d. 1880)
*April 6 – Robert Volkmann, German composer (d. 1883)
*April 24 – Anthony Trollope, British writer (d. 1882)
*June 11 - Julia Margaret Cameron, British Indian photographer (d. 1879)
*August 5 – Edward John Eyre, explorer
*October 16 – Francis Lubbock, Governor of Texas (d. 1905)
*October 31 – Karl Weierstraß, German mathematician (d. 1897)
*November 2 – George Boole, English mathematician and philosopher (d. 1864)
*December 10 – Augusta Ada King (née Byron), Countess of Lovelace, early English computer pioneer (d. 1852)
*November 12 – Elizabeth Cady Stanton, American women's rights activist (d. 1902)
*December 21 – Thomas Couture, French painter (d. 1879)

## Deaths 
*January 8 – Edward Pakenham, British general (killed in battle) (born 1778)
*January 16 – Emma, Lady Hamilton, English mistress of Horatio Nelson (born 1765)
*February 24 – Robert Fulton, American inventor (born 1765)
*February 26 – Prince Josias of Coburg, Austrian general (born 1737)
*March 4 – Frances Abington, English actress (born 1737)
*March 5 – Franz Mesmer, German developer of hypnotism (born 1734)
*April 21 – Joseph Winston, American patriot and Congressman from North Carolina (born 1746)
*June 1 – Louis Alexandre Berthier, French marshal (born 1753)
*June 16 – Friedrich Wilhelm, Duke of Brunswick, German noble and general (killed in battle) (born 1771)
*June 18 – Thomas Picton, British general (killed in battle) (born 1758)
*June 18 – Claude-Etienne Michel, French general (killed in battle) (born 1772)
*June 18 – Guillaume Philibert Duhesme, French general (killed in battle) (born 1766)
*August 2 – Guillaume Marie Anne Brune, French marshal (murdered) (born 1763)
*August 6 – James A. Bayard (elder), U.S. Senator from Delaware (born 1767)
*September 9 – John Singleton Copley, American painter (born 1738)
*September 20 – Nicolas Desmarest, French geologist (born 1725)
*October 13 – Joachim Murat, French marshal and King of Naples (executed) (born 1767)
*December 3 – John Carroll (priest), first American Roman Catholic Archbishop (born 1735)
*December 7 – Michel Ney, French marshal (executed) (born 1769)
*December 29 – Saartjie Baartman, sideshow performer
Bristol

**Bristol** is a city and ceremonial county in England. It is home to nearly 430,000 people. The River Avon runs through it to the Severn estuary.

## Geography 
It is between the counties of Gloucestershire and Somerset. In 1373, King Edward III ordered that it should be a county itself forever. However, it lost county status in 1974, the year after its 600-year celebrations. It became the largest district within the new Avon county. Avon was never popular and was abolished in 1996, when county status returned to Bristol, which became a unitary council.

## History 
*Bristol* comes from Old English *Brycgstow* meaning “bridge-place”. It was a port for 800 years, but now ships are too big to reach the centre, so it has a new port at Avonmouth.

### Historical sites 
It has many historic churches and other buildings. The Clifton Suspension Bridge crosses high above the river. The University of Bristol is also in Clifton.

Bristol was a centre for the slave trade.  During the 2020 George Floyd protests, a crowd pushed down the statue of 17th century slave trader Edward Colston and threw it in the harbour.

Bristol was badly damaged during World War II. It now has many new factories and offices. The Concorde supersonic airliner was made here.

It is also the birthplace of the music genre trip hop, with 3 trip hop bands originating there: Massive Attack, Portishead (named after a North Somerset town) and Tricky.

## Notable people 
Some of the most notable people who are currently living, or who are from the city include:

* Banksy - graffiti artist 
* Stephen Merchant - writer and comedian 
* Russell Howard - comedian and television presenter
* Louie Hill

## References
## Other websites
*
1858

## Events 
* Charles Darwin proposes the natural selection of species.
* A civil war between conservatists and liberals starts in Mexico.
* The British Empire or rule, begins in India after the surrender and exile of the last Mughal emperor, Bahadur Shah II

## Births 
* January 7 – Eliezer Ben-Yehuda, Russian-born advocate of the Hebrew language (d. 1922)
* January 10 – Heinrich Zille, German illustrator and photographer (d. 1929)
* January 11 – Harry Gordon Selfridge, American department store magnate (d. 1947)
* March 10 – Kokichi Mikimoto, Japanese pearl farm pioneer (d. 1954)
* March 18 – Rudolf Diesel, German inventor (d. 1913)
* March 23 – Ludwig Quidde, German pacifist, recipient of the Nobel Peace Prize (d. 1941)
* April 23 – Max Planck, German physicist, Nobel Prize laureate (d. 1947)
* June 16 – King Gustaf V of Sweden (d. 1950)
* June 16 – William Dickson Boyce, founder of the Boy Scouts of America (d. 1929)
* July 9 – Franz Boas, German anthropologist (d. 1942)
* August 1 – Hans Rott, Austrian composer (d. 1884)
* August 11 – Christiaan Eijkman, Dutch physician and pathologist, recipient of the Nobel Prize in Physiology or Medicine (d. 1930)
* August 27 – Giuseppe Peano, Italian mathematician (d. 1932)
* September 18 – Kate Booth, the oldest daughter of William and Catherine Booth (d. 1955)
* October 3 – Eleonora Duse, Italian actress (d. 1924)
* October 27 – Theodore Roosevelt, twenty-sixth President of the United States, Nobel Peace Prize recipient (d. 1919)
* November 20 – Selma Lagerlöf, Swedish writer, Nobel Prize laureate (d. 1940)
* November 30 – Jagdish Chandra Bose, Indian physicist (d. 1937)
* December 22 – Giacomo Puccini, Italian composer (d. 1924)
* December 25 – Herman P. Faris, American temperance movement leader (d. 1936)
Bright Eyes (band)

**Bright Eyes** is an American indie rock band. The people in the band are Conor Oberst, a singer-songwriter; Mike Mogis, a musician and producer; and other friends and session musicians from Omaha, Nebraska, USA.

Many people think the band's songs are about Oberst, but Oberst has said that they are not. For example, one song, "Padraic My Prince", tells the fictional story of a mother drowning her son in a bathtub. In interviews, Oberst has said that he sings about such things to make rich emotions.

## Music
### Albums
**Letting Off the Happiness* (1998)
**Fevers and Mirrors* (2000)
**A Collection of Songs: Recorded 1995-1997* (2000)
**Lifted or the Story Is in the Soil, Keep Your Ear to the Ground* (2002)
**Vinyl Box Set* (7 LP's) (2003)  This collection contains Oberst's first five releases plus bonus material.
*''I'm Wide Awake, It's Morning* (2005)
**Digital Ash in a Digital Urn* (2005)
**Cassadaga* (2007)
**The People's Key* (2011)
**Down in the Weeds, Where the World Once Was* (2020)

### EPs/Singles
The band has made many extended plays (EPs) and singles.
**Every Day and Every Night'' EP (1999)
*"Don't Be Frightened Of Turning The Page" (2001)
*"Oh Holy Fools: The Music of Son, Ambulance & Bright Eyes" (2001) 
*"Drunk Kid Catholic" CDS (2001)
**There Is No Beginning To The Story* EP (2002)
*''Lover I Don't Have To Love* CDS (2002)
**Home: IV* EP (2004)
**One Jug of Wine, Two Vessels* EP (2004)
*"Lua" (2004)
**Take It Easy (Love Nothing)* (2004)
**Four Winds'' EP (2007)

## References
Cytokine

**Cytokines** are a group of signalling molecules made by cells. They help to control the immune system and fight disease. They are similar to hormones and, as we learn more about each, distinctions between the two are fading.

Cytokines carry signals locally between cells, and these signals have an effect on other cells. They are made of proteins, peptides, or glycoproteins. The cytokines are a large family of polypeptide regulators that are produced throughout the body by many groups of cells.

Some well-known cytokines include interferon, prostaglandin and interleukins. Cytokines can be detected using the ELISA and ELISPOT techniques.

Cytokines work by signal transduction. Each cytokine has a matching cell-surface receptor. Then cascades of signals inside the cell changes cell functions. This may include the regulation of several genes, the production of other cytokines, or an increase in surface receptors for other molecules.

## Related pages 
*Cytokine storm
*Signal transduction
*Signal (biology)

## References
Honeycomb

A **honeycomb** is a container made by bees out of wax that they produce. The bees make a honeycomb as a place to keep their honey. Bees make honey from nectar that they collect from flowers. After bees collect nectar from flowers, and make it into honey, the bees then put the honey in the small six sided areas of the honeycomb. Each hexagonal section tessellates with the rest. 

## Uses
Honeycomb wax can be used for making soap and candles. Some people eat honey that is still in the honeycomb. A worker bee grows wax in its abdomen. The wax appears as little spots. The bee pulls it off with its legs and chews it until it becomes soft. The wax is then used to make cells for the honeycomb. Smaller cells are used to raise worker bees. We can use honey present in honeycombs as remedy for cough etc.
Murasaki Shikibu

was a novelist, poet, and servant of the Imperial Court during the Heian period of Japan. She is well known as the author of *The Tale of Genji*, written around year 1003.

Murasaki Shikibu is a nickname; her real name is unknown. 

## Life 
Murasaki was born in Kyoto. She was born into the Fujiwara family. Her father, Fujiwara Tametoki, was not a very nice father and when Murasaki got older he confessed that he regretted she was not a boy. In 999, they had a daughter, Kenshi, who also became a poet. Fujiwara Nobutake died about 1001.

Murasaki started as a writer soon after her husband's unexpected death. She was recognized immediately, and she was asked to the imperial court as a tutor to Empress Shoshi ( Joto Mon'in, 988–1074), daughter of the statesman Fujiwara Michinaga (966–1027).

She died in Kyoto, around the year 1020.

## *The Tale of Genji* 
*The Tale of Genji* is split into 54 different books, and is made up of 795 different poems. It is one of the earliest novels in Japanese, and is often thought of as the first novel in the world. It is a classic of Japanese literature. The masterpiece was about the court life of Prince Genji, and his wife, Aoi in 10th-century Japan. Prince Genji was the illegitimate son of an emperor, and the text is about his relationships in court. *The Tale of Genji* included many beautiful scroll paintings.

## References
Pepsin

**Pepsin** is an enzyme. It acts on proteins in the stomach, which has a low pH because of the Hydrochloric acid. It works best at a pH of about 1.5. It will not work at a pH above 6. 

It was the first animal enzyme to be discovered. Theodor Schwann discovered it in 1836.

Pepsin is used to make cheese.

## References
Greek language

The **Greek language**, also referred to as the **Grecian language**, is an Indo-European language that is the official language of Greece (Hellas) and Cyprus. It was first spoken in Greece and was also once spoken along the coast of Asia Minor (now part of Turkey) and in southern Italy. It also used to be widely used in Western Asia and North Africa. In Greek, the language is called *Ελληνικά* (*Elliniká*).

The language is written using the Greek alphabet. The Latin alphabet, which is used in writing English and many other languages, came indirectly from the Greek alphabet through the Etruscan alphabet. Many other alphabets around the world also came from the Greek alphabet.

Greek has an unbroken history of being a written language for over 3,000 years. That is longer than any other Indo-European language that is spoken today. Its history is often divided into three parts: Ancient Greek, Medieval Greek, and Modern Greek, which is also called Byzzantine Greek because it was spoken in the Byzantine Empire.

Over 13 million people in the world speak Greek as of 2021, mostly live in Greece (almost 11 million) and Cyprus (over 1 million). There are also people in other countries around the world who speak the language, largely because people left Greece and Cyprus and emigrated to other countries. The United States and Australia have a large Greek diaspora.

## Related pages
* Greek numbers

## References
## Other websites
* Greek Dictionary , from Webster's Dictionary .
* Ancient Greek Dictionaries , descriptions of both online dictionaries (with appropriate links) and Greek.
1899

**1899** (MDCCCXCIX) was a common year starting on Sunday in the Gregorian calendar and a common year starting on Friday in the Julian calendar, the 1899th year of the Common Era (CE) and *Anno Domini* (AD) designations, .

## Events 
* January 1 – Queens and Staten Island join with New York City.
* June 19 - The United Kingdom and Egypt begin ruling Sudan together.
### Date unknown 
* Thomson measures the charge and mass of an electron.
* The 1899 San Ciriaco hurricane hits the Bahamas, Florida and North Carolina

## Births 
### January 
]]
* January 17 – Al Capone, American gangster (d. 1947)

### February 
]]
]]
* February 10 - Cevdet Sunay, 5th President of Turkey (d. 1982)
* February 17 – Priscilla Bonner, American film actress (d. 1996)
* February 23 – Erich Kästner, German children's writer (d. 1974)

### March 
]]
* March 27 – Gloria Swanson, American actress (d. 1983)

### April 
]]
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* April 22 – Vladimir Nabokov, Russian writer (d. 1977)
* April 29 – Duke Ellington, American pianist and jazz musician (d. 1974)

### May 
]]
]]
* May 10 – Fred Astaire, American dancer and actor (d. 1987)
* May 24 – Kazi Nazrul Islam, Bangladeshi poet (d. 1976)

### June 
### July 
]]
]]
]]
]]
]]
]]
]]
* July 1 – Konstantinos Tsatsos, President of Greece (b. 1987)
* July 7 - George Cukor, American director (d. 1983)
* July 11 – E. B. White, American writer (d. 1985)
* July 17 – James Cagney, American actor (d. 1986)
* July 21 – Ernest Hemingway, American author (d. 1961)
* July 22 – Sobhuza II of Swaziland, King of Swaziland (d. 1982)
* July 23 – Gustav Heinemann, 3rd President of Germany (d. 1976)

### August 
]]
]]
]]
* August 13 – Alfred Hitchcock, English movie director (d. 1980)
* August 28 – Chang Myon, 2nd, 7th Prime Minister of South Korea (d. 1966)
* August 28 – Charles Boyer, French actor (d. 1978)

### September 
]]
]]
* September 3 – Frank Macfarlane Burnet, Australian physician and virologist (d. 1985)
* September 23 - Louise Nevelson, American sculptor
* September 26 – S. W. R. D. Bandaranaike, Prime Minister of Sri Lanka (d. 1959)

### October 
]]
* October 4 – Franz Jonas, President of Austria (d. 1974)

### November 
]]
* November 24 – Zalman Shazar, 3rd President of Israel (d. 1974)
* November 29 - Genevieve Tobin, American actress (d. 1995)

### December 
]]
]]
* December 3 – Hayato Ikeda, Prime Minister of Japan (d. 1965)
* December 19 – Martin Luther King Sr., American Baptist preacher (d. 1984)
* December 25 – Humphrey Bogart, American actor (d. 1957)
Tapeworm

**Tapeworms** are the class **Cestoda** of segmented flatworms (Platyhelminthes).They are parasitic, which means that they need another larger creature as a . Tapeworms live inside the intestines of vertebrate animals. This includes humans. When a vertebrate has a tapeworm, they may lose weight and become weaker.

Tapeworms can be up to 30 or 36&nbsp;feet (10–12&nbsp;metres) long. They eat by absorbing material directly through their epidermis (outside layer). The head of a tapeworm has four suckers and two rings of hooks. The body of a tapeworm is in segments (pieces that are like each other). Each segment can produce eggs. Little segments of the tapeworm sometimes break off and pass out through the stool of the host, with the eggs. Little segments of its body fall off. They go out of the host body, and are eaten by the next host, which is another type of vertebrate.

Tapeworms are hermaphrodite, with both sexes. Cross-fertilization occurs between two tapeworms in the same intestine. They have a life cycle with a secondary or intermediate host. For example, human tapeworms have cows or pigs as intermediate hosts. The 'definitive' host (humans in this case) is the one where fertilization takes place.

Tapeworms don't have a gut, so they have to absorb nutrients directly across their skin.

File:Taenia solium tapeworm scolex with its four suckers and two rows of hooks 5262 lores.jpg|Tapeworm with four suckers and two rows of hooks
Omnivore

s, dogs, pigs, catfish, crow, meat ant]]

An **omnivore** is an animal whose species gets its energy and nutrients from a diet made up of foods that include plants, animals, algae, fungi and bacteria.

Many omnivores change their eating habits during their life cycle. They are sometimes called "life-history omnivores", because they are only omnivores if their whole life is considered.

Some species, such as grazing waterfowl like geese, are known to eat mainly animals at one stage of their lives, but plants at another. Also, many insects, such as the beatle family Meloidae, eat animal tissue when they are larvae, but eat plant matter after they mature.

## Animal types
All of these animals are omnivores, but have different feeding behaviors and  foods. Being omnivores gives these animals more food security in stressful times. It also makes it easier for them to live in less consistent environments; (those that change along with the season, for example).

Humans, many pigs, many bears, some primates, some rodents, opossums, rails, rheas, most seagulls, and other animals are omnivores.

## Related pages
* Carnivore
* Herbivore
* Insectivore
* Semi-vegetarian

## References
1870

**1870** (MDCCCLXX) was a common year starting on Saturday in the Gregorian calendar and a common year starting on Thursday in the Julian calendar.

## Events 
* Franco-Prussian War (1870-1871)

## Births 
* January 8 – Miguel Primo de Rivera, dictator of Spain (d. 1930)
* January 15 – Pierre S. DuPont, industrialist
* February 7 – Alfred Adler, psychologist
* March 5 – Frank Norris, writer (d. 1902)
* March 17 – Horace Donisthorpe, myrmecologist (d. 1951)
* March 20 – Paul Erich von Lettow-Vorbeck, German general (d. 1964)
* April 22 – Vladimir Lenin, first leader of the USSR
* April 30 – Franz Lehár, composer (d. 1948)
* May 19 – Albert Fish, serial killer (d. 1936; executed by electrocution)
* June 13 Sophia of Prussia Queen of Greece Grand Daughter of Queen Victoria and sister of Kaiser William II of Germany and mother of future 3 kings George II Alexander I Paul I  ( died 1932
* July 3 – Richard Bedford Bennett, eleventh Prime Minister of Canada.
* July 12 – Louis II of Monaco
* July 29 – George Dixon, Black Canadian boxer, first Black world boxing champion in any weight class.
* August 31 – Maria Montessori, educator
* September 26 – King Christian X of Denmark
* November 21 – Sigfrid Edström, Swedish sports official
* December 5 – Vitezslav Novák, composer (d. 1949)

## Deaths 
* February 11 – Jacob M. de Kempenaer, Dutch Minister of Internal Affairs (1848-1849?).
* February 11 – Leopold Eugen Mechura, composer
* February 19 – Nathaniel de Rothschild, French wine grower
* March 28 – George Henry Thomas, American general
* June 9 – Charles Dickens, British novelist
* July 20 – Jules Alfred Huot de Goncourt, *Prix Goncourt*
* October 12 – Robert E. Lee, Confederate General.
* November 4 – Comte de Lautreamont, French poet and writer.
* December 5 – Alexandre Dumas, père, writer
* December 27 – General Prim, Spanish dictator.
* Henry Rowe – Gothic architect
1826

## Events 
* The first photograph was taken.

* John Adams second president, and third president Thomas Jefferson both died same day Independence Day.

## Births 
* January 12 – William Chapman Rawlston, banker and financier
* January 26 – Louis Favre, Swiss engineer (d. 1879)
* February 16 – Joseph Victor von Scheffel, German poet (d. 1886)
* February 16 – Julia Grant, First Lady of the United States (d. 1902)
* March 4 – Theodore Judah, railroad engineer (d. 1863)
* March 24 – Matilda Joslyn Gage, pioneering feminist (d. 1898)
* March 29 – Wilhelm Liebknecht, German journalist and politician (d. 1900)
* April 6 – Gustave Moreau, French painter (d. 1898)
* May 3 – King Charles XV of Sweden and Norway (d. 1872)
* May 4 – Frederic Edwin Church, American painter (b. 1900)
* June 24 – George Goyder, Surveyor-General of South Australia (d. 1898)
* July 4 – Stephen Foster, American songwriter and poet (d. 1864)
* September 17 – Bernhard Riemann, German mathematician (d. 1866)
* November 13 – Charles Frederick Worth, English couturier (d. 1895)
* November 24 – Carlo Collodi, Italian writer (d. 1890)

## Deaths 
* July 4 – John Adams, 90, second President of the United States, heart failure (b. 1735)
* July 4 – Thomas Jefferson, 83, third President of the United States, uremia (b. 1743)

## Books 
**Biographical Sketches and Interesting Anecdotes of Persons of Color* – Abigail Mott
**The Broken Heart* – Catherine Gore
**Cinq-Mars* – Alfred de Vigny
**Deeds of the Olden Time* – Anne Hatton
**Gaston de Blondeville* – Ann Radcliffe
**Granby* – T.H. Lister
**Die Harzreise* (''The Heart's Journey*) – Heinrich Heine
**Henry the Fourth of France* – Alicia Lefanu
**Honor O'Hara* – Anna Maria Porter
**The Last Man* – Mary Shelley
**The Last of the Mohicans* – James Fenimore Cooper
**Tales Round a Winter Hearth* – Jane Porter & Anna Maria Porter
**Vivian Grey* – Benjamin Disraeli
**Woodstock'' – Sir Walter Scott
PH

**pH** is a scale of acidity from 0 to 14. It tells how acidic or alkaline a substance is. 
More acidic solutions have lower pH. More alkaline solutions have higher pH. Substances that aren't acidic or alkaline (that is, neutral solutions) usually have a pH of 7.
Acids have a pH that is less than 7. Alkalis have a pH that is greater than 7.

pH is a measure of the concentration of protons (H+) in a solution. S.P.L. Sørensen introduced this concept in the year 1909. The p stands for the German *potenz*, meaning power or concentration, and the H for the hydrogen ion (H+).

The most common formula for calculating pH is:

:\mbox{pH} = -\log_{10} \left[ \mbox{H}^+ \right]

[H+] indicates the concentration of H+ ions (also written [H3O+], But, this equation in most cases provides the same value as the more common formula, so in introductory chemistry the previous equation is given as the definition of pH.

Most substances have a pH in the range of 0 to 14, although *extremely* acidic or alkaline substances may have pH  14.

Alkaline substances have, instead of hydrogen ions, a concentration of hydroxide ions (OH-).

## pH indicators 
Certain dyes change colour depending on whether they are in an acid solution or an alkaline solution . **pH indicator** is a chemical compound added in small amounts to a solution so the pH (acidity or basicity) of the solution can be seen. The pH indicator is a chemical detector for hydronium ions (H3O+) or hydrogen ions (H+). Normally, the indicator causes the colour of the solution to change depending on the pH.

Typical indicators are phenolphthalein, methyl orange, methyl red, bromothymol blue, and thymol blue. They each change colour at different points on the pH scale, and can be used together as a universal indicator.

Another way is to use litmus paper, which is based on a natural pH indicators. The paper can tell you how strong the chemical is, whether it is a stronger acid or a stronger base.

## Some common pH values 
## Neutralization 
Neutralization can be summed up by the equation:

: +  → 
(acid + base → water)

## Related pages
* Acid
* Base
* Alkali
* Titration
* Transpiration

## Notes 
## Other websites
* pH-Spectra Database  í
* pH Test 
* pH Calculator
1871

**1871** (MDCCCLXXI) was a common year starting on Sunday in the Gregorian calendar and a common year starting on Friday in the Julian calendar.

## Events 
* January 2 – Amadeus I becomes King of Spain.
* January 18 – Germany becomes a unified country called the German Empire when states of the North German Confederation and south German states of the Kingdom of Bavaria, the Kingdom of Württemberg, the Grand Duchy of Baden and the Grand Duchy of Hesse-Darmstadt unite. The King of Prussia becomes the first German Emperor as Wilhelm I of Germany.
* January 10 – France surrenders (gives up) to end the Franco-Prussian War
* March 22 – In North Carolina, William Holden is the first American governor (leader of a U.S. state) to be impeached (removed from office)
* March 26 – The Paris Commune takes power in Paris.
* March 29 – The Royal Albert Hall is opened by Queen Victoria.
* April – Stockholms Handelsbank is formed.
* October 12 – The introduction of the so-called Criminal Tribes Act was enacted in **British India**.

## Births 
* January 17 – David Earl Betty of the North Sea and of Brooksby, British admiral (navy leader) (d. 1936)
* January 30 – Wilfred Lucas, actor (d. 1940)
* February 4 – Friedrich Ebert, president of the Weimar Republic (d. 1925)
* March 5 – Rosa Luxemburg, politician (d. 1919)
* March 27 – Heinrich Mann, speaker and writer (d. 1950)
* May 6 – Christian Morgenstern, writer (d. 1914)
* May 27 – Georges Rouault, painter and artist (d. 1958).
* July 23 – Tsunesaburō Makiguchi (Japanese old Lunar calendar 6 June was an incorrect date using in Gregorian calendar), First president of Soka Gakkai International (SGI) (d. 1944).
* August 19 – Orville Wright of the Wright brothers, Americans who invented the airplane.
* August 29 – Albert Lebrun, French politician (d. 1950)
* September 27 – Grazia Deledda, Sardinian writer – Nobel prize (d. 1936)
* December 13 – Emily Carr, Canadian artist and writer.
* Richard Turner, Canadian soldier with the Royal Canadian Dragoons, who got the Victoria Cross for bravery during the Second Boer War.
* Guangxu, Emperor of the Qing Dynasty in China.

## Deaths 
* February 20 – Paul Kane, painter
* September 23 – Louis-Joseph Papineau, aged 85, Canadian politician and leader of the Patriotes Rebellion.
* October 10 - Octavius Catto, aged 32, American black educator.
* October 18 – Charles Babbage, aged 79, English mathematician and inventor of computing machines.

## References
Roald Amundsen

**Roald Amundsen** was a Norwegian explorer who focused on the poles. He led the first expedition to reach the South Pole and the first that could prove it made it to the North Pole. Amundsen was also the first man known to travel the Northwest Passage.

## Life
When Amundsen was young, he decided he would use his life to explore the wilderness. He was inspired by the lives of Fridtjof Nansen and John Franklin. While his mother was alive he did not go to sea, to keep a promise to her. After her death, he quit university to begin exploring the world at 21 years old.

In 1897, he went on the Belgian Antarctic Expedition as first mate. This was the first expedition to stay over winter at Antarctica, since their ship got stuck in the ice preventing them from leaving.

In 1903, Amundsen led the first expedition to make it through the Northwest Passage.

In October 1911, he began his expedition to Antarctica with four other men in attempt to be the first man to reach the South Pole. Robert Falcon Scott, an explorer from Britain, arrived in Antarctica with his own team only days after Amundsen. Both explorers raced to the South Pole, but Amundsen and his men used skis and dog sleds for transportation. This was more efficient. On 14 December 1911, Amundsen successfully became the first man to reach the South Pole.

In 1926, Amundsen and his men made it to the North Pole. Three other expeditions claimed to make it before then, but their claims have not been verified. Two of them have been considered fraud. This may make Amundsen and his men the first to reach the North Pole.

He disappeared in June 1928 while taking part in a rescue mission.

## Gallery

Nlc amundsen.jpg|Roald Amundsen
Polarskipet Maud.jpg|Maud in June 1918
Roald Amundsen2.jpg|Captain Roald Amundsen at the wheel
Aan de Zuidpool - p1913-160.jpg|Norwegian flag at the South Pole
Roald Amundsen Svalbard 1925.jpg|Roald Amundsen in Svalbard (1925)

## Related pages
* List of people who disappeared mysteriously: 1910–1990

## References
## Other websites
* 
* 
* 
* The Fram Museum (Frammuseet) (Named after one of Amundsen's ships)
* DIO vol.10 2000 Amundsen's record of polar firsts
* 
* 
*
Square

A **square** is a shape with four equal sides and four corners that are all right angles (90 degrees). The diagonals of a square also cross at right angles. The angle between any diagonal and a side of a square is 45 degrees. A square has rotational symmetry of four. It has four lines of regular symmetry. A square with vertices *A*, *B*, *C* and *D* can be written as \square ABCD.

A square is a type of rectangle with all sides of equal length. However, while a square is a type of rectangle and rhombus, the opposite does not need to be true.

A square is also the 2-dimensional surface of a cube.

## Formulas 
If the length of side *a* is known, then we have that:

If the length of diagonal *d* is known, then we have that:

## Related pages 
* Square (algebra)
* Square number
* Square root

## References
Computer hardware

**Computer hardware** or **hardware** means the physical parts that make up a computer.

Some examples are:
* Central processing unit (CPU)
* Random-access memory (RAM)
* Power supply unit (PSU)
* Motherboard
* Graphics processing unit (GPU)
* Network card
* Peripheral equipment
** Modem
** USB flash drive
** Hard drive
** Computer monitor
** Keyboard
** Computer mouse

Hardware needs software to tell it what to do. Without software, the hardware cannot be used.
Anders Celsius

**Anders Celsius** (27 November 1701 &ndash; 25 April 1744) was a Swedish astronomer. Celsius was born in Uppsala in Sweden. Much of his work was in what was later called Geodesy. 

He is more famous for developing the Celsius temperature scale when he worked on meteorology (a science about weather conditions).  It later became an the international standard.  One of his good friends Daniel Gabriel Fahrenheit invented the Fahrenheit scale for the thermometer.