the-french-artist/wikipedia_20220301.simple_sentence_split huggingface dataset:
In mammals under normal conditions most of the lymph is returned to the blood stream through lymph-vein communications at the base of the neck.
Some vertebrates have more complex lymphatic systems.
Amphibians for example have multiple "lymph hearts" to control the flow of lymph.
Chastity is the sexual behavior of a man or woman which is right and proper according to the moral rules of a culture or religion.
It has recently begun to mean sexual abstinence (not having sex at all), especially before marriage.
However, it can also be used for all kinds of people (even married people) with more meaning than simply not having sex.
The word chastity came from the Latin word castitatem, meaning "purity".
Catechism of the Catholic Church (III.2.I)
Early Shaker Writings Relating to Sexual Abstinence
A metallic bond is the sharing of many detached electrons between many positive ions, where the electrons act as a "glue" giving the substance a definite structure.
It is unlike covalent or ionic bonding.
Metals have low ionization energy.
Therefore, the valence electrons can be delocalized throughout the metals.
Delocalized electrons are not associated with a particular nucleus of metal, instead, they are free to move throughout the whole crystalline structure forming a "sea" of electrons.
The electrons and the positive ions in the metal have a strong attractive force between them.
Therefore, metals often have high melting or boiling points.
The principle is similar to that of ionic bonds.
Because the electrons move freely, the metal has some electrical conductivity.
It allows the energy to pass quickly through the electrons, generating an electric current.
Metals conduct heat for the same reason: the free electrons can transfer the energy at a faster rate than other substances with electrons that are fixed into position.
There also are few non-metals that conduct electricity: graphite (because, like metals, it has free electrons), and ionic compounds that are molten or dissolved in water, which have free moving ions.
Metal bonds have at least one valence electron which they do not share with neighboring atoms, and they do not lose electrons to form ions.
Instead, the outer energy levels (atomic orbitals) of the metal atoms overlap.
They are similar to covalent bonds.
Not all metals exhibit metallic bonding.
For example, mercury ions () form covalent metal-metal bonds.
An alloy is a solution of metals.
Most alloys are shiny like pure metals are.
Heat conduction (or thermal conduction) is the movement of heat from one object to another one that has different temperature when they are touching each other.
For example, we can warm our hands by touching hot-water bottles.
When the cold hands touch the hot-water bottle, heat flows from the hotter object (hot-water bottle) to the colder one (hand).
People make things with different thermal conductivity, for example cookware to heat things or insulated containers to keep hot things hot or cold things cold.
Other ways to transfer heat are by thermal radiation and/or convection.
Usually more than one of these processes happen at the same time.
Microscopic explanation
In the atomic theory solids, liquids and gases are made of tiny particles called "atoms".
The temperature of the material measures how fast the atoms are moving and the heat measures the total amount of energy due to the vibration of the atoms.
Conduction can happen when one part of a material is heated.
The atoms in this part vibrate faster and are more likely to hit  their neighbors.
The collisions cause those atoms also to move faster, passing the heat energy to them.
In this way the energy travels through the solid. (
Rather like the way energy passes along a set of tumbling dominos).
The atomic picture also helps explain why conduction is more important in solids: in solids the atoms are close together and unable to move around.
In liquids and gases the particles can move past each other, so the collisions are less common.
Law of heat conduction
Q is the amount of heat transferred, and
t is the time taken, and
k is the material's thermal conductivity' and
S is the area through which the heat is flowing, and
T is the temperature.
Judith Weir (born 11 May 1954) is a British composer.
She is well known for her theatre works, choral music, orchestral music and chamber music.
Weir was born in Cambridge, England to Scottish parents.
While she was still at school she trained with the composer John Tavener.
She played the oboe in the National Youth Orchestra of Great Britain.
She then studied at the University of Cambridge where her teacher was Robin Holloway.
Judith Weir’s music has harmonies which are very exciting and original.
Her Christmas carol Illuminare has become very popular, but it is quite difficult and needs a good choir to pitch the notes of the dissonant chords.
She often uses medieval history as inspiration for her music, as well as music from her native Scotland, e.g. piobaireachd, which is a kind of variation form using small intervals.
Her music often tells stories.
Her operas include A Night at the Chinese Opera, The Vanishing Bridegroom, Blond Eckbert, and Armida, an opera for television.
From 1995 to 2000, she was the Artistic Director of the Spitalfields Festival in London.
She has composed works for the City of Birmingham Symphony Orchestra.
She has received many honours, including the CBE in 1995.
Judith Weir's homepage at Chester Music (music publishers)
Judith Weir (b 1954) (BBC)
21st-century British composers
Greek chorus, a feature of ancient Greek theatre
Choir, a group of singers
Refrain, the part of a song that is repeated
Bridge (music), The verse before the refrain
A vassal during the feudalism of medieval Europe, was someone who had shared duties  with a lord.
Usually the vassal provided soldiers to the lord.
The lord used his army of soldiers from all of his vassals to protect those vassals.
The lord also gave him the piece of land that he held as a fief.
By analogy the term vassal is used also for similar systems in other feudal societies.
Western vassalage
The development of the vassal, in a society that was increasingly organised around the concept of "lordship"– in French the seigneur– is one sign that Antiquity ended and the Early Middle Ages began.
Lordship is the basic social institution as Tacitus described them in his book Germania.
The Roman West experienced them for the first time in the Migration Period.
As the system developed in the seventh century, the vassals were gangs of freemen who subjected themselves, in some degree of formality, to the authority of a leader, from whom they could expect to be fed, clothed and armed.
The quality of a vassal was only in his fighting ability and the strength of his loyalty.
The etymology (where the word came from) of "vassal" is from a Celtic word gwas "boy" that meant a young male slave, with a Latinised form, vassus that appeared in Salic Law (Rouche 1987 p 429), like the way  "knight" came from the from  Old English word cniht and similar words in Frisian and Dutch, all meaning "lad" .
Gokenin, vassals of the shogunate in Japan
Cantor, Norman, The Civilization of the Middle Ages 1993
Ganshof, François Louis, Feudalism translated 1964
The migrations included the Goths, Vandals, Franks, and other Germanic, Bulgar, and Slavic tribes.
They may have been influenced by attacks of the Huns in the East and may also be connected to the Turkic migrations in Central Asia, overpopulation, or climate changes.
The migration period also included groups of Angles, Saxons, Frisians, and some Jutes to Britain.
Migrations would continue well into the Middle Ages, beyond 1000 AD, with successive waves of Slavs, Alans, Avars, Bulgars, Hungarians, Pechenegs, Cumans, and Tatars that changed the ethnic makeup of Eastern Europe.
Western European historians, however, tend to stress the migrations that were most relevant to Western Europe.
J.B. Bury (1923).
History of the Later Roman Empire
The San Francisco Bay Area, also known as the Bay Area, is a metropolitan area that goes around the San Francisco Bay in Northern California.
It includes the cities of San Francisco, San José, and Oakland, and their many suburbs.
It also includes the smaller urban and rural areas of the North Bay.
Over seven million people live in the San Francisco Bay Area.
The San Francisco Bay Area is the 43rd largest metropolitan area in the world in population.
San José is the largest city in the Bay Area since 1990 and the tenth largest city in America.
But for most of its history, San Francisco was the city with the most people.
San Francisco is still the city people pay the most attention to, and it is the major cultural center in the region.
North Bay
The region north of the Golden Gate Bridge is known locally as the North Bay.
This area includes Marin County and continues north into Sonoma and Napa counties and east to Solano County.
With some exceptions, this region is quite rich: Marin County is listed as the richest in the nation.
The City and County of San Francisco is generally placed in a category by itself in terms of geography and culture.
It is separated by water from the north, west and east, and by a county line from its neighbor cities to the South.
San Francisco has been the cultural, financial and urban center of the region for a long time.
For most of the Bay Area's history, it has also been the main population center.
But because the size of the county is limited, the growth of the city was limited as well.
As a result, other cities and counties have had more population growth.
The area between the South Bay and the City and County of San Francisco is the San Francisco Peninsula, known locally as The Peninsula.
This area includes many small cities and suburban communities in San Mateo County and the northwestern part of Santa Clara County, as well as several towns along the Pacific coast, such as Pacifica and Half Moon Bay.
The eastern side of the bay, consisting of Alameda and Contra Costa counties, is known locally as the East Bay.
The East Bay is split into two regions, the inner East Bay, which is on the coast of the Bay, and the outer East Bay, including the inland valleys separated from the inner East Bay by hills and mountains.
South Bay
This region is home to a large number of major technology companies.
Some tech companies in the South Bay are Intel, AMD,  Cisco Systems, Hewlett-Packard, Apple, Google, and Yahoo!,
Microsoft and much much more.
sfbaywildlife.info Guide to wildlife-watching in the San Francisco Bay Area
San Francisco Housing and Real Estate Guide  Aggregates the collective knowledge of the San Francisco real estate community.
San Francisco Bay Area Boat Launch map A collaboratively edited index of public boat launches helping to develop a water trail network.
San Francisco Bay is a shallow, productive estuary through which water draining about forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains and Central Valley, enters the Pacific Ocean.
Technically, both rivers flow into Suisun Bay, which help flows through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay, which connects at its south end to San Francisco Bay, although the entire group of interconnected bays are often referred to as "the San Francisco Bay."
The Bay covers somewhere between 400  and 1,600  square miles (1,040 to 4,160 square kilometres), depending on which sub-bays (such as San Pablo Bay), estuaries, wetlands, and so on are included in the measurement.
1999 Grolier Multimedia Encyclopedia.
1988 Encyclopædia Britannica.
San Francisco Bay: Portrait of an Estuary, David Sanger and John Hart, University of California Press
Barging In - A Short History of Liveaboards on the Bay
Army Corps of Engineers Bay Model: Working scale model of the Bay
BoatingSF.com: Photos of SF Bay and its boats, plus online cruising guide
SF Estuary Institute: San Francisco Bay Historical View Maps
Bays of the United States
Ahmed Yassin (January 1, 1937 – March 22, 2004) was a spiritual leader of the militant Palestinian group Hamas.
Yassin's birth date is in dispute.
He claimed he was born 1/1/1938, however, his passport indicated 1/1/1937.
To some he was a hero, to some he was a notorious member of a terrorist organization.
He was also a symbolic figure for Palestinians to fight against Israel.
Yassin was born in al-Jura, British Mandate of Palestine.
He helped create Hamas and became its spiritual leader in 1987.
To other members of Hamas he was a hero but he was blamed by the Israeli government for planning suicide bombings and other attacks against Israel.
He claimed that was the only way of fighting occupation.
He was confined to a wheelchair because he was paralyzed since age 12, he was also nearly blind and could barely hear.
He was very powerful and influential.
He was assassinated in an airstrike in Gaza City by the Israeli Army after he left a mosque in Gaza in the early morning hours.
Israel Bombing of Refugee Camp
Yassin killed, Ahmed Yassin biography
Yassin's letter and kids named after him
Deaths by airstrike
In physics, the field strength of a field is the magnitude (size) of its (vector) value.
This means that the force exerted by the field on a given object is proportional to the field strength.
In differential geometry, the field strength is another name for the curvature form.
For the electromagnetic field, the curvature form is an antisymmetric matrix whose elements are the electric field and magnetic field: the electromagnetic tensor.
In physics, a field means that a physical quantity is assigned to every point in space (or, more generally, spacetime).
A field is seen as extending throughout a large region of space so that it influences everything.
The strength of a field usually varies over a region.
Michael Faraday became the first to coin the term "field", in 1849.
For some fields, there is a number for each point in space.
They are called scalar fields.
For more complicated fields, there are more than one number for each point in space.
They are called vector fields or tensor fields.
For example, one can model a gravitational field by a vector field where a vector indicates the acceleration a mass would experience at each point in space.
Other examples are temperature fields or air pressure fields, which are often illustrated on weather reports by isotherms and isobars by joining up the points of equal temperature or pressure respectively.
Types of fields
Classical fields
Newtonian gravitation: describes the gravitational force as a mutual interaction between two masses.
Electromagnetism:  electric and magnetic fields are not only fields of force which dictate the motion of particles, but also have an independent physical reality because they carry energy.
Gravitation in general relativity: this is Einstein's theory of gravity.
Waves as fields
Quantum fields
Landau, Lev D. and Lifshitz, Evgeny M. 1971.
Classical theory of fields.
3rd ed, London: Pergamon.
2 of the Course of Theoretical Physics.
In vector calculus, the gradient of a multivariate function measures how steep a curve is.
On a graph of the function, it is the slope of the tangent of that curve.
More generally, it is a vector that points in the direction in which the function grows the fastest.
Its coordinates are partial derivatives of that function.
The gradient of a function f is often written as  or .
In mathematics, the trigonometric functions are a set of functions which relate angles to the sides of a right triangle.
There are many trigonometric functions, the 3 most common being sine, cosine, tangent, followed by cotangent, secant and cosecant.
The last three are called reciprocal trigonometric functions, because they act as the reciprocals of other functions.
Secant and cosecant are rarely used.
The trigonometric functions sometimes are also called circular functions.
They are functions of an angle; they are important when studying triangles, among many other applications.
Trigonometric functions are commonly defined as ratios of two sides of a right triangle containing the angle, and can equivalently be defined as the lengths of various line segments from a unit circle (a circle with radius of one).
Right triangle definitions
In order to define the trigonometric functions for the angle A, start with a right triangle that contains the angle A:
The hypotenuse is the side opposite the right angle, also the longest side of a right-angled triangle, in this case h.
The opposite side is the side opposite to the angle we are interested in, in this case a.
The adjacent side is the side that is in contact with the right angle the angle we are interested in, hence its name.
In this case, the adjacent side is b.
All triangles are taken to exist in Euclidean geometry, so that the inside angles of each triangle sum to π radians (or 180°); therefore, for a right triangle, the two non-right angles are between zero and π/2 radians.
Notice that strictly speaking, the following definitions only define the trigonometric functions for angles in this range.
We extend them to the full set of real arguments by using the unit circle, or by requiring certain symmetries and that they be periodic functions.
1) The sine of an angle is the ratio of the length of the opposite side to the length of the hypotenuse.
In our case
Note that since all those triangles are similar, this ratio does not depend on the particular right triangle that is chosen, as long as it contains the angle A.
The set of zeroes of sine (that is, the values of  for which ) is
2) The cosine of an angle is the ratio of the length of the adjacent side to the length of the hypotenuse.
3) The tangent of an angle is the ratio of the length of the opposite side to the length of the adjacent side.
4) The cosecant csc(A) is the multiplicative inverse of sin(A); it is the ratio of the length of the hypotenuse to the length of the opposite side:
5) The secant sec(A) is the multiplicative inverse of cos(A); it is the ratio of the length of the hypotenuse to the length of the adjacent side:
6) The cotangent cot(A) is the multiplicative inverse of tan(A); it is the ratio of the length of the adjacent side to the length of the opposite side:
Definitions by power series
The hyperbolic functions are like the trigonometric functions, in that they have very similar properties.
Each of six trigonometric functions has a corresponding hyperbolic form.
They are defined in terms of the exponential function, which is based on the constant e.
Hyperbolic sine:
Hyperbolic cosine:
Hyperbolic tangent:
Hyperbolic cotangent:
Hyperbolic secant:
Hyperbolic cosecant:
Joseph, George G., The Crest of the Peacock: Non-European Roots of Mathematics, 2nd ed.
Penguin Books, London. (
2000). .
"Madhava of Sangamagramma" , MacTutor History of Mathematics Archive. (
Weisstein, Eric W., "Tangent" from MathWorld, accessed 21 January 2006.
nanoSouffle Online Grapher  - Extensible features for graphing functions... works in just about every browser, and JavaScript is simply a plus for real-time updates, and not a requirement.
Sine and cosine function   with an implementation in Rexx.
Trigonomic Functions - An interactive sketch showing the trigonometric functions in terms of the unit circle.
An excellent Flash animation for learning the unit circle
Gradient of a function, in vector calculus
Slope or grade, referring to the inclination of a road or other geographic features
Image gradient, a gradual change or blending of color
Concentration gradient, the ratio of solute concentration between two regions next to each other
Electric gradient, the difference in electric charge between two regions next to each other
Pressure gradient, the difference in the exerted force per unit area in two regions next to each other
Sean Archer, character portrayed by John Travolta/Nicolas Cage in the movie Face/Off
Danny Archer, character portrayed by Leonardo DiCaprio in the movie Blood Diamond
Jeffrey Archer, Baron Archer of Weston-super-Mare, British author, former politician
Archer River, one of the best-known rivers in Cape York Peninsula, Australia
Archer (horse) - an Australian racehorse that won the first two Melbourne Cups
Archery is the practice of using a bow to shoot arrows.
Archery has historically been used in hunting and combat and has become a precision sport.
A person practicing archery is called an archer, and one who enjoys or is an expert at archery is sometimes called an toxophilite.
The earliest evidence of archery dates back more than 9,000 years.
The bow probably was used in hunting first and later adopted as a tool of warfare.
It was one of the earliest forms of artillery.
Classical civilizations, notably the Persians, Macedonians, Nubians, Greeks, Parthians, Indians, Japanese, Chinese, and Koreans, had large numbers of archers in their armies.
Archers in chariots were especially important in armies of ancient Egypt.
Arrows were very destructive against massed formations, and the use of archers helped win battles.
The army of the Mongol Empire was mostly archers on horseback.
Archery Interchange UK The UK's largest online archery community.
The Great Northwood Bowmen  Medieval Longbow Archery and re-enactment Society, re-enacting the 15th century, based in London.
Bowhunting Basics
Archery Information
Archery Pictures
John Felix Anthony Cena Jr. (born April 23, 1975) is an American  professional wrestler and actor.
He currently works for the WWE.
Cena has won the WWE Championship/WWE World Heavyweight Championship thirteen times, the World Heavyweight Championship thrice, the United States Championship five times and the World Tag Team Championship twice.
Also, Cena won the Royal Rumble in 2008 and 2013.
As for his musical career, Cena has released an album called you cant see me.
Cena has also been featured in the movies The Marine, 12 Rounds and Legendary.
He will star as Peacemaker in the 2022 movie The Suicide Squad and his own television series for HBO Max.
His most famous catchphrase is "You Can't See Me" which has become a very well-known meme in Western Society.
World Wrestling Entertainment (2001-present)
Cena was signed by then Person in charge of Talent Relations, Jim Ross on behalf on WWF.
According to Ross, when he returned to Connecticut after signing Cena he walked into Vince McMahon's office and told him "I just signed your main event for WrestleMania in 5 years."
Cena would eventually make his WrestleMania debut 3 years later at WrestleMania XX winning the WWE United States Championship from The Big Show, and his Main event WrestleMania debut 4 years later winning the WWE Championship, from John "Bradshaw" Layfield.
During the match between Barrett and Orton, Orton won so Cena was forced to retire.
He was rehired by Wade Barrett and defeated him at TLC: Tables, Ladders and Chairs Pay Per View.
He was defeated by The Rock at WrestleMania XXVIII.
He won his second Royal Rumble in January 2013.
Thus he got another match at WrestleMania XXIX against The Rock for WWE Championship.
He won that match and became the WWE Champion.
He retired the next night on Raw after getting defeated by the debuting Dominik Mysterio, the son of professional wrestler Rey Mysterio.
He was inducted in the 1938 WWE Hall of Fame.
OVW Heavyweight Championship (1 time)
OVW Southern Tag Team Championship (1 time) – with Rico Constantino
PWI Feud of the Year (2006)
PWI Match of the Year (2007)
PWI Most Improved Wrestler of the Year (2003)
PWI Most Popular Wrestler of the Year (2004, 2005, 2007)
PWI Wrestler of the Year (2006, 2007)
PWI ranked #1 of the top 500 singles wrestlers in the PWI 500 in 2006 and 2007
UPW Heavyweight Championship (1 time)
World Wrestling Entertainment/WWE
WWE Championship/WWE World Heavyweight Championship (13 times)
World Heavyweight Championship (3 times)
WWE United States Championship (3 times)
WWE Tag Team Championship (2 times) – with The Miz (1) and David Otunga (1)
World Tag Team Championship (2 times) –  with Batista (1) and Shawn Michaels (1)
Money in the Bank (2012 - WWE Championship contract)
Royal Rumble (2008, 2013)
Slammy Award for Superstar of the Year – 2009, 2010 and 20121
Slammy Award for Holy $#!
+ Move of the Year (2010) – Sends Batista through the stage with an Attitude Adjustment.
Slammy Award for Game Changer of the Year (2011) – with The Rock
Slammy Award for Insult of the Year (2012) - To Dolph Ziggler & Vickie Guerrero: "You're the exact opposite.
One enjoys eating a lot of nuts and the other is still trying to find his."
Slammy Award for Kiss of the Year (2012) – with AJ Lee
Slammy Award for Match of the Year (2013) - vs. The Rock for the WWE Championship at WrestleMania 29
5 Star Match (2011) (vs. CM Punk at Money in the Bank on July 17)
Best Box Office Draw (2007)
Best Gimmick (2003)
Best on Interviews (2007)
Feud of the Year (2011) (vs. CM Punk)
Match of the Year (2011) (vs. CM Punk at Money in the Bank on July 17)
Most Charismatic (2006–2010)
Most Charismatic of the Decade (2000–2009)
Worst Feud of the Year (2012) (vs. Kane)
Worst Worked Match of the Year (2012) (vs. John Laurinaitis at Over the Limit on May 20)
Wrestler of the Year (2007, 2010)
Wrestling Observer Newsletter Hall of Fame (Class of 2012)
1  Cena did not accept the 2012 award, opting to award it to presenter Ric Flair instead.
A signal transduction in biology is a  cellular mechanism.
It converts a stimulus into a response in the cell.
There are two stages in this process:
A signalling molecule attaches to a receptor protein on the cell membrane.
A second messenger transmits the signal into the cell, and a change takes place in the cell.
So, signal transduction starts with a signal to a cell receptor, and ends with a change in cell function.
In either step, the signal can be amplified.
Thus, one signalling molecule can cause many responses.
Receptors are in the cell membrane, with part of the receptor outside and part inside the cell.
The  chemical signal binds to the outer portion of the receptor, changing its shape.
This causes another signal inside the cell.
Some chemical messengers, such as testosterone, can pass through the cell membrane, and bind directly to receptors in the cytoplasm or nucleus.
Sometimes there is a cascade of signals within the cell.
With each step of the cascade, the signal can be amplified, so a small signal can result in a large response.
Eventually, the signal creates a change in the cell, either in the expression of the DNA in the nucleus or in the activity of enzymes in the cytoplasm.
Most often, ordered sequences of biochemical reactions inside the cell are involved.
These are carried out by enzymes and linked through second messengers.
So a "second messenger pathway" is produced.
These things usually happen quickly, sometimes very quickly.
They may last from milliseconds (in the case of ion flux) to days for gene expression.
The number of proteins and other molecules that take part increases during the process.
So a 'signal cascade' develops and a relatively small stimulus may cause a large response.
In bacteria and other single-cell organisms, the transduction processes a cell has limits the number of ways it can respond to its environment.
In multicellular organisms, lots of different signal transduction processes are used to coordinate the behavior of individual cells.
By this means the function of the organism as a whole is organized.
The more complex the organism, the more complex the repertoire of signal transduction processes the organism must possess.
Thus, sensing of both the external and internal environment at the cellular level, relies on signal transduction.
Many disease processes such as diabetes, heart disease, autoimmunity and cancer arise from defects in signal transduction pathways.
This highlights the critical importance of signal transduction to biology and medicine.
[http://stke.sciencemag.org/ Science'''s STKE - Signal transduction knowledge environment], from Science'', published by AAAS.
Cosma Shalizi's Signal transduction notebook
Flux is a term in physics and mathematics.
It is broadly defined as "How much stuff goes through a thing" (or into an area).
The word "flux" is similar to "flow".
For instance, imagine a butterfly net.
The amount of air passing through the net is the flux.
Movement of substances
In the study of transport phenomena (heat transfer, mass transfer and fluid dynamics), flux is defined as flow per unit area, where flow is the movement of some quantity per time.
Flux, in this definition, is a vector.
There are many fluxes used in the study of transport phenomena.
Each type of flux has its own distinct unit of measurement along with distinct physical constants.
Six of the most common forms of flux from the transport literature are defined as:
Momentum flux, the rate of transfer of momentum across a unit area (N·s·m−2·s−1). (
Newtonian fluid, viscous flow)
Heat flux, the rate of heat flow across a unit area (J·m−2·s−1). (
Fourier's Law) (This definition of heat flux fits Maxwell's original definition.)
Chemical flux, the rate of movement of molecules across a unit area (mol·m−2·s−1). (
Fick's law of diffusion)
Volumetric flux, the rate of volume flow across a unit area (m3·m−2·s−1). (
Darcy's law)
Mass flux, the rate of mass flow across a unit area (kg·m−2·s−1). (
Either an alternate form of Fick's law that includes the molecular mass, or an alternate form of Darcy's law that includes the density).
Radiative flux, the amount of energy moving in the form of photons at a certain distance from the source per steradian per second (J·m−2·s−1).
Used in astronomy to study and classify stars.
Also acts as a generalization of heat flux, which is equal to the radiative flux when restricted to the infrared spectrum.
Magnetic flux, the density of a magnetic field.
In the field of electromagnetism, flux is usually the integral of a vector quantity over a finite surface.
The result of this integration is a scalar quantity.
The magnetic flux is thus the integral of the magnetic vector field over a surface, and the electric flux is defined similarly.
Using this definition, the flux of the Poynting vector over a specified surface is the rate at which electromagnetic energy flows through that surface.
Confusingly, the Poynting vector is sometimes called the power flux,  which is an example of the first usage of flux, above.
It has units of watts per square metre (W/m2).
Flux comes from Latin and means flow; it may mean:
Flux, a scientific term describing the rate of flow of something through a surface
Flux (software), a free for non-commercial usage suite of VRML/X3D viewing/authoring software
Flux (metallurgy), a material that aids in smelting and soldering by assisting the flow of the molten metal
Flow (psychology), often referred to as flux
Flux (biochemistry), the rate of turnover of molecules through a metabolic pathway
Flux (novel), a book by Stephen Baxter
Flux Magazine (US), a short-lived American music, comic book & video game magazine from the mid-1990s
Flux Of Pink Indians, the name of a British anarcho-punk band, originally known as Flux of Pink Indians
Fluxx, a card game
Flux Capacitor, a fictional device from Back to the Future that "makes time travel possible"
Fluxus, an art movement
Flux Wildly, one of the main characters from the computer game Toonstruck
Flux (magazine), a magazine published by students at the University of Oregon journalism school
Flux (magazine), a magazine published in the United Kingdom
Neuroscience (or neurobiology) is the scientific study of the nervous system.
It is the branch of biology which investigates every aspect of the brain and nervous system.
The nervous system is made of billions of neurons connected together and to other systems in the body.
The central nervous system includes the brain, spinal cord and retina.
It is connected to the rest of the body via the peripheral nervous system.
Research themes
Neuroscience research focusses on a set of themes and questions.
Behavior/cognition/language
Brain imaging or neuroimaging
Cell imaging & Electrophysiology
Learning/memory
Neurobiology of the neuron
Sensation and perception
Autonomic nervous system and homeostasis
Arousal, attention and emotion
Genetics of the nervous system
Developmental biology of the nervous system
Diseases of the nervous system
Squire, L. et al. (
Fundamental Neuroscience, 2nd edition.
Academic Press;
Byrne and Roberts (2004).
From Molecules to Networks.
Sanes, Reh, Harris (2005).
Development of the Nervous System, 2nd edition.
Siegel et al. (
Basic Neurochemistry, 7th edition.
Rieke, F. et al. (
Spikes: Exploring the Neural Code.
The MIT Press; Reprint edition
Online textbooks
Neuroscience 2nd ed.
Dale Purves et al.
Published by Sinauer Associates, Inc., 2001.
Basic Neurochemistry: Molecular, Cellular, and Medical Aspects 6th ed.
by George J. Siegel et al.
Published by Lippincott, Williams & Wilkins, 1999.
Damasio, A. R. (1994).
Descartes' Error: Emotion, Reason, and the Human Brain.
New York, Avon Books.
(Hardcover)  (Paperback)
Gardner, H. (1976).
The Shattered Mind: The Person After Brain Damage.
New York, Vintage Books, 1976
Luria, A. R. (1997).
The Man with a Shattered World: The History of a Brain Wound.
Cambridge, Massachusetts, Harvard University Press.
Sacks, O. The Man Who Mistook His Wife for a Hat.
Summit Books  (Hardcover)  (Paperback)
Sacks, O. (1990).
Awakenings.
New York, Vintage Books. (
See also Oliver Sacks)  (Hardcover)  (Paperback)
Sternberg, E. (2007) Are You a Machine?
The Brain, the Mind and What it Means to be Human.
Amherst, NY: Prometheus Books.
High-Resolution Cytoarchitectural Primate Brain Atlases
Society for Neuroscience
Neural Plasticity-Open Access Journal (Hindawi Publishing)
Neuroscience.
by Purves et al. (
online textbook)
Conversation analysis (commonly abbreviated as CA) is the study of talk in social interaction.
CA tries to describe the structure and patterns of interaction, whether this is institutional (in the school, doctor's surgery, courts or elsewhere) or casual conversation.
An Introduction to Conversation Analysis  (by  Discourse and Rhetoric Group,  Loughborough University)
Online bibliography of pre-1990 CA literature
Online bibliography of post-1989 CA literature
Online clearinghouse for the CA community
Mark-Anthony Turnage (born Grays, Essex, 10 June 1960) is an English composer.
He is one of the most original composers in his country today.
Turnage studied at the Royal College of Music and won all the major prizes.
He became famous when he wrote an opera called Greek.
It is typical of his musical style: quite lyrical but also very dramatic and aggressive.
His music is often inspired by jazz.
Other works include Kai, Rockaby, Blood on the Floor, Dispelling the Fears, Drowned Out and Three Screaming Popes.
He has written music for the English National Opera, City of Birmingham Symphony Orchestra and the Chicago Symphony Orchestra.
21st-century English composers
A hydrothermal vent is an opening in the seabed of the Earth by which geothermal energy escapes.
Sea water enters, becomes very hot, and rises.
The hottest ones carry many black chemicals, and are called black smokers.
Scientists have found fewer white smokers.
Heat escapes from underground in many places.
If they are on land, they are usually hot springs, geysers, or fumaroles.
Many archaea and bacteria live near hydrothermal vents, which are underwater.
They support giant tube worms, clams and shrimp, and many other eukaryotes.
The earliest known life forms are thought to have lived near such vents.
Biological communities
Deep sea organisms have no access to sunlight, so they must depend on nutrients in the  chemical deposits and hydrothermal fluids in which they live.
Compared to the surrounding sea floor, however, hydrothermal vent zones have a density of organisms 10,000 to 100,000 times greater.
Hydrothermal vent communities are able to sustain such vast amounts of life because vent organisms depend on chemosynthetic bacteria for food.
These bacteria use sulfur compounds, particularly hydrogen sulfide, a chemical highly toxic to most known organisms, to produce organic material through the process of chemosynthesis.
The chemosynthetic bacteria grow into a thick mat which attracts other organisms such as amphipods and copepods which graze upon the bacteria directly.
Larger organisms such as snails, shrimp, crabs, giant tube worms, fish, and octopus form a food chain of predator and prey relationships above the primary consumers.
The main groups of organisms around seafloor vents are worms,  gastropods, and crustaceans, with large bivalves, and 'eyeless' shrimp making up the bulk of non-microbial organisms.
Tube worms form an important part of the community around a hydrothermal vent.
They absorb nutrients directly into their tissues.
There are approximately 285 billion bacteria per ounce of tubeworm tissue.
Tubeworms have red plumes which contain haemoglobin.
Haemoglobin combines hydrogen sulfide and transfers it to the bacteria living inside the worm.
In return the bacteria nourish the worm with carbon compounds.
Other examples of the unique fauna who inhabit this ecosystem are the gastropod Crysomallon squamiferum, a species of snail with a foot reinforced by scales made of iron and organic materials, and the 'Pompeii Worm' Alvinella pompejana, which is capable of withstanding temperatures up to 80°C (176°F).
Over 300 new species have been discovered at hydrothermal vents, many of them "sister species" to others in geographically separated vent areas.
It has been proposed that before the North American plate overrode the Mid-Atlantic Ridge, there was a single biogeographic vent region found in the eastern Pacific.
The subsequent barrier to travel began the evolutionary divergence of species in different locations.
The examples of convergent evolution seen between distinct hydrothermal vents is seen as major support for the theory of natural selection and evolution as a whole.
A species of phototrophic bacterium has been found living near a black smoker off the coast of Mexico at a depth of .
No sunlight penetrates that far into the waters.
Instead, the bacteria, part of the Chlorobiaceae family, use the faint glow from the black smoker for photosynthesis.
This is the first organism discovered in nature to exclusively use a light other than sunlight for photosynthesis.
Guavas are plants in the genus Psidium of the family Myrtaceae.
There are about 100 species of tropical shrubs and small trees in the genus.
They are native to Mexico, the Caribbean, Central America and the northern part of South America.
Now they are found in all the tropical, and in some subtropical, regions because they are edible fruits.
Guava are also a kind of berry fruit on those plants.
There are many kinds of guavas.
The most common guava is the apple guava (Psidium guajava): it is so common that the word 'guava' usually refers to this species.
Red guavas are called maroonguava.
In 100 g of guava are 200 mg of vitamin C, which means that guavas have five times more vitamin C than oranges.
The resting potential of a cell is the membrane potential that would be maintained if there were no action potentials, synaptic potentials, or other active changes in the membrane potential.
In most cells the resting potential has a negative value, which by convention means that there is excess negative charge inside compared to outside.
The resting potential is mostly determined by the concentrations of the ions in the fluids on both sides of the cell membrane and the ion transport proteins that are in the cell membrane.
How the concentrations of ions and the membrane transport proteins influence the value of the resting potential is outlined below.
Neuroscience - online textbook by Purves, et al.
Basic Neurochemistry Molecular, Cellular, and Medical Aspects by Siegel, et al.
Bertil Hille Ion channels of excitable membranes, 3rd ed.,
Generation of resting membrane potential Wright, S.H., Advances in Physiology Education, 28(1-4): 139-142, 2004,
Thrust is a force or a push.
When a system pushes or accelerates mass in one direction, there is a thrust (force) just as large in the opposite direction.
In math and physics, this is described by Isaac Newton’s second and third laws.
Thrust is used to describe how strongly an engine pushes.
It can be used for many kinds of vehicles and engines such as rockets, motorboats, propellers, and jet engines.
Thrust is measured in “pounds of thrust” in the U.S. and in newtons in the metric system.
4.45 newtons of thrust equals 1 pound of thrust.
A pound of thrust is how much thrust it would take to keep a one-pound object unmoving against the force of gravity on earth.
Thrust compared to power
A very common question is how to compare the thrust number of an airplane engine with the mechanical power of a piston engine (the kind of engine in cars and in many airplanes with propellers).
It is hard to compare these two.
This is because they are not measuring the same exact thing.
A piston engine does not move the plane.
It just turns the propeller, which moves the plane.
Because of this, piston engines are rated by how much power they give to the propeller.
However, a jet engine has no propeller – it pushes the aircraft by moving hot air behind it.
A useful way to measure the power of a jet engine is to how much power the jet engine gives to the aircraft through its thrust force.
This is called the “propulsive power of the jet engine."
Power is how much force it takes to move something over a distance, divided by the time it takes to move that distance:
Where P is power, F is force, d is distance, and t is time.
For a rocket or jet engine, the force is the same as thrust produced by the engine.
Distance divided by time is also called speed.
So power is the same as thrust times speed
Where T is thrust and v is speed.
This is the power being delivered by the engine at a certain thrust or velocity.
The propulsive power of a jet engine increases with its speed.
Thrust compared to weight
When the thrust of a rocket or an engine is compared to the weight, it is called the Thrust-to-weight ratio.
The number that comes from this comparison does not have any units, because it is a ratio.
A ratio in this case means that the thrust of the engine (in Newtons) is divided by the weight (in Newtons).
The purpose of this comparison is to show how well the engine or vehicle performs, for example how much acceleration.
It is a number that can be used to compare various types of motors like airplane motors, jet engines, rocket engines, or car engines.
This comparison number can change while the engine is running.
This is because the weight of the engine gets lighter as fuel is used.
The thrust-to-weight ratio is used to actually compare engines is the number found when the engine is first running.
Thrust is measured in “pounds of thrust” in the U.S. and in Newtons in the metric system.
4.45 Newtons of thrust equals 1 pound of thrust.
An airplane makes forward thrust when air is pushed in the direction opposite to flight.
The thrust is made by the spinning blades of a propeller.
Thrust can also be made by a rotating fan pushing air out from the back of a jet engine.
Another way is by ejecting hot gases from a rocket engine.
Reverse thrust is the opposite of forward thrust.
In this way air is pushed in the same way as the motion of the body.
Reverse thrust can be used to help braking after landing.
This can be done by redirecting the thrust in a turbofan or jet engine or by changing the blade angle of a propeller driven aircraft.
A boat with a motor makes thrust or reverse thrust when the propellers are turned to push water backwards (or forwards).
The thrust that this makes pushes the boat in the opposite direction than the water is being pushed.
A rocket is pushed forward by a thrust force as large as the force the exhaust gas makes when going out of the rocket nozzle.
The force the exhaust gas makes is called the exhaust velocity.
The velocity is measured compared to the rocket.
For vertical launch of a rocket to work, the starting thrust must be more force than the weight of the rocket.
Thrust is a reaction force described by Newton's Second and Third Law.
For this meaning, see Thrust.
For the land-speed record breaking car, see ThrustSSC and Thrust2
For the computer game, see Thrust (computer game)
For the rapper, see Thrust (rapper)
For the Transformers characters, see Thrust (Transformers)
For the Herbie Hancock fusion album, Thrust (album)
For the semi-professional magazine which later changed its name to Quantum, see Thrust (magazine)
Thrust fault in geology
Robert Anson Heinlein (July 7, 1907 – May 8, 1988) was an American writer.
He mostly wrote science fiction books.
He won the Hugo Award four times.
Probably his best-known novels are Starship Troopers (1959, Hugo Award, was made into a film), and Stranger in a Strange Land (1961, Hugo Award).
Two other Hugo awards were for Double Star (1956) and The Moon is a Harsh Mistress (1966).
Together with Isaac Asimov and Arthur C. Clarke he is seen as one of the Big Three of Science Fiction.
There are many computer and video game genres.
Here is a list of some of the common ones.
Role-playing game (RPG)
Massively-Multiplayer Online Role-Playing Game (MMORPG)
A fable is a type of story which shows something in life or has a meaning to a word.
A fable teaches a lesson or suggests a moral from it.
A fable starts in the middle of the story, that means, jumps into the main event without detailed introduction of characters.
The characters of a fable may be animals, plants and legendary creatures.
When animals are used in fables, they think and talk like people, even though they act like animals.
For example, in a fable a clay pot might say that it is frightened of being broken.
The stories told by fables are usually very simple.
To understand a fable, the reader or listener does not need to know all about the characters, only one important thing.
For this reason animals are often used in fables in a way that is easily understood because it is always the same.
They keep the same characteristics from story to story.
A lion is noble
A rooster is boastful
A peacock is proud
A fox is cunning
A wolf is fierce
A horse is brave
A donkey is hard-working
The most famous fables are those attributed to Aesop (6th century B.C.).
Many fables are so well-known that their morals have become English sayings.
If a person says "sour grapes!"
then they are referring to "The Fox and the Grapes".
This fable is about a fox who saw a beautiful bunch of grapes hanging on a vine.
He wanted to eat them but they were high up.
He tried and tried to jump high enough to pull them down.
When he was too tired to jump anymore, he went away saying "I'll bet those grapes were sour!"
So, if a person sees a beautiful thing that they want, but cannot have, sometimes they say "I don't want it, anyway!
I'll bet it is really no good!"
This way of thinking is called "sour grapes".
"Crying wolf" is another well-known English saying.
This comes from "The Boy Who Cried Wolf".
This fable is about a boy who was sent to mind the sheep.
The boy got lonely while minding the sheep, so he shouted "Wolf!
Wolf!"
The people came running.
The next day, he did it again and they were very angry.
On the third day the boy saw a wolf.
He cried "Wolf!
but no one came and the wolf ate him.
So if a person always makes a great fuss to get attention, or if a person says something bad has happened when it has not, then it is called "crying wolf" and people will stop bothering to pay attention, even when things go really wrong.
Animal Symbolism List of frequently described animals and their characteristics
The Dragon-Tyrant
Fables - Collection and guide to fables for children
Imaginexus  A collection of interconnected stories that anyone can edit
Beast Fable Society  An academic society focused on fables and related genres
Drainage is the natural or artificial removal of surface and sub-surface water from a given area.
Many agricultural soils need drainage to improve production or to manage water supplies.
The earliest archaeological record of an advanced system of drainage comes from the  Indus Valley Civilization from around 3100 BC in what is now Pakistan and North India.
The ancient Indus systems of sewerage and drainage that were developed and used in cities throughout the civilization were far more advanced than any found in contemporary urban sites in the Middle East and even more efficient than those in some areas of modern Pakistan and India today.
All houses in the major cities of Harappa and Mohenjo-daro had access to water and drainage facilities.
Waste water was directed to covered drains, which lined the major streets.
Reasons for artificial drainage
Wetland soils may need drainage to be used for agriculture.