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Human skin color

Human skin color ranges in variety from the darkest brown to the lightest hues. An individual's skin pigmentation is the result of genetics, being the product of both of the individual's biological parents' genetic makeup, exposure to sun. In evolution, skin pigmentation in human beings evolved by a process of natural selection to regulate the amount of ultraviolet radiation penetrating the skin, controlling its biochemical effects; the actual skin color of different humans is affected by many substances, although the single most important substance is the pigment melanin. Melanin is produced within the skin in cells called melanocytes and it is the main determinant of the skin color of darker-skinned humans; the skin color of people with light skin is determined by the bluish-white connective tissue under the dermis and by the hemoglobin circulating in the veins of the dermis. The red color underlying the skin becomes more visible in the face, when, as consequence of physical exercise or the stimulation of the nervous system, arterioles dilate.

Color is not uniform across an individual's skin. There is a direct correlation between the geographic distribution of ultraviolet radiation and the distribution of indigenous skin pigmentation around the world. Areas that receive higher amounts of UVR located closer to the equator, tend to have darker-skinned populations. Areas that are far from the tropics and closer to the poles have lower intensity of UVR, reflected in lighter-skinned populations. Researchers suggest that human populations over the past 50,000 years have changed from dark-skinned to light-skinned and vice versa as they migrated to different UV zones, that such major changes in pigmentation may have happened in as little as 100 generations through selective sweeps. Natural skin color can darken as a result of tanning due to exposure to sunlight; the leading theory is that skin color adapts to intense sunlight irradiation to provide partial protection against the ultraviolet fraction that produces damage and thus mutations in the DNA of the skin cells.

In addition, it has been observed that females on average are lighter in skin pigmentation than males. Females need more calcium during lactation; the body synthesizes vitamin D from sunlight. Females evolved to have lighter skin; the social significance of differences in skin color has varied across cultures and over time, as demonstrated with regard to social status and discrimination. Melanin is produced by cells called melanocytes in a process called melanogenesis. Melanin is made within small membrane–bound packages called melanosomes; as they become full of melanin, they move into the slender arms of melanocytes, from where they are transferred to the keratinocytes. Under normal conditions, melanosomes cover the upper part of the keratinocytes and protect them from genetic damage. One melanocyte supplies melanin to thirty-six keratinocytes according to signals from the keratinocytes, they regulate melanin production and replication of melanocytes. People have different skin colors because their melanocytes produce different amount and kinds of melanin.

The genetic mechanism behind human skin color is regulated by the enzyme tyrosinase, which creates the color of the skin and hair shades. Differences in skin color are attributed to differences in size and distribution of melanosomes in the skin. Melanocytes produce two types of melanin; the most common form of biological melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids, their reduced forms. Most are derived from the amino acid tyrosine. Eumelanin is found in hair and skin, the hair colors gray, black and brown. In humans, it is more abundant in people with dark skin. Pheomelanin, a pink to red hue is found in large quantities in red hair, the lips, glans of the penis, vagina. Both the amount and type of melanin produced is controlled by a number of genes that operate under incomplete dominance. One copy of each of the various genes is inherited from each parent; each gene can come in several alleles. Melanin controls the amount of ultraviolet radiation from the sun that penetrates the skin by absorption.

While UV radiation can assist in the production of vitamin D, excessive exposure to UV can damage health. Loss of body hair in Hominini species is assumed to be related to the emergence of bipedalism some 5 to 7 million years ago. Bipedal hominin body hair may have disappeared to allow better heat dissipation through sweating; the emergence of skin pigmentation dates to at about 1.2 million years ago, under conditions of a megadrought that drove early humans into arid, open landscapes. Such conditions caused excess UV-B radiation; this favored the emergence of skin pigmentation in order to protect from folate depletion due to the increased exposure to sunlight. A theory that the pigmentation helped counter xeric stress by increasing the epidermal permeability barrier has been disproved. With the evolution of hairless skin, abundant sweat glands, skin rich in melanin, early humans could walk and forage for food for long periods of time under the hot sun without brain damage due to overheating, giving them an evolutionary advantage over other species.

By 1.2 million years ago, around the time of Homo ergaster, archaic humans had the same receptor protein as modern sub-Saharan Africans. This was the genoty

Ready Steady Who

Ready Steady Who is the first 7" EP by The Who, released only in the UK on 11 November 1966, about a month prior to their album A Quick One. The title refers to a Ready Steady Go! TV special the band had appeared in, but the EP contains different recordings from those performed on the TV show; the record consists of two original songs by Pete Townshend, as well as covers of the theme from the Batman TV series and Jan and Dean's "Bucket T". Included is a cover of The Regents' "Barbara Ann", a song whose famous arrangement by the Beach Boys the Who follows more closely. Despite what the title indicates, the EP was not recorded on Ready Steady Go!. All of the songs are available as bonus tracks on the 1995 reissue CD of A Quick One, except for "Circles", which differs from the version on the 2002 deluxe version of the My Generation LP, can be found on Two's Missing; the original EP credits the song "Batman" to Don Altfeld and Fred Weider. The song was written by Neal Hefti, is not a cover of the Jan and Dean-embellished version.

The credit was corrected in the liner notes to the 1995 CD release of A Quick One. An abridged version of My Generation was not included; this version was included as a bonus track on the 1995 remaster of A Quick One. The main difference between this version and the original is that it is abridged and instead of the hail of feedback which ends the original, the band play a chaotic rendition of Edward Elgar's "Land of Hope and Glory." In the album's liner notes the song is credited to both Elgar. The EP was released on 11 November 1966 in the United Kingdom in mono only, it reached number one on the British EP chart, a position it would hold for four non-consecutive weeks on 17 December 1966, once again on 7 January 1967. As the EP was not issued in the United States at the time, the tracks were long considered rare collectibles. Although the tracks "Disguises" and "Bucket'T'" saw a release on the 1968 compilation album Magic Bus: The Who on Tour, the remainder of the tracks would not see official US releases until the deluxe edition of A Quick One and Two's Missing.

"Bucket'T'" was released as a single in several European countries. It fared well in Sweden, where it stayed on the charts for seven weeks, peaked at number one for a week in February 1967. Upon its release, it garnered mixed to positive reviews. In a retrospective review, AllMusic critic Richie Unterberger states that "it seemed undecided as to whether it was a joke cover record, or a home for leftovers" and thought that "it ended up a little bit of both" The Who Official Band Website - Ready Steady Who List of The Who singles

Wang Chao (director)

Wang Chao is a Chinese film director and screenwriter, sometimes considered part of the loosely defined "sixth generation." Wang began his career serving as an assistant director to the fifth generation auteur, Chen Kaige, working with the elder director on epics like Farewell My Concubine and The Emperor and the Assassin. At the same time, he began to write fiction including several short stories and novellas, one of which would go on to serve sa the basis of Wang's directorial debut, The Orphan of Anyang. With Orphan, Wang Chao would begin what was the first film of a trilogy of films based on modern life in China, he completed the trilogy with 2006's Luxury Car. His 2014 film Fantasia was selected to compete in the Un Certain Regard section at the 2014 Cannes Film Festival. Wang Chao at AllMovie Wang Chao on IMDb Wang Chao at the Chinese Movie Database