the-french-artist/wikipedia_20220301.simple_sentence_split huggingface dataset:
Its chemical formula is Bi2O5.
It is a scarlet red solid.
It decomposes to bismuth(III) oxide and oxygen easily.
It is made by electrolysis of bismuth(III) oxide in a hot concentrated alkali like sodium hydroxide.
Bismuth(V) fluoride, colorless solid
Bismuth(V) oxide, unstable red solid
Bismuthate, the ion
Sodium bismuthate, light brown solid, insoluble in water
Bismuth was known since ancient times.
It was confused with tin and lead, though.
No one is credited for discovering bismuth.
In the 1500s, people started realizing that bismuth was different than tin or lead.
Bismuth is not very common in the earth.
It is only about twice as common as gold.
Bismite, a bismuth oxide mineral, and bismuthinite, a bismuth sulfide, are two common ores.
Bismuth is sometimes found as a metal, too.
Bismuth and its minerals are too rare to be mined.
They are gotten by "secondary extraction".
It is normally found in lead metal.
The lead metal is purified by electrolysis, leaving the bismuth behind as a sludge on the bottom of the container.
The copper is taken out of the sludge and the bismuth is purified by being reduced in a furnace and all the impurities are filtered out.
China makes the most bismuth.
Peru, Mexico, and Japan also make bismuth.
Bismuth can also be recycled.
This is difficult in many places because bismuth is used for things like bullets, solder, and stomach medicine that get scattered all over and cannot easily be gotten again.
Bismuth is used in alloys with very low melting points.
Some of them melt in hot water.
They are also found in solder that does not have lead in it.
It can make alloys with other metals to make them more malleable.
It is also used in bullets to replace lead.
In some places lead bullets are outlawed as birds eat them and get lead poisoning.
It is also used in alloys for plumbing.
It is used in fishing sinkers.
Bismuth is used in some medicines such as Pepto-Bismol.
This medicine has bismuth subsalicylate in it.
It is also used as an internal deodorant and to treat eye infections and peptic ulcers.
Bismuth oxychloride is used in cosmetics.
Bismuth telluride is used in electronic thermometers.
Another compound is used in superconductors and becomes a superconductor at a high temperature.
It can be used as a pigment and in fireworks to make crackling sounds.
It is used in the nuclear fuel of a nuclear reactor.
Bismuth is much less toxic than other heavy metals.
This is why it is replacing lead in many things.
It does not add up in the body like other heavy metals do.
A very large amount of bismuth can poison the kidneys and liver, though.
Because its oxide does not dissolve in water, it is considered safe for the environment.
Iridium is the 77th element on the periodic table.
Its symbol is Ir and its atomic number is 77.
Iridium is a metal.
Like other metals in the platinum group, Iridium is a rare and expensive "noble metal" and is a transition metal.
It looks like platinum and is found in asteroids and comets.
Iridium deposits are used to identify relative dates of collisions of foreign bodies.
Iridium can fold and bend just like aluminum, and remains very shiny.
Most iridium is found in the Americas, though some is mined in Myanmar, South Africa, and Russia.
Iridium melts at 2410 °C, and boils at 4130 °C.
It is the most corrosion resistant metal.
A man named Smithson Tennant first found it in the year 1803.
Smithson Tennant found it in the remains when he left crude platinum in a mixture of hydrochloric acid and nitric acid.
The transition metals are a group of metals that are found in the middle of the periodic table.
The alkaline earth metals, beginning with beryllium are to the left and the boron group elements are to the right.
The term "transition element" was invented for them in 1921.
The atomic numbers of these metals are from 21-30, 39-48, 57, 72-80, 89 and 104-112.
Many elements like Zn, Cd, Hg, La and Ac have a highly debatable position in the transition series of elements.
La and Ac are also classed in the lanthanide series  and actinide series respectively.
Transition metals have several general properties.
They are harder and less reactive than the alkaline earth metals.
They are also harder than the post transition metals.
They make colorful chemical compounds with other elements.
Most of them have more than one oxidation state.
Like other metals, they are electrical conductors.
Some of the transition metals are necessary to keep humans healthy, such as iron, zinc, and chromium.
Other elements in the transition metals can be harmful to our body, like cadmium and mercury.
Other elements like gold or silver do not harm or help us.
There are more transition metals than any other groups in the periodic table.
Osmium is a chemical element.
It is element number 76 on the periodic table.
Its symbol is Os.
There is not much osmium on earth.
There is actually such a small amount that osmium is very expensive.
It was discovered in 1804 by Smithson Tennant in London, England.
He found it together with Iridium in a bit of Platinum, which he had dissolved in Aqua regia.
Osmium has a blue-grey hue and is the densest stable element; it is about twice as dense as lead and slightly denser than iridium.
Osmium is a hard but brittle metal that stays shiny even at high temperatures.
It has a very low squeezability.
Accordingly, its size module is extremely high, reported between 395 and 462 GPa, which is comparable to that of diamond (443 GPa).
The hardness of osmium is moderately high at 4 GPa.
Because of its hardness, brittleness, low vapour pressure , and very high melting point, solid osmium is difficult to machine, form, or work.
Radon is a chemical element in the periodic table.
It is element 86 on the periodic table and its symbol is Rn.
It is an odorless, tasteless noble gas.
It is quite radioactive and can decay very quickly.
27 isotopes of Radon are known today.
The most stable of them has a half life of about 3.8 days.
Radon is a gas and is part of the group known as the noble gases.
It does not react with other elements, so it is found pure.
Radon is radioactive, meaning that it can give off harmful rays.
Some people have high levels of radon in their houses, and this can be very dangerous.
A lot of radon can get stuck in the basement of old houses, and so people end up breathing it in.
It gets stuck in the lungs and has been known to cause cancer.
There are groups that try to make sure there is no dangerous radon in houses.
It can occur naturally in the Earth, but its a very small amount.
As elements like Thorium and Uranium decay, some of that gets turned into Radon.
Radon can cause lung cancer, and is second most popular cause of lung cancer straight after smoking.
Radon was the fifth radioactive element to be discovered, in 1899 by Ernest Rutherford and Robert B. Owens at McGill University in Montreal, after uranium, thorium, radium, and polonium.
In 1899, Pierre and Marie Curie saw that the gas given off by radium remained radioactive for a month.
Later that year, Rutherford and Owens noticed different types of them when trying to measure radiation from thorium oxide.
It is sometimes uses in radiation therapy.
However it is very dangerous to use.
FTP, also known as File Transfer Protocol, is a communication protocol for the rapid, simple transmission of files across a network supporting the TCP/IP.
This network is generally the Internet, or a local network.
FTP is a way of accessing files on another computer.
FTP uses the Client-Server architecture, meaning that there is a server, that holds the files, and does the authentication, and a client, or the end-user, who is accessing the files.
The server listens on the network for connection requests from other computers.
The client can make a connection to the FTP server by using FTP client software.
Once connected and authenticated (via rsh or SFTP) the client can do things such as uploading files to the server, downloading files (taking the server's files and putting them on his own computer) from the server, and renaming, deleting files on the server, changing file permissions, etc.
Most modern operating systems support FTP.
This implies that any computer connected to a TCP/IP based network can manipulate files on another computer on that network regardless of which operating systems are involved, provided that they are open to FTP connections.
There are many existing FTP client and server programs, many of these are available free, or open source.
FTP return codes
FTP server return codes show their status by the digits within them.
A short explanation of various digits' meanings are given below:
1xx: Positive Preliminary reply.
The action requested is being initiated but there will be another reply before it begins.
2xx: Positive Completion reply.
The action requested has been completed.
The client may now issue a new command.
3xx: Positive Intermediate reply.
The command was successful, but a further command is required before the server can act upon the request.
4xx: Transient Negative Completion reply.
The command was not successful, but the client is free to try the command again as the failure is only temporary.
5xx: Permanent Negative Completion reply.
The command was not successful and the client should not attempt to repeat it again.
x0x: The failure was due to a syntax error.
x1x: This response is a reply to a request for information.
x2x: This response is a reply relating to connection information.
x3x: This response is a reply relating to accounting and authorization.
x4x: Not used.
x5x: These responses indicate the status of the Server file system vis-a-vis the requested transfer or other file system action.
FTP modes
FTP may run in active or passive mode, which determines how the data connection is established.
In both cases, the client creates a TCP control connection from a random, usually an unprivileged, port N to the FTP server command port 21.
In active mode, the client starts listening for incoming data connections from the server on port M. It sends the FTP command PORT M to inform the server on which port it is listening.
The server then initiates a data channel to the client from its port 20, the FTP server data port.
In situations where the client is behind a firewall and unable to accept incoming TCP connections, passive mode may be used.
In this mode, the client uses the control connection to send a PASV command to the server and then receives a server IP address and server port number from the server, which the client then uses to open a data connection from an arbitrary client port to the server IP address and server port number received.
File Transfer Protocol Secured (Using SSL / TLS)
SSH File Transfer Protocol (Using SSH)
FTP Servers
FileZilla Server (Windows)
Pure-FTPd (Unix)
VsFTPd (Unix)
ProFTPd (Unix)
FTP Server Online Tester Authentication, encryption, mode and connectivity.
Hypertext Transfer Protocol (often abbreviated to HTTP) is a communications protocol.
It is used to send and receive webpages and files on the internet.
It was developed by Tim Berners-Lee and is now coordinated by the W3C. HTTP version 1.1 is the most common used version today.
It is defined in RFC 2616.
HTTP works by using a user agent to connect to a server.
The user agent could be a web browser or spider.
The server must be located using a URL or URI.
This always contains http:// at the start.
It normally connects to port 80 on a computer.
A more secure version of HTTP is called HTTPS (Hypertext Transfer Protocol Secure).
This contains https:// at the beginning of the URL.
It encrypts all the information that is sent and received.
This can stop malicious users such as hackers from stealing the information and is often used on payment websites.
HTTPS uses port 443 for communication instead of port 80.
Request Message
Request line, such as GET /images/logo.gif HTTP/1.1, which requests the file logo.gif from the /images directory
Headers, such as Accept-Language: en
An optional message body
The request line and headers must all end with two characters: a carriage return followed by a line feed, often written <CR><LF>.
The empty line must consist of only <CR><LF> and no other whitespace.
In the HTTP/1.1 protocol, all headers except Host are optional.
Ethernet is a way of connecting computers together in a local area network or LAN.
It has been the most widely used method of linking computers together in LANs since the 1990s.
The basic idea of its design is that multiple computers have access to it and can send data at any time.
This is comparatively easy to engineer.
If two computers send data at the same time, a collision will occur.
When this happens, the data sent is not usable.
In general, both computers will stop sending, and wait a random amount of time, before they try again.
A special protocol was developed to deal with such problems.
It is called Carrier sense multiple access with collision detection or CSMA/CD.
Different cable types
There are different Ethernet standards.
Today, Ethernet cables look like thick telephone cables.
They connect to boxes called hubs or switches.
Each cable runs from a computer's network interface card (NIC) to such a box.
This cable is called 10BaseT or 100BaseT, or 1000BaseT Cable.
10Base2 and 10Base5: These coaxial cables are like those used in television, but thinner.
They are also called "thinnet" or "coax".
Each computer has a "T" plugged into it, and cables plug into each side of the "T".
Sometimes, instead of a "T", a vampire tap is used.
It supports 10MBits per second transfer speed.
It was the first to be adopted, and became rare during the 21st century.
10BaseT: Cables look like thick phone cables, but with 8 copper wires instead of 2 or 4, and they go from each computer' to a Hub or a Switch.
Supported speed is 10 MBit/second.
10BaseF: Same as 10BaseT, but cables transmit light pulses, instead of electrical signals.
100BaseT:  Cables look the same as 10BaseT, but can run at up to  100 MBits per second
1000BaseT: Cables look the same as 10BaseT, but can run at up to 1GBit (1000MBit) per second.
Today, the cables for 10BaseT, 100BaseT, and 1000BaseT are the same.
Their transmission medium is unshielded twisted pair for Category 5 (UTP-Cat5) or 5e.
Shielded cable (STP-Cat5 or Cat5e) can be used when there is a lot of electrical noise, and Category 6 (UTP-Cat6 or STP-Cat6) works better with faster signals such as 1GBit or 10GBit.
Different devices
Other devices, such as video game consoles, can also be connected using the same kind of cabling.
Certain computer peripherals, for example printers and certain hard disks can be directly connected to the network with such cables.
Ethernet can go at different speeds.
In the beginning, Ethernet was at 10 MBits per second.
The Ethernet most often used today is at 100 MBits per second.
Most new computers now have the NIC built in, and can go at 1GBit per second.
There are also standards for 1GBit per second and 10 GBit per second.
100 MBit can usually talk to 10 MBit, and 1 GBit can talk to 100 MBit and usually to 10 MBit (both full and half duplex).
Obesity is the condition of being much too heavy for one's height so that one's health is affected.
In other words, it means to be too overweight.
Also known as being fat.
It is considered a disease and has been described as an epidemic.
To know if a person is overweight, the body mass index (BMI) is calculated, by dividing the person's weight (in kilograms), by their height (in metres) squared (multiplied by itself). (
This is only meaningful for adults who are fully grown, and should not be used for children.
Growth charts can be used to measure obesity in children.)
A BMI between 18.5 and 25 is considered normal.
People with a BMI of 25 or more are said to be overweight; with 30 and above, they are considered obese, and with 35 and above, they are considered severely obese (this used to be called morbidly obese).
In general, the BMI number is a good quantifiable measurement of a person's obesity.
However, it is a poor predictor in people who are very athletic, because a person with a higher than average amount of muscle tissue will weigh more than an average person, thus resulting in a BMI that is higher than normal, even if that person is very large.
The most common cause for obesity is getting more calories than are used by the body.
Other factors that often contribute to obesity are:
Poor nutrition
Hormonal problems (for example, caused by hypothyroidism)
Problems with the metabolism, e.g. weight cycling (the so-called yo-yo effect)
Eating disorders (for example, binge eating disorder)
Psychological problems, like depression
Lack of sleep or sleeping problems
Lack of exercise
Genetics are known to contribute to obesity.
Low levels of leptin, a hormone, is linked to obesity.
Many health problems are associated with obesity.
An example is Type 2 diabetes.
A woman with a BMI higher than 35 is 93 times more likely to develop diabetes.
A 2009 review found that people with a BMI between 40 and 50 were 22.5 times more likely to die from diabetes than people with BMIs between 22.5 and 25.
Risk is associated with where the excess fat is stored on the body.
Abdominal obesity is particularly dangerous.
Some people think that the idea that obesity causes bad health is not completely true and has been exaggerated.
An example is J. Eric Oliver.
He wrote a book called Fat Politics: The Real Story Behind America's Obesity Epidemic.
There is evidence for this belief.
The Centers for Disease Control and Prevention said in 2003 that 400,000 people died because of being obese in 2000.
Then in 2004 they said that the number was wrong.
A 2013 review of scientific papers found that Grade 1 obesity (BMI 30-34.9) is not associated with increased deaths.
Grades 2 (BMI 35-39.9) and 3 (40+) obesity are associated with much higher rates of death.
It has been suggested that obesity is associated with mortality (death) because of mortality in Grade 2 and 3 obesity.
People with grade 2 and 3 obesity are 29% more likely to die.
'Metabolically healthy obesity' is increasingly being recognized.
Up to 40% of obese people are metabolically healthy.
They are not more likely to get heart disease or die than metabolically healthy non-obese people.
The 'obesity paradox' is a term used to describe how obesity can lower the risk of death.
Obesity increases the chance of getting heart disease.
But obese people with heart disease are less likely to die in a 7-year period.
The obesity paradox has also been found in patients with stroke, diabetes, and chronic obstructive pulmonary disease.
Scientists have not yet found a 'cure' for obesity that most people are willing to implement.
It is common wisdom that people who lose weight will regain it all within 5 years.
However, this position has been scientifically challenged for over a decade.
Additionally, modern research has achieved significantly higher success rates than the figure that dominates the popular internet.
Therefore, diet and exercise is the most common recommended treatment for obesity - it has the potential for a very high treatment success rate.
Surgery can be used to treat obesity.
Gastric bypass is the most common weight loss surgery.
It makes a person's stomach smaller so that they feel full after eating less food and causes their body to absorb less calories.
People who have surgery are usually very obese.
Some people think that obesity should not be treated at all.
This position is contradicted by substantial medical research.
Weight loss medicines can make people want to eat less or make less of the energy from food be absorbed by their bodies.
The only weight loss drug approved by the FDA for long term use is orlistat.
The U.S. Food and Drug Administration has not approved other drugs because they have side effects.
Also they are worried that people who are not obese will take them.
Societal views
In the West, people associate obesity with negative characteristics such as laziness, ugliness, stupidity, etc.
These attitudes are increasing.
Discriminating against someone because of their weight is legal in the United States.
The fat acceptance movement says that this is wrong and is a kind of prejudice called fatphobia.
In some cultures, obesity is viewed as positive.
To those cultures, obesity is associated with wealth, beauty, and fertility.
Bariatrics (the part of medicine that deals with obesity)
Physiques
Radon, a gas that is a basic chemical element
Registered nurse, a nursing specialist in the medical field
Royal Navy,
Phillips Academy (also called Andover, Phillips Andover, or  PA) is a high school for boys and girls in Andover, Massachusetts, near Boston, USA.
The school is a boarding school.
75% of the students live there.
Phillips Academy is one of the oldest private boarding schools in the United States.
Two American Presidents, George H. W. Bush and George W. Bush, went to school there.
Phillips Academy was founded during the American Revolution as an all-boys school in 1778.
George Washington's nephews went to the school, and he once spoke at an assembly while visiting.
John Hancock, the famous signer of the United States Declaration of Independence, signed the articles of incorporation.
Phillips Exeter Academy was made three years later in Exeter, New Hampshire by Samuel Phillips' uncle John.
The football teams have played against each other almost every year since 1878.
This makes their rilvalry one of the oldest high school rivalries in the country.
Paul Revere put bees, a beehive, and the sun into the school's great seal.
The school's main motto, Finis Origine Pendet, means "the end depends upon the beginning."
It is written at the bottom of the seal.
The school's second motto, Non Sibi means "not for self."
Schools in Massachusetts
1778 establishments in the United States
18th-century establishments in Massachusetts
Gluttony is a wasting of resources.
Usually it is food that is wasted.
Either one person eats too much, or the person does something so the food (or the resources) do not reach those who need it.
Greed is a desire to have more goods, or more wealth than is needed.
Christianity says that greed is one of the Seven deadly sins.
There it is listed as avarice, or in Latin avaritia.
nl:Hoofdzonde#Avaritia
"Mazurek Dąbrowskiego" in Mp3 format  (Full version)
"Mazurek Dąbrowskiego" in Mp3 format  (Instrumental version)
1797 establishments
Establishments in Poland
1790s establishments in Europe
CSA can mean the Confederate States of America.
CSA was Czechoslovak State Airlines (now called Czech Airlines)
Fornication is a word that means having sex with someone who is not your spouse.
Many Christians and Muslims believe it is sinful.
nl:Seksueel misbruik#Ontucht
Profit is how much money somebody (normally a company) makes.
This is found by subtracting how much money they have spent (expenditure) from how much money they have brought in (revenue).
If John spends $15 on some ice cream cones, and then sells them for $20, he has made a profit of $5.
This is because he made $20 but when the $15 he used to buy the ice cream cones is subtracted, what is left is $5.
In the end, he has $5 more than he had before he bought and sold the ice cream cones.
Roasting is a way of cooking.
Something gets roasted if it is put over a fire, and some is burnt.
The same effect can also be attained with a grill at a barbecue.
In different countries people like to roast different things.
People usually roast meats such as pork, beef, chicken, lamb, and duck.
The roasted meat, along with its accompanying vegetables, is often called a roast.
Most meat being roasted has to cook for a relatively long time, to ensure that it is cooked through.
Variations to this include lamb and beef, which may be left "pink" or partially uncooked towards the centre.
Other things can be roasted too.
For example, vegetables, coffee and chocolate.
Coffee and chocolate are always roasted.
Influenza, better known as the flu and sometimes called the grippe, is a common childhood illness, but is not as common among adults.
It is not limited to humans, most mammals and many birds can also catch influenza.
It is caused by several different viruses (see: RNA virus), which is why people can have the flu more than once.
The name influenza comes from , meaning "influence".
Flu transmission and symptoms
Human Influenza can pass from one person to another very easily.
It is most commonly spread by the microscopic droplets of mucus and fluid that are sent into the air when the sick person coughs or sneezes.
Symptoms include cough, sore throat, muscle aches and pains, fever, headache, and rarely vomiting and diarrhoea.
Influenza can also lead to other diseases, such as pneumonia.
This makes it especially dangerous to young children and elderly people.
Although there is no cure for  influenza, Antiviral drugs can be used to treat the illness so it is not as severe and does not last as long.
The  influenza  season runs from late fall to spring because most people catch it in the winter months.
When there are more cases of influenza than expected, it will sometimes be called an epidemic.
When there are a large number of cases of the same type of influenza all over the world, it is often called a pandemic.
Changes in the influenza virus
Small changes that happen as flu is passed from one person to another is the most common way flu viruses change.
This is the main reason that people can catch the flu every year.
The CDC keeps track of the different flu viruses that are circulating, and gives this information to the companies that make flu shots.
Since the flu changes so much from year to year, flu shots have to be given for each new flu season.
Flu shots only protect against the most common flu viruses, and every now and then a slightly different type spreads more than expected.
Usually when this happens, the existing flu shot gives some protection so that even if a person who had a flu shot catches it, they do not get as sick.
Some flu viruses are caught from animals.
Bird flu, for example, is usually only caught by people in contact with sick birds (usually chickens).
These types of flu virus are usually very limited, and while they can make a person very ill, usually other people do not catch the virus from the sick person.
Another way that the flu can change is when a person or animal catches two different flu viruses.
The two viruses can exchange some of their genetic information, which can create a brand new flu that nobody has ever caught before.
If an animal flu virus changes in this way to one that can easily pass from human to human, many people become ill because nobody has any immunity to the new virus.
Often, a brand new virus is more severe and kills more people.
New types of flu virus are usually what causes pandemics, and that is the reason many scientists have been following Bird Flu so closely—it kills six people out of every ten who catch it.
This would be a very serious problem if it changes enough to spread easily between people.
Swine flu (March/April 2009)
This new flu virus got its name because it contains genetic parts that are commonly found in flu viruses that infect pigs.
It is not spread by pigs or by eating pork—this is a new human virus being spread by humans.
The name was the 2009 flu pandemic.
CDC info on influenza
World Health Organization Fact Sheet Overview of influenza.
NHS Direct Health encyclopedia entry
Both overview and technical details on influenza viruses with emphasis on the potential H5N1 pandemic Includes details of various nonhuman influenza viruses.
Extensive and well done.
Another overview of influenza
The pancreas is an organ that makes hormones and enzymes to help digestion.
The pancreas helps break down carbohydrates, fats, and proteins.
The pancreas is behind the stomach and is on the left side of the human body.
The part of the pancreas that makes hormones is called the Islets of Langerhans.
The Islets of Langerhans are a small part (2%) of the total cells in the pancreas.
The Islets of Langerhans change which chemical they make depending on how much of other chemicals are already in the blood.
So, the pancreas works to keep the level of chemicals in balance in the body.
If the Islets of Langerhans stop working, a person will suffer from a disease called diabetes.
Doctors are experimenting with taking the Islets of Langerhans cells from a donor body and putting them into the pancreas of a person with diabetes to make that person well.
Insulin (which decreases the amount of glucose or sugar in the blood)
Glucagon (which increases the amount of glucose in the blood)
Somatostatin (which reduces production of insulin and glucagon)
Digestive enzymes
Lipase (which breaks down fats)
Amylase (which breaks down carbohydrates)
Trypsinogen and Chymotrypsin (which break down proteins)
Erepsin, which digests peptones into amino acids.
Pancreatic Cancer Info
A chloroplast is a small organelle inside the cells of plants and algae.
They absorb light to make sugar in a process called photosynthesis.
The sugar can be stored in the form of starch.
Chloroplasts contain the molecule chlorophyll, which absorbs sunlight for photosynthesis.
In addition to chlorophyll, a chloroplast uses carbon dioxide (CO2) and water (H2O) to form sugar and gives off oxygen (O2).
Chlorophyll is what gives green plants their green colour.
Chloroplasts also contain various yellow and orange pigments to assist in photon capture for photosynthesis.
Each chloroplast is surrounded by a double walled semi-permeable membrane.
These are collectively known as peristromia.
In the layered stacks are flat disk-shaped thylakoids.
They contain light-absorbing pigments, including chlorophyll and carotenoids, as well as proteins which bind the pigments.
Like mitochondria, chloroplasts also contain their own DNA and ribosomes.
Chloroplasts are one of the many different types of organelles in the cell.
They are thought to have originated as endosymbiotic cyanobacteria.
This was first suggested by Konstantin Mereschkowski in 1905 after an observation by Schimper in 1883 that chloroplasts closely resembled cyanobacteria.
Almost all chloroplasts are thought to derive directly or indirectly from a single endosymbiotic event.
Mitochondria also had a similar origin, but chloroplasts are found only in plants and protista.
In green plants, chloroplasts are surrounded by two lipid-bilayer membranes.
They are thought to correspond to the outer and inner membranes of the ancestral cyanobacterium.
Chloroplasts have their own genome, which is much smaller than that of free-living cyanobacteria.
The DNA which remains shows clear similarities with the cyanobacterial genome.
Plastids may contain 60–100 genes whereas cyanobacteria often contain more than 1500 genes.
Many of the missing genes are encoded in the nuclear genome of the host.
In some algae (such as the heterokonts), chloroplasts seem to have evolved through a secondary event of endosymbiosis, in which a eukaryotic cell engulfed a second eukaryotic cell containing chloroplasts, forming chloroplasts with three or four membrane layers.
In some cases, such secondary endosymbionts may have themselves been engulfed by still other eukaryotes, thus forming tertiary endosymbionts.
In the alga Chlorella, there is only one chloroplast, which is bell-shaped.
In some groups of mixotrophic protists such as the dinoflagellates and some sea slugs, chloroplasts are separated from a captured alga or diatom and used temporarily.
These klepto (stolen) chloroplasts may only have a lifetime of a few days and are then replaced.
Chlorophyll is a chemical in the chloroplasts of plants.
It allows plants to absorb and use light.
Energy from the light is used in photosynthesis to make glucose.
This contains lots of stored energy which the plant needs to release.
It does this through respiration.
This energy is then used when the plant grows or repairs damage.
Chlorophyll also makes the stem and leaf of the plant green.
Chlorophyll  is a green pigment in almost all plants, algae, and cyanobacteria.
It absorbs light most strongly in the blue portion of the electromagnetic spectrum, followed by the red portion.
However, it is a poor absorber of green and near-green portions of the spectrum.
Chlorophyll was first isolated in 1817.
Chlorophyll and photosynthesis
Chlorophyll molecules are arranged in and around the membranes of chloroplasts.
It serves two main functions.
The function of most chlorophyll (up to several hundred molecules per photosystem) is to absorb light and transfer that light energy to reaction centres.
These pigments are named after the wavelength (in nanometers) of their red-peak absorption maximum.
These chlorophyll pigments can be separated in a simple paper chromatography experiment.
The function of the reaction center chlorophyll is to use the energy transferred to it from the other chlorophyll pigments to undergo a specific redox reaction.
In this reaction the chlorophyll gives an electron to an electron transport chain.
This reaction is how photosynthetic organisms such as plants produce O2 gas, and is the source for practically all the O2 in Earth's atmosphere.
Photosystem I typically works in series with Photosystem II.
The electron flow produced by the reaction center chlorophyll pigments is used to shuttle H+ ions across the membrane, setting up a chemiosmotic potential used mainly to produce ATP chemical energy; and those electrons ultimately reduce NADP+ to NADPH, a universal reductant used to reduce CO2 into sugars as well as for other biosynthetic reductions.
A green sea slug, Elysia chlorotica, has been found to use the chlorophyll it has eaten to perform photosynthesis for itself.
This process is known as kleptoplasty, and no other animal has been found to have this ability.
Why green and not black?
It still is unclear exactly why plants have mostly evolved to be green.
Green plants reflect mostly green and near-green light rather than absorbing it.
Other parts of the system of photosynthesis still allow green plants to use the green light spectrum (e.g. through a light-trapping leaf structure, carotenoids, etc.).
Green plants do not use a large part of the visible spectrum as efficiently as possible.
A black plant can absorb more radiation, and this could be very useful, notwitstandanding the problems of disposing of this extra heat (e.g. some plants must close their openings, called stoma, on hot days to avoid losing too much water).
More precisely, the question becomes why the only light absorbing molecule used for power in plants is green and not simply black.
The biologist John Berman has said that evolution is not an engineering process, so it often has limits that an engineer or other designer does not.
Even if black leaves were better, evolution's limitations can prevent species from becoming as efficient as possible.
Berman wrote that achieving pigments that work better than chlorophyll could be very difficult.
In fact, all higher plants (embryophytes) are believed to have evolved from a common ancestor that is a sort of green algae – so chlorophyll has evolved only once (common ancestor).
Shil DasSarma, a microbial geneticist at the University of Maryland, has pointed out that species of archaea use another light-absorbing molecule, retinal, to get power from the green spectrum.
Some scientists believe that green-light-absorbing archae were once the most common in the earth environment.
This could have left open a "niche" for green organisms which would absorb the other wavelengths of sunlight.
This is just a possibility, and Berman wrote that scientists are still not convinced of any one explanation.
Chemical structure
Chlorophyll is a chlorin pigment, which is structurally similar to and produced through the same metabolic pathway as other porphyrin pigments such as haem.
At the center of the chlorin ring is a magnesium ion.
For the structures depicted in this article, some of the ligands attached to the Mg2+ center are omitted for clarity.
The chlorin ring can have several different side chains, usually including a long phytol chain.
There are a few different forms that occur naturally, but the most widely distributed form in terrestrial plants is chlorophyll a. The general structure of chlorophyll a was worked out by Hans Fischer in 1940.
By 1960, when most of the stereochemistry of chlorophyll a was known, Robert Burns Woodward published a total synthesis of the molecule.
In 1967, the last remaining stereochemical elucidation was completed by Ian Fleming, and in 1990 Woodward and co-authors published an updated synthesis.
In 2010, a near-infrared-light photosynthetic pigment called chlorophyll f might have been discovered in cyanobacteria and other oxygenic microorganisms that form stromatolites.
Measuring chlorophyll
Chlorophyll Content meters measure the optical absorption of a leaf to estimate its chlorophyll content.
Chlorophyll molecules absorb in the blue and red bands, but not the green and infra-red bands.
Chlorophyll content meters measure the amount of absorption at the red band to estimate the amount of chlorophyll present in the leaf.
To compensate for varying leaf thickness, Chlorophyll Meters also measure absorption at the infrared band which is not significantly affected by chlorophyll.
The chlorophyll content of leaves can be non-destructively measured using hand-held, battery-powered meters.
The measurements made by these devices are simple, quick and relatively inexpensive.
They now have large data storage capacity, averaging and graphical displays.
Spectrophotometry
In diethyl ether, chlorophyll a has approximate absorbance maxima of 428 nm and 660 nm, while chlorophyll b has approximate maxima of 453 nm and 642 nm.
The absorption peak of chlorophyll a is at 666 nm.
Biosynthesis
In Angiosperms, the last step in the synthesis of chlorophyll is light-dependent.
Such plants are pale (etiolated) if grown in the darkness.
Non-vascular plants and green algae have an additional light-independent enzyme and grow green in the darkness instead.
Chlorosis is a condition in which leaves do not make enough chlorophyll, so they become yellow.
Chlorosis can be caused by a not having enough iron—called iron chlorosis—or by not having enough magnesium or nitrogen.
Soil pH sometimes affects these kinds of chlorosis.
Many plants are adapted to grow in soils with specific pH levels and their ability to absorb nutrients from the soil can  depend on this.
Chlorosis can also be caused by pathogens including viruses, bacteria and fungal infections, or sap-sucking insects.
The oak tree is a tree or shrub in the genus Quercus.
There are about 600 living species.
The common name "oak (Oaks)" may also appear in the names of species in related genera, such as Lithocarpus.
The genus Quercus is native to the Northern Hemisphere.
It includes deciduous and evergreen species from cool temperate to tropical latitudes in Asia and the Americas.
North America has the largest number of oak species: about 90 occur in the United States.
Mexico has 160 species, of which 109 are endemic.
The second greatest center of oak diversity is China, which has about 100 species.
Oaks have spirally arranged leaves, with rounded edges in many species; some have leaves with jagged edges or entire leaves with smooth margins.
Many deciduous species do not drop dead leaves until spring.
In spring, a single oak tree produces both male flowers (as catkins) and small female flowers.
The fruit is a nut called an acorn, carried in a cup-like structure.
Each acorn has one seed (rarely two or three) and takes 6–18 months to mature, depending on species.
The so-called "live oaks" are evergreen.
They are not a taxonomic group, just a life style which occurs across the genus.
The oak is a kind of hardwood forest tree.
They are well known as a climax vegetation in the temperate zone of the northern hemisphere.
That means, left untouched by humans, it would be the dominant tree.
Much of England was covered by oak forests before modern farming took over the land.
The last extensive oak woodlands were cut down to build ships for the Royal Navy in the 18th century.
Some kinds of oak wood are very hard.
That is why people in past centuries cut them down to make ships, furniture and other things.
The wood is now scarce and expensive and only used to make a few things anymore.
Much cheaper are softwoods like pine.
Associated animals
A mature oak tree stands about 100 feet tall (~30 metres).
It is a home for more animals than any other European tree.
30 species of birds, 45 different bugs and over 200 species of moth have been found on oaks.
Beetles burrow under the bark, and some drill holes into the wood.
The leaves are eaten by many caterpillars.
Many leaves carry strange little bumps on the underside.
These are insect galls, caused by many little animals.
Midges, moths, worms and tiny wasps lay their eggs in leaves or leaf buds.
The leaf reacts by forming a growth around the eggs.
Inside the gall, larvae develop.
The leaf falls, but the larvae may come out only the next spring.
Small galls only have one larva, but larger galls may contain as many as 30 larvae.
Acorns
Oak trees produce acorns once a year which ripen in autumn.
Oak trees may start producing acorns when they are about 20 years old.
A mature oak may produce 90,000 acorns a year; this is several millions in its lifetime.
Glucose (C6H12O6 ) is a simple carbohydrate, or sugar.
It is one of several kinds of sugars.
It is important because cells in an organism use it as a source of energy.
Turning glucose into energy is called cellular respiration, which is done inside the cells of a living organism.
Excess glucose is converted to fats and are stored in adipose tissues.
Glucose is made by plants in a process called photosynthesis.
It can also be made by animals in their liver or kidneys.
Having the right amount of glucose available in a person's body is important.
Glucose is essential in the proper functioning of the brain.
It can be measured with a simple blood test.
People that do not have enough glucose have low blood sugar levels.
This is a health condition called hypoglycemia.
People with too much glucose have hyperglycemia.
They might have a health condition called diabetes.
Its chemical formula is C6H12O6.
This means it has six carbon atoms, 12 hydrogen atoms, and six oxygen atoms bonded together.
How sugars work, and how glucose can be formed, was studied by a German chemist named Emil Fischer in the 1890s.
His work earned him the 1902 Nobel Prize in Chemistry.
Isomers
There are two forms of glucose, the α- and β- forms.
The only difference between them is the position of the hydroxyl group, above and below the plane of the ring of the molecule.
Cellulose is the main chemical that forms the main structure of plants.
It is the most abundant macromolecule on Earth.
It is also a kind of fiber.
Cellulose is a very complex carbohydrate and consisting of 3,000 or more glucose units.
Cellulose was discovered by Anselme Payen in 1838.
He isolated it from plant matter and determined its chemical formula.
Cellulose is the most common organic compound on Earth.
Cellulose has no taste.
It is odorless and hydrophilic.
It is insoluble in water and most organic solvents.
It is chiral and is biodegradable.
Cellulose is made from a form of glucose and makes up most of the cell wall of plant cells.
This is what keeps a plant in shape.
Humans and other animals cannot digest cellulose but some animals such as termites and ruminants use bacteria to digest it.
It is a polysaccharide, which is repeating units of a monosaccharide joined together by a glycosidic bond by a condensation reaction, there is a by-product of water, found in plants.
It is very tough because when you join beta glucose together, they are opposite ways up, the bonds are straight, forming straight chains.
There is hydrogen bonds between the polymers.
These fibers are in bundles of about 40, called microfibrils.
Microfibrils are embedded in a hydrated network of other polysaccharides.
The cell wall is assembled in place.
The parts are made inside the cell and then assembled by enzymes associated with the cell membrane.
It is mainly used to make paper.
It is also used to make as cotton, linen, and rayon for clothes, nitrocellulose for explosives, and cellulose acetate for films.
Cellulose is used as insulation in transformers, cables, and other electrical equipment.
Microcrystalline cellulose and powdered cellulose are used as inactive fillers in drug tablets.
Cellulose derivatives are used as emulsifiers, thickeners and stabilizers in processed foods.
Cellulose can be converted into cellophane.
Cellulose is used to make water-soluble adhesives and binders such as methyl cellulose and carboxymethyl cellulose.
Wikiquote is a sister (related) project of Wikipedia.
It is one of many projects run by the Wikimedia Foundation.
Wikiquote was based on an idea by Daniel Alston and made by Brion Vibber.
The goal of the project is to produce a large reference of quotations from famous people, books, and proverbs, and to give details about them.
The project was first created in English.
However, in July 2004, more languages were added.
Some of there are:
Afrikaans language: Wikiquote
Arabic language: ويكي الاقتباس
Bulgarian language: Уикицитат
Catalan language: Viquidites
Chinese language: 維基語錄
Danish language: Wikiquote
Dutch language: Wikiquote
English language: Wikiquote
French language: Wikiquote
German language: Wikiquote
Greek language: Βικιφθέγματα
Hindi language: Wikiquote
Hebrew language: ויקיציטוט
Hungarian language: Wikidézet
Italian language: Wikiquote
Japanese language: ウィキクォート
Korean language: 위키인용집
Latin language: Vicicitatio
Malayalam language: മലയാളം Wikiquote
Marathi language: Wikiquote
Punjabi language: Wikiquote
Pushto language: Wikiquote
Persian language: ویکی‌گفتاورد
Polish language: Wikicytaty
Portuguese language: Wikiquote
Romanian language: Wikicitat
Russian language: Викицитатник
Spanish language: Wikiquote
Tamil language: விக்கி மேற்கோள்
Telugu language: వికీవ్యాఖ్య
Thai language: วิกิคำคม
Turkish language: Vikisöz
Urdu language: Wikiquote
As of May 2016, 31 versions each have more than 1,000 articles.
The largest Wikiquote is the English project with over 26,500 content pages, followed by the Italian and Polish versions, both with over 22,000 content pages.
In total, 60 languages have over 100 content pages.
It can still be read, however.
Brasília () is the capital city of Brazil.
The name is commonly spelled Brasilia in English.
The city and its Federal District are in the Central-West region of the country.
It is on a plateau known as Planalto Central.
Brasília has a population of about 2,557,000 (3,599,000 in the metropolitan area) as of the 2008 IBGE estimate.
It is the fourth largest city in Brazil.
But the Brasília metropolitan area is the sixth largest in the nation.
It is listed as a World Heritage Site.
Brasília hosts 124 foreign embassies.
Viewed from above, the main portion of the city resembles an airplane or a butterfly.
The Monumental Axis goes east-west and holds government buildings and monuments.
The other axis is curved in a north south direction.
The city is commonly referred to as Capital Federal, or simply BSB.
As the national capital, Brasília is the seat of all three branches of the Brazilian government.
The city also hosts the headquarters of many Brazilian companies.
Planning policies place residential buildings around expansive urban areas.
The plan includes large avenues.
It divides the city into sectors with different purposes, including accommodation and tourism.
The city is built around an artificial lake, Lake Paranoá.
Residents of Brasília are known as brasilienses or candangos. (
The candangos are people who moved to Brasília when the city was established).
In local usage, the word "Brasília" usually refers only to the First Administrative Region within the Distrito Federal (Federal District), where the most important government buildings are.
Brasília has a unique status in Brazil, as it is an administrative division rather than a legal municipality like nearly all cities in Brazil.
In the rest of Brazil, Brasília is almost always means the Brazilian Federal District.
There are several "satellite cities," which are also part of the Federal District.
The city was planned and developed as a new town in 1956.
Lúcio Costa was the principal urban planner and Oscar Niemeyer was the principal architect.
Roberto Burle Marx was the landscape designer.
They created the Plano Piloto de Brasília.
Brasília was built in 41 months, from 1956 to April 21, 1960.
The Brasília subway system (Metrô de Brasília) has 24 stations on two lines  long.
The subway currently covers the south half of the metropolitan area.
In 2010, a light rail line was added.