Aarushhh/wikipedia-simple-splitted huggingface dataset:
Status today 
Archaeopteryx used to be considered the first bird. Nowadays, it is not the only fossil of a bird-like dinosaur. A similar species called Anchiornis huxlei lived from 160 to 155 million years ago. It had feathers on both front and rear legs, and could probably glide. It may or may not have had some ability to fly. This discovery means we cannot say Archaeopteryx is the first known bird, but its contribution to science has been huge. We now know for sure that a whole group of small theropod dinosaurs had feathers, and that flight was a later, secondary, use of feathers. The first use of feathers was temperature regulation, and probably also signalling (see Epidexipteryx). 

Many scientists nowadays do not consider Archaeopteryx a true bird (=a member of the lineage Aves). They only consider it a relative of birds. This classification does not reflect a different evolutionary hypothesis, it simply defines Aves (birds) less broadly.
Directly ancestral or not? 
It may be that Archaeopteryx is not directly ancestral to modern birds, but it is still a fine transitional fossil.
"Archaeopteryx, for example, is not necessarily directly ancestral to birds. It may have been a species on a side-branch. However, that in no way disqualifies it as a transitional form, or as evidence for evolution. Evolution predicts that such fossils will exist, and if there was no link between reptiles and birds then Archaeopteryx would not exist, whether it is directly ancestral or not".

Related pages 
 Origin of birds
 Paraves
 Anchiornis

Further reading 
Chambers P. 2002. Bones of contention: the fossil that shook science. London: John Murray. 
Shipman P. 1998. Taking wing: Archaeopteryx and the evolution of bird flight. London: Weidenfeld & Nicolson.

References 

Birds
Coelurosaurs
Dinosaurs of Europe
Jurassic dinosaurs
Feathered dinosaurs
Mosel-Saar-Ruwer is a German wine-growing-region in the valleys of the rivers Moselle, Saar and Ruwer near Koblenz and Trier, Rhineland-Palatinate. It is famous for its wines of Riesling, Elbling and Müller-Thurgau grapes. 

There are the following six sub-regions with 19 large vineyards: 

Region Cochem / Untermosel
Weinhex
Goldbäumchen
Rosenhang
Grafschaft
Schwarze Katz (Zell)

Region Bernkastel / Mittelmosel
Vom heißen Stein (Reil)
Schwarzlay
Nacktarsch (Kröv)
Münzlay
Badstube (Bernkastel)
Beerenlay
Kurfürstlay 
Michelsberg
St. Michael
Probstberg
Römerlay

Region Ruwer

Region Saar

Region Obermosel
Königsberg
Gipfel

Region Moseltor
Schloß Bübinger (Perl)

Other websites 

Mosel-Saar-Ruwer

German food
Geography of Rhineland-Palatinate
Geography of Saarland
Wine regions
A snail is a common name for a kind of mollusc. The term is used for a gastropod with a coiled shell. Their fossil records extends back into the Carboniferous period.

Land snails and slugs breathe with a kind of lung. They used to be put together in a group, the Pulmonata. This was a well-known order in traditional taxonomy. However, the Pulmonata is polyphyletic. This means the same life-style evolved in a number of different lines. This is called convergent evolution. Therefore, the Pulmonata is no longer an official term in biological classification.

The term "snail" is also sometimes used for aquatic snail-like gastropods, which usually have gills. Actually, most snail species are marine snails. There are more species of them, and they are far greater in numbers. Many kinds of snails can also be found in fresh water habitats.

Most land snails and slugs are herbivorous. Aquatic snails and slugs are usually omnivores or predatory carnivores.
In many countries around the world, people eat snails as a delicacy. In France, snails are called escargots, which is also the name of the dish. In French cuisine, the snails are cooked in salt water and then served with a garlic sauce.

The biggest snail is the giant African snail. Their foot is up to 35 cm long.
The fastest snail is the Helix aspersa. It can reach speeds up to 0.047 kmh.
There are known more than 43000 species of snails all over the world.

Body parts

Shell 
Snails are invertebrates, which are animals with no backbones. The shell on the snail helps protect it, and also reduces the loss of water by evaporation. Shells have many different shapes, sizes, and colors. Snails do not breathe through their mouths, instead they have a breathing hole under their shells.
Foot 
A snails "foot" is a muscle which allows it to move slowly across the ground. The foot puts out ('exudes') slime, which eases the snail's movement, leaving a trail. Snails can absorb mineral nutrients through their foot by simply sitting on a rock.

Head 
The head is attached to the foot. On the head there are 15 mm stalks. At the end of the stalks are snail’s eyes.

Habitat 
Snails are found all over the world. Generally speaking, land snails live in  damp habitats. They live in caves and dark places. Snails can be found in dark places such as in a garden under plant's foliage leaves. Some species live in cold places like the Arctic and a few are found in warm places like beaches and deserts.
Food 
Land snails eat vegetables and fruits, such as lettuce, carrots, cucumber and apples. Aquatic snails are often carnivorous. Snails use their radula to cut food. The radula is a hard, rough plate in the mouth. Radula teeth are like little pieces of sandpaper. They are good for cutting up plants and if the snail eats meat they are good for tearing the meat apart. 

Many animals eat snails. Fireflies, snakes, beetles, fish, insects, turtles and people eat snails too. To defend themselves, snails pull back into their shells.

Related pages 
 Ampullariidae
 Gastropoda
 Helix (genus)
 Slug
 Sea slug

References 

 O’Neil, Sarah 1999. Snails. Scholastic Canada. .
 Henwood, Chris 2005. Keeping minibeasts: snails and slugs. Sea to Sea. .
 Stidworthy, John 2002. Cool facts: creepy crawlies. Parragon 2000. .
 Ghesquiere, Stijn 1998. Apple snails. 
 

Gastropods
The Ruwer is a river in Germany with a length of , a tributary of the Mosel River.  The valley of the Ruwer is a part of the wine-growing region Mosel-Saar-Ruwer near Trier in Rhineland-Palatinate. It is famous for its Riesling wines.

At the lower Ruwer valley are the villages Waldrach, Kasel, Mertesdorf, Eitelsbach and Ruwer.

Tributaries
Tributaries are Alkenbach, Altbach, Altweiherbach, Apfelbach, Avelbach, Bausbach, Benninger Bach, Bingelbach, Burg Heider Bach, Burkelsbach, Eitelsbach, Enterbach, Eschbach, Eselsbach, Flonterbach, Gimpelbach, Gondersbach, Grindelbach, Großbach, Hinzerter Bach, Kittelbach, Klinkbach, Kreidbach, Kundelbach, Labach, Lehbach, Misselbach, Moertschelbach, Mühlscheider Bach, Pehlbach, Rauruwer, Rimperterbach, Riveris, Rothbach, Siebenbornbach, Thielenbach, Waldbach, Waschbach, Weiherbach, Wenigbach, Wenzelbach and Weschbach.

Geography of Rhineland-Palatinate
Rivers of Germany
Slug is a general term for a gastropod mollusc which has no shell, or just a small internal shell. 

Slugs belong to several different families which also include snails with shells. Snails are gastropods with a coiled shell large enough for the animal to pull back inside. The families of land slugs are not very closely related, despite looking similar. The shell-less slug type is an example of convergent evolution, and so the category "slug" is  not a taxonomic category.

The name "slug" is used for air-breathing land slugs, while the marine forms are usually known as sea slugs. Land gastropods with a shell that is too small to hide the body are sometimes called semislugs.

Body parts and behaviour 

Like land snails, most slugs have four 'feelers' or tentacles on their head. The upper two (the "optical tentacles") see light and have eyespots at the ends, while the lower two (the "sensory tentacles") are used for smelling. The tentacles are retractable, and can regrow if lost.
On top of the slug, behind the head, is a body part called the mantle, and under this are the genital opening and anus. On one side (almost always the right side) of the mantle is a breathing hole, which is easy to see when open, but difficult to see when closed. Inside the mantle in some species is a very small, flat shell.

The bottom of a snail is called a "foot". Like other snails, a slug moves by rhythmic waves of muscle contraction on the bottom of its foot. At the same time, it secretes a layer of mucus on which it travels, which helps prevent damage to the foot. Around the edge of the foot is the 'foot fringe'. 

Some slug species hibernate underground during the winter in places with cold winters, but in other species, the adults die in the autumn.

Gastropods
Ruwer could mean:

 Ruwer River, in Rhineland-Palatinate, Germany
 Ruwer (municipality), a convention community (Verbandsgemeinde) in Rhineland-Palatinate
 Ruwer (suburb), a suburban part of Trier
 Ruwer (region), a part of the German wine-growing region Mosel-Saar-Ruwer near Trier
Ruwer is a municipality (a convention community called Verbandsgemeinde Ruwer) on the River Ruwer. The administrative offices are in the town of Waldrach, and it should not be confused with the nearby town of Ruwer, which is for administrative purposes a part of the city of Trier.

Members

Photos

Related pages 
Ruwer-Hochwald-Radweg

Other websites 

 Homepage of the municipality
 Touristinformation Ruwer

Geography of Rhineland-Palatinate
Gunpowder (or gun powder) is a mix of chemical substances (75%  saltpeter, 15% charcoal and 10% sulfur). It is used primarily in firearms, burns very quickly, and creates gases. Those gases use up more space than the gunpowder they come from, so they push outward. If the gunpowder is in a small space, the gases will push on the walls of the space, building up pressure. In a gun, the pressure pushes against a bullet, causing it to fly out at high speeds. If the pressure became too high, it could destroy the gun barrel.
Gunpowder was invented by the Chinese. The first references of black powder, the original form of gunpowder, date to the 9th century. According to legend, Chinese alchemists were looking for a formula to create the elixir of life, or the mythical potion that causes whoever drinks it to become immortal, when they accidentally created gunpowder. Because the powder was highly flammable, or burned very easily, they decided to call it "fire medicine" (Simplified Chinese: 火药 / Traditional Chinese: 火藥). The Chinese soon weaponized the substance, or made weapons out of it. In later centuries they made many weapons using gunpowder, including rockets, bombs, flamethrowers, and land mines, before making cannons and guns. The oldest weapon that uses gunpowder dates back to a bronze handheld cannon made in northeastern China in 1288. The first mention in Europe was in the 13th century when Roger Bacon described the formula of black powder
. Gunpowder was extremely valuable to the Chinese civilization, in fact so valuable that sometimes it was traded for gold.
Other websites 
 Gunpowder -Citizendium

References 

Firearms
A mayor is a person who is in charge of the administration of a city.  Some mayors are elected by the people who live in that city.  For other cities, a central government body may choose the mayor.  Some large cities have a Lord Mayor.

In federal countries like Germany the mayor can also be head of the government of a city state. The Mayor of Hamburg runs the government just like the Minister President of Bavaria runs the Bavarian government. In some big cities such as Tokyo the Mayor is a Governor.

In many countries, such as the United Kingdom and Australia, the mayor is not in charge of the daily functions of a city or town. That job is done by a Town Clerk or Chief Executive, who is appointed to a full-time paid job. The mayor works part-time, usually without payment, and represents the city at events and civic functions. 

 
Government occupations
Surabhi: She was a cow. She was called the cow of plenty.
Varuni: He was the goddess of wine.
Parijata: It was a tree. The story tells that this tree granted all the wishes of the person standing below it.
Apsaras: They were beautiful women. They would never grow old. They used to dance in the court of Indra, a god of the Indo-Aryan period.
The moon: The Hindu scriptures name the moon as the Chandra. It rose from the ocean when the gods and the demons were churning the ocean. 
Kalakuta: It was a dangerous poison. When it came out of the ocean, Shiva drank it.
Dhanvantari: He was the first physician of Ayurvedic system of medicine and medication.
Lakshmi: She came out of the ocean seated on a lotus. She is a goddess of Hindus.
Uchchaishravas: It was a horse with seven heads. The legend states that it pulls the chariot of the sun-god, Surya.
Airavata: It was a three-headed elephant. It was taken by Indra.
Kaustuba: It was a very important gem. God Vishnu kept it.
The Hindu scriptures and the Hindu mythology tell that all the above things came out of the ocean for the good of human beings.

References
Dictionary of Hindu Lore and Legend () by Anna Dallapiccola

Hindu mythology
Martha Dandridge Custis Washington (June 2, 1731 – May 2, 1802) was the wife of George Washington, the first President of the United States.  Although people only started using the term decades after her death, Martha Washington is considered to be the first First Lady of the United States.

Early life
She was born  on June 2, 1731, at Chestnut Grove Plantation near Williamsburg, Virginia.  Her parents were John Dandridge, an immigrant from England, and his wife Frances Jones. Her education consisted of the womanly arts such as needlework and playing musical instruments. Later in life, she would learn to manage a plantation.
Marriage 
At 18, she married Daniel Parke Custis, a wealthy tobacco planter 20 years older than her. She bore him four children. Only two, John "Jacky" and Martha "Patsy", survived to young adulthood. She was widowed in 1757 at age 26. In 1759, she married George Washington, a colonel in the colonial militia. Their marriage was one of mutual affection and respect, but not one of passion.  The Washingtons had no biological children.

Personal life
During the American Revolutionary War, Martha visited the cold and starving Continental troops spending the winter at Valley Forge, Pennsylvania. She donated as much food as possible, and sewed clothing for the soldiers.  She nursed those who were ill or dying. She urged local women to do the same. Her commitment to the welfare of the veterans of the Revolution would remain lifelong. They addressed her as "Lady Washington."
First Lady
Washington was unanimously elected president in 1789. Martha served as First Lady from April 30, 1789 to March 4, 1797. She found the job unpleasant. She complained of the journalists who followed her everywhere (even to the circus with her grandson), and of the many restrictions placed upon her as First Lady (she was not allowed to accept dinner invitations, for example).

She set many of the customs and standards that were observed by future First Ladies. She retired to Mount Vernon with her husband after serving her country.

Death
She died in Mount Vernon on May 22, 1802. Her obituary (death notice) was widely printed in regional newspapers. She is buried in the vault at Mount Vernon. She was the first historical female figure to be depicted by the United States government on postage stamps and currency.

Gallery

References

1731 births
1802 deaths
18th-century American people
First Ladies of the United States
People from Virginia
Abigail Smith Adams (November 11, 1744 – October 28, 1818) was the wife of John Adams, the second President of the United States. She was also the mother of John Quincy Adams, the sixth president. Later on, people started to address the wife of the president as the First Lady. So, she became the second First Lady of the United States. She was born in Weymouth, Massachusetts. She belonged to a famous family of Massachusetts (the Quincy Family).

In 1801, the couple retired and lived in Quincy. Abigail died in 1818, at age 74 of typhoid fever.

Early life 
Abigail Adams advocated for an equal education in public schools for boys and girls. In her earliest years, she was often in poor health. She spent most of her time reading. In addition to that, she corresponded to family and friends before getting married.
Adams did not get any formal education in any school or college. Her father had a big library, so she studied many books and became smart that way. She married John Adams in 1764. In the next ten years, she had five children (a sixth was stillborn). One of her children was John Quincy Adams, the sixth President of the United States.

Political involvement 
Adams was a vital confidant and adviser to her husband John Adams. She opposed slavery and supported women's rights. In 1776, her husband participated in the First Continental Congress in Philadelphia. There, Adams wrote her most famous letter to the Founding Fathers "remember the ladies." 

In 1784, Adams joined at her husband at his diplomatic post in Paris. She became interested in the manners of the French. After 1785, she filled the difficult role of wife of the First US Minister to Great Britain. She did so with dignity.

References

Other websites
Other websites 

1744 births
1818 deaths
18th-century American people
19th-century American people
First Ladies of the United States
Second Ladies of the United States
John Adams
People from Massachusetts
Martha Washington Jefferson Randolph (September 27, 1772 – October 10, 1836) was the daughter of Thomas Jefferson and his wife Martha Wayles Skelton Jefferson. Thomas Jefferson was the third President of the United States. Because her father was a widower, Martha Washington Jefferson Randolph acted as the First Lady of the United States from March 4, 1801 to March 3, 1809.

Martha was born in Monticello, near Charlottesville, Virginia. She was named Martha Washington in honor of Martha Washington, the wife of the first President of the United States, George Washington. She was educated in Philadelphia, Pennsylvania and Paris.

In 1790, Martha married Thomas Mann Randolph Jr. They had twelve children. Shortly before her death, she and her husband developed differences. She died in 1836 in Albemarle County, Virginia at the age of 64.

People from Virginia
1772 births
1836 deaths
First Ladies of the United States
Children of Presidents of the United States
Thomas Jefferson
Aracaju is the modern capital city of the state of Sergipe in the northeastern region of Brazil. It has about 470.000 inhabitants (estimate 2003) and lies between the cities of Salvador and Maceio, also in the northeast of Brazil. It was planned and built to be the state capital in 1855.

Cities in Sergipe
Capitals of Brazilian states
1855 establishments
19th-century establishments in Brazil
1850s establishments in South America
A Midsummer Night's Dream is a play by William Shakespeare. The exact date the play was written is unknown. It is generally accepted that the play was written in 1595 or 1596. It was first printed in 1600. In 1623, the play was printed in the First Folio, a collection of all of Shakespeare's plays. 

Shakespeare's sources include works by Plutarch, Apuleius, Ovid,  Geoffrey Chaucer, and Edmund Spenser. He found a description of Puck in Reginald Scot's The Discoverie of Witchcraft (1584). It is generally believed that the play was written for the festivities surrounding the aristocratic marriage of either Elizabeth Vere, Lord Burghley’s granddaughter, in 1595, or Elizabeth Carey, daughter of Sir George Carey, in 1596.

The play is about four confused young lovers, a group of clumsy workmen, the royal court of Duke Theseus, and the royal fairy court of King Oberon and Queen Titania.  The play is set mostly at night in the woods near Athens.
The play has been made into movies on numerous occasions. One movie stars Mickey Rooney as the fairy Puck. Benjamin Britten wrote an opera based on the play, George Balanchine and Frederick Ashton have both made ballets about it, and Felix Mendelssohn wrote many pieces of music for the play which include an "Overture" and a "Wedding March".

Characters

The Court at Athens:
 Theseus, Duke of Athens, engaged to Hippolyta
 Hippolyta, Queen of the Amazons, engaged toTheseus 
 Philostrate, Master of the Revels at the Court
 Egeus, father of Hermia

The Lovers:
 Hermia, Egeus' daughter; loved by Lysander
 Lysander; loved by Hermia
 Helena; loves Demetrius
 Demetrius; loves Hermia, whose father wants them to marry

The Fairies:
 Oberon, King of the Fairies
 Titania, Queen of the Fairies
 Puck, Oberon's servant
 Peaseblossom, a fairy serving Titania
 Moth, a fairy serving Titania
 Cobweb, a fairy serving Titania
 Mustardseed, a fairy serving Titania
The Rustics:
 Nick Bottom, a weaver
 Peter Quince, a carpenter
 Robin Starveling, a tailor
 Francis Flute, a bellows mender
 Snug, a joiner
 Tom Snout, a tinker

Story
Egeus wants his daughter Hermia to marry Demetrius. Hermia does not want to marry him. She loves another man named Lysander. Hermia and Lysander decide to run away. Demetrius follows them. Helena, Hermia's best friend, is in love with Demetrius. She follows him. All four become lost in the woods near Athens.
 
Meanwhile, Oberon and Titania are having an argument. Oberon decides to teach Titania a lesson. He puts a love potion into her eyes while she is asleep. This potion will make her fall in love with the first thing she sees when she wakes.  

Oberon finds Helena and Demetrius. He tells Puck to give Demetrius some of the love potion so that he will love Helena. Puck makes a mistake and puts the potion in Lysander's eyes. When Lysander wakes up, he loves Helena instead of his real sweetheart Hermia.
The workmen are practicing a play in the woods for the upcoming marriage of Theseus and Hippolyta. Puck plays a trick on Nick Bottom by giving him a donkey head. The other actors run away, so Bottom goes to sleep. He is sleeping near Titania. After Oberon puts love potion in her eyes, she wakes up and falls in love with him.

Oberon realises everything is all mixed up. He gives some of the love potion to Demetrius. Now Demetrius and Lysander both love Helena. Sad and confused, all the lovers fall asleep. At last, Puck rights all the wrongs. He makes Lysander love Hermia again, and makes Demetrius love Helena. Everyone is happy.

The workmen perform their play for the wedding of Theseus and Hippolyta. Lysander and Hermia also get married, and so do Demetrius and Helena. Titania once again loves Oberon, not the donkey-headed Nick Bottom. They are happy with each other again. The fairies use their magic to bless all the lovers.

References

Other websites
Other websites 

 David Strathairn Online: A Midsummer Night's Dream
 MIT html version .
 First Folio Facsimile  – HTML diplomatic transcription of 1623 text.
 Midsummer Night's Dream – plain vanilla text from Project Gutenberg.
 The Sources and Analogues of 'A Midsummer Night's Dream', 1908 publication compiled by Frank Sidgwick, from Project Gutenberg.

Plays by William Shakespeare
1590s plays
Vodka is a Russian alcoholic drink that is usually about 40% alcohol. It is clear (but can be flavoured), though it is sometimes mixed with other liquids before people drink it. It was first popular in the Slavic countries of Eastern Europe and former republics of the Soviet Union.

Things that are made into vodka 

Vodka can be made from different things:
 Molasses (which comes from the production of sugar) are used to produce the cheapest vodka. Because of the ingredient, this kind usually tastes sweeter than vodka made from grain. Soy beans, grapes or sugar beets may also be used, but are less common.
 Potatoes have been used for centuries to make vodka.
 Grain is used to produce the highest grade vodka - like potatoes, vodka is also traditionally made from grain.

The process to make vodka is:
The raw material is crushed and dissolved in water. This is called mashing
 The mash is heated to 60 °C. All starch will break up into sugars.
 Yeast is added and the mash vessel is closed airtight with airlock. The yeast will ferment the sugar into alcohol.
 The fermented mash is then distilled. It can be made either in simple pot still or sophisticated industrial patent still.
 If the still used is a pot still, the distillation is usually repeated at least twice to remove any foul-tasting or poisonous impurities away. If the still used is a patent still, the result is spirit; very high contents alcohol unsuitable for drinking. Pure water is added to lower the alcohol contents to desired. This is called dilution.

Unlike cognac or whisky, vodka is not usually matured in barrels, but bottled immediately. Some Scandinavian vodkas called akvavit (Latin aqua vitae, "water of life") are matured in oak barrels before they are bottled. When the vodka is bottled, it is ready for drinking.

History
Most people think the name vodka comes from the Slavic word for water in its diminutive form, "little water". The earliest mention of Vodka in Poland is in 1405. The Russians are known to have first used the word in June 8, 1751. It is not known if it was the Russians or the Poles who made the first drinks that could be classified as vodka, as sources provide various views on this topic (though it's important to remember that the first mention of the word "vodka" in Cyrillic refers to a medicinal drink bought by the merchants of Kievan Rus from Poland). It is also worth noting that vodka was first used as medicine. When it became a popular drink, it was first known in Polish as gorzałka - from the Old Polish word gorzeć, meaning burn. At first, gorzałka was a people's drink, but in the Slavic countries it soon became common among the nobility as well. it is worth noting that the common Ukrainian word for vodka is horilka which bears an extremely close resemblance to the Polish gorzalka
. Both words roots have the same meaning (hority - to burn; gorzeć, also to burn)
Different kinds of vodka 

There are two basic kinds of Vodka: clear vodka and flavored vodka. Some types of vodka have plants or herbs added to the unflavored vodka to make it taste better. Contrary to popular belief, flavoured vodka is not new - it has been a part of Polish drinking tradition for centuries. It is only relatively recently in history that clear and flavoured vodkas have found their way to Western countries such as the UK or US.
How vodka is consumed 
Vodka is either drunk pure, or cocktails are made with it. The simplest form of cocktail is to mix it with orange or lemon juice. Usually, vodka is drunk during a longer meal. Usually salty or sour things (not sweets) are served. In Poland and Russia (as well as some of their neighbours, such as Ukraine or Lithuania), vodka is drunk from glasses that can hold about 100 grams (0,1 litres) of vodka. The glass is usually emptied in one draught, while holding the breath. Directly afterwards something small is eaten. In most Eastern European countries it is consumed with pickled cucumbers. Before drinking, a toast is given.
Cultural 
Vodka is a key element of Slavic tradition in some countries of Eastern Europe (especially Poland, Belarus, Ukraine and Russia). It has also spread to become a part of national culture in Baltic countries like Lithuania and Nordic countries like Sweden. It's traditional in Russia and other Slavic countries (as well as some Roma communities in Eastern Europe) to put a glass of vodka with a slice of bread (usually black bread) on top on graves or near photos of the deceased in their memory. This is similar to what people in Western countries do with flowers.

References 

Alcoholic spirits
Sexual reproduction is how most animals and plants reproduce. Some protists and fungi also reproduce this way. Organisms that reproduce sexually have two different sexes: male and female.

In sexual reproduction, offspring are produced when sperms fertilise eggs from the female. Various steps are involved in this process.

Cell biology 
The cells of an animal or higher plant have two sets of chromosomes: they are diploid. When gametes (sex cells) are produced, they have only one set of chromosomes: they are haploid. They have undergone a process of cell division called "reduction division" or meiosis. Two things happen during meiosis, each of which makes the offspring more variable. That means they are different from their parents and from each other.
Assortment 
Assortment is when the double set of chromosomes becomes a single set in each gamete. Of each pair of chromosomes, which one goes into a single gamete is random. Because the gene alleles on each chromosome are not always the same, this means that there is genetic variation between gametes. This process was Mendel's 'first law', the law of segregation.

Crossing over 
Because crossing over occurs during meiosis, this increases the variety of the chromosomes. This makes recombination possible. 

Assortment and crossing over make it certain that normally no two offspring of the same mother and father are identical. Identical twins are the exception. They are identical genetically because they developed from the same fertilised egg.
Advantages and disadvantages 
There are advantages and disadvantages of sexual reproduction, compared to asexual reproduction. The main issues are:
Advantages: More variation assists with survival. It increases the chance that at least some offspring of a parent survive. To give an example, suppose a deadly infection occurs in the population. Greater variety increases the chance that some of the population will survive.
Disadvantages: Requires two parents. So, supposing the total number of eggs laid by a female is the same, a population reproducing sexually would produce only half as many offspring as a population reproducing asexually. The actual search for a partner, and mating, often takes huge chunks of time out of the lifetime of sexual animals.

Various terms 
Gonads are specialized sex organs where gametes are formed. In the male, the gonad is the testes; in the female, the gonad is the ovaries.
Gametes are specialized sex cells formed in gonads by gametogenesis. The male gamete is the sperm, and the female is ovum.
Spermatogenesis: the process which produces haploid sperm.
Oogenesis: the process which produces haploid egg cells.

Hermaphrodite: an organism with male and female sex organs. Examples: earthworms, snails, hydra.

Fertilization: sperm penetrates the cell membrane of ovum. What now exists is a single cell called a zygote. 
Internal fertilization: sperm are deposited in or near the female reproductive tract. 
External fertilization: eggs are shed by the female and are fertilised by sperm in the external environment.
Development 
Cleavage: early stage of embryo development. Cell number increases by cell division.
1. Morula: a solid ball of cells
2. Blastula: a hollow ball of cells filled with fluid 
3. Gastrulation: blastula continues to grow, and cells multiply by mitosis. Several hundred cells on one side begin to move in and form a two-layered embryo. It develops into a three-layered embryo with endoderm, mesoderm, and ectoderm.

Ectoderm develops into the nervous system, which includes the brain, spinal cord, and peripheral nerves. Also, the linings of various organs: mouth, anus, nostrils, epidermis including sweat glands, hair, nails.

Mesoderm develops into bones, muscles, reproductive system, kidneys, blood, blood vessels, inner layer of skin.

Endoderm develops into the linings of the digestive system, respiratory system, liver, pancreas, and bladder.

Growth and differentiation: embryonic cells multiply and change into specialized cells in tissues and organs.
Origin of sexual reproduction 
The origin of sexual reproduction is an advanced topic that cannot be dealt with here. A source that may help readers who are graduates in biological science may be helpful.

Related pages 
 Asexual reproduction
 The evolution of sex
 Gender
 Sex
 Sexual intercourse

References 

Methods of reproduction
Leprosy is a contagious disease. It has been known for a very long time. Today, it is mostly called Hansen's disease, named after the person who discovered the bacterium, Gerhard Armauer Hansen. It is caused by a bacterium, Mycobacterium leprae. A person with leprosy is called a leper.

As of 2004, the estimated number of new infections was about 400,000.

Getting the disease is hard, since it requires close contact with someone who has it, over a long period of time. In addition, about 95% of people seem to be naturally immune to it.

Most cases of leprosy occur in India, and other developing countries. It has known to have been in the US before. There are practically no cases of leprosy in the developed world. This is because there are excellent drugs and people regularly take antibiotics which will kill the leprosy bacteria.

In former times, leprosy was seen as a divine punishment for sins committed.
Symptoms 
The symptoms of leprosy are irregular spots and patches on the skin. These are either lighter colored than the surrounding skin, or reddish in color. On those patches, hair will fall out, and they will feel numb to the patient. Nerves will form knots there.
With the illness progressing the sense of touch will become less and less (until the patient feels completely numb). So called leptomes and ulcers will eat away the skin, the flesh and the organs on the patches.

Usually people do not die of leprosy, but of secondary infections and diseases they get.

For many years there was a leprosy colony on the Hawaiian Island of Molokai called Kalaupapa. Tens of thousands of people from the United States that had the disease were sent there.

Gallery

Diseases caused by bacteria
Dolley Payne Todd Madison (May 20, 1768 – July 12, 1849) was the wife of US President  James Madison. James Madison was president from 1809 to 1817 while Dolley Madison was the First Lady of the United States. She is best known for saving Washington's portrait when the British burned the White House in the War of 1814. Though she is also a famous entertainer, the first to serve ice cream in the White House.

Dolley was born in New Garden. Now the place is known as Guilford County. It is in North Carolina. Some other account tells that she was born in a village named Payne’s Tavern. It is in Person County, North Carolina.

Her father’s name was John Payne. As an unsuccessful farmer, he always faced shortage of money. Dolley’s mother was Mary Coles.
Dolley spent her teenage years in Philadelphia, Pennsylvania. On January 7, 1790, she married John Todd, Jr. (1764-1793). Todd was a lawyer. They had two sons. Their names were John Payne (1792-1852) and William Temple (born and died in 1793). William died in a yellow fever epidemic. In the same year, her husband also died of the same yellow fever epidemic.

Dolley Todd married James Madison on September 14, 1794. They had no children, but they raised Dolley's son from her first marriage, John Payne Todd. John Payne Todd was a notorious drunkard and gambler, which caused his mother many financial problems, especially after Madison died.

In 1814, the British army had burnt the White House. Fleeing from her burning home, Dolley saved many records and papers. Legend states she also saved a painting of George Washington, though had to break it out of its frame.

On the National First Lady Library she says, "There is one secret, and that is the power we have in forming our own destinies."

References
References

1768 births
1849 deaths
First Ladies of the United States
James Madison
American Christians
People from Greensboro, North Carolina
People from Virginia
Quakers
Elizabeth Kortright Monroe (June 30, 1768 – September 23, 1830) was the wife of James Monroe. James Monroe was the fifth President of the United States.

Elizabeth Monroe was born in an old family of New York. When she was a girl of 17 years, she married James Monroe. At that time, Monroe was a lawyer. He was aged 27 years. Once, the government sent Monroe as an envoy to Versailles. She also went along with her husband. 
                                 
During her last years, Elizabeth Monroe became very sick. She could not take part in social functions. She became more distant from people. Some people thought her to be a snob. But, her husband always understood her problems. After a long illness, she died on September 23, 1830 at her home in Oak Hill at age 62.

1768 births
1830 deaths
First Ladies of the United States
James Monroe
Celestia is a free 3D astronomy program for Windows, Mac OS X, and Linux. It was created by Chris Laurel and is licensed under the GPL.

The program is based on the Hipparcos Catalogue (118,218 Stars) and allows users to display objects from artificial satellites to entire galaxies in three dimensions in OpenGL. Different from other planetarium software, the user is free to travel in the universe.

NASA and ESA have used Celestia, but it is not to be confused with Celestia 2000, ESA's own program.

On 31st October 2022, a Chinese game developer named Linfeng Li created a mobile version of Celestia for android devices.

Related pages 
 Astronomy

References

Software
Astronomy
Bill Cullen (February 18, 1920 – July 7, 1990) was an American television game show host.  His full name was William Lawrence Cullen.

Cullen was originally from Pittsburgh, Pennsylvania.  He suffered from polio as a child. He had a limp for the remainder of his life.

Cullen was best known for hosting the original version of The Price is Right on the television networks NBC and ABC.  That show is now on CBS and hosted by Drew Carey.  He also hosted a version of The $25,000 Pyramid, Child's Play, and Blockbusters.

Bill Cullen died in Bel Air, California in 1990 from lung cancer after smoking for most of his life.

American radio personalities
American television presenters
Deaths from lung cancer
American game show hosts
Actors from Pittsburgh
1920 births
1990 deaths
Rudi Carrell (real name Rudolf Wijbrand Kesselaar) was a very successful comedian, singer and television presenter. He was born on December 19, 1934 in Alkmaar, in the Netherlands. He died of lung cancer on July 7, 2006 in Bremen, Germany. He was very popular in Germany, for shows like Die Rudi Carrell Show.

He was awarded various prizes, amongst others the Goldene Kamera for a lifetime of good work, in February of 2006 (which was his last public appearance) as well as the Bundesverdienstkreuz (the only award given by the Federal Republic of Germany, for extraordinary achievements in politics or culture) in 1985.

Other websites 

1934 births
2006 deaths
Cancer deaths in Germany
German comedians
Deaths from lung cancer
Dutch singers
Dutch television presenters
Musicians from North Holland
People from Alkmaar
Lung cancer is the uncontrollable growth of abnormal cells in one or both of the lungs. Cigarette smoking causes most lung cancers when smoke gets in the lungs. Lung cancer kills 1.8 million people each year, more than any other cancer. It has a 80-90% death rate, and is the leading cause of cancer death in men, and the second leading cause of cancer death in women. 

The large majority of people who get lung cancer have smoked for many years. However, there are types of lung cancers that appear in otherwise healthy patients who have never smoked. 

There are two main types of lung cancer, small cell lung cancer and non-small cell lung cancer. Small cell lung cancer typically responds well to chemotherapy and radiotherapy, and non-small cell lung cancer is more commonly treated with surgical removal of the lung tumor.

Non-small cell lung cancer
Non-small cell lung cancer (NSCLC) account for about 85% to 90% of lung cancer cases. People who have a deficient low pigment count have a higher chance of contracting lung cancer. There are three types of non-small cell lung cancer: 
Squamous cell (epidermoid) carcinoma
Adenocarcinoma
Large cell (undifferentiated) carcinoma

Symptoms:
Chest pain
Coughing
Congestion 
Heart burn

References 

Cancer
Whitchurch is a small market town in the north of the county of Shropshire, England. It is the oldest town inhabited in Shropshire.  The town lies 2 miles (3 km) east of the Welsh border. As of 2011, the town has a population of 9,781. 

The town was founded by the Romans and there are still some Roman artefacts that can be visited in a Museum.

The town has a railway station on the Welsh Marches Line.

Gallery

References

Towns in Shropshire
Civil parishes in Shropshire
Panthera is a genus of the family Felidae.
It has five living species, which are the biggest cats in the Felidae.  The tiger is the largest Panthera species, and the largest of all cats. The leopard is the smallest Panthera species.

Results of genetic analysis indicate that the snow leopard also belongs to the Panthera, a classification that was accepted by IUCN assessors in 2008. The genus Neofelis is also closely related.

Taxonomy 
 Genus Panthera
 Lion, Panthera leo
 Jaguar, Panthera onca
 Leopard, Panthera pardus
 Tiger, Panthera tigris
 Snow leopard, Uncia uncia, now Panthera uncia

References
A superpower is a country that is one of the most powerful countries in the world. It is more powerful than a great power and less powerful than a hyperpower. Right now, only the United States is a superpower. However, China may become a superpower in the future. Some say it is already one. Others say that it will not become a superpower.

In the years following World War II, the United Nations was formed. The 5 countries that would later have nuclear bombs – those who would be able to start a nuclear war – were all given permanent seats on the Security Council. This means they are on the Security Council forever. They were also all given equal veto power over decisions in the Security Council. These five countries were: United States, United Kingdom, China, France, and the Soviet Union.
For most of the 1900s, the Soviet Union was a superpower. After the Soviet Union split into a lot of smaller countries in 1991, it was not a superpower anymore. Russia got most of the Soviet Union's nuclear weapons, and also its permanent seat in the Security Council. Some other countries also have nuclear weapons now, and can also start a nuclear war just as well, but they are not permanent members with veto power. The Republic of India, and Pakistan are a few countries like this. In order to be a superpower, a country must dominate economic, cultural, and military as well as diplomatic influence.

Related pages
 Great power
Hyperpower

References

Country classifications

International politics
The snow leopard (Panthera uncia), also known as the Irbis and ounce, is a feline, which lives in central Asia. It used to be thought not to be closely related to the smaller leopard, which is why they were put in different genera before. However, recent research has discovered this is not correct. The cat is closely related to the other big cats in the genus Panthera.

Appearance 
Snow leopards are about 2-5 meters long in the body, and have a 90-100 centimeter long tail. They weigh up to 75 kilograms. They have grey and white fur with dark rosettes and spots, and their tails have stripes. Its fur is very long and thick to protect it against the cold. Their feet are also big and furry, which helps them to walk on snow more easily. They use their long tails for balance and as blankets to cover sensitive body parts against the severe mountain chill.
Voice 
They are one of the cats which cannot purr: "In five cat species (lion, tiger, jaguar, leopard and snow leopard) the epihyoideum is an elastic ligament, whereas in all other species of the Felidae the epihyal is completely ossified (bony)... those felids with an elastic epihyoid are able to roar but not purr, while species with a completely ossified hyoid are able to purr but not to roar". Despite this, it seems now that snow leopards cannot roar, though they can make a number of other sounds.

Hunting 
Snow leopards are well camouflaged, and are crepuscular (most active at dawn and dusk). They stalk and eat medium-sized prey like Ibex, bharal (mountain sheep) and wild goats. It can survive on a single sheep for two weeks.

Snow leopards prefer to ambush prey from above, using broken terrain to conceal their approach. They try to land on the sheep, and kill it directly. If the sheep runs, they pursue it down steep mountainsides, using the momentum of their initial leap to chase prey for up to .
They kill with a bite to the neck, and may drag the prey to a safe location before feeding. They consume all edible parts of the carcass, and can survive on a single bharal (blue sheep) for two weeks before hunting again. Annual prey needs is 20–30 adult bharals.

Habitats 
In summer, snow leopards usually live above the tree line on mountainous meadows and in rocky regions at altitudes from . In winter, they come down into the forests to altitudes around . Snow leopards prefer broken terrain, and can travel without difficulty in snow up to  deep, although they prefer to use existing trails made by other animals.

They live alone. After a pregnancy of about a hundred days the female gives birth to 2 or 3 cubs. Snow leopards are protected in most of the countries they live in. However, people do still kill them for their fur, or to protect their cattle.
Distribution
The snow leopard has a huge range in central Asia. It is in Afghanistan, Bhutan, China, India, Kazakhstan, Kyrgyzstan, Nepal, Pakistan, Russia, Tajikistan, Uzbekistan, Kashmir, Kunlun, and the Himalaya to southern Siberia, Mongolia, and Tibet.

Since many estimates are rough and outdated, its numbers could be falsely viewed as low. The total wild population of the snow leopard was estimated in 2008 as 4,510 to 7,350 individuals.

Taxonomy and evolution 
The snow leopard was not thought closely related to the Panthera or other living big cats. However, recent molecular studies put the species firmly in the genus Panthera: its closest relative is the tiger (Panthera tigris). MSW3 still refers to the snow leopard as Uncia uncia, but the more recent IUCN classifies it as Panthera uncia.

In popular culture
The snow leopard is an official  symbol of Kazakhstan.

References 

Felines
Mammals of Asia
National symbols of Pakistan
National symbols of Afghanistan
Yonkers is the 4th largest city in the American state of New York. It is the southwestern part of Westchester County

Yonkers borders the New York City borough of The Bronx and is 2 miles (3 km) north of Manhattan. Broadway runs through all three, and railroads also connect them to Grand Central Terminal. The Bronx River separates Yonkers from Mount Vernon, New York on the east. The Hudson River is on the west. The city's best-known attraction is Yonkers Raceway, a harness racing track. There is a large shopping area along Central Park Avenue. It is sometimes called "Central Avenue" by area residents.

Sources 

 
1640s establishments in the Thirteen Colonies
17th-century establishments in New York
Louisa Catherine Johnson Adams (February 12, 1775 – May 15, 1852) was the wife of the 6th President of the United States, John Quincy Adams. As the wife of the president of the United States, she was the First Lady of the United States from 1825 to 1829.

She was born in London. Her mother, Catherine Nuth Johnson was an English lady. Her father, Joshua Johnson, was from the US and a citizen of the USA. Louisa Adams was then the only First Lady not born in the United States. John Adams, the second president of the US, was her father-in-law.

In 1794, John Quincy Adams met Louisa in London. At that time, Adams was a US diplomat. After about three years, they married. The couple also lived in Berlin where Adams got a posting. Louisa along with her husband arrived to the US in 1801. They lived in different places before her husband became the President.She went to school in London and France.

She died in 1852, aged 77. She is buried in the United States Parish Church, Quincy, Massachusetts.
1775 births
1985 deaths
First Ladies of the United States
John Quincy Adams