1.
Sunbather (album)
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Sunbather is the second studio album by the American metal band Deafheaven. The recording process brought a member into the fold with drummer Dan Tracy who would go on to become a permanent fixture of the band. The album was recorded in The Atomic Garden Recording Studio, owned by Jack Shirley who had been a long time producer of the band and this trend was further continued on Sunbather. The album also contains a few interludes that include sampling, field recording, Sunbather was released in June 2013 and received universal critical acclaim, with Metacritic acknowledging it as the best-reviewed major album of the year. Deafheaven began as a band with vocalist George Clarke and guitarist Kerry McCoy as the two musicians and songwriters. After getting the attention of record label Deathwishs co-founder Tre McCarthy when he found Deafheavens untitled demo on the internet, despite being plagued with an inconsistent group line up since the inception of the band, Deafheaven were able to record their debut album Roads to Judah as a quintet. Following a live album and a split EP release after Roads to Judah, after writing the entirety of Sunbather in an apartment Clarke and McCoy occupied in the year before its release, the two members went to record their work at Atomic Garden Studios in East Palo Alto. On Shirleys performance as producer, Clarke said, for record, he definitely took on the role of producer much more than our previous efforts. It honestly felt like we accomplished this together and it felt great, the recording process took six days in January 2013 with each day focusing mostly on recording specific instrumental tracks or completing album interludes. Each day of recording took eight hours of work. When the band recorded Roads to Judah, the members did not make part of their main focus. As a result, Clarke and McCoy wanted Sunbather to sound bigger and slicker than previous releases, musician Dan Tracy was brought in to work on the drumming. That is definitely not the case with this record, there are sections where drums absolutely make the song pop, which is a huge development. Tracy began work on the first day by recording the bulk of the percussion, the microphones used to record the drums varied depending on the role of the percussion in different parts of a track. Uptempo drum parts were recorded with closer microphones while spacier sections were recorded with ribbon microphones, guitar work was started on the second day with most of the day consisting of recording distorted guitar parts. Using a Gibson Les Paul, McCoy would typically track four guitar layers, tracking each rhythm, the following day began with recording bass guitar using a 1970s Fender Precision Bass model and quickly concludes to start on clean guitar parts. Although McCoy used a Les Paul for some of parts, a Gretsch 6117 model was mostly played for recording. The next two days focused on clean sections and interludes, for these parts, a Kawai upright piano was employed as well as a 1960s Hammond M3 organ
2.
Tan line
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A tan line is a visually clear division on the human skin between an area of pronounced comparative paleness relative to other areas that have been suntanned by exposure to ultraviolet radiation. The source of the radiation may be the sun, or artificial UV sources such as tanning lamps, tan lines are usually an inadvertent result of a work environment or of recreational activities, but are sometimes intentional. Many people regard visible tan lines as un-aesthetic, and seek to avoid tan lines that will be visible when regular clothes are worn, a farmers tan refers to the typical tan lines developed by regular outdoor activity. The farmers tan is usually started with a suntan covering the parts of the arms. It is distinct in that the shoulders, chest, and back remain unaffected by the sun, tennis and golf additionally cause recognizable tans on the middle section of the legs, due to the wearing of shorts and socks for prolonged hours in the sun. The Texas tan is similar, with the exception that the shoulders are also affected by the sun, a sandal tan is a set of distinctive tan lines on the feet, resulting from the straps of sandals worn throughout the summer by such different professions as lifeguards and monks. Wearing a bikini in the sun results in the skin becoming suntanned. These tan lines separate pale breasts, crotch, and buttocks from otherwise tanned skin, racing stripes may refer to the portion of a bikini tan line exposed when wearing one-piece swimwear. A bikers tan is a tan line three-quarters up each leg, depending on the activity, the inner side of the arms may be paler than the outer side. Unless the biker uses cycling gloves made to allow tanning, the area on the back of hand will usually not be tanned. Raccoon-like tan lines can emerge around the eyes after wearing goggles, common among skiers, snowboarders, golfer tan — a tan on the back of a shaved or bald head that forms when a baseball cap is worn. There is a semicircle shaped tan that forms from the strap which adjusts the hats size. Soccer tan — a stripe of tan from the thighs to the bottom of the knees common to soccer players. Football tan — a stripe of tan from below the knees to just above the ankle, often the arms are tanned similarly to a farmers tan, but the face is untanned due to wearing a helmet. This tanning effect can be particularly pronounced since many football teams run two-a-day practices during the summer, tiger tan — two tan stripes on the arm of a lacrosse player, resulting from the gaps between gloves, elbow pads, and shoulder pads. One of the uses for tanning beds is the option of tanning completely nude to reduce the appearance of tan lines. In contrast, some prefer to have tan lines. Additionally, tanning stickers can be purchased that attach to the skin while tanning, common designs are a heart, Playboy bunny, and dolphins, but many different designs exist
3.
Human skin color
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Human skin color ranges in variety from the darkest brown to the lightest hues. An individuals skin pigmentation is the result of genetics, being the product of both of the biological parents genetic makeup. The actual skin color of different humans is affected by many substances, 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 skin is determined mainly by the bluish-white connective tissue under the dermis. The red color underlying the skin becomes more visible, especially in the face, Color is not entirely uniform across an individuals skin, for example, the skin of the palm and the sole is lighter than most other skin, and this is especially noticeable in darker-skinned people. There is a correlation between the geographic distribution of UV radiation and the distribution of indigenous skin pigmentation around the world. Areas that receive higher amounts of UVR, generally located closer to the equator, areas that are far from the tropics and closer to the poles have lower intensity of UVR, which is reflected in lighter-skinned populations. Natural skin color can darken as a result of tanning due to exposure to sunlight. In addition, it has observed that adult human females on average are significantly lighter in skin pigmentation than males. Females need more calcium during pregnancy and lactation, the body synthesizes vitamin D from sunlight, which helps it absorb calcium. Females evolved to have lighter skin so their bodies absorb more calcium, 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 arms of melanocytes. Under normal conditions, melanosomes cover the part of the keratinocytes. One melanocyte supplies melanin to thirty-six keratinocytes according to signals from the keratinocytes and they also regulate melanin production and replication of melanocytes. People have different skin colors mainly because their melanocytes produce different amount, the genetic mechanism behind human skin color is mainly regulated by the enzyme tyrosinase, which creates the color of the skin, eyes, and hair shades. Differences in skin color are also attributed to differences in size, melanocytes produce two types of melanin. The most common form of melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids
4.
Ultraviolet
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Ultraviolet is an electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays. UV radiation constitutes about 10% of the light output of the Sun. It is also produced by electric arcs and specialized lights, such as lamps, tanning lamps. Consequently, the effects of UV are greater than simple heating effects. Suntan, freckling and sunburn are familiar effects of over-exposure, along with risk of skin cancer. Living things on dry land would be damaged by ultraviolet radiation from the Sun if most of it were not filtered out by the Earths atmosphere. More-energetic, shorter-wavelength extreme UV below 121 nm ionizes air so strongly that it is absorbed before it reaches the ground, Ultraviolet is also responsible for the formation of bone-strengthening vitamin D in most land vertebrates, including humans. The UV spectrum thus has both beneficial and harmful to human health. Ultraviolet rays are invisible to most humans, the lens in a human eye ordinarily filters out UVB frequencies or higher, and humans lack color receptor adaptations for ultraviolet rays. Under some conditions, children and young adults can see ultraviolet down to wavelengths of about 310 nm, near-UV radiation is visible to some insects, mammals, and birds. Small birds have a fourth color receptor for ultraviolet rays, this gives birds true UV vision, reindeer use near-UV radiation to see polar bears, who are poorly visible in regular light because they blend in with the snow. UV also allows mammals to see urine trails, which is helpful for animals to find food in the wild. The males and females of some species look identical to the human eye. Ultraviolet means beyond violet, violet being the color of the highest frequencies of visible light, Ultraviolet has a higher frequency than violet light. He called them oxidizing rays to emphasize chemical reactivity and to them from heat rays. The terms chemical and heat rays were eventually dropped in favour of ultraviolet and infrared radiation, in 1878 the effect of short-wavelength light on sterilizing bacteria was discovered. By 1903 it was known the most effective wavelengths were around 250 nm, in 1960, the effect of ultraviolet radiation on DNA was established. The discovery of the ultraviolet radiation below 200 nm, named vacuum ultraviolet because it is absorbed by air, was made in 1893 by the German physicist Victor Schumann
5.
Sunlight
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Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is filtered through Earths atmosphere, and is obvious as daylight when the Sun is above the horizon, when the direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When it is blocked by clouds or reflects off other objects, the World Meteorological Organization uses the term sunshine duration to mean the cumulative time during which an area receives direct irradiance from the Sun of at least 120 watts per square meter. Other sources indicate an Average over the earth of 164 Watts per square meter over a 24 hour day. The ultraviolet radiation in sunlight has both positive and negative effects, as it is both a principal source of vitamin D3 and a mutagen. Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun. A photon starting at the center of the Sun and changing every time it encounters a charged particle would take between 10,000 and 170,000 years to get to the surface. Researchers may record sunlight using a sunshine recorder, pyranometer, or pyrheliometer, to calculate the amount of sunlight reaching the ground, both Earths elliptical orbit and the attenuation by Earths atmosphere have to be taken into account. In this formula dn–3 is used, because in modern times Earths perihelion, the closest approach to the Sun and, therefore, the value of 0.033412 is determined knowing that the ratio between the perihelion squared and the aphelion squared should be approximately 0.935338. The solar illuminance constant, is equal to 128×103 lx, the atmospheric extinction brings the number of lux down to around 100000. The total amount of energy received at ground level from the Sun at the zenith depends on the distance to the Sun and it is about 3. 3% higher than average in January and 3. 3% lower in July. In terms of energy, sunlight at Earths surface is around 52 to 55 percent infrared,42 to 43 percent visible, and 3 to 5 percent ultraviolet. At the top of the atmosphere, sunlight is about 30% more intense, having about 8% ultraviolet, direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux. This is higher than the efficacy of most artificial lighting, which means using sunlight for illumination heats up a less than using most forms of artificial lighting. Multiplying the figure of 1050 watts per square metre by 93 lumens per watt indicates that bright sunlight provides an illuminance of approximately 98000 lux on a surface at sea level. The illumination of a surface will be considerably less than this if the Sun is not very high in the sky. Averaged over a day, the highest amount of sunlight on a horizontal surface occurs in January at the South Pole, dividing the irradiance of 1050 W/m2 by the size of the suns disk in steradians gives an average radiance of 15.4 MW per square metre per steradian. Multiplying this by π gives a limit to the irradiance which can be focused on a surface using mirrors,48.5 MW/m2
6.
Tanning lamp
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Tanning lamps are the part of a tanning bed, booth or other tanning device which produces ultraviolet light responsible for tanning. There are hundreds of different kinds of tanning lamps most of which can be classified in two groups, low pressure and high pressure. Within the industry, it is common to call high-pressure units bulbs and low-pressure units lamps, although there are many exceptions and this is likely due to the size of the unit, rather than the type. Both types require a free environment inside the lamp. Fluorescent tanning lamps require an electrical ballast to limit the amount of current going through the lamp, while the resistance of an incandescent lamp filament inherently limits the current inside the lamp, tanning lamps do not and instead have negative resistance. They are plasma devices, like a sign, and will pass as much current as the external circuit will provide. Thus a ballast is needed to regulate the current through them, tanning lamps are installed in a tanning bed, tanning booth, tanning canopy or free standing single bulb tanning unit. The quality of the tan depends upon the spectrum of the light that is generated from the lamps, high-pressure bulbs are 3 to 5 inches long and typically powered by a ballast with 250 to 2,000 watts. The most common is the 400 watt variety that is used as an added face tanner in the tanning bed. High-pressure lamps use quartz glass, and as such do not filter UVC, because UVC can be deadly, a special dichroic filter glass is required that will filter out the UVC and UVB. The goal with high-pressure tanning bulbs is to produce an amount of UVA only. Unfiltered light from a lamp is rich in UVC used in germicidal lamps, for water purification. The contents of a high-pressure lamp are inert gas and mercury, there are no phosphors used, and the mercury is clearly visible if it is not in a gaseous state. During installation, even an amount of oil from fingertips can cause the quartz envelope to fail in operation. Most commercial replacement bulbs come with a special pocket wipe, usually containing alcohol, because the bulb contains mercury, great care should be used if a bulb is broken, to prevent accidental contact or vapor exposure. Like all fluorescent lamps, low-pressure tanning lamps have a ballast to start the lamps, the plasma of excited mercury atoms inside the lamp emits ultraviolet light directly. The lamps are coated on the inside with special phosphors, unlike high-pressure lamps, the glass that is used in low-pressure lamps filters out all UVC. Once the plasma is formed, the plasma strips away the outer electrons from the mercury
7.
Indoor tanning
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Indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. Vertical devices are known as tanning booths or stand-up sunbeds, first introduced in the 1920s, indoor tanning became popular with white people in the Western world, particularly in Scandinavia, in the late 1970s. The practice finds a parallel in skin whitening in Asian countries. Most indoor tanners are women, 16–25 years old, who want to improve their appearance or mood, acquire a pre-holiday tan, as of 2010 the indoor-tanning industry employed 160,000 in the United States, where 10–30 million tanners visit 25,000 indoor facilities annually. In the United Kingdom,5,350 tanning salons were in operation in 2009, from 1997 several countries and US states banned under-18s from indoor tanning. The commercial use of tanning beds was banned entirely in Brazil in 2009, injuries caused by tanning devices lead to over 3,000 emergency-room cases a year in the United States alone. Physicians may use or recommend tanning devices to treat conditions such as psoriasis. The WHOs International Agency for Research on Cancer includes tanning devices, along with radiation from the sun. Ultraviolet radiation is part of the spectrum, just beyond visible light. Ultraviolet wavelengths are 100 to 400 nanometres and are divided into three bands, A, B and C, UVA wavelengths are the longest,315 to 400 nm, UVB are 280 to 315 nm, and UVC wavelengths are the shortest,100 to 280 nm. About 95% of the UVR that reaches the earth from the sun is UVA and 5% UVB, while tanning systems before the 1970s produced some UVC, modern tanning devices produce no UVC, a small amount of UVB and mostly UVA. Classified by the WHO as a group 1 carcinogen, UVR has complex and it triggers the synthesis of vitamin D and endorphins in the skin, but it also causes skin cancer and other damage, including wrinkles. In 1890 the Danish physician Niels Ryberg Finsen developed an arc lamp that produced ultraviolet radiation for use in skin therapy. He won the 1903 Nobel Prize in Physiology or Medicine for his work, until the late 19th century in Europe and the United States, pale skin was a symbol of high social class among white people. Victorian women would carry parasols and wear wide-brimmed hats and gloves, but as the working classes moved from country work to city factories, and to crowded, dark, unsanitary homes, pale skin became increasingly associated with poverty and ill health. In 1923 Coco Chanel returned from a holiday in Cannes with a tan, later telling Vogue magazine, tanned skin had become a fashion accessory. In parallel physicians began advising their patients on the benefits of the sun cure, sunshine was promoted as a treatment for depression, diabetes, constipation, pneumonia, high and low blood pressure, and many other ailments. Home-tanning equipment was introduced in the 1920s in the form of sunlamps or health lamps, UV lamps that emitted a large percentage of UVB, leading to burns
8.
Sunless tanning
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Sunless tanning, also known as UV-free tanning, self tanning, spray tanning, or fake tanning, refers to the application of chemicals to the skin to produce an effect similar in appearance to a suntan. The popularity of sunless tanning has risen since the 1960s after health authorities confirmed links between UV exposure and the incidence of skin cancer, artificial sunscreen absorbs ultraviolet light and prevents it from reaching the skin. In addition, carotenoids have been linked to more attractive skin tone than suntan, carotenes also fulfil the function of melanin in absorbing the UV radiation and protecting the skin. For example, they are concentrated in the macula of the eye to protect the retina from damage and they are used in plants both to protect chlorophyll from light damage and harvest light directly. Carotenaemia is the presence in blood of the yellow pigment carotene from excessive intake of carrots or other containing the pigment resulting in increased serum carotenoids. It can lead to subsequent yellow-orange discoloration and their subsequent deposition in the outermost layer of skin, carotenemia and carotenoderma is in itself harmless, and does not require treatment. In primary carotenoderma, when the use of quantities of carotene is discontinued the skin color will return to normal. It may take up to months, however, for this to happen. Lycopene is a key intermediate in the biosynthesis of beta-carotene and xanthophylls, lycopene may be the most powerful carotenoid quencher of singlet oxygen. Due to its color and non-toxicity, lycopene is a useful food coloring and is approved for usage in the USA, Australia and New Zealand. A sunless-tanning product is tanning pills which contain beta-carotene, however, chronic, high doses of synthetic β-carotene supplements have been associated with increased rate of lung cancer among those who smoke. Canthaxanthin is most commonly used as an additive in certain foods. Although the FDA has approved the use of canthaxanthin in food, when used as a color additive, only very small amounts of canthaxanthin are necessary. As a tanning agent, however, much larger quantities are used, after canthaxanthin is consumed, it is deposited throughout the body, including in the layer of fat below the skin, which turns an orange-brown color. These types of tanning pills have been linked to various effects, including hepatitis and canthaxanthin retinopathy. Other side effects including damage to the system and skin surface have also been noted. The FDA withdrew approval for use of canthaxanthin as a tanning agent, DHA is not a dye, stain or paint, but causes a chemical reaction with the amino acids in the dead layer on the skin surface. One of the pathways is a free radical-mediated Maillard reaction, the other pathway is the conventional Maillard reaction, a process well known to food chemists that causes the browning that occurs during food manufacturing and storage
9.
Melanin
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Melanin /ˈmɛlənɪn/ is a broad term for a group of natural pigments found in most organisms. Melanin is produced by the oxidation of the amino acid tyrosine, the pigment is produced in a specialized group of cells known as melanocytes. There are three types of melanin, eumelanin, pheomelanin, and neuromelanin. The most common is eumelanin, of which there are two types—brown eumelanin and black eumelanin, pheomelanin is a cysteine-containing red polymer of benzothiazine units largely responsible for red hair, among other pigmentation. Neuromelanin is found in the brain, though its function remains obscure, in the skin, melanogenesis occurs after exposure to UV radiation, causing the skin to visibly tan. Melanin is an effective absorber of light, the pigment is able to dissipate over 99. 9% of absorbed UV radiation, because of this property, melanin is thought to protect skin cells from UVB radiation damage, reducing the risk of cancer. e. Nonetheless, the relationship between skin pigmentation and photoprotection is still being clarified, in humans, melanin is the primary determinant of skin color. It is also found in hair, the pigmented tissue underlying the iris of the eye, in the brain, tissues with melanin include the medulla and pigment-bearing neurons within areas of the brainstem, such as the locus coeruleus and the substantia nigra. It also occurs in the zona reticularis of the adrenal gland, the melanin in the skin is produced by melanocytes, which are found in the basal layer of the epidermis. Although, in general, human beings possess a concentration of melanocytes in their skin. Some humans have very little or no melanin synthesis in their bodies, because melanin is an aggregate of smaller component molecules, there are many different types of melanin with differing proportions and bonding patterns of these component molecules. Both pheomelanin and eumelanin are found in skin and hair. Eumelanin polymers have long thought to comprise numerous cross-linked 5, 6-dihydroxyindole and 5. There are two types of eumelanin and black eumelanin—which chemically differ from each other in their pattern of polymeric bonds. A small amount of black eumelanin in the absence of other pigments causes grey hair, a small amount of brown eumelanin in the absence of other pigments causes blond color hair. As the body ages, it continues to produce black melanin but stops producing the brown version, pheomelanins impart a pink to red hue, depending upon the concentration. Pheomelanins are particularly concentrated in the lips, nipples, glans of the penis, when a small amount of brown eumelanin in hair, which would otherwise cause blond hair, is mixed with red pheomelanin, the result is red hair. Pheomelanin is also present in the skin, and redheads consequently often have a pinkish hue to their skin as well
10.
Genetics
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Genetics is the study of genes, genetic variation, and heredity in living organisms. It is generally considered a field of biology, but intersects frequently with other life sciences and is strongly linked with the study of information systems. The father of genetics is Gregor Mendel, a late 19th-century scientist, Mendel studied trait inheritance, patterns in the way traits are handed down from parents to offspring. He observed that organisms inherit traits by way of discrete units of inheritance and this term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism, genetics has given rise to a number of subfields, including epigenetics and population genetics. Organisms studied within the broad field span the domain of life, including bacteria, plants, animals, genetic processes work in combination with an organisms environment and experiences to influence development and behavior, often referred to as nature versus nurture. The intracellular or extracellular environment of a cell or organism may switch gene transcription on or off, a classic example is two seeds of genetically identical corn, one placed in a temperate climate and one in an arid climate. The word genetics stems from the ancient Greek γενετικός genetikos meaning genitive/generative, the observation that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding. The modern science of genetics, seeking to understand this process, prior to Mendel, Imre Festetics, a Hungarian noble, who lived in Kőszeg before Mendel, was the first who used the word genetics. He described several rules of inheritance in his work The genetic law of the Nature. His second law is the same as what Mendel published, in his third law, he developed the basic principles of mutation. Other theories of inheritance preceded his work, a popular theory during Mendels time was the concept of blending inheritance, the idea that individuals inherit a smooth blend of traits from their parents. Mendels work provided examples where traits were not blended after hybridization. Blending of traits in the progeny is now explained by the action of genes with quantitative effects. Another theory that had some support at that time was the inheritance of acquired characteristics, other theories included the pangenesis of Charles Darwin and Francis Galtons reformulation of pangenesis as both particulate and inherited. Modern genetics started with Gregor Johann Mendel, a scientist and Augustinian friar who studied the nature of inheritance in plants, the importance of Mendels work did not gain wide understanding until the 1890s, after his death, when other scientists working on similar problems re-discovered his research. William Bateson, a proponent of Mendels work, coined the word genetics in 1905, Bateson popularized the usage of the word genetics to describe the study of inheritance in his inaugural address to the Third International Conference on Plant Hybridization in London in 1906. After the rediscovery of Mendels work, scientists tried to determine which molecules in the cell were responsible for inheritance, in 1911, Thomas Hunt Morgan argued that genes are on chromosomes, based on observations of a sex-linked white eye mutation in fruit flies
11.
Europe
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Europe is a continent that comprises the westernmost part of Eurasia. Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, yet the non-oceanic borders of Europe—a concept dating back to classical antiquity—are arbitrary. Europe covers about 10,180,000 square kilometres, or 2% of the Earths surface, politically, Europe is divided into about fifty sovereign states of which the Russian Federation is the largest and most populous, spanning 39% of the continent and comprising 15% of its population. Europe had a population of about 740 million as of 2015. Further from the sea, seasonal differences are more noticeable than close to the coast, Europe, in particular ancient Greece, was the birthplace of Western civilization. The fall of the Western Roman Empire, during the period, marked the end of ancient history. Renaissance humanism, exploration, art, and science led to the modern era, from the Age of Discovery onwards, Europe played a predominant role in global affairs. Between the 16th and 20th centuries, European powers controlled at times the Americas, most of Africa, Oceania. The Industrial Revolution, which began in Great Britain at the end of the 18th century, gave rise to economic, cultural, and social change in Western Europe. During the Cold War, Europe was divided along the Iron Curtain between NATO in the west and the Warsaw Pact in the east, until the revolutions of 1989 and fall of the Berlin Wall. In 1955, the Council of Europe was formed following a speech by Sir Winston Churchill and it includes all states except for Belarus, Kazakhstan and Vatican City. Further European integration by some states led to the formation of the European Union, the EU originated in Western Europe but has been expanding eastward since the fall of the Soviet Union in 1991. The European Anthem is Ode to Joy and states celebrate peace, in classical Greek mythology, Europa is the name of either a Phoenician princess or of a queen of Crete. The name contains the elements εὐρύς, wide, broad and ὤψ eye, broad has been an epithet of Earth herself in the reconstructed Proto-Indo-European religion and the poetry devoted to it. For the second part also the divine attributes of grey-eyed Athena or ox-eyed Hera. The same naming motive according to cartographic convention appears in Greek Ανατολή, Martin Litchfield West stated that phonologically, the match between Europas name and any form of the Semitic word is very poor. Next to these there is also a Proto-Indo-European root *h1regʷos, meaning darkness. Most major world languages use words derived from Eurṓpē or Europa to refer to the continent, in some Turkic languages the originally Persian name Frangistan is used casually in referring to much of Europe, besides official names such as Avrupa or Evropa
12.
Woman
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A woman is a female human. The term woman is usually reserved for an adult, with the girl being the usual term for a female child or adolescent. The term woman is sometimes used to identify a female human, regardless of age. Women with typical genetic development are usually capable of giving birth from puberty until menopause, the spelling of woman in English has progressed over the past millennium from wīfmann to wīmmann to wumman, and finally, the modern spelling woman. In Old English, wīfmann meant female human, whereas wēr meant male human, the medial labial consonants f and m in wīfmann coalesced into the modern form woman, while the initial element, which meant female, underwent semantic narrowing to the sense of a married woman. It is a misconception that the term woman is etymologically connected to womb. Womb is actually from the Old English word wambe meaning stomach, the symbol for the planet Venus is the sign also used in biology for the female sex. It is a representation of the goddess Venuss hand-mirror or an abstract symbol for the goddess. The Venus symbol also represented femininity, and in ancient alchemy stood for copper, alchemists constructed the symbol from a circle above an equilateral cross. Womanhood is the period in a life after she has passed through childhood and adolescence. The word woman can be used generally, to any female human or specifically. The word girl originally meant young person of either sex in English, in particular, previously common terms such as office girl are no longer widely used. Referring to a female human as a woman may, in such a culture, imply that she is sexually experienced. There are various words used to refer to the quality of being a woman, menarche, the onset of menstruation, occurs on average at age 12-13. The earliest women whose names are known through archaeology include, Neithhotep, the wife of Narmer, merneith, consort and regent of ancient Egypt during the first dynasty. She may have been ruler of Egypt in her own right, merit-Ptah, also lived in Egypt and is the earliest known female physician and scientist. Peseshet, a physician in Ancient Egypt, puabi, or Shubad – queen of Ur whose tomb was discovered with many expensive artifacts. Other known pre-Sargonic queens of Ur include Ashusikildigir, Ninbanda, kugbau, a taverness from Kish chosen by the Nippur priesthood to become hegemonic ruler of Sumer, and in later ages deified as Kubaba
13.
Direct DNA damage
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Direct DNA damage can occur when DNA directly absorbs a UVB photon, or for numerous other reasons. UVB light causes thymine base pairs next to other in genetic sequences to bond together into pyrimidine dimers, a disruption in the strand. It causes sunburn and it triggers the production of melanin, DNA transforms more than 99. 9% of the photons into harmless heat. The transformation of energy into harmless heat occurs via a photochemical process called internal conversion. In DNA, this conversion is extremely fast, and therefore efficient. This ultrafast internal conversion is a powerful photoprotection provided by single nucleotides, however, the Ground-State Recovery is much slower in G·C−DNA duplexes and hairpins. It is presumed to be even slower for double-stranded DNA in conditions of the nucleus, the absorption spectrum of DNA shows a strong absorption for UVB radiation and a much lower absorption for UVA radiation. Since the action spectrum of sunburn is indistinguishable from the spectrum of DNA. While the human body reacts to direct DNA damages with a warning signal. Direct DNA damage is reduced by sunscreen, when the sunscreen is at the surface of the skin, it filters the UV rays, which attenuates the intensity. Even when the molecules have penetrated into the skin, they protect against direct DNA damage, because the UV light is absorbed by the sunscreen
14.
Indirect DNA damage
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Indirect DNA damage occurs when a UV-photon is absorbed in the human skin by a chromophore that does not have the ability to convert the energy into harmless heat very quickly. Molecules that do not have this ability have an excited state. This long lifetime leads to a probability for reactions with other molecules - so-called bimolecular reactions. Melanin and DNA have extremely short excited state lifetimes in the range of a few femtoseconds. The excited state lifetime of these substances is 1,000 to 1,000,000 times longer than the lifetime of melanin, the molecule that originally absorbs the UV-photon is called a chromophore. Bimolecular reactions can occur either between the chromophore and DNA or between the excited chromophore and another species, to produce free radicals and Reactive Oxygen Species. These reactive chemical species can reach DNA by diffusion and the bimolecular reaction damages the DNA and it is important to note that indirect DNA damage does not result in any warning signal or pain in the human body. Sunscreen photoprotection direct DNA damage Free radical damage to DNA
15.
Pyrimidine dimer
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Pyrimidine dimers are molecular lesions formed from thymine or cytosine bases in DNA via photochemical reactions. Ultraviolet light induces the formation of covalent linkages by reactions localized on the C=C double bonds, in dsRNA, uracil dimers may also accumulate as a result of UV radiation. Two common UV products are cyclobutane pyrimidine dimers and 6,4 photoproducts and these premutagenic lesions alter the structure of DNA and consequently inhibit polymerases and arrest replication. Dimers may be repaired by photoreactivation or nucleotide excision repair, pyrimidine dimers are the primary cause of melanomas in humans. A cyclobutane pyrimidine dimer contains a four membered ring arising from the coupling of the C=C double bonds of pyrimidines, such dimers interfere with base pairing during DNA replication, leading to mutations. 6, 4-photoproducts, or 6,4 pyrimidine-pyrimidones, occur at one third the frequency of CPDs but are more mutagenic, spore photoproduct lyase provides another enzymatic pathway for repair of thymine photodimers. Translesion polymerases frequently introduce mutations at pyrimidine dimers, both in prokaryotes and in eukaryotes, although the thymine-thymine CPDs are the most frequent lesions caused by UV light, translesion polymerases are biased toward introduction of As, so that TT dimers are often replicated correctly. On the other hand, any C involved in CPDs is prone to be deaminated, pyrimidine dimers introduce local conformational changes in the DNA structure, which allow recognition of the lesion by repair enzymes. In most organisms they can be repaired by photoreactivation, photoreactivation is a repair process in which photolyase enzymes directly reverse CPDs via photochemical reactions. Lesions on the DNA strand are recognized by enzymes, followed by the absorption of light wavelengths >300 nm. This absorption enables the photochemical reactions to occur, which results in the elimination of the pyrimidine dimer, nucleotide excision repair is a more general mechanism for repair of lesions. This process excises the CPD and synthesizes new DNA to replace the surrounding region in the molecule, xeroderma pigmentosum is a genetic disease in humans in which the nucleotide excision repair process is lacking, resulting in skin discolouration and multiple tumours on exposure to UV light. Unrepaired pyrimidine dimers in humans may lead to melanoma
16.
Sun Protection Factor
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Sunscreen, also known as suncream or sunblock, is a lotion, spray, gel or other topical product that absorbs or reflects some of the suns ultraviolet radiation and thus helps protect against sunburn. Depending on the mode of action, sunscreens can be classified into physical sunscreens or chemical sunscreens, medical organizations such as the American Cancer Society recommend the use of sunscreen because it aids in the prevention of squamous cell carcinomas. Many sunscreens do not block UVA radiation, which does not primarily cause sunburn but can increase the rate of melanoma, the use of broad-spectrum sunscreens can address this concern. Diligent use of sunscreen can slow or temporarily prevent the development of wrinkles. Sunscreens are commonly rated and labeled with a sun protection factor that measures the fraction of sunburn-producing UV rays that reach the skin, for example, SPF15 means that 1/15th of the burning radiation reaches the skin through the recommended thickness of sunscreen. Other rating systems indicate the degree of protection from non-burning UVA radiation, Sunscreen use can help prevent melanoma and squamous cell carcinoma, two types of skin cancer. There is little evidence that it is effective in preventing basal cell carcinoma, a 2013 study concluded that the diligent, everyday application of sunscreen can slow or temporarily prevent the development of wrinkles and sagging skin. The study involved 900 white people in Australia and required some of them to apply a broad-spectrum sunscreen every day for four and it found that people who did so had noticeably more resilient and smoother skin than those assigned to continue their usual practices. Minimizing UV damage is important for children and fair-skinned individuals. To date, the current weight of evidence suggests that TiO2, concerns have also been raised about potential vitamin D deficiency arising from prolonged use of sunscreen. Typical use of sunscreen does not usually result in vitamin D deficiency, however, Sunscreen prevents ultraviolet light from reaching the skin, and even moderate protection can substantially reduce vitamin D synthesis. However, adequate amounts of vitamin D can be produced with moderate sun exposure to the face, arms and legs, the sun protection factor is a measure of the fraction of sunburn-producing UV rays that reach the skin. For example, SPF15 means that 1/15th of the radiation will reach the skin. A user can determine the effectiveness of a sunscreen by multiplying the SPF factor by the length of time it takes for him or her to suffer a burn without sunscreen. It is important to note that sunscreens with higher SPF do not last or remain effective on the skin any longer than lower SPF and must be continually reapplied as directed, usually every two hours. The SPF is a measure of skin damage because invisible damage and skin aging are also caused by ultraviolet type A. Conventional sunscreen blocks very little UVA radiation relative to the nominal SPF, according to a 2004 study, UVA also causes DNA damage to cells deep within the skin, increasing the risk of malignant melanomas. Even some products labeled broad-spectrum UVA/UVB protection have not always provided good protection against UVA rays, owing to consumer confusion over the real degree and duration of protection offered, labeling restrictions are enforced in several countries
17.
Ozone layer
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The ozone layer or ozone shield is a region of Earths stratosphere that absorbs most of the Suns ultraviolet radiation. It contains high concentrations of ozone in relation to parts of the atmosphere. The ozone layer contains less than 10 parts per million of ozone, the ozone layer is mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometres above Earth, although its thickness varies seasonally and geographically. The ozone layer was discovered in 1913 by the French physicists Charles Fabry and it was deduced that the missing radiation was being absorbed by something in the atmosphere. Eventually the spectrum of the radiation was matched to only one known chemical. Its properties were explored in detail by the British meteorologist G. M. B, Dobson, who developed a simple spectrophotometer that could be used to measure stratospheric ozone from the ground. Between 1928 and 1958, Dobson established a network of ozone monitoring stations. The Dobson unit, a convenient measure of the amount of overhead, is named in his honor. The ozone layer absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light, the United Nations General Assembly has designated September 16 as the International Day for the Preservation of the Ozone Layer. Venus also has an ozone layer at an altitude of 100 kilometers from the planets surface. The photochemical mechanisms that give rise to the layer were discovered by the British physicist Sydney Chapman in 1930. The ozone molecule is unstable and when light hits ozone it splits into a molecule of O2 and an individual atom of oxygen. Chemically, this can be described as, O2 + ℎνuv → 2O O + O2 ↔ O3 About 90 percent of the ozone in the atmosphere is contained in the stratosphere. Ozone concentrations are greatest between about 20 and 40 kilometres, where they range from about 2 to 8 parts per million, if all of the ozone were compressed to the pressure of the air at sea level, it would be only 3 millimetres thick. Although the concentration of the ozone in the layer is very small. Extremely short or vacuum UV is screened out by nitrogen, UV radiation capable of penetrating nitrogen is divided into three categories, based on its wavelength, these are referred to as UV-A, UV-B, and UV-C. UV-C, which is harmful to all living things, is entirely screened out by a combination of dioxygen. Nevertheless, some UV-B, particularly at its longest wavelengths, reaches the surface, Ozone is transparent to most UV-A, so most of this longer-wavelength UV radiation reaches the surface, and it constitutes most of the UV reaching the Earth
18.
Reactive oxygen species
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Reactive oxygen species are chemically reactive chemical species containing oxygen. Examples include peroxides, superoxide, hydroxyl radical, and singlet oxygen, in a biological context, ROS are formed as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis. However, during times of stress, ROS levels can increase dramatically. This may result in significant damage to cell structures, cumulatively, this is known as oxidative stress. ROS are also generated by sources such as ionizing radiation. Ionizing radiation can generate damaging intermediates through the interaction with water, since water comprises 55–60% of the human body, the probability of radiolysis is quite high under the presence of ionizing radiation. In the process, water loses an electron and becomes highly reactive, then through a three-step chain reaction, water is sequentially converted to hydroxyl radical, hydrogen peroxide, superoxide radical and ultimately oxygen. The hydroxyl radical is extremely reactive and immediately removes electrons from any molecule in its path, turning that molecule into a free radical, mitochondria convert energy for the cell into a usable form, adenosine triphosphate. The process in which ATP is produced, called oxidative phosphorylation, the last destination for an electron along this chain is an oxygen molecule. Superoxide is not particularly reactive by itself, but can inactivate specific enzymes or initiate lipid peroxidation in its protonated form, the pKa of hydroperoxyl is 4.8. Thus, at physiological pH, the majority will exist as superoxide anion, if too much damage is present in mitochondria, a cell undergoes apoptosis or programmed cell death. This cytochrome C binds to Apaf-1, or apoptotic protease activating factor-1, using energy from the ATPs in the mitochondrion, the Apaf-1 and cytochrome C bind together to form apoptosomes. The apoptosomes bind to and activate caspase-9, another free-floating protein, the caspase-9 then cleaves the proteins of the mitochondrial membrane, causing it to break down and start a chain reaction of protein denaturation and eventually phagocytosis of the cell. Superoxide dismutases are a class of enzymes catalyze the dismutation of superoxide into oxygen and hydrogen peroxide. As such, they are an important antioxidant defense in all cells exposed to oxygen. In mammals and most chordates, three forms of superoxide dismutase are present, sOD1 is located primarily in the cytoplasm, SOD2 in the mitochondria and SOD3 is extracellular. The first is a dimer, while the others are tetramers, sOD1 and SOD3 contain copper and zinc ions, while SOD2 has a manganese ion in its reactive centre. The genes are located on chromosomes 21,6, and 4, respectively
19.
Von Luschan's chromatic scale
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Von Luschans chromatic scale is a method of classifying skin color. It is also called the von Luschan scale or von Luschans scale and it is named after its inventor, Felix von Luschan. The equipment consists of 36 opaque glass tiles which were compared to the subjects skin, Fitzpatrick to describe sun tanning behavior. The von Luschan scale was used throughout the first half of the 20th century in race studies. However, it was considered problematic, even by its practitioners, in many instances, different investigators would give different readings of the same person. The von Luschan scale was largely abandoned by the early 1950s, the following table shows the 36 categories of the von Luschan scale in relation to the six categories of the Fitzpatrick scale, von Luschan F. Beiträge zur Völkerkunde der Deutschen Schutzgebieten. Von Luschan F. Völker, Rassen, Sprachen, Anthropologische Betrachtungen, von Luschans Chromatic Scale and other anthropometric instruments at the Natural History Museum of Florence
20.
Brown (racial classification)
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Brown or brown people is a racial and ethnic classification. Like black people and white people, it is a metaphor for race based on skin color. In Brazil, brown people is a term for pardo. In the 18th and 19th century, racialist written works proposed geographically based scientific differences among the races, jean Baptiste Julien dOmalius dHalloys five-race scheme differed from Blumenbachs by including Ethiopians in the brown race, as well as Oceanic peoples. Louis Figuier adopted and adapted dOmalius dHalloys classification and also included Egyptians in the brown race, in 1915, Donald Mackenzie conceived a Mediterranean or Brown race, the eastern branch of which reaches to India and the western to the British Isles and Ireland. Stoddards brown is one of five races, contrasting with white, black, yellow. In this popular conception, the Brown Race consisted of a joint Mediterranean-Hamite-Semite grouping of related peoples. These and other racialist theories have been dismissed scientifically, in the 19th century, the notion of a single brown people was sometimes superseded by multiple brown peoples. Cust mentions Grammar in 1852 denying that there was one single brown race, the appellation brown people has been applied in the 20th and 21st centuries to several groups. Edward Telles, a sociologist of race and ethnicity, and Jack Forbes both argue that this classification is biologically invalid, however, as Telles notes, it is still of sociological significance. Forbes remarks upon a process of lumping, whereby characteristics other than color, such as hair color or curliness. In 1950s South Africa the brown people were the Coloreds, referring to those born of black-white sexual unions out of wedlock, the Afrikaans terms, which incorporate many subtleties of heritage, political agenda, and identity, are bruin, bruines, and bruinmense. Some South Africans prefer the appellation bruinmense to Colored, the South African pencil test was one example of a characteristic other than skin color being used as a determiner. The pencil test, which distinguished either black from Colored or Colored from white, relied upon curliness, the pencil test could trump skin color. Steve Biko, in his trial in 1976, rejected the appellation brown people when it was put to him incorrectly by Judge Boshoff, Boshoff, I mean you people are more brown than black. Biko, In the same way as I think white people are more pink and yellow, but now why do you not use the word brown then. And we choose this one precisely because we feel it is most accommodating and this contrasts with Piet Uithalder, fictional protagonist of the satirical column Straatpraatjes that appeared in the Dutch-Afrikaans section of the newspaper APO between May 1909 and February 1922. Uithalder would self-identify as a Colored person, with the column targeted at a Colored readership, introducing himself as een van de ras, in popular use, Brazilians also use a category of moreno m. morena f. lit
21.
Dark skin
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Human skin color ranges in variety from the darkest brown to the lightest hues. An individuals skin pigmentation is the result of genetics, being the product of both of the biological parents genetic makeup. The actual skin color of different humans is affected by many substances, 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 skin is determined mainly by the bluish-white connective tissue under the dermis. The red color underlying the skin becomes more visible, especially in the face, Color is not entirely uniform across an individuals skin, for example, the skin of the palm and the sole is lighter than most other skin, and this is especially noticeable in darker-skinned people. There is a correlation between the geographic distribution of UV radiation and the distribution of indigenous skin pigmentation around the world. Areas that receive higher amounts of UVR, generally located closer to the equator, areas that are far from the tropics and closer to the poles have lower intensity of UVR, which is reflected in lighter-skinned populations. Natural skin color can darken as a result of tanning due to exposure to sunlight. In addition, it has observed that adult human females on average are significantly lighter in skin pigmentation than males. Females need more calcium during pregnancy and lactation, the body synthesizes vitamin D from sunlight, which helps it absorb calcium. Females evolved to have lighter skin so their bodies absorb more calcium, 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 arms of melanocytes. Under normal conditions, melanosomes cover the part of the keratinocytes. One melanocyte supplies melanin to thirty-six keratinocytes according to signals from the keratinocytes and they also regulate melanin production and replication of melanocytes. People have different skin colors mainly because their melanocytes produce different amount, the genetic mechanism behind human skin color is mainly regulated by the enzyme tyrosinase, which creates the color of the skin, eyes, and hair shades. Differences in skin color are also attributed to differences in size, melanocytes produce two types of melanin. The most common form of melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids
22.
Health effects of sunlight exposure
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The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a principal source of vitamin D3 and a mutagen. A dietary supplement can supply vitamin D without this mutagenic effect, Vitamin D has a wide range of positive health effects, which include strengthening bones and possibly inhibiting the growth of some cancers. UV exposure also has positive effects for endorphin levels, and possibly for protection against multiple sclerosis, long-term sunlight exposure is known to be associated with the development of skin cancer, skin aging, immune suppression, and eye diseases such as cataracts and macular degeneration. Short-term over-exposure is the cause of sunburn, snow blindness, there is a general consensus that sunburn should always be avoided. UVB radiation with a wavelength of 290–315 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, UVB radiation does not penetrate glass, so exposure to sunshine indoors through a window does not produce vitamin D. Individuals with limited sun exposure need to include good sources of vitamin D in their diet or take a supplement, the only way to quantify adequate levels of vitamin D is with a serum 25D3 test. In the United States, serum 25D3 was below the level for more than a third of white men in a 2005 study, with serum levels even lower in women. This indicates that vitamin D deficiency may be a problem in the US. Australia and New Zealand have had similar findings, which indicate insufficient protection against rickets for children, the first map at right shows levels of UVB radiation in June 2008, expressed in Vitamin D Equivalents. Exposure to the radiation of sunlight appears to be most important. Ultraviolet irradiation present in sunlight is a human carcinogen. The toxic effects of UV from natural sunlight and therapeutic artificial lamps are a concern for human health. The major acute effects of UV irradiation on normal human skin comprise sunburn inflammation erythema, tanning, the most deadly form, malignant melanoma, is mostly caused by indirect DNA damage from UVA radiation. This can be seen from the absence of a direct UV signature mutation in 92% of all melanoma, UVC is the highest-energy, most-dangerous type of ultraviolet radiation, and causes adverse effects that can variously be mutagenic or carcinogenic. Lifetime cumulative UV exposure to skin is responsible for significant age-associated dryness, wrinkling, elastin and collagen damage, freckling, age spots. The American Academy of Dermatology advises that photoprotective measures be taken, including the use of sunscreen, short-term over-exposure causes the pain and itching of sunburn, which in extreme cases can produce more-severe effects like blistering. Light to the eyes, primarily light, is important for the entrainment. Exposure to sunlight in the morning is particularly effective, it leads to earlier melatonin onset in the evening, bright morning light has been shown to be effective against insomnia, premenstrual syndrome and seasonal affective disorder
23.
Sunscreen
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Sunscreen, also known as suncream or sunblock, is a lotion, spray, gel or other topical product that absorbs or reflects some of the suns ultraviolet radiation and thus helps protect against sunburn. Depending on the mode of action, sunscreens can be classified into physical sunscreens or chemical sunscreens, medical organizations such as the American Cancer Society recommend the use of sunscreen because it aids in the prevention of squamous cell carcinomas. Many sunscreens do not block UVA radiation, which does not primarily cause sunburn but can increase the rate of melanoma, the use of broad-spectrum sunscreens can address this concern. Diligent use of sunscreen can slow or temporarily prevent the development of wrinkles. Sunscreens are commonly rated and labeled with a sun protection factor that measures the fraction of sunburn-producing UV rays that reach the skin, for example, SPF15 means that 1/15th of the burning radiation reaches the skin through the recommended thickness of sunscreen. Other rating systems indicate the degree of protection from non-burning UVA radiation, Sunscreen use can help prevent melanoma and squamous cell carcinoma, two types of skin cancer. There is little evidence that it is effective in preventing basal cell carcinoma, a 2013 study concluded that the diligent, everyday application of sunscreen can slow or temporarily prevent the development of wrinkles and sagging skin. The study involved 900 white people in Australia and required some of them to apply a broad-spectrum sunscreen every day for four and it found that people who did so had noticeably more resilient and smoother skin than those assigned to continue their usual practices. Minimizing UV damage is important for children and fair-skinned individuals. To date, the current weight of evidence suggests that TiO2, concerns have also been raised about potential vitamin D deficiency arising from prolonged use of sunscreen. Typical use of sunscreen does not usually result in vitamin D deficiency, however, Sunscreen prevents ultraviolet light from reaching the skin, and even moderate protection can substantially reduce vitamin D synthesis. However, adequate amounts of vitamin D can be produced with moderate sun exposure to the face, arms and legs, the sun protection factor is a measure of the fraction of sunburn-producing UV rays that reach the skin. For example, SPF15 means that 1/15th of the radiation will reach the skin. A user can determine the effectiveness of a sunscreen by multiplying the SPF factor by the length of time it takes for him or her to suffer a burn without sunscreen. It is important to note that sunscreens with higher SPF do not last or remain effective on the skin any longer than lower SPF and must be continually reapplied as directed, usually every two hours. The SPF is a measure of skin damage because invisible damage and skin aging are also caused by ultraviolet type A. Conventional sunscreen blocks very little UVA radiation relative to the nominal SPF, according to a 2004 study, UVA also causes DNA damage to cells deep within the skin, increasing the risk of malignant melanomas. Even some products labeled broad-spectrum UVA/UVB protection have not always provided good protection against UVA rays, owing to consumer confusion over the real degree and duration of protection offered, labeling restrictions are enforced in several countries
24.
DNA
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Deoxyribonucleic acid is a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and RNA are nucleic acids, alongside proteins, lipids and complex carbohydrates, most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix. The two DNA strands are termed polynucleotides since they are composed of simpler units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases—cytosine, guanine, adenine, or thymine —a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two polynucleotide strands are bound together, according to base pairing rules, with hydrogen bonds to make double-stranded DNA. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037, in comparison the total mass of the biosphere has been estimated to be as much as 4 trillion tons of carbon. The DNA backbone is resistant to cleavage, and both strands of the double-stranded structure store the same biological information and this information is replicated as and when the two strands separate. A large part of DNA is non-coding, meaning that these sections do not serve as patterns for protein sequences, the two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases and it is the sequence of these four nucleobases along the backbone that encodes biological information. RNA strands are created using DNA strands as a template in a process called transcription, under the genetic code, these RNA strands are translated to specify the sequence of amino acids within proteins in a process called translation. Within eukaryotic cells DNA is organized into structures called chromosomes. During cell division these chromosomes are duplicated in the process of DNA replication, eukaryotic organisms store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast prokaryotes store their DNA only in the cytoplasm, within the eukaryotic chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed, DNA was first isolated by Friedrich Miescher in 1869. DNA is used by researchers as a tool to explore physical laws and theories, such as the ergodic theorem. The unique material properties of DNA have made it an attractive molecule for material scientists and engineers interested in micro-, among notable advances in this field are DNA origami and DNA-based hybrid materials. DNA is a polymer made from repeating units called nucleotides
25.
Psoralen
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Psoralen is the parent compound in a family of natural products known as furocoumarins. It is structurally related to coumarin by the addition of a furan ring. Psoralen occurs naturally in the seeds of Psoralea corylifolia, as well as in the fig, celery, parsley, West Indian satinwood. It is widely used in PUVA treatment for psoriasis, eczema, vitiligo, many furocoumarins are extremely toxic to fish, and some are deposited in streams in Indonesia to catch fish. Psoralen is a mutagen, and is used for purpose in molecular biology research. Psoralen plus UVA therapy has shown clinical efficacy. Unfortunately, an effect of PUVA treatment is a higher risk of skin cancer. An important use of psoralen is in PUVA treatment for skin problems such as psoriasis and eczema and this takes advantage of the high UV absorbance of psoralen. The psoralen is applied first to sensitise the skin, then UVA light is applied to clean up the skin problem, psoralen has also been recommended for treating alopecia. Psoralens are also used in photopheresis, where they are mixed with the extracted leukocytes before UV radiation is applied, despite the photocarcinogenic properties of psoralen, it had been used as a tanning activator in sunscreens until 1996. Psoralens are used in tanning accelerators, although psoralen increases the sensitivity to light. Some patients have had severe skin loss after sunbathing with psoralen-containing tanning activators, patients with lighter skin colour suffer four times as much from the melanoma-generating properties of psoralens than those with darker skin. An additional use for optimized psoralens is for the inactivation of pathogens in blood products, the synthetic amino-psoralen, amotosalen HCl, has been developed for the inactivation of infectious pathogens in platelet and plasma blood components prepared for transfusion support of patients. Prior to clinical use, amotosalen-treated platelets have been tested and found to be non-carcinogenic when using the established p53 knockout mouse model, the technology is currently in routine use in certain European blood centers and has been recently approved in the US. Psoralen intercalates into the DNA double helix where it is positioned to form adduct with adjacent pyrimidine bases, preferentially thymine. Several physicochemical methods have been employed to derive binding constants for psoralen-DNA interactions, water solubility is important for two reasons, pharmokinetics relating to drug solubility in blood and necessitating the use of organic solvents. Psoralens can also be activated by irradiation with long wavelength UV light, while UVA range light is the clinical standard, research that UVB is more efficient at forming photoadducts suggests that its use may lead to higher efficacy and lower treatment times. The photochemically reactive sites in psoralens are located at each of the double bonds in the furan ring
26.
Claude Monet
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Monets ambition of documenting the French countryside led him to adopt a method of painting the same scene many times in order to capture the changing of light and the passing of the seasons. From 1883 Monet lived in Giverny, where he purchased a house and property, Claude Monet was born on 14 November 1840 on the fifth floor of 45 rue Laffitte, in the 9th arrondissement of Paris. He was the son of Claude Adolphe Monet and Louise Justine Aubrée Monet. On 20 May 1841, he was baptized in the parish church, Notre-Dame-de-Lorette, as Oscar-Claude. Despite being baptized Catholic, Monet later became an atheist, in 1845, his family moved to Le Havre in Normandy. His father wanted him to go into the familys ship-chandling and grocery business and his mother was a singer, and supported Monets desire for a career in art. On 1 April 1851, Monet entered Le Havre secondary school of the arts, locals knew him well for his charcoal caricatures, which he would sell for ten to twenty francs. Monet also undertook his first drawing lessons from Jacques-François Ochard, a student of Jacques-Louis David. On the beaches of Normandy around 1856 he met fellow artist Eugène Boudin, Boudin taught Monet en plein air techniques for painting. Both received the influence of Johan Barthold Jongkind, on 28 January 1857, his mother died. At the age of sixteen, he left school and went to live with his widowed, childless aunt, when Monet traveled to Paris to visit the Louvre, he witnessed painters copying from the old masters. Having brought his paints and other tools with him, he would go and sit by a window. Monet was in Paris for several years and met other painters, including Édouard Manet and others who would become friends. After drawing a low number in March 1861, Monet was drafted into the First Regiment of African Light Cavalry in Algeria for a seven-year period of military service. His prosperous father could have purchased Monets exemption from conscription but declined to do so when his son refused to give up painting. While in Algeria Monet did only a few sketches of scenes, a single landscape. In a Le Temps interview of 1900 however he commented that the light, after about a year of garrison duty in Algiers, Monet contracted typhoid fever and briefly went absent without leave. Following convalescence, Monets aunt intervened to get him out of the army if he agreed to complete a course at an art school and it is possible that the Dutch painter Johan Barthold Jongkind, whom Monet knew, may have prompted his aunt on this matter
27.
Bonnet (headgear)
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Bonnet is a term for a wide variety of styles of headgear for both sexes, but most often female, which has been in use from the Middle Ages to the present. However the term has also used, for example, for steel helmets. This was from Scotland, where the term has long been especially popular, Bonnet derives from the same word in French, where it originally indicated a type of material. In the 21st century, only a few kinds of headgear are still referred to as bonnets, most commonly worn by babies. The most common kind of bonnet worn today is a soft headcovering for babies and they are shaped similarly to the kind of bonnets women used to wear, that is they cover the hair and ears, but not the forehead. In the mid-17th and 18th century house bonnets worn by women and girls were generally brimless headcoverings which were secured by tying under the chin, and they were worn indoors, to keep the hair tidy, and outdoors, to keep dust out of the hair. From Waterloo, more structured fashionable bonnets made by milliners rapidly grew larger and this ornament is partially placed on one side, the edge of the bonnet finished by blond laid on strait. Straw was available again after 1815, the best straw bonnets came from Leghorn, as a bonnet developed a peak, it would extend from the entire front of the bonnet, from the chin over the forehead and down the other side of the face. Some styles of bonnets between ca 1817 and 1845 had a peak which effectively prevented women from looking right or left without turning their heads. Others had a peak which was angled out to frame the face. In the 1840s it might be crimped at the top to frame the face in a heart shape, as the bonnet became more complicated, under it might be worn a lace cornette to hold the hair in place. Bonnets remained one of the most common types of headgear worn by women throughout most of the 19th century, for a widow, a bonnet was de rigueur. Silk bonnets, elaborately pleated and ruched, were worn outdoors, or in places like shops, galleries, churches. Under the French Second Empire, parasols took the place of protection from sun, most middle-class women in the 19th century would have had at least two bonnets, one suitable for summer weather, often made from straw, and one made from heavier fabric for winter wear. This is where the tradition of an Easter bonnet originated, when women would switch from their winter bonnet to their summer bonnet, wealthier women would have many bonnets, suitable for different occasions. In some religious groups it has been customary for women to wear bonnets and this was the case among the Friends until well into the 20th century, and is still the case among the Old Order Mennonites and the Amish. Bonnets were adopted by The Salvation Army as part of regalia for women. Initially, bonnets were introduced as protection for women soldiers and were reinforced with black tar to turn them into helmets, later versions were smaller when there was no longer any need for protection
28.
Umbrella
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An umbrella or parasol is a folding canopy supported by wooden or metal ribs, which is usually mounted on a wooden, metal, or plastic pole. It is designed to protect a person against rain or sunlight, the word umbrella typically refers to a device used for protection from rain. The word parasol usually refers to a designed to protect from the sun. Often the difference is the used for the canopy, some parasols are not waterproof. Umbrella canopies may be made of fabric or flexible plastic, Umbrellas and parasols are primarily hand-held portable devices sized for personal use. The largest hand-portable umbrellas are golf umbrellas, another distinction can be made between manually operated umbrellas and spring-loaded automatic umbrellas which spring open at the press of a button. Hand-held umbrellas have some type of handle, either a wooden or plastic cylinder or a bent crook handle, Umbrellas are available in a range of price and quality points, ranging from inexpensive, modest quality models sold at discount stores to expensive, finely made, designer-labeled models. The collapsible/folding umbrella, the predecessor to the modern umbrella. These Chinese umbrellas were internally supported with bendable, retractable, an umbrella may also be called a brolly, parapluie, rainshade, gamp, or bumbershoot. The word parasol is a combination of para, meaning to stop or to shield, parapluie similarly consists of para combined with pluie, which means rain. Hence, a parasol shields from sunlight while a parapluie shields from rain, the word umbrella evolved from the Latin umbella or umbra, meaning shaded or shadow. In Britain, umbrellas were sometimes referred to as gamps after the character Mrs. Gamp in the Charles Dickens novel Martin Chuzzlewit, Mrs. Gamps character was well known for carrying an umbrella. Brolly is a word for umbrella, used often in Britain, Ireland, New Zealand, Australia, South Africa. Bumbershoot is a fanciful Americanism from the late 19th century, in all written records, the oldest reference to a collapsible umbrella dates to the year 21 AD, when Wang Mang had one designed for a ceremonial four-wheeled carriage. The 2nd-century commentator Fu Qian added that this collapsible umbrella of Wang Mangs carriage had bendable joints which enabled them to be extended or retracted. A 1st century collapsible umbrella has since recovered from the tomb of Wang Guang at Lelang Commandery in the Korean Peninsula, illustrated in a work by Harada. However, the Chinese collapsible umbrella is perhaps a concept that is yet centuries older than Wangs tomb. An even older source on the umbrella is perhaps the ancient book of Chinese ceremonies, called Zhou Li, dating 2400 years ago, which directs that upon the imperial cars the dais should be placed
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Skin whitening
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Skin whitening is the practice of using substances, mixtures, or physical treatments to lighten skin color. Skin whitening treatments work by reducing the content of melanin of the skin, many agents have been shown to be effective in skin whitening, some have beneficial side effects, some are a significant risk to health. Specific zones of abnormally high such as lentigo spots, moles. In cases of vitiligo, unaffected skin may be lightened to achieve a uniform appearance. Thus, the development and discovery of melanogenesis inhibitors illustrates many of the used in drug design. Some of the most potent competitive reversible tyrosinase inhibitors are synthetic compounds with a potency hundreds of times that of kojic acid, for a review of mechanism of action of skin whitening agents, see Chang or Ebanks, Wickett, Boissy. Melanin is the substance responsible for the color of the skin. Melanin is class of dark polymers generated by the body through the process of melanogenesis, the variation of skin color among individuals is mostly because of variation of the content of melanin in the skin. Skin with little or no melanin is almost white, other factors influence skin color in a lesser degree, including the amount of blood in blood vessels, skin thickness and content of carotenoids in skin. Melanin in synthesized in melanosomes which are produced in melanocytes. Melanocytes are cells dedicated to this function that are present in the skin, hair follicles, the synthesis of melanin involves a chain of enzyme-catalyzed chemical reactions and non-enzyme-catalyzed reactions. The main precursor to melanin is L-tyrosine, L-tyrosine is taken by the melanocytes from the intercellular medium, then transported to the melanosomes. L-tyrosine is also synthesized within the melanocytes from L-phenylalanine by the enzyme phenylalanine hydroxylase.1164 Melanosomes are transferred to keratinocytes, most of the melanin of skin is found in keratinocytes. Additionally, melanocytes interact with keratinocytes through chemical signaling, see § Preventing the transfer of melanosomes to keratinocytes. Skin whitening agents work by reducing the presence of melanin in the skin, to accomplish this, there are several possible mechanism of actions, Inhibition of the activity of tyrosinase, The catalytic action of tyrosinase is inhibited by the skin whitening agent. Inhibition of the expression or activation of tyrosinase, The antimelanogenic agent causes that less tyrosinase is generated or that tyrosinase is not activated to its functional form, scavenging of the intermediate products of melanin synthesis. Preventing the transfer of melanosomes to keratinocytes, many tyrosinase inhibitors have been discovered or developed. Very many inhibitors of tyrosinase are known, most are of the reversible type, for a review of tyrosinase inhibitors see Chang
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Arsenic
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Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in minerals, usually in combination with sulfur and metals. It has various allotropes, but only the form is important to industry. The primary use of arsenic is in alloys of lead. Arsenic is a common dopant in semiconductor electronic devices. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, a few species of bacteria are able to use arsenic compounds as respiratory metabolites. Trace quantities of arsenic are a dietary element in rats, hamsters, goats, chickens. However, arsenic poisoning occurs in multicellular life if quantities are larger than needed, Arsenic contamination of groundwater is a problem that affects millions of people across the world. The three most common allotropes are metallic gray, yellow, and black arsenic, with gray being the most common. Gray arsenic adopts a structure consisting of many interlocked, ruffled, six-membered rings. Because of weak bonding between the layers, gray arsenic is brittle and has a relatively low Mohs hardness of 3.5. Nearest and next-nearest neighbors form an octahedral complex, with the three atoms in the same double-layer being slightly closer than the three atoms in the next. This relatively close packing leads to a density of 5.73 g/cm3. Gray arsenic is a semimetal, but becomes a semiconductor with a bandgap of 1. 2–1.4 eV if amorphized, gray arsenic is also the most stable form. Yellow arsenic is soft and waxy, and somewhat similar to tetraphosphorus, both have four atoms arranged in a tetrahedral structure in which each atom is bound to each of the other three atoms by a single bond. This unstable allotrope, being molecular, is the most volatile, least dense, solid yellow arsenic is produced by rapid cooling of arsenic vapor, As 4. It is rapidly transformed into gray arsenic by light, the yellow form has a density of 1.97 g/cm3. Black arsenic is similar in structure to red phosphorus, black arsenic can also be formed by cooling vapor at around 100–220 °C
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Victorian era
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The Victorian era was the period of Queen Victorias reign, from 20 June 1837 until her death on 22 January 1901. It was a period of peace, prosperity, refined sensibilities. Some scholars date the beginning of the period in terms of sensibilities, the era followed the Georgian period and preceded the Edwardian period. The later half of the Victorian age roughly coincided with the first part of the Belle Époque era of continental Europe, culturally there was a transition away from the rationalism of the Georgian period and toward romanticism and mysticism with regard to religion, social values, and arts. The end of the saw the Boer War. Domestically, the agenda was increasingly liberal with a number of shifts in the direction of political reform, industrial reform. Two especially important figures in period of British history are the prime ministers Benjamin Disraeli and William Gladstone. Disraeli, favoured by the queen, was a gregarious Conservative and his rival Gladstone, a Liberal distrusted by the Queen, served more terms and oversaw much of the overall legislative development of the era. The population of England and Wales almost doubled from 16.8 million in 1851 to 30.5 million in 1901, Scotlands population also rose rapidly, from 2.8 million in 1851 to 4.4 million in 1901. However, Irelands population decreased sharply, from 8.2 million in 1841 to less than 4.5 million in 1901, mostly due to the Great Famine. Between 1837 and 1901 about 15 million emigrants departed the UK permanently, in search of a life in the United States, Canada, South Africa, New Zealand, Australia. During the early part of the era, politics in the House of Commons involved battles between the two parties, the Whigs/Liberals and the Conservatives. These parties were led by such prominent statesmen as Lord Melbourne, Sir Robert Peel, Lord Derby, Lord Palmerston, Gladstone, Disraeli, Victoria became queen in 1837 at age 18. Her long reign until 1901 was mainly a time of peace, Britain reached the zenith of its economic, political, diplomatic and cultural power. The era saw the expansion of the second British Empire, Historians have characterised the mid-Victorian era as Britains Golden Years. There was prosperity, as the income per person grew by half. There was peace abroad, and social peace at home, opposition to the new order melted away, says Porter. The Chartist movement peaked as a movement among the working class in 1848, its leaders moved to other pursuits, such as trade unions
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