Aarushhh/wikipedia-simple-splitted huggingface dataset:
Position 
The position of an object tells you where it is. For example, if you live in New York City and your friend lives in Seattle, your friend has a position of 3,876 kilometers (2,408 miles) west from you. But your friend would say that you have a position of 3,876 kilometers (2,408 miles) east from them instead. This is because position depends on where "position zero" or the origin is. For you, the origin is in New York City, but for your friend, the origin is in Seattle. So we make sure to always say where the origin is when we talk about position.

We talk about position using vectors: we first say a distance (such as 3,000 km) and then the direction (such as east, left, or 38 degrees south). If there is no direction, position is simply distance. Position can sometimes be negative: for example, New York City is 3,876 kilometers (2,408 miles) east of Seattle and Seattle is negative 3,876 kilometers (2,408 miles) east of New York City. However, it is easier to say "west" instead of "negative east".
Velocity 
When something moves, its position changes. You may pull a book closer to you, and the book has a new position. Or, you may walk away from your house and you have a new position. The velocity of an object tells you how fast the object changes position, and where it is moving. Velocity is a vector just like position: a car can move "160 kilometers per hour west" (100 miles per hour west) or "31 miles per hour south" (50 kilometers per hour south). Since position can be negative, velocity can be negative too.

Acceleration 
When something speeds up or slows down, its velocity changes. The acceleration of an object tells you how fast the object speeds up or slows down. Acceleration is a vector, too, and we can use negative acceleration when we want to say that an object slows down: for example, if you drive your car south and slow down, your acceleration is positive going north but negative going south.

Newton's three laws
Newton's laws of motion are important to classical mechanics.  Isaac Newton discovered them.  They tell us how forces change how things move, but they do not say what causes the forces.

Newton's first law 
Newton's first law of motion says that objects do not change how they move unless something pushes or pulls them. Things that push or pull objects are called forces.
Before Isaac Newton, people thought that things do not move forever: they will always stop even if nothing touches them. On Earth, this seems correct: if you roll a ball on the grass, the ball will stop; if you push a book across a table, the book stops moving. But this does not happen everywhere. In outer space, rockets and planets move and they do not slow down or stop. So something on Earth makes objects stop moving, and this is a force called friction. Every object that touches another object feels friction. Even when you throw something like a baseball, the baseball feels friction because of the air. This is called drag or air resistance. In outer space, there is no friction because outer space is a vacuum: there are no objects there, including no air.Gravity is another force that changes how objects move on Earth, but in outer space gravity is very small unless you are close to a planet or a star.
Newton's first law of motion also tells us that an object that is not moving will stay still unless something pushes or pulls it. This makes sense because a book on your bookshelf does not suddenly fly away.

Newton's second law 
Newton's second law of motion says that bigger objects need a bigger force to change how they move, and smaller objects need a smaller force to change how they move. For example, it is easy to push a marble across the floor but it is really hard to push a car across the road. This is because the car is very heavy and the marble is not.
We sometimes write Newton's second law of motion as an equation: .  is the amount of force you need,  is the mass of the object you want to move, and  is the amount of acceleration (change of velocity) that the object gets when you try to move it. We can also write the equation as , where  is momentum and  is the way we write "change in momentum over time" using calculus. Momentum is the mass of an object times how fast it is moving (its speed): , where  is the speed. A bumblebee has a small mass, but it moves very fast so it has lots of momentum. The Earth moves very slow, but it has a large mass so it also has lots of momentum.
Newton's third law 
Newton's third law of motion says that forces always come in pairs. When you push a book, the book also pushes you, but it does not push you very far because you have a much larger mass. However, if you and your friend go ice skating and you push your friend, you and your friend both move back.
Consider a book lying on a table. The weight of book is acting on the table in the downward direction. This is action. The reaction of table act on the book in upward direction.
 
A rocket works because of Newton's third law of motion: the bottom of the rocket makes very hot gas and the gas pushes the colder air. Then the rocket goes up because the colder air also pushes the bottom of the rocket. The force that makes a rocket go up is called thrust. Birds and airplanes fly because of Newton's third law of motion: this is because both birds and airplanes push air down when they move, and the air pushes them up. This force is called lift. Without lift, birds and airplanes fall on the ground.
Kinematic Equations
In physics, kinematics is the part of classical mechanics that explains the movement of objects without looking at what causes the movement or what the movement affects.

1-Dimensional Kinematics 
1-Dimensional (1D) Kinematics are used only when an object moves in one direction: either side to side (left to right) or up and down. There are equations with can be used to solve problems that have movement in only 1 dimension or direction. These equations come from the definitions of velocity, acceleration and distance.
The first 1D kinematic equation deals with acceleration and velocity. If acceleration and velocity do not change. (Does not need include distance)
Equation: 
Vf is the final velocity.
vi is the starting or initial velocity
a is the acceleration
t is time - how long the object was accelerated for.
The second 1D kinematic equation finds the distance moved, by using the average velocity and the time. (Does not need include acceleration)
Equation: 
x is the distance moved.
Vf is the final velocity.
vi is the starting or initial velocity
t is time
The third 1D kinematic equation finds the distance travelled, while the object is accelerating. It deals with velocity, acceleration, time and distance. (Does not need include final velocity)
Equation: 
 is the final distance moved
xi is the starting or initial distance
vi is the starting or initial velocity
a is the acceleration
t is time
t is time
The fourth 1D kinematic equation finds the final velocity by using the initial velocity, acceleration and distance travelled. (Does not need include time)
Equation: 
Vf is the final velocity
vi is the starting or initial velocity
a is the acceleration
x is the distance moved
2-Dimensional Kinematics
2-Dimensional kinematics is used when motion happens in both the x-direction (left to right) and the y-direction (up and down). There are also equations for this type of kinematics. However, there are different equations for the x-direction and different equations for the y-direction. Galileo proved that the velocity in the x-direction does not change through the whole run. However, the y-direction is affected by the force of gravity, so the y-velocity does change during the run.

X-Direction Equations
Left and Right movement
The first x-direction equation is the only one that is needed to solve problems, because the velocity in the x-direction stays the same.
Equation: 
X is the distance moved in the x-direction
Vx is the velocity in the x-direction
t is time
Y-Direction Equations
Up and Down movement. Affected by gravity or other external acceleration
 The first y-direction equation is almost the same as the first 1-Dimensional kinematic equation except it deals with the changing y-velocity. It deals with a freely falling body while its being affected by gravity. (Distance is not needed)
Equation: 
Vfy is the final y-velocity
viy is the starting or initial y-velocity
g is the acceleration because of gravity which is 9.8  or 32 
t is time
The second y-direction equation is used when the object is being affected by a separate acceleration, not by gravity. In this case, the y-component of the acceleration vector is needed. (Distance is not needed)
Equation: 
Vfy is the final y-velocity
viy is the starting or initial y-velocity
ay is the y-component of the acceleration vector
t is the time
t is the time
The third y-direction equation finds the distance moved in the y-direction by using the average y-velocity and the time. (Does not need acceleration of gravity or external acceration)
Equation: 
Xy is the distance moved in the y-direction
Vfy is the final y-velocity
viy is the starting or initial y-velocity
t is the time
 The fourth y-direction equation deals with the distance moved in the y-direction while being affected by gravity. (Does not need final y-velocity)
Equation: 
 is the final distance moved in the y-direction
xiy is the starting or initial distance in the y-direction
viy is the starting or initial velocity in the y-direction
g is the acceleration of gravity which is 9.8  or 32 
t is time
The fifth y-direction equation deals with the distance moved in the y-direction while being affected by a different acceleration other than gravity. (Does not need final y-velocity)
Equation: 
 is the final distance moved in the y-direction
xiy is the starting or initial distance in the y-direction
viy is the starting or initial velocity in the y-direction
ay is the y-component of the acceleration vector
t is time
The sixth y-direction equation finds the final y-velocity while it is being affected by gravity over a certain distance. (Does not need time)
Equation: 
Vfy is the final velocity in the y-direction
Viy is the starting or initial velocity in the y-direction
g is the acceleration of gravity which is 9.8  or 32 
xy is the total distance moved in the y-direction
The seventh y-direction equation finds the final y-velocity while it is being affected by an acceleration other than gravity over a certain distance. (Does not need time)
Equation: 
Vfy is the final velocity in the y-direction
Viy is the starting or initial velocity in the y-direction
ay is the y-component of the acceleration vector
xy is the total distance moved in the y-direction
Related pages
Dynamics
Newton's laws of motion

Other websites 
Science aid: Newton's laws of motion
 The Engineering Wiki's shorter page: Newton's laws of motion - engineers may improve it!
 Newtonian Physics  - an on-line textbook
 Newtonian attraction for three Planets (Mathcad Application Server)
 Gravity - Newton's Law for Kids
  On Line Study Guide-study guide for high school students

Mechanics
References
Grant McCall (1995). "Rapanui (Easter Island) ." Pacific Islands Year Book 17th Edition. Fiji Times. Retrieved August 8, 2005.
Thor Heyerdahl, Arne Skjølsvold, and Pavel Pavel  The "Walking" Moai of Easter Island. Retrieved August 8, 2005.
Kathy Pelta (2001). Rediscovering Easter Island. North Minneapolis, USA:Lerner Publications. .
Rupert Matthews (1988). Ancient Mysteries. East Sussex, England:Wayland. .

Other websites 

Unofficial Easter Island Homepage 
PBS NOVA: Secrets of Easter Island
PBS NOVA: Secrets of Lost Empires: Easter Island
 How to make Walking Moai: A hypothesis about transportation method on Easter island

Statues
Easter Island
2nd millennium works
Diogenes of Sinope (or Diogenes the Cynic) was an Ancient Greek philosopher. He was born in the town of Sinope (now called Sinop, Turkey) around the year 412 BC and died in the city of Corinth, Greece on the year 323 BC.

After being exiled for debasing the currency, he moved to Athens.  He had a simple life-style and behaviour. This gave him a basis to criticize the social values and institutions of the corrupt, confused society he saw around him.

Diogenes made a virtue of poverty. He begged for a living and often slept in a large ceramic jar in the marketplace. He became notorious for his philosophical stunts. He used to carry a lamp during the day, and claimed he was looking for an honest man.

He criticized Plato, disputed his interpretation of Socrates. He sabotaged Plato's lectures, distracting attenders by bringing food and eating during the discussions. Diogenes was also noted for having publicly mocked Alexander the Great.
Diogenes helped Antisthenes create cynicism, a philosophy that focuses on living a simple life without the need for money, fame, power, or possessions. He also made a notion of "cosmopolitan" on world citizenship first time in history.

Diogenes was captured by pirates and sold into slavery. Eventually he settled in Corinth. There he explained cynicism to Crates, who taught it to Zeno of Citium. Zeno worked on  stoicism, which became one of the main schools of Greek philosophy.

None of Diogenes' writings have survived, but there are some details of his life from anecdotes. The anecdotes come from Diogenes Laërtius' book Lives and Opinions of Eminent Philosophers and some other sources.

References 

Ancient Greek philosophers
323 BC deaths
Simple living
A vaccination is a treatment which makes the body stronger against an infection.

The body fights infections using the immune system, which is made up of millions upon millions of cells including T cells and B cells. An important part of the adaptive immune system is that it is much stronger when fighting a disease that it has already fought against before. Vaccination involves showing the immune system something which looks very similar to a particular virus or bacteria, which helps the immune system be stronger when it is fighting against the real infection.

The  World Health Organisation estimates that vaccines save 4-5 million lives per year.

Vaccination versus immunization
Another word used for vaccines is immunization. These words mean things that are a little different. Vaccination is when a person is given something to make the immune system learn to fight an infectious disease.
Immunization is when a person's immune system learns to fight an infection. Immunization can happen from vaccination. But immunization can also happen from getting the infection. For example, a person can be immune to hepatitis B if he gets sick with hepatitis B. After a person gets hepatitis B and then gets well, he is immunized from getting it again. A person can also be immunized from hepatitis B by taking the hepatitis B vaccination.

So vaccination and immunization have meanings that are a little different. But when people say these words, they usually mean the same thing.

Herd immunity
Herd immunity 

Herd immunity is an important part of how vaccines work. A herd is a group of animals. Herd immunity happens when most of the animals in a group are immune to an infection. If most animals are immune they cannot get the disease. If they do not get the disease, they cannot give it to other animals. So even one animal who is not immune is safer. If none of the other animals in a herd get the infection, they cannot give the infection to the one who is non immune.

This is important in people too. If 95% of people in a place are immune to a disease, the other 5% are safer. They are not near infected people, so they won't get infected.
The people who are in the 5% are there for many reasons. Some got the vaccine but did not react to it. Their immune system did not learn how to fight it well. Some of them are too sick to get the vaccine. It can be children who are too sick with other diseases to get vaccines. It can be a pregnant woman who cannot get the vaccine because it could hurt her baby. It can be a person with cancer who does not have a strong immune system. It can be an older person who has a weak immune system.

So if everyone in a place gets vaccinated, it protects these people too. If they are not protected by herd immunity, they can get more sick from an infection. They get the infection more easily and they get sicker from it. So it is important that people who are healthy get their vaccinations. It protects the healthy people. But it also is important to protect other people who are old, weak, or sick.

Types of vaccines
Types of vaccines 

There are different types of vaccines:
 Inactivated vaccines contain particles (usually viruses). These have been grown for the purpose. They have been killed, using formaldehyde or by other means. But the virus still looks intact; the immune system can develop antibodies against it.
 Attenuated vaccines contain live viruses, that have been weakened. They will reproduce, but very slowly, making it an "easy win" for the immune system. Such vaccines cannot be used on patients with a severely weakened immune system, such as those with AIDS, as they are unable to defeat even this very weak virus. 
 Subunit vaccines show antigens to the immune system, without introducing virus material.

There are various other methods. All aim to develop the immune response without allowing the full viral infection to happen.
Delivery 
In England the School Age Immunisation Services deliver vaccinations in schools  every Autumn for Human Papilloma Virus, Diphtheria, Tetanus and Polio, Meningococcal ACWY , Measles, Mumps and Rubella  and Flu.

Safety of vaccination 
Today in modern countries almost all people are vaccinated, which has caused many serious diseases to become rare. However, some people argue against vaccination, as they are worried about possible side effects from the vaccination.

Vaccinations do have some side effects. These include swelling and redness around the injection site, a sore arm, or fever. These effects are because of the immune system fighting with the viruses or bacteria which have been injected. Very rarely, the immune system overreacts so much to the virus that the immune system damages other areas in the body.
As well as these real side effects of vaccinations, some people believe that vaccines cause other serious problems like autism, brain damage, or diabetes. There is no evidence for this. Almost all doctors and scientists believe that vaccination does not cause any of these things.

Overall, the vast majority of medical professionals and scientists believe that vaccinations are a good thing and that the benefits of avoiding diseases are far greater than the very small risk of side effects. All medical organizations around the world, including the World Health Organization(WHO), the American Medical Association, the American Academy of Pediatrics, and the United States Centers for Disease Control support vaccination.

Origin 
The word "vaccine" was created by Edward Jenner. The word comes from the Latin word vacca, meaning cow. A virus that mainly affects cows (Cowpox) was used in the first scientific demonstration that giving a person one virus could protect against a related and more dangerous one.
History of vaccination 

The first vaccination ever was for smallpox. The earliest hints of the practice of inoculation for smallpox in China come during the 10th century.

In 1796 an English doctor, Edward Jenner, noticed something. He saw that people who got cowpox did not get sick from smallpox. He gave a young boy the cowpox virus to protect him from smallpox. This was done by scratching liquid from cowpox sores into the boy's skin. This same method using the liquid from sores was also used to give people smallpox. People did this so they might get smallpox on one place on their bodies. Then they could pick which body part got scars from smallpox. But sometimes people who did this got very sick from smallpox. Some even died. This was a dangerous thing to do. But people did it because it was less dangerous than getting smallpox.
Edward Jenner gave the boy cowpox in the same way people tried to give smallpox. Six weeks later, he scratched smallpox into the boy's skin. The boy did not get sick from smallpox. This boy was the first person ever to get a vaccination.

It was not until almost 100 years after the smallpox vaccination that the next vaccine for cholera was found in 1879. After that, vaccines for many types of infectious diseases became available.

References

Other websites 
 World Health Organization about vaccines 
 Sabin Vaccine Institute
 Jenner Institute for Vaccine Research 
 Walter Reed National Vaccine Healthcare Centers Network (US) 
 American Academy of Pediatrics Vaccine Information 
 Vaccination -Citizendium 

Immunization
The vice president of the United States (often referred to as VP or VPOTUS) is the second highest executive officer of the federal government of the United States, after the president. The vice president ranks first in the presidential line of succession and is also the officer of the legislative branch and the president of the Senate and the presiding officer of the Senate.

Kamala Harris is the 49th and current vice president of the United States, in office since January 2021.

Eligibility and requirements 
Article II, Section 1, Clause 5 of the constitution states for a person to serve as vice president must:

 be a natural-born citizen of the United States.
 be at least thirty-five years old.
 be a permanent resident in the United States for at least fourteen years.
Election process 
The vice president is indirectly elected by the people through the Electoral College to a four-year term, along with the presidential candidate or the incumbent president of the United States as their running mate. The presidential candidate or incumbent president must have at least 270 electoral college votes in order to win the election.

Vice President-elect of the United States 
The vice president-elect of the United States is the candidate who has won the United States presidential election along with the presidential candidate and is awaiting inauguration to become the vice president.

Inauguration 
The president elect, vice president-elect, or incumbent president and vice president immediately began their four-year team on inauguration day every four years on January 20. The original inauguration date was held on March 4, but was later changed in 1933.
Presidential line of succession 
The vice president ranks first in the presidential line of succession, if the president dies, resigns, or is impeached. Only eight vice presidents have succeeded the president in resignation or death such as, John Tyler, Millard Fillmore, Andrew Johnson, Chester A. Arthur, Theodore Roosevelt, Calvin Coolidge, Harry S. Truman, Lyndon B. Johnson, and Gerald Ford. 

Although it's unclear who succeeds the vice president in resignation, death or impeachment, but the speaker of the house might rank in the succession.

John C. Calhoun and Spiro Agnew are the only U.S. vice presidents to have resigned from office.
Office of the Vice President 
The Office of the Vice President includes personnel staff who directly support or advise the vice president of the United States. It is primarily office is in the Eisenhower Executive Office Building with offices for the vice president also in the West Wing of the White House, the United States Capitol, and in the vice president's official residence.

Travel and Transportation 

Although any U.S. Air Force aircraft the vice president is aboard is referred to as "Air Force Two", during of the flight. In-country trips are typically handled with just one of the two planes, while overseas trips are handled with both.

Residence 

Number One Observatory Circle is the official residence of the vice president and the second family. It has been the official residence of every U.S. vice president since Nelson Rockefeller in 1974.

Protection 

The United States Secret Service is in charge of protecting the vice president and the second family at all times.
Living former vice presidents of the United States
As of 2023, there are only five living former vice presidents. 

The most recent former vice president to die was Walter Mondale (1977–1981) on April 19, 2021 at the age of 93.

References 

Government of the United States
Richard Bruce "Dick" Cheney (born January 30, 1941) is an American politician and businessman. He was the 46th vice president of the United States from 2001 to 2009. As a Republican, he ran in the 2000 United States presidential election with George W. Bush, and successfully won re-election in the 2004 United States presidential election. Before he became vice president, he was the Secretary of Defense from 1989 to 1993, during George H. W. Bush's presidency. He was also a member of the House of Representatives from 1979 to 1989, and was White House chief of staff from 1975 to 1977.

Early life
Cheney was born at Bryan Medical Center East Campus in Lincoln, Nebraska to Richard Cheney and Marjorie Cheney. Cheney grew up in Casper, Wyoming.

Political career
Dick Cheney was the former representative for Wyoming's At-large congressional district. He served in the George H. W. Bush administration from 1989 to 1993 as a cabinet member. He was a Congressman, and White House Chief of Staff.
Business career
He was also in charge of a large defense company called Halliburton when he was out of office during the Clinton presidency.

Vice presidency (2001–2009)
As Vice President, Cheney was the head of the Senate and cast six tie-breaking votes and he was replaced by Joe Biden as vice president on January 20, 2009.

Personal life
Cheney lives in Wyoming. He is an active hunter. In 2006, he shot a friend by mistake while hunting. He did not run for president in 2008. He has criticized President Barack Obama. His wife Lynne Cheney is a distant cousin of President Barack Obama and he is an 8th cousin of President Barack Obama. He is a 9th cousin, once removed of George W. Bush. Cheney is distantly related to Harry S. Truman and Robert Duvall by the Duvall family. He is distantly related to American Express founder Benjamin Pierce Cheney.

Health
On March 24, 2012, Cheney underwent a seven-hour heart transplant process. Cheney has had several heart attacks.
Family
Dick and Lynne Cheney have 2 daughters, Elizabeth and Mary. Mary is openly lesbian and Dick supports same sex marriage along with Mary. Liz is the Congresswoman at-large from Wyoming in the United States House of Representatives.

References

Other websites

 US Department of State from the Internet Archive
  The New York Times — Dick Cheney archives
 Vice Presidential Debate, October 5, 2004: Transcript text, Audio and Video (RealPlayer or MPG format)

1941 births
Living people
Businesspeople from Nebraska
American Methodists
Organ transplant recipients
People from Lincoln, Nebraska
Politicians from Nebraska
United States representatives from Wyoming
United States Secretaries of Defense
Republican Party (United States) politicians
White House Chiefs of Staff
21st-century American politicians
20th-century American politicians
Recipients of the Order of the Rising Sun
Businesspeople from Wyoming
Toad the Wet Sprocket is an American alternative rock band from California. They formed in 1986, while they were in high school. Their name comes from a monologue (one person doing all the talking) performed by Eric Idle, called "Rock Notes" on the 1980 album, Monty Python's Contractual Obligation Album.

American rock bands
Musical groups from California
Santa Barbara, California
Musical groups established in 1986
1986 establishments in the United States
1980s establishments in California
Musical groups disestablished in 1998
1998 disestablishments in the United States
1990s disestablishments in California
Musical groups established in 2002
2002 establishments in the United States
2000s establishments in California
Boyz II Men is an American boy band from Philadelphia, Pennsylvania. They were popular in the early 1990s. Founded in 1988 as a quintet (group of five people), Boyz II Men found fame as a quartet (group of four), with members Nathan Morris, Michael McCary, Shawn Stockman, and Wanya Morris, on Motown Records during the early 1990s.

Based on sales, Boyz II Men is the most successful R&B male vocal group of all time. It has recorded five #1 R&B hits between 1992 and 1997 and has since sold more than 90 million albums and 50 million singles. Three of its #1 hits, "End of the Road", "I'll Make Love to You", and "One Sweet Day" (with Mariah Carey), set and broke records for the longest period of time a single remained at #1 on the Billboard Hot 100.

1988 establishments in the United States
 
African-American musical groups
American boy bands
American R&B bands
Musical groups established in 1988
Musical groups from Philadelphia
1980s establishments in Pennsylvania
John Lester "Johnny" Nash Jr. (August 19, 1940 – October 6, 2020) was an American reggae and soul singer. His best known singles were "I Can See Clearly Now", "Hold Me Tight" and "Tears on My Pillow".

Career
His biggest hit was "I Can See Clearly Now" in 1972.
On June 25, 2019, The New York Times listed Johnny Nash among hundreds of artists whose material was reportedly destroyed in the 2008 Universal fire.

Personal life
Nash was born in Houston, Texas. He died on October 6, 2020 in Houston at the age of 80.

References

Other websites

1940 births
2020 deaths
American soul singers
American composers
American singer-songwriters
Musicians from Houston
Writers from Houston
Actors from Houston
Singers from Houston
American reggae musicians
Linda Ronstadt (born July 15, 1946) is an American singer. She was born in Tucson, Arizona. She has won ten Grammy Awards and many other awards.

Ronstadt has never been married. She has an adopted daughter and adopted son. She has been diagnosed with Parkinson's disease. Her autobiography was published in 2013.

Related pages
List of country musicians from Arizona

References

1946 births
Living people
20th-century American actors
21st-century American actors
20th-century American composers
21st-century American composers
20th-century American singers
21st-century American singers
American actors
American pop singers
American rock singers
American television actors
Country musicians from Arizona
Mexican singers
Mexican television actors
People with Parkinson's disease
Singers from Tucson, Arizona
 
Kennedy Center honorees
Grammy Award winners
Latin Grammy Award winners
The heart is an organ found in every vertebrate. It is a very strong muscle. It is on the left side of the body in humans and is about the size of a fist. It pumps blood throughout the body. It has regular contractions, or when the heart squeezes the blood out into other parts of the body. 

Cardiac and cardio both mean "about the heart", so if something has the prefix cardio or cardiac, it has something to do with the heart.

Myocardium means the heart muscle: 'myo' is from the Greek word for muscle - 'mys', cardium is from the Greek word for heart - 'kardia'.

Structure 
The human heart has four chambers or closed spaces. Some animals have only two or three chambers.
In humans, the four chambers are two atria and two ventricles. Atria is talking about two chambers; atrium is talking about one chamber. There is a right atrium and right ventricle. These get blood that comes to the heart. They pump this blood to the lungs. In the lungs blood picks up oxygen and drops carbon dioxide. Blood from the lungs goes to the left atrium and ventricle. The left atrium and ventricle send the blood out to the body. The left ventricle works six times harder than the right ventricle because it carries oxygenated blood. 

Blood is carried in blood vessels. These are arteries and veins. Blood going to the heart is carried in veins. Blood going away from the heart is carried in arteries. The main artery going out of the right ventricle is the pulmonary artery. (Pulmonary means about lungs.) The main artery going out of the left ventricle is the aorta.
The veins going into the right atrium are the superior vena cava and inferior vena cava. These bring blood from the body to the right heart. The veins going into the left atrium are the pulmonary veins. These bring blood from the lungs to the left heart.

When the blood goes from the atria to the ventricles it goes through heart valves. When blood goes out of the ventricles it goes through valves. The valves make sure that blood only goes one way in or out.

The four valves of the heart are:
 Atria to ventricle valves
 Tricuspid valve – blood goes from right atrium to right ventricle
 Mitral valve – blood goes from left atrium to left ventricle
 Ventricles to arteries
 Pulmonic valve – blood goes out of the right ventricle to the lungs (through the pulmonic artery)
 Aortic valve – blood goes out of the left ventricle to the body (through the aorta)
The heart has three layers. The outer covering is the pericardium. This is a tough sack that surrounds the heart. The middle layer is the myocardium. This is the heart muscle. The inner layer is the endocardium. This is the thin smooth lining of the chambers of the heart.

Cardiac cycle 

A heart beat is when the heart muscle contracts. This means the heart pushes in and this makes the chambers smaller. This pushes blood out of the heart and into the blood vessels. After the heart contracts and pushes in, the muscle relaxes or stops pushing in. The chambers get bigger and blood coming back to the heart fills them.
When the heart muscle contracts (pushes in) it is called systole. When the heart muscle relaxes (stops pushing in), this is called diastole. Both atria do systole together. Both ventricles do systole together. But the atria do systole before the ventricles. Even though the atrial systole comes before ventricular systole, all four chambers do diastole at the same time. This is called cardiac diastole

The order is: atrial systole → ventricular systole → cardiac diastole. When this happens one time, it is called a cardiac cycle.
Heart's pacemaker 
Systole (when the heart squeezes) happens because the muscle cells of the heart gets smaller in size. When they get smaller we also say they contract. Electricity going through the heart makes the cells contract. The electricity starts in the sino-atrial node (acronym SA Node) The SA Node is a group of cells called pacemaker cells in the right atria. These cells start an electrical impulse. This electrical impulse sets the rate and timing at which all cardiac muscle cells contract. This motion is called 'atrial systole'. Once electrical impulse goes through the atrio-ventricular node (AV Node). The AV Node makes the impulse slow down. Slowing down makes the electrical impulses get to the ventricles later. That is what makes the ventricular systole occur after atrial systole, and lets all the blood leave the atria before ventricle contracts (meaning squeeze).
After the electrical impulse goes through the AV Node, the electrical impulse will go through the conduction system of the ventricle. Conduction means heat or electricity traveling through something. This brings the electrical impulse to the ventricles. The first part of the conduction system is the bundle of His. His is named for the doctor (Wilhelm His, Jr) who discovered it. Bundle means strings or wires grouped together in parallel. Once the bundle (meaning a group of strings or wires going in parallel directions) goes through the ventricle muscle, it divides into two bundle branches, the left bundle branch and the right bundle branch. The left bundle branch travels to the left ventricle and the right bundle branch travels to the right ventricle. At the end of the bundle branches, the electrical impulse goes into the ventricular muscle through the Purkinje Fibers. This is what makes ventricle contraction take place and makes ventricular systole.
The order is:
Sino-Atrial Node → Atria (systole) → Atrio-Ventricular Node → Bundle of His → Bundle branches → Purkinje Fibers → Ventricles (systole)

ECG 
ECG is an acronym for ElectroCardioGram. It is also written EKG for ElectroKardioGram in German. The ECG shows what the electricity in the heart is doing. An ECG is done by putting electrodes on a person's skin. The electrodes see the electricity going through the heart. This is written on paper by a machine. This writing on the paper is the ECG.

Doctors learn about the person's heart by looking at the ECG. The ECG shows some diseases of the heart like heart attacks or problems with the rhythm of the heart (how the electricity goes through the heart's conduction system.)
The ECG shows atrial systole. This is called a P-wave. Then ventricular systole happens. This is called the QRS or QRS-complex. It is called a complex because there are three different waves in it. The Q-wave, R-wave, and S-wave. Then the ECG shows ventricular diastole. This is called the T-wave. Atrial diastole happens then too. But it is not seen separate from ventricular diastole.

The PR-Interval is the space between atrial systole (P) and ventricular systole (QRS). The QT-Interval is from when the QRS starts to when the T ends. The ST-segment is the space between the QRS and T.

References

Other websites

Symptoms of heart disease
What is the heart? - NIH
The gross physiology of the cardiovascular system (2nd Ed., 2012) – Robert M. Anderson, M.D. (CC-BY-NC)
Atlas of human cardiac anatomy
" healthy heart  " Blog
Basic English 850 words
 
Anatomy of the cardiovascular system
Types of heart disease
The three most common types of acquired heart disease are:
 Coronary Artery Disease (acronym CAD) – This is a problem with the blood vessels that deliver blood to the heart muscle. If these blood vessels get very small, or if they become blocked, blood cannot flow through them normally. Since less blood is supplied to the heart muscle, the muscle cannot work at normal capacity. The heart muscle can become sick and weak. Heart muscle can even die if blood flow stops. Blocked arteries in the heart are often caused by smoking, high cholesterol, high blood pressure, diabetes, and inherited traits from parents. All of these problems damage the lining of the heart's blood vessels and make them become narrowed or blocked completely.
Congestive Heart Failure (CHF) – This is a condition that means that the heart is not pumping at normal levels. Two common causes are a weak or sick heart muscle and abnormal heart valves. The valves may not let enough blood through because they are too narrowed. Or the valve may "leak" and let blood flow backwards (the wrong direction) inside the heart. When the heart valves do not work normally, the heart muscle has to do extra work and it can become tired.
 Bad Heart Rhythms – This is a problem with electrical activity in the heart. This can make the heart beat too fast or too slow. Very bad heart rhythms may make the heart stop pumping blood. The heart needs a normal rhythm to pump the blood well. If the rhythm is too fast, the heart may not have time for blood to enter the chambers, so there is not enough blood moving through the heart with each beat. If the heart is too slow, there may not be enough contractions of the heart to supply the body with the blood that it needs.
Symptoms
A person can have heart disease and not feel sick. Some people with heart disease have symptoms. This is when there are changes or pain in the body to show a disease is there. Some symptoms of heart disease are:
 Pain in the chest—the heart muscle is not getting enough flow to keep it going.
 Trouble breathing—blood may back up into the lungs.
 Palpitations (a feeling that the heart is beating too fast, too hard, or not regularly).
 Swelling of feet or legs—blood is backing up from the heart into the lower body.
 Feeling weak because the body and brain are not getting enough blood to supply them with oxygen.
 Cyanosis (skin turning a blue colour) means that too little oxygen is in the bloodstream to supply the cells in the body.
Deaths
Heart disease is the biggest killer of both men and women in the United States, England, Wales, and Canada. For example, heart disease causes 4 out of every 10 deaths in the United States. This is more than all kinds of cancer put together. Also, one person dies of heart disease about every minute in the United States alone.
Congenital heart disease
Congenital heart disease refers to a form of heart problem that starts before birth (congenital). Congenital heart disease includes a large number of conditions. The formation of the heart before birth is very complex and is sometimes abnormal. For example, if a part of the main artery that comes from the heart is narrowed, that is called coarctation of the aorta. There may be holes inside the heart which keep the blood from flowing normally inside the heart. Other congenital heart problems are caused by abnormal heart valves. In some cases, congenital heart problems are discovered at birth. Other times the problems may not be detected until the person is older.

Other websites
 Mayo Clinic 
 WebMD Heart Disease 
 Freedom Years Heart Disease  
 American Heart Association 
 Understanding Heart Disease: Causes, Symptoms, Diagnosis, Treatment, and Prevention
North Dakota is a state in the United States. About 780,000 people lived in North Dakota in the year 2020.  The capital and seat of government is Bismarck and the largest city is Fargo.

Geography 
North Dakota is south of Manitoba and Saskatchewan, east of Montana, north of South Dakota, and west of Minnesota.  Manitoba and Saskatchewan are provinces - part of Canada.  Montana, South Dakota, and Minnesota are other states in the United States.

Weather 
North Dakota is not close to any big bodies of water (oceans or seas). Because of this, temperatures in North Dakota are very hot in the summer and very cold in the winter. In the summer, there are sometimes strong thunderstorms. These storms can have tornadoes and hail.

History 

Before European people came, Native American people lived in the area now called North Dakota. One important tribe was the Mandan.
North Dakota was one of the last US states to be settled by people of European ancestry. (To have people go there to make homes and live.) On November 2, 1889, North Dakota (and South Dakota) became part of the United States.

Economy 
Most of the economy is based on agriculture. The most important agricultural crops are durum, a type of wheat, which is grown all across the state.  In the Red River Valley, there is more rain, and maize (corn) and sugar beets are grown as well.  In the Badlands, there is less rain, and more cattle are raised than crops.

North Dakota has the only bank in the United States that is owned by the state. The Bank of North Dakota is where all of the money from all government agencies is held. Most banks in the United States are guaranteed by the FDIC (acronym for Federal Deposit Insurance Corporation.) The FDIC guarantees that people will not lose money if a bank fails. But the Bank of North Dakota is insured by the state of North Dakota.
Related pages
 Colleges and universities in North Dakota
 List of counties in North Dakota

References 

 
1889 establishments in the United States
LGBT is an initialism that means lesbian, gay, bisexual, and transgender. It refers to the a community of people who are not heterosexual, which means to be attracted to the other gender, or cisgender, which means to identify as the gender you were born as.  It has been taken up by many sexuality and gender identity-related community centers.

History 
Before the "sexual revolution" of the 1960s, there was no neutral word or group of words for people who were not heterosexual. 

The word "homosexual"  started being used in America to describe sexual orientations that were not heterosexual. However, this word began to have bad connotations, as many people thought that it sounded like a condition or mental illness, and therefore the word "homophile" was used instead. After that, the word "gay" replaced the word "homophile" in the 1970s.
As lesbians became more public about their sexuality in the 1970s, the group of words "gay and lesbian" was often used, and a phase of lesbian feminism started. This meant that certain lesbian feminist groups separated because did not have knowledge of if they should put feminism or LGBT rights first.

Lesbian feminists viewed the separation between "butch" and "femme" in mainstream gay (male) culture of the time in the same way that they viewed the separation in society over gender roles between men and women. They saw these ideas as patriarchal and did not want to join the mainstream gay rights movement because of what they saw as the chauvinism of gay men, and refused to take up their cause. Many lesbians who were not lesbian feminists saw this as not giving help to the gay rights movement.
This was followed by many bisexual and transgender people wanting to be seen as respected groups in the LGBT community. Before gender reassignment surgery was massively improved in later years, transgender people had a hard time being accepted. Still, they fought for their rights, and were greatly boosted when plastic surgery and hormone surgery helped them to be accepted as the gender they identify with. 

After the Stonewall riots, there was a change in points of view among the gay and lesbian community. Many gays and lesbians became less accepting of bisexual and transgender persons in general. Many gays and lesbians thought that transgender people were acting out stereotypes and that bisexuals were actually gay, but in too much fear to "come out of the closet". This separation still exists today, and it only became common to speak of all members of the LGBT community with equal respect in the trouble for LGBT rights in the late 1990s.
Acceptance of LGBT people 
Some people who are LGBT may not "come out", as they may be a target of discrimination or prejudice, such as homophobia or transphobia. Many countries have discriminatory laws against LGBT people, some even giving out the death penalty for being gay or bisexual.

Different forms of the acronym

Shortening of the term 
When not including transgender persons in general, the acronym is sometimes shortened to just "LGB".

Other letters
Other letters 

Many other letters are added to the acronym, so much so that it has been described as an "alphabet soup" by some. A few of the other letters added are:
 Queer or Questioning—added to the acronym to make it more inclusive.
 Intersex—recorded use in the acronym since 1999. (This acronym is used in all parts of "The Activist's Guide" of the Yogyakarta Principles in Action.)
 Asexual, Aromantic or Agender
 Polyamorous or Pansexual— however, "pansexual" is often thought of as being a category of "bisexuality", as well as the terms "omnisexual" and "fluid".
 Hijra—the acronym LGBTIH has seen use in India, in order to join the traditional Indian hijra third gender identity and the related subculture.
 Non-binary
 Demisexual

Not everyone is in agreement what should or should not be covered in the acronym, or which order the letters should go in.
Different terms 
The group of words gender and sexual diversity (GSD) has been shown as a different option to LGBT by some, as it is seen as more inclusive and less limiting.

SGL (same-gender loving) is sometimes used among gay male African Americans as a way of distinguishing themselves from what they think of as white LGBT groups of persons.

MSM (men who have sex with men) is used to describe men who have sex with other men without having relation to their sexual orientation, often in a medical context.

WSW (women who have sex with women) is the opposite of MSM. It includes all women who have sex with women.

AMAB (assigned male at birth) is used to describe people who were assigned the male sex at birth.

AFAB (assigned female at birth) is used to describe people who were assigned the female sex at birth.