title: Uralic languages

text: The proto-Uralic languages and the early Uralic people originated somewhere in eastern Siberia or possibly Northeast Asia. They were closely related to other Siberian and East Asian but also Inuit people. They migrated into central Siberia and then about 3,000 years ago started to migrate to the Baltic region in northeastern Europe. They assimilated many Paleo-European tribes. Genetic and anthropologic studies show that the early Uralic people were similar to various Siberian and East Asian people (Mongoloids).


title: Uralic languages

text: Several linguists and geneticists suggest that the Uralic languages are related to various Siberian languages and possibly also some languages of northern Native Americans. A proposed family is named Uralo-Siberian. It includes Uralic, Yukaghir, Eskimo–Aleut (Inuit), possibly Nivkh and Chukotko-Kamchatkan.


title: Flag of Saudi Arabia

text: The flag of Saudi Arabia is the flag used by the government of Saudi Arabia since March 15, 1973. It is a green flag featuring in white an Arabic inscription and a sword.


title: Flag of Saudi Arabia

text: The script on the flag is written in the "Thuluth" script. It is the "shahadah" or Islamic declaration of faith:


title: Flag of Saudi Arabia

text: Green flags with this or other Arabic scripts are commonly seen in Islam. They should not be confused with the Saudi national flag. These other flags normally do not have the sword symbol.


title: Flag of Saudi Arabia

text: The flag is made so that the "shahada" reads correctly, from right to left, from either side. The sword points from hoist to fly on both sides. The flag is sinister hoisted. This means that the obverse side (front) has the hoist side (flagpole side) to the right.


title: Physical exercise

text: People do physical exercises as a part of their healthy lifestyle to get stronger and healthier or stay strong and healthy or to improve their body image. There are three basic modes of physical exercises:


title: Physical exercise

text: Exercise can be fun, but it is important for the exerciser to do what he likes and eat enough calories , so when he exercises he is building up muscles, not just breaking them down for fuel. Carbohydrates are muscle-sparing; and if one does not get enough calories overall, there is the risk of burning muscles up with the fat to make up the deficit.


title: Physical exercise

text: Benefits of exercise for all ages have been known since antiquity. Marcus Cicero, around 65 BC, stated: “It is exercise alone that supports the spirits, and keeps the mind in vigor.”


title: Physical exercise

text: The CDC recommends that adults should get 150 minutes of physical activity weekly. Regular exercise has been shown to help high blood pressure, obesity, heart disease, diabetes, and depression, among others. Exercise also helps people feel less tired.


title: Physical exercise

text: Regular exercise can have a profoundly positive impact on depression, anxiety, and ADHD. It also relieves stress, improves memory, helps sleep better, and boosts overall mood. Studies show that exercise can treat mild to moderate depression as effectively as antidepressant medication but without the side-effects, of course.


title: Light microscope

text: A light microscope works like a refracting telescope except that the object is very close to the objective lens. An object to be studied, for example a tiny organism so small it looks like just a dot, is put on a slide, which is usually a flat piece of glass. The clips on the microscope's flat stage hold the slide in place. The stage can be adjusted to add more light. It also moves to allow different layers of the object to be in focus. The user looks through the microscope eyepiece. A mirror at the bottom of the microscope reflects light rays up to the object through a hole in the stage. Objective lenses magnify the image which is made even larger when it is seen through the eyepiece lenses. Some light microscopes are actually digital cameras, made to photograph small things but having no eyepiece.


title: Light microscope

text: Many microscopes, often used in colleges and high schools, normally have a top magnification of 40x with the option of having 4x and 8x. This lets the microscope show basic cells and other items. Others can magnify hundreds of times, or thousands.


title: Light microscope

text: All modern optical microscopes designed for viewing samples by transmitted light share the same basic components of the light path, listed here in the order the light travels through them. Also almost all microscopes have the same 'structural' components:


title: Light microscope

text: Optical microscopes cannot show things that are smaller than light waves, because of the diffraction limit. Microscopes which can see smaller things include:


title: Biodiversity

text: The term biological diversity was used first by wildlife scientist and conservationist Raymond F. Dasmann in 1968, where he advocated conservation. It was widely adopted only in the 1980s.


title: Biodiversity

text: The term biodiversity first appeared in a publication in 1988 when entomologist E. O. Wilson used it as a title. Since then, the term has often been used by biologists, environmentalists, political leaders, and citizens. A similar term in the United States is "natural heritage." It predates the others and is more accepted by the wider audience interested in conservation. Broader than biodiversity, it includes geology and landforms.


title: Biodiversity

text: Biologists most often define biodiversity as the "totality of genes, species, and ecosystems of a region". An advantage of this definition is that it seems to describe most circumstances. There are three levels at which biological variety can been identified:


title: Bronny James

text: LeBron "Bronny" Raymone James Jr. (; born October 6, 2004) is an American basketball player who attends Sierra Canyon School in Los Angeles. He is the elder son of professional basketball player LeBron James.


title: Bronny James

text: James has a younger brother Bryce, born in 2007, and a younger sister Zhuri, born in 2014. And his godfather is basketball player Chris Paul, who is a ten-time NBA All-Star.


title: Bronny James

text: James has worn the number 0 jersey as inspiration from his favorite NBA player Russell Westbrook. Entering eighth grade, he switched to a number 23 jersey in honor of his father's number.


title: Bronny James

text: Bronny was born on October 6, 2004 to NBA All-Star player LeBron James, age 19, and his longtime girlfriend (now wife) Savannah Brinson. James was raised by both of his parents.


title: Bronny James

text: As a child, James played several sports including basketball and soccer, but his father did not allow him to play American football or ice hockey over safety concerns. In 2014, James was featuring in basketball highlight reels that drew national attention. In February 2018, James guided Old Trail School in Bath Township, Summit County, Ohio, where he attended middle school, to an Independent School League tournament win.


title: Bronny James

text: James competed with various Amateur Athletic Union (AAU) basketball teams before high school. At age nine, he played for the Miami City Ballers at a fourth grade AAU tournament while being observed by Kentucky Wildcats head coach John Calipari. In June 2015, James led the Gulf Coast Blue Chips AAU team to a fourth grade championship at the League Dallas/Hype Sports Summer Jam.


title: Bronny James

text: In March 2018, he helped the North Coast Blue Chips capture a John Lucas All-Star Weekend title in Houston. On April 2, 2018, his Blue Chips finished undefeated and claimed the under-13 championship at the NY2LA Swish 'N Dish tournament in Wisconsin. In June, James represented the same team at the Jr. National Basketball Association (NBA) Midwest Championships against ninth grade opponents and advanced to the quarterfinals. In April 2019, despite being younger than most of the competition at age 14, he joined AAU team Strive for Greatness at the under-16 Nike EYBL in Indianapolis, where he faced a number of highly coveted recruits and drew praise from scouts.


title: Bronny James

text: In August 6, 2018, James enrolled at Crossroads School, a private K–12 school in Santa Monica, California. California state rules prevented him from immediately joining the varsity team because he was in eighth grade. On December 3, 2018, in his first game for the school, James scored 27 points in a 61–48 victory over Culver City Middle School.


title: Orion (constellation)

text: Orion is one of the largest constellations in the sky. It is supposed to look like the warrior Orion from Greek mythology. The constellation has other names in different cultures: it is mentioned under a Hebrew name in the Book of Job.


title: Orion (constellation)

text: The constellation has a clear hour-glass shape with "Orion's Belt" in the centre. That part is made up of three bright stars (Alnitak, Alnilam, Mintaka) in line. The Orion constellation has 81 visible stars, including some of the brightest and most important stars in the night sky. Rigel is the brightest star in it, and Betelgeuse is a huge, rather unstable red supergiant.


title: Orion (constellation)

text: The constellation includes a series of starburst nebulae where new stars are forming. The whole group of nebulae is known as the Orion complex. The complex is 1,500 to 1,600 light-years away, and hundreds of light-years across. It includes


title: Orion (constellation)

text: In Greek mythology, Orion was a great hunter who joined Artemis's Hunt. He was the first ever male to ever enter the Hunt. Inevitably, he slowly started getting closer to Artemis, and eventually fell in love with her, even though he knew she had sworn an oath of maidenhood. Artemis did not sense this at the time, so she let him stay in the Hunt. The problem was that Orion was too good a hunter, and got in over his head. He killed too many animals, which was against the Hunters' nature, which was not to harm nature if it was not of danger to them. Gaea, the Earth Spirit, sensed this, and sent a giant scorpion to kill him, to punish him for his sins against nature. Artemis mourned his death, and herself made a constellation dedicated him, namely, the Orion's Belt.


title: Orion (constellation)

text: The ancient Egyptians equated the constellation with Osiris, god of the afterlife. The ancient Egyptian "First Time", "when Osiris walked on the Earth", has by some fringe archeologists been held to be around 10,500 BC; thanks to precession (which was known to the astronomers of the Early Dynasties), around that time at the Spring Equinox the constellation could be seen "walking" on the horizon just before dawn.


title: Orion (constellation)

text: Extend the line of the Belt southeastward to find Sirius (α CMa); northwestward to find Aldebaran (α Tau). A line eastward across the two shoulders is the direction of Procyon (α CMi). A line from Rigel through Betelgeuse points to Castor and Pollux (α Gem and β Gem).


title: Nihari

text: Nihari () is a stew from Pakistan, mostly consumed by the Muslim Punjabi people of the Lahore region. consisting of slow-cooked meat, mainly shank meat of beef or lamb and mutton, goat meat and chicken, along with bone marrow. It is flavored with long pepper (pippali), a relative of black pepper. It is considered as the ""National Dish of Pakistan"" respectively. Medically, "Nihari" is also used as a home remedy for fever, rhinorrhea and the common cold.


title: Nihari

text: Nihari comes from the Arabic nahaar (), meaning "morning". It was originally eaten by Nawabs in the Mughal Empire as a breakfast item after their Islamic morning prayer of Fajr.


title: Nihari

text: Nihari is a traditional dish of Muslims of Delhi, Bhopal and Lucknow. After the Partition of British India and creation of Pakistan in 1947, many Urdu speaking Muslims from northern India migrated to Karachi and established restaurants. In Karachi, Nihari became a roaring success and soon was found all over Pakistan. Now Nihari is available in Pakistani restaurants around the world. A particular favorite is nalli nihari, which is made with marrow added to nihari, and makes the stew very rich. In some restaurants, a few kilos from each day's leftover Nihari is added to the next day's pot. This re-used portion of Nihari is called "taar" and is believed to provide the unique flavour. Some Nihari outlets in old Delhi boast of an unbroken taar going back more than a century.


title: Rounding

text: The word "rounding" for a numerical value means replacing it by another value that is approximately equal but has a shorter, simpler, or more explicit form. For example, US$23.74 could be rounded to US$24, the fraction 312/937 could be rounded to 1/3, and the expression formula_1 could be rounded to 1.41.


title: Rounding

text: Rounding is often done on purpose to obtain a value that is easier to write and handle than the original. It may also be done to indicate the accuracy of a computed number; for example, a quantity that was computed as 123,456, but is known to be accurate only to within a few hundred units, is better stated as "about 123,500".


title: Rounding

text: On the other hand, rounding can introduce some "round-off error" as a result. Rounding is almost unavoidable in many computations, especially when dividing two numbers in integer or doing fixed-point arithmetic; when computing mathematical functions such as square roots, logarithms, and sines; or when using a floating point representation with a fixed number of significant digits. In a sequence of calculations, these rounding errors generally accumulate, and in certain "ill-conditioned" cases, they may make the result meaningless.


title: Rounding

text: Accurate rounding of transcendental mathematical functions is difficult, because the number of extra digits that need to be calculated to resolve whether to round up or down cannot be known in advance. This problem is known as "the table-maker's dilemma" ("below").


title: Rounding

text: Rounding has many similarities to the quantization that occurs when physical quantities must be encoded by numbers or digital signals.


title: Rounding

text: The most common type of rounding is to round to an integer; or, more generally, to an integer multiple of some increment—such as rounding to whole tenths of seconds, hundredths of a dollar, to whole multiples of 1/2 or 1/8 inch, to whole dozens or thousands, etc..


title: Rounding

text: In general, rounding a number "x" to a multiple of some specified increment "m" entails the following steps:


title: Rounding

text: For example, rounding "x" = 2.1784 dollars to whole cents (that is, to a multiple of 0.01) entails computing "y" = "x"/"m" = 2.1784/0.01 = 217.84, then rounding "y" to the integer "q" = 218, and finally computing "z" = "q"×"m" = 218×0.01 = 2.18.


title: Rounding

text: When rounding to a predetermined number of significant digits, the increment "m" depends on the magnitude of the number to be rounded (or of the rounded result).


title: Rounding

text: The increment "m" is normally a finite fraction in whatever numeral system that is used to represent the numbers. For display to humans, that usually means the decimal numeral system (that is, "m" is an integer times a power of 10, like 1/1000 or 25/100). For intermediate values stored in digital computers, it often means the binary numeral system ("m" is an integer times a power of 2).


title: Rounding

text: The abstract single-argument "round()" function that returns an integer from an arbitrary real value has at least a dozen distinct concrete definitions presented in the rounding to integer section. The abstract two-argument "round()" function is formally defined here, but in many cases it is used with the implicit value "m" = 1 for the increment and then reduces to the equivalent abstract single-argument function, with also the same dozen distinct concrete definitions.


title: Rounding

text: The most basic form of rounding is to replace an arbitrary number by an integer. All the following rounding modes are concrete implementations of the abstract single-argument "round()" function presented and used in the previous sections.


title: Rounding

text: The first four methods are called directed rounding, as the displacements from the original number "y" to the rounded value "q" are all directed towards or away from the same limiting value (0, +∞, or −∞).


title: Rounding

text: If "y" is positive, round-down is the same as round-towards-zero, and round-up is the same as round-away-from-zero. If "y" is negative, round-down is the same as round-away-from-zero, and round-up is the same as round-towards-zero. In any case, if "y" is integer, "q" is just "y". The following table illustrates these rounding methods:


title: Rounding

text: Where many calculations are done in sequence, the choice of rounding method can have a very significant effect on the result. A famous instance involved a new index set up by the Vancouver Stock Exchange in 1982. It was initially set at 1000.000, and after 22 months had fallen to about 520 — whereas stock prices had generally increased in the period. The problem was caused by the index being recalculated thousands of times daily, and always being rounded down to 3 decimal places, in such a way that the rounding errors accumulated. Recalculating with better rounding gave an index value of 1098.892 at the end of the same period.


title: Rounding

text: Rounding a number "y" to the nearest integer requires some tie-breaking rule for those cases when "y" is exactly half-way between two integers — that is, when the fraction part of "y" is exactly 0.5.


title: Rounding

text: The following tie-breaking rule, called round half up (or round half towards plus infinity), is widely used in many disciplines. That is, half-way values "y" are always rounded up.


title: Rounding

text: If it were not for the 0.5 fractions, the roundoff errors introduced by the round to nearest method would be quite symmetric: for every fraction that gets rounded up (such as 0.268), there is a complementary fraction (namely, 0.732) that gets rounded down, by the same amount. When rounding a large set of numbers with random fractional parts, these rounding errors would statistically compensate each other, and the expected (average) value of the rounded numbers would be equal to the expected value of the original numbers.


title: Rounding

text: However, the "round half up" tie-breaking rule is not symmetric, as the fractions that are exactly 0.5 always get rounded up. This asymmetry introduces a positive bias in the roundoff errors. For example, if the fraction of "y" consists of three random decimal digits, then the expected value of "q" will be 0.0005 higher than the expected value of "y". For this reason, round-to-nearest with the "round half up" rule is also (ambiguously) known as asymmetric rounding.


title: Rounding

text: One reason for rounding up at 0.5 is that only one digit need be examined. When seeing 17.50000..., for example, the first three figures, 17.5, determines that the figure would be rounded up to 18. If the opposite rule were used (round half down), then all the zero decimal places would need to be examined to determine if the value is exactly 17.5.


title: Rounding

text: One may also use round half down (or round half towards minus infinity) as opposed to the more common "round half up" (the "round half up" method is a common convention, but is nothing more than a convention).


title: Rounding

text: The "round half down" tie-breaking rule is not symmetric, as the fractions that are exactly 0.5 always get rounded down. This asymmetry introduces a negative bias in the roundoff errors. For example, if the fraction of "y" consists of three random decimal digits, then the expected value of "q" will be 0.0005 lower than the expected value of "y". For this reason, round-to-nearest with the "round half down" rule is also (ambiguously) known as asymmetric rounding.


title: Rounding

text: The other tie-breaking method commonly taught and used is the round half away from zero (or round half towards infinity), namely:


title: Rounding

text: This method treats positive and negative values symmetrically, and therefore is free of overall bias if the original numbers are positive or negative with equal probability. However, this rule will still introduce a positive bias for positive numbers, and a negative bias for the negative ones.


title: Rounding

text: It is often used for currency conversions and price roundings (when the amount is first converted into the smallest significant subdivision of the currency, such as cents of a euro) as it is easy to explain by just considering the first fractional digit, independently of supplementary precision digits or sign of the amount (for strict equivalence between the paying and recipient of the amount).


title: Rounding

text: One may also round half towards zero (or round half away from infinity) as opposed to the more common "round half away from zero" (the "round half away from zero" method is a common convention, but is nothing more than a convention).


title: Rounding

text: This method also treats positive and negative values symmetrically, and therefore is free of overall bias if the original numbers are positive or negative with equal probability. However, this rule will still introduce a negative bias for positive numbers, and a positive bias for the negative ones.


title: Rounding

text: This method also treats positive and negative values symmetrically, and therefore is free of overall bias if the original numbers are positive or negative with equal probability. In addition, for most reasonable distributions of "y" values, the expected (average) value of the rounded numbers is essentially the same as that of the original numbers, even if the latter are all positive (or all negative). However, this rule will still introduce a positive bias for even numbers (including zero), and a negative bias for the odd ones.


title: Rounding

text: This variant of the round-to-nearest method is also called unbiased rounding (ambiguously, and a bit abusively), convergent rounding, statistician's rounding, Dutch rounding, Gaussian rounding, or bankers' rounding. This is widely used in bookkeeping.


title: Rounding

text: This method also treats positive and negative values symmetrically, and therefore is free of overall bias if the original numbers are positive or negative with equal probability. In addition, for most reasonable distributions of "y" values, the expected (average) value of the rounded numbers is essentially the same as that of the original numbers, even if the latter are all positive (or all negative). However, this rule will still introduce a negative bias for even numbers (including zero), and a positive bias for the odd ones.


title: Rounding

text: This variant is almost never used in most computations, except in situations where one wants to avoid rounding 0.5 or −0.5 to zero, or to avoid increasing the scale of numbers represented as floating point (with limited ranges for the scaling exponent), so that a non "infinite" number would round to infinite, or that a small "denormal" value would round to a normal non-zero value (these could occur with the "round half to even" mode). Effectively, this mode prefers preserving the existing scale of tie numbers, avoiding out of range results when possible.


title: Rounding

text: Like round-half-to-even, this rule is essentially free of overall bias; but it is also fair among even and odd "q" values. On the other hand, it introduces a random component into the result; performing the same computation twice on the same data may yield two different results. Also, it is open to unconscious bias if humans (rather than computers or devices of chance) are "randomly" deciding in which direction to round.


title: Rounding

text: This suppresses the random component of the result, if occurrences of 0.5 fractional parts can be effectively numbered. But it can still introduce a positive or negative bias according to the direction of rounding assigned to the first occurrence, if the total number of occurrences is odd.


title: Rounding

text: In some contexts, all the rounding methods above may be unsatisfactory. For example, suppose that "y" is an accurate measurement of an audio signal, which is being rounded to an integer "q" in order to reduce the storage or transmission costs. If "y" changes slowly with time, any of the rounding method above will result in "q" being completely constant for long intervals, separated by sudden jumps of ±1. When the "q" signal is played back, these steps will be heard as a very disagreeable noise, and any variations of the original signal between two integer values will be completely lost.


title: Rounding

text: One way to avoid this problem is to round each value "y" upwards with probability equal to its fraction, and round it downwards with the complement of that probability. For example, the number 23.17 would be rounded up to 24 with probability 0.17, and down to 23 with probability 1 - 0.17 = 0.83. (This is equivalent to rounding down "y" + "s", where "s" is a random number uniformly distributed between 0 and 1.) With this special rounding, known as dithering, the sudden steps get replaced by a less objectionable noise, and even small variations in the original signal will be preserved to some extent. Like the stochastic approach to tie-breaking, dithering has no bias: if all fraction values are equally likely, rounding up by a certain amount is as likely as rounding down by that same amount; and the same is true for the sum of several rounded numbers. On the other hand, dithering introduces a random component in the result, much greater than that of stochastic tie-breaking.


title: Rounding

text: More precisely, the roundoff error for each dithered number will be a uniformly distributed random variable with mean value of zero, but with a standard deviation formula_12, which is better than the 1/2 standard deviation with the simple predictive methods, but slightly higher than with the simpler stochastic method. However, the sum of "n" rounded numbers will be a random variable with expected error zero, but with standard deviation formula_13 (the total remaining noise) which diverges semi-quadratically and may become easily perceptible, even if the standard deviation of the roundoff error per sample will be formula_14 which slowly converges semi-quadratically to zero. So, this random distribution may still be too high for some applications that are rounding a lot of data.


title: Rounding

text: This variant of the simple dithering method still rounds values with probability equal to its fraction. However, instead of using a random distribution for rounding isolated samples, the roundoff error occurring at each rounded sample is totalled for the next surrounding elements to sample or compute; this accumulated value is then added to the value of these next sampled or computed values to round, so that the modified values will take into account this difference using a predictive model (such as Floyd–Steinberg dithering).


title: Rounding

text: The modified values are then rounded with any one of the above rounding methods, the best ones being with stochastic or dithering methods: in this last case, the sum of "n" rounded numbers will still be a random variable with expected error zero but with an excellent constant standard deviation of formula_15, instead of diverging semi-quadratically when dithering isolated samples; and the overall average roundoff error deviation per rounded sample will be formula_16 that will converge hyperbolically to zero, faster than with the semi-hyperbolic convergence when dithering isolated samples.


title: Rounding

text: In practice, when rounding large sets of sampled data (such as audio, image and video rendering), the accumulation of roundoff errors is most frequently used with a simple predictive rounding of the modified values (such as rounding towards zero), because it will still preserve the hyperbolic convergence towards zero of the overall mean roundoff error bias and of its standard deviation. This enhancement is frequently used in image and audio processing (notably for accurate rescaling and antialiasing operations, where the simple probabilistic dithering of isolated values may still produce perceptible noise, sometimes even worse than the moiré effects occurring with simple non-probabilistic rounding methods applied to isolated samples).


title: Rounding

text: The effective propagation of accumulated roundoff errors may depend on the discrete dimension of the sampled data to round: when sampling bidimensional images, including colored images (that add the discrete dimension of color planes), or tridimensional videos (that add a discrete time dimension), or on polyphonic audio data (using time and channel discrete dimensions), it may still be preferable to propagate this error into a preferred direction, or equally into several orthogonal dimensions, such as vertically vs. horizontally for bidimensional images, or into parallel color channels at the same position and/or timestamp, and depending on other properties of these orthogonal discrete dimensions (according to a perception model). In those cases, several roundoff error accumulators may be used (at least one for each discrete dimension), or a ("n"-1)-dimension vector (or matrix) of accumulators.


title: Rounding

text: In some of these cases, the discrete dimensions of the data to sample and round may be treated non orthogonally: for example, when working with colored images, the trichromatic color planes data in each physical dimension (height, width and optionally time) could be remapped using a perceptive color model, so that the roundoff error accumulators will be designed to preserve lightness with a higher probability than hue or saturation, instead of propagating errors into each orthogonal color plane independently; and in stereophonic audio data the two rounded data channels (left and right) may be rounded together to preserve their mean value in priority to their effective difference that will absorb most of the remaining roundoff errors, in a balanced way around zero.


title: Rounding

text: In some contexts it is desirable to round a given number "x" to a "neat" fraction — that is, the nearest fraction "z" = "m"/"n"


title: Rounding

text: whose numerator "m" and denominator "n" do not exceed a given maximum. This problem is fairly distinct from that of rounding a value to a fixed number of decimal or binary digits, or to a multiple of a given unit "m". This problem is related to Farey sequences, the Stern-Brocot tree, and continued fractions.


title: Rounding

text: This type of rounding, which is also named rounding to a logarithmic scale, is a variant of Rounding to a specified increment but with an increment that is modified depending on the scale and magnitude of the result. Concretely, the intent is to limit the number of significant digits, rounding the value so that non-significant digits will be dropped. This type of rounding occurs implicitly with numbers computed with floating-point values with limited precision (such as IEEE-754 "float" and "double" types), but it may be used more generally to round any real values with any positive number of significant digits and any strictly positive real base.


title: Rounding

text: For example it can be used in engineering graphics for representing data with a logarithmic scale with variable steps (for example wave lengths, whose base is not necessarily an integer measure), or in statistical data to define classes of real values within intervals of exponentially growing widths (but the most common use is with integer bases such as 10 or 2).


title: Rounding

text: This type of rounding is based on a logarithmic scale defined by a fixed non-zero real scaling factor "s" (in most frequent cases this factor is "s"=1) and a fixed positive base "b">1 (not necessarily an integer and most often different from the scaling factor), and a fixed integer number "n">0 of significant digits in that base (which will determine the value of the increment to use for rounding, along with the computed effective scale of the rounded number).


title: Rounding

text: The primary argument number (as well as the resulting rounded number) is first represented in exponential notation "x" = "s"·"a"·"m"·"b", such that the sign "s" is either +1 or −1, the absolute mantissa "a" is restricted to the half-open positive interval [1/"b",1), and the exponent "c" is any (positive or negative) integer. In that representation, all significant digits are in the fractional part of the absolute mantissa whose integer part is always zero.


title: Rounding

text: If the source number (or rounded number) is 0, the absolute mantisssa "a" is defined as 0, the exponent "c" is fixed to an arbitrary value (0 in most conventions, but some floating-point representations cannot use a null absolute mantissa but reserve a specific maximum negative value for the exponent "c" to represent the number 0 itself), and the sign "s" may be arbitrarily chosen between −1 or +1 (it is generally set to +1 for simple zero, or it is set to the same sign as the argument in the rounded value if the number representation allows to differentiate positive and negative zeroes, even if they finally represent the same numeric value 0).


title: Rounding

text: A scaled exponential representation as "x" = "a"·"s"·"b" may also be used equivalently, with a signed mantissa "a" either equal to zero or within one of the two half-open intervals (−1,−1/"b"] and [+1/"b",+1), and this will be the case in the algorithm below.


title: Rounding

text: For the abstract "round()" function, this type of rounding can use any one of the "rounding to integer" modes described more completely in the next section, but it is most frequently the "round to nearest" mode (with tie-breaking rules also described more completely below).


title: Rounding

text: Finished lumber, writing paper, capacitors, and many other products are usually sold in only a few standard sizes.


title: Rounding

text: Many design procedures describe how to calculate an approximate value, and then "round" to some standard size using phrases such as "round down to nearest standard value", "round up to nearest standard value", or "round to nearest standard value".


title: Rounding

text: In floating-point arithmetic, rounding aims to turn a given value "x" into a value "z" with a specified number of "significant" digits. In other words, "z" should be a multiple of a number "m" that depends on the magnitude of "z". The number "m" is a power of the base (usually 2 or 10) of the floating-point form.


title: Rounding

text: Apart from this detail, all the variants of rounding discussed above apply to the rounding of floating-point numbers as well. The algorithm for such rounding is presented in the Scaled rounding section above, but with a constant scaling factor "s"=1, and an integer base "b">1.


title: Rounding

text: For results where the rounded result would overflow the result for a directed rounding is either the appropriate signed infinity, or the highest representable positive finite number (or the lowest representable negative finite number if "x" is negative), depending on the direction of rounding. The result of an overflow for the usual case of "round to even" is always the appropriate infinity.


title: Rounding

text: In addition, if the rounded result would underflow, i.e. if the exponent would exceed the lowest representable integer value, the effective result may be either zero (possibly signed if the representation can maintain a distinction of signs for zeroes), or the smallest representable positive finite number (or the highest representable negative finite number if "x" is negative), possibly a "denormal" positive or negative number (if the mantissa is storing all its significant digits, in which case the most significant digit may still be stored in a lower position by setting the highest stored digits to zero, and this stored mantissa does not drop the most significant digit, something that is possible when base "b"=2 because the most significant digit is always 1 in that base), depending on the direction of rounding. The result of an underflow for the usual case of "round to even" is always the appropriate zero.


title: Rounding

text: Rounding a number twice in succession to different precisions, with the latter precision being coarser, is not guaranteed to give the same result as rounding once to the final precision except in the case of directed rounding. For instance rounding 9.46 to one decimal gives 9.5, and then 10 when rounding to integer using rounding half to even, but would give 9 when rounded to integer directly.


title: Rounding

text: Some computer languages and the IEEE 754-2008 standard dictate that in straightforward calculations, the result should not be rounded twice. This has been a particular problem with Java as it is designed to be run identically on different machines, special programming tricks have had to be used to achieve this with x87 floating point.


title: Rounding

text: The Java language was changed to allow different results where the difference does not matter and require a "strictfp" qualifier to be used when the results have to conform accurately.


title: Rounding

text: It is possible to use rounded arithmetic to evaluate the exact value of a function with a discrete domain and range. For example, if we know that an integer "n" is a perfect square, we can compute its square root by converting "n" to a floating-point value "x", computing the approximate square root "y" of "x" with floating point, and then rounding "y" to the nearest integer "q". If "n" is not too big, the floating-point roundoff error in "y" will be less than 0.5, so the rounded value "q" will be the exact square root of "n". In most modern computers, this method may be much faster than computing the square root of "n" by an all-integer algorithm.


title: Rounding

text: William Kahan coined the term "The Table-Maker's Dilemma" for the unknown cost of rounding transcendental functions:


title: Rounding

text: The IEEE floating point standard guarantees that add, subtract, multiply, divide, square root, and floating point remainder will give the correctly rounded result of the infinite precision operation. However, no such guarantee is given for more complex functions and they are typically only accurate to within the last bit at best.


title: Rounding

text: Using the Gelfond–Schneider theorem and Lindemann–Weierstrass theorem, many of the standard elementary functions can be proved to return transcendental results when given rational non-zero arguments; therefore it is always possible to correctly round such functions. However determining a limit for a given precision on how accurate results needs to be computed before a correctly rounded result can be guaranteed may demand a lot of computation time.


title: Rounding

text: There are some packages around now that offer full accuracy. The MPFR package gives correctly rounded arbitrary precision results. IBM has written a package for fast and accurate IEEE elementary functions and in the future the standard libraries may offer such precision.


title: Rounding

text: It is possible to devise well-defined computable numbers which it may never be possible to correctly round no matter how many digits are calculated. For instance, if Goldbach's conjecture is true but unprovable, then it is impossible to correctly round down 0.5 + 10 where n is the first even number greater than 4 which is not the sum of two primes, or 0.5 if there is no such number. This can however be approximated to any given precision even if the conjecture is unprovable.


title: Rounding

text: The concept of rounding is very old, perhaps older even than the concept of division. Some ancient clay tablets found in Mesopotamia contain tables with rounded values of reciprocals and square roots in base 60.


title: Rounding

text: The "Round-to-even" method has served as the ASTM (E-29) standard since 1940. The origin of the terms "unbiased rounding" and "statistician's rounding" are fairly self-explanatory. In the 1906 4th edition of "Probability and Theory of Errors" Robert Simpson Woodward called this "the computer's rule" indicating that it was then in common use by human computers who calculated mathematical tables. Churchill Eisenhart's 1947 paper "Effects of Rounding or Grouping Data" (in "Selected Techniques of Statistical Analysis", McGrawHill, 1947, Eisenhart, Hastay, and Wallis, editors) indicated that the practice was already "well established" in data analysis.


title: Rounding

text: The origin of the term "bankers' rounding" remains more obscure. If this rounding method was ever a standard in banking, the evidence has proved extremely difficult to find. To the contrary, section 2 of the European Commission report "The Introduction of the Euro and the Rounding of Currency Amounts" suggests that there had previously been no standard approach to rounding in banking; and it specifies that "half-way" amounts should be rounded up.


title: Rounding

text: Until the 1980s, the rounding method used in floating-point computer arithmetic was usually fixed by the hardware, poorly documented, inconsistent, and different for each brand and model of computer. This situation changed after the IEEE 754 floating point standard was adopted by most computer manufacturers. The standard allows the user to choose among several rounding modes, and in each case, specifies precisely how the results should be rounded. These features made numerical computations more predictable and machine-independent, and made possible the efficient and consistent implementation of interval arithmetic.


title: Rounding

text: Most programming languages provide functions or special syntax to round fractional numbers in various ways. The earliest numeric languages, such as FORTRAN and C, would provide only one method, usually truncation (towards zero). This default method could be implied in certain contexts, such as when assigning a fractional number to an integer variable, or using a fractional number as an index of an array. Other kinds of rounding had to be programmed explicitly; for example, rounding a positive number to the nearest integer could be implemented by adding 0.5 and truncating.


title: Rounding

text: In the last decades, however, the syntax and/or the standard libraries of most languages have commonly provided at least the four basic rounding functions (up/ceiling, down/floor, to nearest, and towards zero). The tie-breaking method may vary depending the language and version, and/or may be selectable by the programmer. Several languages follow the lead of the IEEE-754 floating-point standard, and define these functions as taking a double precision float argument and returning the result of the same type, which then may be converted to an integer if necessary. Since the IEEE double precision format has 52 fraction bits, this approach may avoid spurious overflows in languages have 32-bit integers. Some languages, such as PHP, provide functions that round a value to a specified number of decimal digits, e.g. from 4321.5678 to 4321.57 or 4300. In addition, many languages provide a "printf" or similar string formatting function, which allows one to convert a fractional number to a string, rounded to a user-specified number of decimal places (the "precision"). On the other hand, truncation (round to zero) is still the default rounding method used by many languages, especially for the division of two integer values.


title: Rounding

text: On the opposite, CSS and SVG do not define any specific maximum precision for numbers and measurements, that are treated and exposed in their Document Object Model and in their Interface-description-language interface as strings as if they had infinite precision, and do not discriminate between integers and floating point values; however, the implementations of these languages will typically convert these numbers into IEEE-754 double floating points before exposing the computed digits with a limited precision (notably within standard Javascript or ECMAScript interface bindings).


title: Rounding

text: In a guideline issued in mid-1966, the U.S. Office of the Federal Coordinator for Meteorology determined that weather data should be rounded to the nearest round number, with the "round half up" tie-breaking rule. For example, 1.5 rounded to integer should become 2, and −1.5 should become −1. Prior to that date, the tie-breaking rule was "round half away from zero".


title: Rounding

text: Some meteorologists may write "-0" to indicate a temperature between 0.0 and -0.5 degrees (exclusive) that was rounded to integer. This notation is used when the negative sign is considered important, no matter how small is the magnitude; for example, when rounding temperatures in the Celsius scale, where below zero indicates freezing.


title: Rounding

text: An introduction to different rounding algorithms that is accessible to a general audience but especially useful to those studying computer science and electronics.


title: Bobby Charlton

text: Sir Robert Charlton, (born 11 October 1937) is a retired English footballer who played for the England national team. He played over 600 times for Manchester United. He also played for England over 100 times and scored more goals than any other player. He played for England when they beat Germany in the World Cup final in 1966. He is regarded as one of the greatest footballers of all time.


title: Bobby Charlton

text: He is the last survivor of the Munich air disaster, where his life was saved by fellow teammate Harry Gregg.


title: Oxidation state

text: The oxidation state (or oxidation number) of an element is used to predict what sort of chemical compounds form.


title: Oxidation state

text: For example, if you put hydrogen and oxygen together, they form HO, and not HO because the oxidation number of oxygen is −2, which means that we need two +1 hydrogens for the numbers to balance.


title: Oxidation state

text: You can look up the oxidation state(s) of an element on many periodic tables. They are usually between −2 and +3.


title: Oxidation state

text: Oxidation states were invented by Antoine Lavoisier to predict how oxygen reacted in chemical reactions; hence the name. Later on, we learned that Lavoisier's theory can be used to predict other reactions too, many of them have nothing to do with oxygen.


title: Oxidation state

text: In ionic compounds, oxidation states tell us about the movement of charge within the compound. For example, chlorine has a very high electronegativity which means that it really likes electrons and sodium has a very low electronegativity which means that it really hates electrons. When sodium and chlorine are close together, sodium will give away an electron to chlorine. A change in charge has taken place; chlorine's charge has gone down which we call reduction, and sodium's charge has gone up which we call oxidation.


title: Environmental factor

text: An environmental factor (also called eco factor) is any factor which influences living organisms. Abiotic factors include ambient temperatures, the amounts of sunlight and PH of water soil in which organisms live. Biotic factors include the availability of food organisms and the presence of predators, parasites and competitors.


title: Environmental factor

text: Cancers are often related to environmental factors. Having a healthy diet, healthy weight, limiting alcoholic drinks and quitting or not starting smoking cuts down the risks of getting cancer.


title: Ford Model T

text: The Ford Model T was an American car built between 1908 and 1928 by the Ford Motor Company of Detroit, Michigan. It is one of the most important cars in history because it was one of the first cars to be sold for very little money, making it easy for people to travel from place to place.


title: Ford Model T

text: The Model T, also known as the "Tin Lizzie", changed the way Americans live, work and travel. Henry Ford’s revolutionary advancements in assembly-line automobile manufacturing made the Model T the first car to be affordable for a majority of Americans. For the first time car ownership became a reality for average American workers, not just the wealthy. More than fifteen million Model Ts were built in Detroit and Highland Park, Michigan, and the automobile was also assembled at a Ford plant in Manchester, England, and at plants in continental Europe.


title: Ford Model T

text: Before the Model T, most cars cost lots of money. Only rich people could afford them. Even Ford's cars before the Model T cost a lot. The Model T went for around $980. A car built in 1903 called the Oldsmobile Curved Dash was very easy to buy, but was a very simple and slow car that was more like a carriage than a car.


title: Ford Model T

text: Even before it lost favor to larger, more powerful, and more luxurious cars, the Model T, known popularly as the "Tin Lizzie" or the "flivver", had become an American folkloric symbol, essentially realizing Ford’s goal to "democratize the automobile".


title: Ford Model T

text: The man who owned the company, Henry Ford, heard about meat being cut on a disassembly line, which moved meat from worker to worker so that the meat could be cut up. Assembly lines were not much used at the time. Ford knew that if he built his cars on an assembly line instead of one at a time like other cars, he could make a car that anyone could afford and would be built like cars that cost more money. He also knew that he could pay his workers more money.


title: Ford Model T

text: The Model T was offered in several body styles, including a five-seat touring car, a two-seat runabout, and a seven-seat town car. All bodies were mounted on a uniform 100-inch (2.5m)-wheelbase chassis. A choice of colors was originally available, but from 1913 to 1925 the car was mass-produced in only one color—black. The engine was simple and efficient, with all four cylinders cast in a single block and the cylinder head detachable for easy access and repair. The engine generated 20 horsepower and propelled the car to modest top speeds of 40–45 miles per hour (65–70 km/h). In most models the engine was started by a hand crank, which activated a magneto connected to the flywheel, but after 1920 some models were equipped with battery-powered starters.


title: Ford Model T

text: The transmission, having two forward gears and one reverse, was of the planetary type, controlled by foot pedals rather than the more common hand lever used in sliding-gear transmissions. Spark and throttle were controlled by a hand lever on the steering column. The ten gallon fuel tank was located under the front seat. Because gasoline was fed to the engine only by gravity, and also because the reverse gear offered more power than the forward gears, the Model T frequently had to be driven up a steep hill backward. Such deficiencies, along with its homely appearance, less-than-comfortable ride at top speeds, and incessant rattling, made the Model T the butt of much affectionate humor in innumerable jokes, songs, poems, and stories.


title: Ford Model T

text: The Ford Model T car was designed by Henry Ford, Childe Harolde Wills, and two Hungarian men named József Galamb and Eugene Farkas. The Model T had a 177-cubic-inch (2.9-litre) four-cylinder engine producing 20 horsepower (15 kW) for a top speed of 45 miles per hour (72 km/h). The engine had side valves and three main bearings. Fuel economy was 14 to 21 miles per gallon (11 to 17 l/100km).


title: Ford Model T

text: Ford began building the Model T in his Piquette factory on October 6, 1908 as a 1909 model. Workers from all over the world wanted to work for Ford because of the good pay. Workers could even save their money for a Model T of their own. The price of the Model T dropped over the years, making it even easier to buy.


title: Ford Model T

text: Work began at one end of the assembly line, starting with an empty chassis. From there, the chassis moved slowly down the assembly line. Workers on the assembly line added parts to the chassis. Before long, a new Model T rolled off the other end of the line. Different body styles were available, even a truck, or Model TT. At first, the only color available was black. Black paint was used because it was cheaper and lasted longer than other paints and Ford was obsessed with increasing profit. As car paint got better over the years, Ford began offering other colors. The time it took a chassis to become a finished car was over 12 hours when the first Model Ts were built. By the time the last Model T came off of the line, Ford had so many plants, it was making one car every twenty-seven seconds!


title: Ford Model T

text: Even though the Model T sold for little money, Ford used the best materials he could buy to make his car. Most roads in the Model T's day were dirt, gravel, or even mud. That meant the Model T had to be very strong, and it was. The wheels and tyres were very tall and skinny so that they could sink into mud roads and not get stuck. It was also very simple.


title: Ford Model T

text: Ford made the Model T easy to drive compared to today's cars since the people to whom he sold his cars did not know how to drive anything other than a horse. It is not like driving a modern car, though three pedals are on the floor like a modern manual transmission car. A Model T has a steering wheel that works the same way as in cars of today, but almost everything else is different.


title: Ford Model T

text: The first Model Ts did not even have a starter like a modern car. This is the powerful electric motor in a car that turns the engine to make it run when it is turned off. The engine on the Model T was started with a hand crank on the front of the car. A wire loop near the radiator worked the choke on the carburetor to give the engine extra fuel to help start it when it was cold. This could be dangerous if the operator was not careful. If the levers that controlled the engine were not set the right way, especially the spark control, the engine could backfire, or spin the wrong way. Many people got broken arms this way. Doctors even had a name for this kind of break: the "Ford fracture". Many Model T owners added electric starters to their cars and it was not long before Ford started doing the same. A Model T is in high gear by default, so if the parking/clutch lever was not engaged, the car had a tendency to run over the operator when started.


title: Ford Model T

text: To make a modern car go or accelerate once the engine is running, a person steps on a pedal on the floor to engage the transmission into low gear. To make a Model T accelerate, move two levers near the steering wheel. The lever on the right was the throttle (or engine speed), and the lever on the left adjusted the time that the spark plugs fired. These levers needed to be set properly before the engine could be started.


title: Ford Model T

text: The three pedals on the floor of the Model T were for the brake on the right, reverse in the middle to make the Model T go backwards, and a pedal on the left to shift the gears from low to high speed. A lever on the floor worked the brakes as well as the clutch. Pulling the lever toward the driver would set the parking brake and help keep the car from moving while parked. When the lever was placed in the middle, the transmission would be in neutral.


title: Ford Model T

text: Once the engine is running, the driver now has to make the Model T move on its own. Step on the pedal all the way to the left, move the throttle lever to "give it the gas" and gently move the floor lever forward. This is low gear, the powerful gear used to get the Model T moving. Once it is moving, move the right lever up, let the left pedal come all the way up, and give it more gas to shift into high. To make the car go faster still, move the throttle lever as well as the spark advance lever. Stepping on the left pedal only halfway puts the car in neutral, the same as the lever. This helps the Model T come to a stop without causing the engine to stop as well.


title: Ford Model T

text: The brakes on a Model T work the rear wheels by the use of brake bands inside the transmission. Modern cars have brakes on all four wheels. No brakes are on the front wheels of a Model T.


title: Ford Model T

text: More than fifteen million Model Ts were built. That record was broken in 1972 when the Volkswagen Beetle surpassed it. Today, the record for the most cars built is held by the Toyota Corolla.


title: Ford Model T

text: The Model T was nicknamed the "Tin Lizzie" and "Flivver" by the people who drove it. A new car took the place of the Model T in 1928, named the Ford Model A.


title: Bivalve

text: They have a hard calcareous shell made of two parts or 'valves'. The soft parts are inside the shell. The shell is usually bilaterally symmetrical.


title: Bivalve

text: There are over 30,000 species of bivalves, including the fossil species. There are about 9,200 living species in 1,260 genera and 106 families. All of them live in the water, most of them in the sea or in brackish water. Some live in fresh water. All are filter feeders: they lost their radula in the course of evolution. A few are carnivorous, eating much larger prey than the tiny microalgae eaten by other bivalves.


title: Bivalve

text: Bivalves have two shells or valves connected by a hinge with hinge teeth. They are made of a calcareous mineral, calcite or aragonite. The valves are covered by a periostracum, which is an organic horny substance. This forms the familiar coloured layer on the shell.


title: Bivalve

text: The shells are usually held shut by strong adductor muscles. Scallops can use their muscles to flap the valves and swim.


title: Bivalve

text: Some (but not all) molluscs have a part of their mantle known as the siphon (a tube). Siphons, if they exist, come in pairs, one to suck in, one to expel.


title: Bivalve

text: Anything that is small enough to fit inside the hole of its incurrent siphon enters the bivalve. When the floating material comes in, it gets stuck in slimy mucus that is on the surface of the bivalve's gills. The food is moved down to the mouth, which is on the other side of the siphon. Food is digested in the bivalve's stomach and intestine, and everything that is not digested goes out through the other siphon, with water.


title: Bivalve

text: The siphons are an adaptation of burrowing molluscs. Those that live above the substrate (sediment), such as scallops and oysters, do not need them.


title: Bivalve

text: As a group, the bivalves are adapted to penetrate into, and to move along horizontally along, soft ground such as mud and sand. Common examples of this are razor shells, which can dig themselves into the sand with great speed to escape enemies, and cockles.


title: Bivalve

text: Scallops and file clams can swim to escape a predator, clapping their valves together to create a jet of water. Cockles can use their foot to leap from danger. However these methods quickly exhaust the animal. In the razor shells the siphons can break off only to grow back later.


title: Bivalve

text: The file shells can produce a noxious secretion when threatened, and the fan shells of the same family have a unique, acid-producing organ.


title: Bivalve

text: Bivalves are superficially similar to brachiopods, but the construction of the shell is completely different in the two groups. In brachiopods, the two valves are on the dorsal and ventral surfaces of the body, while in bivalves, they are on the left and right sides.


title: Bivalve

text: Bivalves appeared late in the Cambrian explosion and came to increase in the Palaeozoic, and dominate over brachiopods during the Mesozoic. So, it was thought that bivalves are better adapted to aquatic life than the brachiopods, and this caused brachiopods to be out-competed and relegated to minor niches.


title: Bivalve

text: However, after the Permian-Triassic extinction event bivalves had a huge adaptive radiation while brachiopods were devastated, losing 95% of their diversity.


title: Bivalve

text: The upshot was that bivalves took over the desirable inshore habitats. Brachiopods now live in deeper waters where food is scarcer.


title: Pantheism

text: Pantheism is the belief that God and the universe are equivalent (the same thing). A pantheist believes that everything that exists is a part of God or that God is a part of everything that exists. The name pantheism comes from the Greek words theism (belief in God) and pan (all).


title: Pantheism

text: Any doctrine or philosophy that believes that the universe and everything in it is God is said to be pantheistic. Most pantheists believe the universe is sacred and the earth and nature are divine.


title: Pantheism

text: Most of the early Greek philosophers from Thales on to the Stoics believed in some sort of pantheism.


title: Pantheism

text: Pantheism is an important part of many eastern religions such as Hinduism, Buddhism and Taoism, and modern religions such as Druidism.


title: Pantheism

text: Some Christians, Jews and Sufis are Pantheists. However, their majority believes that while God is in everything, there is more to God than just the universe.


title: Pantheism

text: There are several different types of pantheism, including panpsychism (The belief the universe itself has a mind), naturalistic pantheism (The belief the universe is identifiable with the title of "God", as it can be seen as a wondrous and transcendent power), or the worship of nature as a life-giving force.


title: Merostomata

text: Merostomata is a name given to the now extinct sea scorpions (Eurypterida) and the horseshoe crabs (Xiphosura). There are four known species of horsehoe crabs still alive. James Dwight Dana introduced the name to refer to the horseshoe crabs only. Henry Woodward later extended it to refer to both taxa.


title: Tottenham Hotspur Stadium

text: Tottenham Hotspur Stadium is a stadium that serves as the home ground for Tottenham Hotspur in north London, replacing the club's previous stadium, White Hart Lane. It has a capacity of 62,062, making it one of the largest stadiums in the Premier League and the largest club stadium in London. It is designed to be a multi-purpose stadium and features the world's first dividing, retractable football pitch, which reveals a synthetic turf pitch underneath for NFL London Games, concerts and other events.


title: Tottenham Hotspur Stadium

text: "Tottenham Hotspur Stadium" is unlikely to remain the official stadium name indefinitely, it is widely expected that the rights to the naming of the stadium will be sold. The stadium is occasionally referred to as New White Hart Lane by fans and some in the media.


title: Tottenham Hotspur Stadium

text: The stadium is accessible through a number of London Overground, London Underground and National Rail stations: Seven Sisters, Tottenham Hale, Northumberland Park, and White Hart Lane stations. The nearest station, at around 200 m away, is White Hart Lane (London Overground), which is being rebuilt, and a Wembley-style walkway for fans from the station to the stadium is planned. The stadium area is also served by up to 144 buses an hour. Bus routes that stop close to the ground are 149, 259, 279, 349, and W3. The club will also operate two high frequency shuttle bus services to the stadium, one from Alexandra Palace through Wood Green, and the other from Tottenham Hale.


title: Police car

text: A police car is a motor vehicle used by police. It is used to assist with their duties in patrolling and responding to incidents. Typical uses of a police car include transportation for officers to reach the scene of an incident quickly. Police cars are also used to transport suspects, or to an area. Some police cars are adapted for certain functions such as traffic control, to transport police dogs or bomb disposal.


title: Police car

text: Police cars usually marked to identify them. There are two reasons for this: firstly, so that other drivers know to get out of the way of a police car that is rushing to a crime scene, and secondly so that the car can be a to crime. Police cars also have sirens and flashing lights which are also used when they rush to a crime scene. However, some police cars are unmarked, so that police can carry out work without being noticed.


title: Police car

text: In the United Kingdom in the early 1900s, police vehicles were first used to chase speeding motorists. This had very poor results until police schools were opened to teach officers how to use their vehicles properly. In 1910 the first police car in the US was used in Akron, Ohio. By 1920 police cars were in wide use in the US. It was noticed that patrol cars allowed police to respond faster. It also allowed an officer to cover a wider area. By the 1960s most major cities had shifted away from foot patrols altogether in favor of police cars. But studies proved a mix of foot officers and police vehicles worked best.


title: Police car

text: Police cars are used for chases ("pursuits") against suspects. The crime the suspect is believed to have committed may have been anything from a to a major felony. Suspects often attempt to lose law enforcement by driving away, sometimes at high speed. From 1990 to 2005, 136 people were killed in the US in high speed pursuits by police. Despite controversy as to whether high speed chases are necessary police continue to work on the problem using technology and new techniques. One technique is the 'take out'. A take out is a technique used to cause the fleeing vehicle to lose control and be turned sideways by the police vehicle.


title: Police car

text: When rushing to a crime scene, police officers can drive their cars through red lights and break the speed limit and other traffic laws. They must still be careful when doing this, however.


title: Police car

text: Terms for police cars include (police) cruiser, squad car, area car and patrol car. They may also be informally known as a cop car, a 'Black and white', a 'Cherry top', a 'gumball machine', a 'jam sandwich' or 'panda car'. Depending on the configuration of the emergency lights and livery, a police car may be considered a marked or unmarked unit.


title: Bal Gangadhar Tilak

text: Bal Gangadhar Tilak (; ; born Keshav Gangadhar Tilak on 23 July 1856 – died 1 August 1920) was a leader of nationalism, teacher, and an Independence activist in British-ruled India. He was also conferred with the title of "Lokmanya", which means "accepted by the people (as their leader)". Mahatma Gandhi called him "The Maker of Modern India".


title: Bal Gangadhar Tilak

text: A militant member of the 'extremist' wing within the Indian National Congress (and a member of the famous 'Lal, Pal and Bal' trio), he was twice imprisoned by the British for his nationalist activities. He helped to found the Home Rule League in 1914.


title: Boiling point

text: The boiling point of a substance is the temperature at which the substance boils, or enters a state of rapid evaporation. For pure water this is 100° Celsius or 212° Fahrenheit. This is measured at one atmosphere, that is, the air pressure at sea level


title: Boiling point

text: Boiling points can be changed in several ways. The addition of solutes or other substances usually changes the boiling point. Additionally, changing the pressure on a liquid changes its boiling point.


title: Boiling point

text: The boiling point of a liquid depends on the pressure of the surrounding air. An increase in air pressure increases the boiling point; a decrease decreases the boiling point. In the low pressure environment at the top of Mt Everest for example, water boils at only 69 °C. (156.2 °F).


title: Boiling point

text: It can also be defined in terms of vapour pressure as the temperature at which vapour pressure of liquid becomes equal to atmospheric pressure


title: Boiling point

text: Sugar, salt or other non-volatile solutes in water will usually make the boiling point higher. Alcohol, in contrast, is a volatile chemical that lowers the boiling point of water. Even a large amount dissolved in the water will usually make only small changes in the boiling point.


title: George III

text: King George III (born George William Frederick, 4 June 1738 29 January 1820) was King of Great Britain and Ireland from 25 October 1760 to 1 January 1801, when he became King of the United Kingdom of Great Britain and Ireland until his death. He was also Elector of Hanover, which made him a Prince of the Holy Roman Empire.


title: George III

text: During George's reign, he lost control of the United States of America. His two kingdoms, Great Britain and Ireland, were merged into the United Kingdom of Great Britain and Ireland. Also during his reign, the British were at war with republican and Napoleon I's France. The Electorate of Hanover eventually became a Kingdom.


title: George III

text: George suffered from periodic bouts of mental illness. One of them caused a crisis in 1788, and attempts were made to nominate his son George IV as regent. The king quickly recovered and prevented that from happening.


title: George III

text: George signed the Quebec Act of 1774, which abolished William III's anti-Catholic laws in the American colonies. Also during his reign, George III signed legislation abolishing some of the anti-Catholic Laws in Great Britain and Ireland. For example, the Catholic Relief Acts of 1772 and 1774 allowed Roman Catholics to have land leases in Great Britain. In 1793, Hogart's Act allowed Roman Catholics to vote in Irish elections, but George blocked a proposal in 1800 to allow Catholics to sit in the British Parliament.


title: George III

text: In the later part of his life, George suffered from recurrent mental illness, which was eventually permanent. Although it has since been suggested that he suffered from a genetic blood disease, porphyria, the cause of his illness is not certain. After a final relapse in 1810, a regency was established, and George's eldest son, George, Prince of Wales, ruled as Prince Regent. On George III's death, the Prince Regent succeeded his father as George IV.


title: George III

text: Because of "his plain, homely, thrifty manners and tastes", George III has had the nickname of "Farmer George".


title: Chord

text: A chord in music is when two or more notes are played together (some text books say that it is when "three" or more notes are played).


title: Chord

text: A chord which is built up of the 1st, 3rd and 5th notes of a scale is called a "tonic triad". If it is made from a major scale, it is a major chord. If it is made from a minor scale it is a minor chord. However, any combination of notes played simultaneously is considered a chord.


title: Chord

text: When only two notes are played together, it’s more often called “double stops” (referring to the different banks of pipes on a pipe organ, controlled by valves called “stops”).


title: Chord

text: Chords can be played on instruments such as piano, keyboard, organ, harp, guitar, harmonica, ukulele and xylophone. Chords with two notes can be played on string instruments by bowing on two strings together. By bowing on two strings and then quickly on the other two strings a violinist can sound as if he is playing a four-part chord. Some players of wind instruments are able to make chords by playing two or more harmonics together.


title: Reed (instrument)

text: A reed is a piece of dry bamboo that is used in some musical instruments such as saxophones, clarinets and oboes. The musician blows air through the mouthpiece where the reed is firmly placed, and the air makes the reed vibrate; this vibration in the mouthpiece produces sound all along the instrument, which is changed into specific musical notes depending on the physical nature of the instrument.


title: Reed (instrument)

text: Musical instruments that use reeds are members of the woodwind family, because many years ago the instruments were all made of wood. Today the instruments can be made of metal (brass, silver, gold), wood, or a hard plastic made to look like wood.


title: Reed (instrument)

text: The bassoon family of instruments and the oboe family of instruments play with a double reed. Players play through blowing air through the double reed, making the reeds vibrate. A mouthpiece is not needed.


title: Honeyberry

text: The honeyberry ("Lonicera caerulea") (also known as a blue honeysuckle, sweetberry honeysuckle, fly honeysuckle, blue fly honeysuckle, blue-berried honeysuckle or haskap) is a fruit that is edible. It is a member of the honeysuckle family. It is easy to grow and has few pests. They are native to Russia and can tolerate very cold weather. They can survive down to . They have been raised for centuries in Asia and Eastern Europe. Honeyberry is a well-behaved plant that is not seen as being an Invasive species.


title: Manhattan Project

text: The Manhattan Project was the program based in the United States which tried to make the first nuclear weapons. The project went on during World War II, and was run by the U.S. Army. The head of the project was General Leslie R. Groves, who had led the building of the Pentagon. The top scientist on the project was Robert Oppenheimer, a famous physicist. The project cost $2 billion, and created many secret cities and bomb-making factories, such as a laboratory in Los Alamos, New Mexico, a nuclear reactor in Hanford, Washington, and a uranium processing plant in Oak Ridge, Tennessee.


title: Manhattan Project

text: The Manhattan Project had to find solutions to two difficulties. The first difficulty is how to make the special isotopes of uranium (uranium-235) or plutonium. This process is called separation and is very slow. The United States built very big buildings with three different kinds of machine for separation. They made enough fissionable special isotopes for a few nuclear weapons. The second difficulty was how to make a bomb that will produce a big nuclear explosion every time. A weapon with a bad design can make a much smaller nuclear explosion. This is called a "fizzle". In July 1945, the Manhattan Project solved the two difficulties and made the first nuclear explosion. This test of a nuclear weapon was called "Trinity" and was a success.


title: Manhattan Project

text: The Manhattan Project operated under a blanket of tight security. This was to prevent the Axis countries, especially Nazi Germany, from accelerating their own nuclear projects or undertaking covert operations against the project. The possibility of sabotage was always present. At times, people suspected sabotage when equipment failed. While there were some problems believed to be the result of careless or disgruntled employees, there were no confirmed instances of Axis-instigated sabotage. However, on 10 March 1945, a Japanese fire balloon struck a power line, and the resulting power surge caused the three reactors at Hanford to be temporarily shut down.


title: Manhattan Project

text: Maintaining security was difficult because so many people worked on the project. A special Counter Intelligence Corps detachment handled the project's security issues. By 1943, it was clear that the Soviet Union was trying to penetrate the project. Lieutenant Colonel Boris T. Pash, the head of the Counter Intelligence Branch of the Western Defense Command, investigated suspected Soviet espionage at the Radiation Laboratory in Berkeley. Oppenheimer informed Pash that he had been approached by a fellow professor at Berkeley, Haakon Chevalier, about passing information to the Soviet Union.


title: Manhattan Project

text: The most successful Soviet spy was Klaus Fuchs. Fuchs was a member of the British Mission who played an important part at Los Alamos. The 1950 revelation of Fuchs' espionage activities damaged the United States' nuclear cooperation with Britain and Canada. Subsequently, other instances of espionage were uncovered, leading to the arrest of Harry Gold, David Greenglass and Ethel and Julius Rosenberg. Other spies like George Koval remained unknown for decades. People will never know the value of the espionage. One reason was that the Soviet atomic bomb project was held back by a shortage of uranium ore. The consensus is that espionage saved the Soviets one or two years of effort.


title: Lichen

text: Lichens are a living thing that grows on rocks. They are a mixture of two very different things, a fungus and an algae. The fungus lives with the algae, and they trade things with each other. The lichen looks like a plant, but it is not. Botanists did not know this until 1875.


title: Lichen

text: Lichens are made up of three different living things. The fungus gives them their shape and holds them together. The algae gives them their color. The cyanobacteria give them their food. They are all different kinds of living things, so some scientists say they can't be classified together. But some scientists say they can, because they are all living together and they are all doing the same thing. So they have to be the same kind of living thing.20% (one in five) of fungal species live in lichens. Lichen fungi belong to several different groups of fungi.


title: Lichen

text: Most common (over 40%) are Ascomycetes, which produce spores in a sac-shaped container, the "ascus". Only a few types of alga occur within lichens; these algae also have their own names. Algae may be sometimes the dominant partner in so-called 'jelly lichens', "Collema" and "Leptogium", but this is rare. More usually, the algae are the green alga "Trebouxia". Other species are the orange "Trentepohli", and the cyanobacterium "Nostoc".


title: Lichen

text: Lichens can occur anywhere on land, and some can live in aquatic environments. The nearest rock, wall or roof probably has lichen on it. Often the lichen is mat-like, and clings to the surface. Some are like little bushes: see the photos. Lichens are famous for not needing a regular supply of water; their metabolism can go into suspension, and later revive. When growing on mineral surfaces, some lichens slowly break down the substrate, and extract tiny amounts of mineral nutrient. Fungi form the main part of the thallus (body), with the photobiont contributing 20% or less. The photobiont is usually on the inside of the thallus.


title: Lichen

text: Lichen thalli may grow together and fuse, and this may happen between different species and genera. These are called 'mechanical hybrids'. They get noticed when the two forms are differently colored.


title: Lichen

text: Lichen do survive extreme conditions. They are found in some of the most extreme places on Earth – the frozen north, hot deserts, rocky coasts. They are common as epiphytes on leaves and branches in rain forests and temperate woods. They can live on bare rock, walls and gravestones, and on exposed soil surfaces. There are about 200 different kinds of lichens in Antarctica. In the Horlick Mountains, at 86 degrees south, there are six different kinds of lichen. In the Himalayas, they grow at altitudes up to 18,000 feet (~5500m).


title: Lichen

text: The European Space Agency discovered that lichen can survive unprotected in space. Two species of lichen were sealed in a capsule and launched on a Russian Soyuz rocket. Once in orbit the capsules were opened. Two species of lichen were exposed to the vacuum of space, to cosmic radiation and huge swings of temperature. After 15 days the lichens were retrieved and were found to be in full health: no damage was found.


title: Lichen

text: There are a huge number of lichen species in rainforests, far outnumbering flowering plants. The lichen are mostly epiphytes, living on trees. A single site in Costa Rica yielded about 300 species of lichen on leaves, in the understory of the rain forest; a single fallen "Elaeocarpus" tree in New Guinea held 173 species; the evergreen laurel "Ocotea atirrensis" was found with 50–80 lichen species on a "single leaf".


title: Lichen

text: When partnerships are very close, it is difficult to assign benefits to either partner. Their success is as a pair (or trio). Sometimes the partners can exist as separate organisms: certainly their close relatives can. Probably most of the algae and all of the cyanobacteria can survive on their own, though in more restricted habitats. The details vary according to the specific species or strains involved. The man who first realised the nature of lichen, Simon Schwedener, thought of the partnership as one of controlled parasitism. Obviously, the photobiont provides photosynthetic products: carbohydrates as sugar alcohols (green algae) or glucose (cyanobacteria). The bacteria also convert atmospheric nitrogen (N) to ammonium ions (NH) which the fungus can use in amino acids for proteins.


title: Lichen

text: The alga certainly benefits from a supply of water (which the fungus is good at storing). There is also general mechanical protection. Algae get protection from ultraviolet light, which in some environments is quite significant. Probably, algae get access to the minute amounts of minerals, which the fungus gets from the substrate or from dust settling on the thallus. Algal cells are sometimes destroyed in the course of nutrient exchange, though the algal cells divide and replace them. Above all, the partnership is a resounding success, and gets to places where few plants can survive.


title: Lichen

text: Many lichens reproduce without sex (asexual reproduction). They make small groups of algal cells surrounded by fungal filaments. These "soridia" can be blown by wind. Some lichens just break up into fragments when they dry. Wind carries the pieces, which grow when moisture returns. Also, lichen fungi can reproduce sexually by forming fruiting bodies containing spores. These fruiting bodies are usually perennial, and may be long-lasting: some in the Swiss Alps have lived for over 50 years. After dispersal by wind, such fungal spores must meet with an algal partner to form a lichen.


title: Lichen

text: The fossil record for lichen dates back 400 million years for certain, and the signs are that earlier forms existed 600 million years ago. They must have been one of the earliest life-forms on land. It is thought, from the number of fungal and algal species involved, that the symbiosis must have taken place many times between different species.


title: Lichen

text: It has been suggested that some or all of the Ediacaran biota might be lichen. The proposal has been received with some skepticism.


title: Lichen

text: Lichenometry is a method of dating exposed rock by using the growth of lichen. It uses an estimate of how long the lichen's radius or width grows over time.


title: Lichen

text: Many lichen are sensitive to changes around them. For this reason, they are used by scientists to show changes in the environment, such as air pollution, ozone depletion, and metal contamination. Lichens have also been used to make dyes, perfumes, and herbal medicines.


title: Lichen

text: Some lichen produce natural antibiotics that kill bacteria. Humans have used these compounds as natural antibiotics. Extracts from many "Usnea" species were used to treat wounds in Russia in the mid-twentieth century.


title: Lichen

text: The map lichen "Rhizocarpon geographicum" grows extremely slowly, and can reach an age of over 1000 years. It may be used for dating: the diameter of the largest lichen of a species on a rock surface shows the time that the rock has been exposed.


title: Lichen

text: Lichen are the main winter food for reindeer. The deer can get at shrubby lichen under the snow. In summer they have much more choice of food. Some lichen are eaten by humans. A kind of lichen, which is called "Iwatake" in Japanese and "Seogi" in Korean language, is collected from cliffs, and used in various Korean and Japanese foods. Lichen have a high level of acid. Care must be taken, as there are at least two kinds of lichen that are toxic.


title: Lichen

text: The bacterial or algal partners produce pigments that absorb sunlight in photosynthesis. There are reports dating back almost 2000 years of purple and red colours being extracted from lichens. Lichens of the family Roccellaceae are commonly called 'orchella weed' . They have been important in history, because they could supply orcein, a dye. "Rocella tinctoria" is the source of the pH indicator litmus. Orcein is got by boiling the lichen, and litmus is produced by adding ammonia and air. Orcein is also used as a food dye, with the E number E121.


title: Incumbent

text: An incumbent is someone who currently holds a political office. This word is usually used when talking about elections, which are often between the incumbent and one other person or several other people. For example, Joe Biden is the incumbent President of the United States since he is still president. It can also be used in sports to let people know if a sportsman still holds the position or award in question.


title: Lindsey Pearlman

text: Lindsey Erin Pearlman (October 5, 1978 – February 18, 2022) was an American actress. She was known for her roles on "General Hospital" and "Chicago Justice". She also appeared in "The Ms. Pat Show" and "". Pearlman was born in Chicago, Illinois.


title: Lindsey Pearlman

text: On February 13, 2022 she went missing in Los Angeles. Five days later, she was found dead in a car near Runyon Canyon Park in Hollywood, California at aged 43. In August 2022, the cause of death was suicide by overdose of sodium nitrite.


title: Vespasian

text: Vespasian (Titus Flavius Vespasianus, 17 November 9 AD – 23 June 79), was Roman Emperor from 69 AD to 79.


title: Vespasian

text: Vespasian was the founder of the Flavian dynasty which ruled the empire for 27 years. Although he held the consulship in 51 AD, Vespasian became more highly regarded as a successful military commander. He took part in the Roman invasion of Britain in 43 AD, and the Jewish rebellion of 66 AD.


title: Vespasian

text: While Vespasian was preparing to besiege Jerusalem during the latter campaign, emperor Nero committed suicide, plunging the empire into a year of civil war known as the Year of the Four Emperors. After the emperors Galba and Otho died in quick succession, Vitellius became emperor in April 69 AD.


title: Vespasian

text: In response, the armies in Egypt and Judaea declared Vespasian emperor on July 1. In his bid for imperial power, Vespasian joined forces with Mucianus, the governor of Syria, and Primus, a general in Pannonia. Primus and Mucianus led the Flavian forces against Vitellius, while Vespasian gained control of Egypt. On 20 December, Vitellius was defeated, and the following day Vespasian was declared emperor by the Roman Senate.


title: Vespasian

text: Little factual information survives about Vespasian's government during the ten years he was emperor. His reign is best known for financial reforms, the successful campaign against Judaea, and several ambitious construction projects such as the Colosseum. Upon his death in 79, he was succeeded by his eldest son Titus.


title: Corsica

text: Corsica is the fourth largest island in the Mediterranean Sea (after Sicily, Sardinia, and Cyprus). It is west of Italy, southeast of France, and north of the island of Sardinia.


title: Corsica

text: Corsica has 1,000 km of coastline and more than 200 beaches, and is very mountainous, with Monte Cinto as the highest peak at 2706m and 20 other peaks of more than 2000m.


title: Corsica

text: Corsica is the most mountainous Mediterranean island. The low ground has a Mediterranean climate. Summers are hot and dry. Winters are mild with moderate rainfall. The climate of the high ground is cold and is wetter. The natural vegetation is Mediterranean forests, woodlands, and shrubs. The mountains are rich of forests of oak, and pine, except for the high ground. Much of the coastal lowlands has been cleared for agriculture, which has reduced the mountain forests considerably. The island has a natural park (Parc Naturel Régional de Corse), which protects thousands of rare animal and plant species. The park was created in 1972 and includes the Golfe de Porto, the Réserve Naturelle de Scandola (a UNESCO World Heritage Site), and some of the highest mountains on the island. This park is protected.


title: Corsica

text: The capital of the territorial collectivity of Corsica is Ajaccio (). The territorial collectivity is divided in two "départements": Corse-du-Sud and Haute-Corse. These two "départements" were created on September 15, 1975 by the "département" of Corse.


title: Corsica

text: Tourism is the biggest source of Corsican economy. The island has a pleasant climate, beautiful mountains and really beautiful coastlines that make it a popular destination among the French and other Western Europeans. However, the island has not had the same level of intensive development as other parts of the Mediterranean. Tourism is particularly concentrated in the area around Porto Vecchio and Bonifacio in the south of the island and Calvi in the northwest.


title: Corsica

text: Corsica is currently governed almost as any other "région" of France. There are lots of movements on the island the independence of Corsica and of Corsicans from France. The French government is against full independence. There is support on the island for to have more autonomy, but polls show that a large majority of Corsicans are opposed to full independence. Some groups who claim to support Corsican independence have carried out a violent campaign since the 1970s that includes bombings and a few accidental assassinations, usually against "pieds-noirs" and other non-Corsicans, or buildings of the French government. Corsican independence groups attack when they are sure there won't be a danger for victims. However, not all groups for independence has "nice treaties", Sometimes independence groups are known to practice extortion and other intimidatory tactics, similar to mafia activity in Sicily and southern Italy. Non-Corsican homeowners may be threatened with the destruction of their home, or they are constrict to pay a "revolutionarian tax",for to help the groups in the attacks.


title: Corsica

text: In 2000, Prime Minister Lionel Jospin agreed to give more autonomy to Corsica but just for stopping the violence. The propose of autonomy for Corsica would have included greater protection for the Corsican language (Corsu), the island's traditional language (which is also considered to be a dialect of Italian). However, the plans for increased autonomy were opposed by the Gaullist opposition in the French National Assembly. In a referendum on July 6,2003, a narrow majority of Corsican voters opposed to the project from the government of Jean-Pierre Raffarin and Interior Minister Nicolas Sarkozy that would have suppressed the two "départements" of the island and granted more autonomy to the territorial collectivity of Corsica.


title: Corsica

text: In Corsica the official language is French, but lots of people speak, "u corsu", the language of Corsica, protected by UNESCO. Corsu shares some similarities with Tuscan dialects (with their accents) or to Gallurese language, spoken in the nearby island of Sardinia. Corsu has two varietes, "Supranacciu", common in the northeast of theisland, (Bastia, Corte), and the "Suttanacciu" common in the south of the island, (Ajaccio, Sartene). The native Corsican language is closer to Italian than French, but both come from Latin. The ancient Romans spoke Latin.


title: Corsica

text: In Corsica, football is a very common sport. The island has in the first league of France ('Ligue 1'), 2 teams. The AC Ajaccio and the SC Bastia. Another very famous sport in Corsica, is volleyball, with the "GFCO Ajaccio Volley-Ball' team.


title: Convict

text: A convict is "a person found guilty of a crime and sentenced by a court" or "a person serving a sentence in prison". The word is sometimes abbreviated as "con". After a conviction, convicts often become prisoners in a prison. People convicted and sentenced but not sent to prison are not usually called "convicts". An ex-convict (or short: ex-con) is a person who has been let out of prison.


title: Convict

text: In past centuries many convicts were send to penal colonies. Many British convicts were sent to the Thirteen Colonies as cheap workers, but that stopped after the War of Independence. After this, convicts were transported to Australia in 1788, the very start of European settlement. They were used as cheap workers. Transportation was stopped in 1868. British convicts were also sent to Canada and India.


title: Blue-green

text: On the older red-yellow-blue pigment color wheel (in which red, yellow and blue were called the primary colors and orange, green, and violet were called the secondary colors), "blue-green" was a third color between blue and green. The other third colors on a red-yellow-blue (RYB) color wheel were called red-violet, blue-violet, yellow-green, yellow-orange and red-orange.


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

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


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

text: There are various other methods. All aim to develop the immune response without allowing the full viral infection to happen.


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

text: 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.


title: Vaccination

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


title: Vaccination

text: 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.