Saturday, 27 June 2015
Thursday, 25 June 2015
Why Hair fall
More than
95% of hair loss in men is male pattern baldness (MPB). MPB is characterized by
hair receding from the lateral sides of the forehead (known as a "receding
hairline") and/or a thinning crown (balding to the area known as the
‘vertex’).Both become more pronounced until they eventually meet, leaving a
horseshoe-shaped ring of hair around the back of the head.
The
incidence of pattern baldness varies from population to population and is based
on genetic background. Environmental factors do not seem to affect this type of
baldness greatly. One large scale study in Maryborough, Victoria, Australia
showed the prevalence of mid-frontal baldness increases with age and affects
73.5 percent of men and 57 percent of women aged 80 and over. A rough rule of
thumb is that the incidence of baldness in males corresponds roughly to
chronological age. For example, according to Medem Medical Library's website,
MPB affects roughly 40 million men in the United States. Approximately one in
four men will have noticeable hair loss by age 30, and this figure increases to
two in three men by age 60. In rare cases, MPB can begin as early as age 12.
The
genetics of MPB are not yet fully understood. Most likely there are multiple
genes that contribute towards MPB, the most important of which appears to be
the Androgen Receptor gene, located on the X chromosome (inherited from the mother).
It was previously believed that baldness was inherited from the maternal
grandfather. While there is some basis for this belief, it is now known that
both parents contribute to their offspring's likelihood of hair loss. Most
likely, inheritance involves many genes with variable penetrance.[medical
citation needed]
The
trigger for this type of baldness is dihydrotestosterone, a more potent form of
testosterone often referred to by its acronym DHT. DHT is an androgenic
hormone, body- and facial-hair growth promoter that can adversely affect the
prostate as well as the hair located on the head.The mechanism by which DHT
accomplishes this is not yet fully understood. In genetically prone scalps
(i.e., those experiencing male or female pattern baldness), DHT initiates a
process of follicular miniaturization, in which the hair follicle begins to
deteriorate. As a consequence, the hair’s growth phase (anagen) is shortened,
and young, unpigmented vellus hair is prevented from growing and maturing into
the deeply rooted and pigmented terminal hair that makes up 90 percent of the
hair on the head. In time, hair becomes thinner, and its overall volume is
reduced so that it resembles fragile vellus hair or "peach fuzz"
until, finally, the follicle goes dormant and ceases producing hair completely.
Hair Care
Hair cleaning
One way to distribute the hair's natural oils through the hair is by brushing with a natural bristle brush. The natural bristles effectively move the oil from the scalp through to the hair's mid-lengths and ends, nourishing these parts of the hair. Brushing the scalp also stimulates the sebaceous gland, which in turn produces more sebum. When sebum and sweat combine on the scalp surface, they help to create the acid mantle, which is the skin's own protective layer.
Washing hair removes excess sweat and oil, as well as unwanted products from the hair and scalp. Often hair is washed as part of a shower or bathing with shampoo, a specialized surfactant. Shampoos work by applying water and shampoo to the hair. The shampoo breaks the surface tension of the water, allowing the hair to become soaked. This is known as the wetting action. The wetting action is caused by the head of the shampoo molecule attracting the water to the hair shaft. Conversely, the tail of the shampoo molecule is attracted to the grease, dirt and oil on the hair shaft. The physical action of shampooing makes the grease and dirt become an emulsion that is then rinsed away with the water. This is known as the emulsifying action. Sulfate free shampoos are less harming on color treated hair than normal shampoos that contain sulfates. Sulfates strip away natural oils as well as hair dye. Sulfates are also responsible for the foaming effect of shampoos.
Shampoos have a pH of between 4 and 6 and do not contain soap. Soapless shampoos are acidic and therefore closer to the natural pH of hair. Acidic shampoos are the most common type used and maintain or improve the condition of the hair as they don't swell the hairshaft and don't strip the natural oils. Conditioners are often used after shampooing to smooth down the cuticle layer of the hair, which can become roughened during the physical process of shampooing. There are three main types of conditioners: anti-oxidant conditioners, which are mainly used in salons after chemical services and prevent creeping oxidation; internal conditioners, which enter into the cortex of the hair and help improve the hair's internal condition (also known as treatments); and external conditioners, or everyday conditioners, which smooth down the cuticle layer, making the hair shiny, combable and smooth. Conditioners can also provide a physical layer of protection for the hair against physical and environmental damage.
One way to distribute the hair's natural oils through the hair is by brushing with a natural bristle brush. The natural bristles effectively move the oil from the scalp through to the hair's mid-lengths and ends, nourishing these parts of the hair. Brushing the scalp also stimulates the sebaceous gland, which in turn produces more sebum. When sebum and sweat combine on the scalp surface, they help to create the acid mantle, which is the skin's own protective layer.
Washing hair removes excess sweat and oil, as well as unwanted products from the hair and scalp. Often hair is washed as part of a shower or bathing with shampoo, a specialized surfactant. Shampoos work by applying water and shampoo to the hair. The shampoo breaks the surface tension of the water, allowing the hair to become soaked. This is known as the wetting action. The wetting action is caused by the head of the shampoo molecule attracting the water to the hair shaft. Conversely, the tail of the shampoo molecule is attracted to the grease, dirt and oil on the hair shaft. The physical action of shampooing makes the grease and dirt become an emulsion that is then rinsed away with the water. This is known as the emulsifying action. Sulfate free shampoos are less harming on color treated hair than normal shampoos that contain sulfates. Sulfates strip away natural oils as well as hair dye. Sulfates are also responsible for the foaming effect of shampoos.
Shampoos have a pH of between 4 and 6 and do not contain soap. Soapless shampoos are acidic and therefore closer to the natural pH of hair. Acidic shampoos are the most common type used and maintain or improve the condition of the hair as they don't swell the hairshaft and don't strip the natural oils. Conditioners are often used after shampooing to smooth down the cuticle layer of the hair, which can become roughened during the physical process of shampooing. There are three main types of conditioners: anti-oxidant conditioners, which are mainly used in salons after chemical services and prevent creeping oxidation; internal conditioners, which enter into the cortex of the hair and help improve the hair's internal condition (also known as treatments); and external conditioners, or everyday conditioners, which smooth down the cuticle layer, making the hair shiny, combable and smooth. Conditioners can also provide a physical layer of protection for the hair against physical and environmental damage.
Historical Bai Mei
Historical Bai Mei
It is easy to see how a past work of fiction, originally written as a piece of propaganda, became interwoven in the fullness of time into the collective mind as historical fact. The Bai Mei caricature, a mysterious monk originating from the Shaolin Temple with white eyebrows and awesome power, was in all probability employed to create a lineage with the said Temple, giving the style a veritable heritage as well as alluding to wisdom and venerability. The oral tradition is that Chan master Bai Mei had a disciple, Guanghui, to whom he passed on the arts.
Guanghui means Vast Benevolence and is a typical Buddhist nomination for either a monk or a temple; indeed there are several temples throughout China that bear this name. Yet on searching through the surviving gazetteers for Mount Emei there is no mention of a monk named Guanghui. There is no material evidence to suggest that Guanghui came from Emei Shan; all we have is the oral tradition from Zhang Liquan (Cheung Lai Chuen) that his Shifu, Zhu Fayun, came from a temple in Sichuan Province.
Zhu Fayun. Fa, in the context of a monk's name, means Buddhist Teachings and Yun means Cloud. The Chinese character Zhu formed part of the ancient word Tianzhu, meaning India. Zhu Fayun is said to have been a Buddhist monk from Emei Shan in Sichuan Province on a pilgrimage to the Guangxiao (Bright Filial Monastery), in Guangzhou. This is entirely plausible as the Guangxiao monastery is one of the oldest temples in south China as well as being one of the most influential Buddhist shrines. During his stay in Guangxiao, Zhu Fayun committed to teach Zhang Liquan (Cheung Lai Chuen) the Baimei arts.
Zhang Liquan (1882-1964). It would seem that Zhang Liquan was essentially an honest man with respect to his martial arts. He learnt three different styles from three different masters prior to having met Zhu Fayun. He formally acknowledges each of his former Shifu by name and honors them by keeping at least one of their forms in the Pak Mei syllabus. At a later stage in his career, Zhang Liquan formulated several of his own forms, including Tuotiao Quan (Cantonese: Tit Til Kuen) and Simen Bagua (Cantonese: Say Mun Ba Gua) which he openly professed were his own works. It would appear contradictory to suggest that such a man, who has been totally honest about the origins of all that he has learnt, would deny the existence of one teacher, or indeed invent a fictional character to disguise his own works when he has already affirmed creating several of his own.
All the supplementary forms in the Pak Mei syllabus, whatever the original style, fall under the collective classification of Nan Quan (Southern Fist) or more precisely DongJiang Quan (East River Fist). A common denominator to all these forms is that they are divided into two parts; the second being a repetition of the first, performed in the opposite direction. They also have numerous stances and techniques in common and share similar terminology and methodology. Accordinly there have been attempts to suggest that Baimei quan forms part of these southern or Hakka styles or indeed is a concoction of these various styles. Yet none of the four Baimei original forms are performed in two halves, nor do they share any stances or techniques with the supplementary forms. Similary the Baimei opening salutation, Wuhu Sihai (Cantonese: Ng Wu Say Hoi) is not found in any other style apart from Baimei derivatives.[1]
It is easy to see how a past work of fiction, originally written as a piece of propaganda, became interwoven in the fullness of time into the collective mind as historical fact. The Bai Mei caricature, a mysterious monk originating from the Shaolin Temple with white eyebrows and awesome power, was in all probability employed to create a lineage with the said Temple, giving the style a veritable heritage as well as alluding to wisdom and venerability. The oral tradition is that Chan master Bai Mei had a disciple, Guanghui, to whom he passed on the arts.
Guanghui means Vast Benevolence and is a typical Buddhist nomination for either a monk or a temple; indeed there are several temples throughout China that bear this name. Yet on searching through the surviving gazetteers for Mount Emei there is no mention of a monk named Guanghui. There is no material evidence to suggest that Guanghui came from Emei Shan; all we have is the oral tradition from Zhang Liquan (Cheung Lai Chuen) that his Shifu, Zhu Fayun, came from a temple in Sichuan Province.
Zhu Fayun. Fa, in the context of a monk's name, means Buddhist Teachings and Yun means Cloud. The Chinese character Zhu formed part of the ancient word Tianzhu, meaning India. Zhu Fayun is said to have been a Buddhist monk from Emei Shan in Sichuan Province on a pilgrimage to the Guangxiao (Bright Filial Monastery), in Guangzhou. This is entirely plausible as the Guangxiao monastery is one of the oldest temples in south China as well as being one of the most influential Buddhist shrines. During his stay in Guangxiao, Zhu Fayun committed to teach Zhang Liquan (Cheung Lai Chuen) the Baimei arts.
Zhang Liquan (1882-1964). It would seem that Zhang Liquan was essentially an honest man with respect to his martial arts. He learnt three different styles from three different masters prior to having met Zhu Fayun. He formally acknowledges each of his former Shifu by name and honors them by keeping at least one of their forms in the Pak Mei syllabus. At a later stage in his career, Zhang Liquan formulated several of his own forms, including Tuotiao Quan (Cantonese: Tit Til Kuen) and Simen Bagua (Cantonese: Say Mun Ba Gua) which he openly professed were his own works. It would appear contradictory to suggest that such a man, who has been totally honest about the origins of all that he has learnt, would deny the existence of one teacher, or indeed invent a fictional character to disguise his own works when he has already affirmed creating several of his own.
All the supplementary forms in the Pak Mei syllabus, whatever the original style, fall under the collective classification of Nan Quan (Southern Fist) or more precisely DongJiang Quan (East River Fist). A common denominator to all these forms is that they are divided into two parts; the second being a repetition of the first, performed in the opposite direction. They also have numerous stances and techniques in common and share similar terminology and methodology. Accordinly there have been attempts to suggest that Baimei quan forms part of these southern or Hakka styles or indeed is a concoction of these various styles. Yet none of the four Baimei original forms are performed in two halves, nor do they share any stances or techniques with the supplementary forms. Similary the Baimei opening salutation, Wuhu Sihai (Cantonese: Ng Wu Say Hoi) is not found in any other style apart from Baimei derivatives.[1]
Trichotillomania
Classification
Trichotillomania is defined as a self-induced and recurrent loss of hair. It includes the criterion of an increasing sense of tension before pulling the hair and gratification or relief when pulling the hair. However, some people with trichotillomania do not endorse the inclusion of "rising tension and subsequent pleasure, gratification, or relief" as part of the criteria; because many individuals with trichotillomania may not realize they are pulling their hair, patients presenting for diagnosis may deny the criteria for tension prior to hair pulling or a sense of gratification after hair is pulled.
Because trichotillomania can be present in multiple age groups, it is helpful in terms of prognosis and treatment to approach three distinct subgroups by age: preschool age children, preadolescents to young adults, and adults.
Trichotillomania is often not a focused act, but rather hair pulling occurs in a "trance-like" state; hence, trichotillomania is subdivided into "automatic" versus "focused" hair pulling. Children are more often in the automatic, or unconscious, subtype and may not consciously remember pulling their hair. Other individuals may have focused, or conscious, rituals associated with hair pulling, including seeking specific types of hairs to pull, pulling until the hair feels "just right", or pulling in response to a specific sensation. Knowledge of the subtype is helpful in determining treatment strategies.
Signs and symptoms
Trichotillomania is usually confined to one or two sites, but can involve multiple sites. The scalp is the most common pulling site, followed by the eyebrows, eyelashes, face, arms, and legs. Some less common areas include the pubic area, underarms, beard, and chest. The classic presentation is the "Friar Tuck" form of vertex and crown alopecia. Children are less likely to pull from areas other than the scalp.
People who suffer from trichotillomania often pull only one hair at a time and these hair-pulling episodes can last for hours at a time. Trichotillomania can go into remission-like states where the individual may not experience the urge to "pull" for days, weeks, months, and even years.
Individuals with trichotillomania exhibit hair of differing lengths; some are broken hairs with blunt ends, some new growth with tapered ends, some broken mid-shaft, or some uneven stubble. Scaling on the scalp is not present, overall hair density is normal, and a hair pull test is negative (the hair does not pull out easily). Hair is often pulled out leaving an unusual shape. Individuals with trichotillomania may be secretive or shameful of the hair pulling behavior.
An additional psychological effect can be low self-esteem, often associated with being shunned by peers and the fear of socializing due to appearance and negative attention they may receive. Some people with trichotillomania wear hats, wigs, false eyelashes, eyebrow pencil, or style their hair in an effort to avoid such attention. There seems to be a strong stress-related component. In low-stress environments, some exhibit no symptoms (known as "pulling") whatsoever.
Trichotillomania is defined as a self-induced and recurrent loss of hair. It includes the criterion of an increasing sense of tension before pulling the hair and gratification or relief when pulling the hair. However, some people with trichotillomania do not endorse the inclusion of "rising tension and subsequent pleasure, gratification, or relief" as part of the criteria; because many individuals with trichotillomania may not realize they are pulling their hair, patients presenting for diagnosis may deny the criteria for tension prior to hair pulling or a sense of gratification after hair is pulled.
Because trichotillomania can be present in multiple age groups, it is helpful in terms of prognosis and treatment to approach three distinct subgroups by age: preschool age children, preadolescents to young adults, and adults.
Trichotillomania is often not a focused act, but rather hair pulling occurs in a "trance-like" state; hence, trichotillomania is subdivided into "automatic" versus "focused" hair pulling. Children are more often in the automatic, or unconscious, subtype and may not consciously remember pulling their hair. Other individuals may have focused, or conscious, rituals associated with hair pulling, including seeking specific types of hairs to pull, pulling until the hair feels "just right", or pulling in response to a specific sensation. Knowledge of the subtype is helpful in determining treatment strategies.
Signs and symptoms
Trichotillomania is usually confined to one or two sites, but can involve multiple sites. The scalp is the most common pulling site, followed by the eyebrows, eyelashes, face, arms, and legs. Some less common areas include the pubic area, underarms, beard, and chest. The classic presentation is the "Friar Tuck" form of vertex and crown alopecia. Children are less likely to pull from areas other than the scalp.
People who suffer from trichotillomania often pull only one hair at a time and these hair-pulling episodes can last for hours at a time. Trichotillomania can go into remission-like states where the individual may not experience the urge to "pull" for days, weeks, months, and even years.
Individuals with trichotillomania exhibit hair of differing lengths; some are broken hairs with blunt ends, some new growth with tapered ends, some broken mid-shaft, or some uneven stubble. Scaling on the scalp is not present, overall hair density is normal, and a hair pull test is negative (the hair does not pull out easily). Hair is often pulled out leaving an unusual shape. Individuals with trichotillomania may be secretive or shameful of the hair pulling behavior.
An additional psychological effect can be low self-esteem, often associated with being shunned by peers and the fear of socializing due to appearance and negative attention they may receive. Some people with trichotillomania wear hats, wigs, false eyelashes, eyebrow pencil, or style their hair in an effort to avoid such attention. There seems to be a strong stress-related component. In low-stress environments, some exhibit no symptoms (known as "pulling") whatsoever.
Hikimayu
Hikimayu first appeared in the eighth century, when the Japanese court adopted Chinese customs and styles. Japanese noblewomen started painting their faces with a white powder called oshiroi. One putative reason for hikimayu is that removing the natural eyebrows made it easier to put on the oshiroi. At this time the eyebrows were painted in arc shapes, as in China. Women also started painting their teeth black, which is known as ohaguro.
Japanese culture began to flourish in its own right during the Heian period, from AD 794. At the imperial court the arts reached a pinnacle of refinement. Women started wearing extremely elaborate costumes, painting their faces more thickly, and painting eyebrows as ovals or smudges on their foreheads. One possibility is that when they started letting their hair hang down on each side, it was felt that the forehead became too prominent; painting the eyebrows as ovals halfway up the forehead was supposed to redress the balance of the face.
The Heian period ended in 1185. In its later years, even men painted their faces white, blackened their teeth, and did hikimayu. As a fashion for women, hikimayu lasted for many centuries. In the noh drama, which started in the 14th century, the masks for the roles of young women usually have eyebrows in this style.
In the Edo period, from the 17th century, hikimayu and ohaguro were only done by married women. In the latter half of the 19th century, the Japanese government ended its policy of isolationism and started to adopt Western culture. Eyebrows painted on the forehead and black teeth were no longer appropriate for modern society, and in 1870 hikimayu and ohaguro were banned. Nowadays they are only used in historical drama such as noh, and occasionally in local festivals.
In cinema
Hikimayu can be seen in Rashomon, Ugetsu, and Ran. In the first two films the actress is Machiko Kyo. In Rashomon, which is set in the Heian period, she plays a samurai's wife who arouses the desire of a bandit. Ugetsu, also known as Ugetsu Monogatari, is set in the Sengoku (civil war) period of 1493–1573. In this she plays an enchantress or ghost who seduces the main character. In Ran, which is based on King Lear, hikimayu can be seen on Mieko Harada as Lady Kaede, who attempts to destroy the Ichimonji clan by manipulating the patriarch Hidetora and his three sons to kill each other.
Japanese culture began to flourish in its own right during the Heian period, from AD 794. At the imperial court the arts reached a pinnacle of refinement. Women started wearing extremely elaborate costumes, painting their faces more thickly, and painting eyebrows as ovals or smudges on their foreheads. One possibility is that when they started letting their hair hang down on each side, it was felt that the forehead became too prominent; painting the eyebrows as ovals halfway up the forehead was supposed to redress the balance of the face.
The Heian period ended in 1185. In its later years, even men painted their faces white, blackened their teeth, and did hikimayu. As a fashion for women, hikimayu lasted for many centuries. In the noh drama, which started in the 14th century, the masks for the roles of young women usually have eyebrows in this style.
In the Edo period, from the 17th century, hikimayu and ohaguro were only done by married women. In the latter half of the 19th century, the Japanese government ended its policy of isolationism and started to adopt Western culture. Eyebrows painted on the forehead and black teeth were no longer appropriate for modern society, and in 1870 hikimayu and ohaguro were banned. Nowadays they are only used in historical drama such as noh, and occasionally in local festivals.
In cinema
Hikimayu can be seen in Rashomon, Ugetsu, and Ran. In the first two films the actress is Machiko Kyo. In Rashomon, which is set in the Heian period, she plays a samurai's wife who arouses the desire of a bandit. Ugetsu, also known as Ugetsu Monogatari, is set in the Sengoku (civil war) period of 1493–1573. In this she plays an enchantress or ghost who seduces the main character. In Ran, which is based on King Lear, hikimayu can be seen on Mieko Harada as Lady Kaede, who attempts to destroy the Ichimonji clan by manipulating the patriarch Hidetora and his three sons to kill each other.
Eyebrow
Eyebrows are a major facial feature. Cosmetic methods have been developed to alter the look of one's eyebrows, whether the goal is to add or remove hair, change the color, or change the position of the eyebrow.
Several options exist for removing hair to achieve a thinner or smaller eyebrow, or to "correct" a unibrow, including manual and electronic tweezing, waxing, and threading. The most common method is to use tweezers to thin out and shape the eyebrow. Waxing is becoming more popular.[5] Lastly, there is threading eyebrows, where a cotton thread is rolled over hair to pull it out. Small scissors are sometimes used to trim the eyebrows, either with another method of hair removal or alone. All of these methods can be painful for some seconds or minutes due to the sensitivity of the area around the eye but, often, this pain decreases over time as the individual becomes used to it. In time, hair that has been plucked will stop growing back. Some people wax or shave off their eyebrows and leave them bare, stencil or draw them in with eye liner, or tattoo them on. In Western societies, it has become more common for men to pluck part of their eyebrows.
To create a fuller look, eyebrows can be cloned in an eyebrow transplant: Individual strands of the eyebrow are mimicked to create a natural-looking eyebrow of the desired shape. Eyebrow brushes and shaders are used to further define the eyebrow. A fairly recent trend in eyebrow modification is in eyebrow tinting: Permanent dye, similar to hair color, is used on the eyebrow, often to darken them.
An eyebrow lift, a cosmetic surgery to raise the eyebrow, usually to create a more feminine or youthful appearance, is a new phenomenon. They can be affected during a face lift or an eye lift. More recently, doctors inject patients' eyebrows with botox or similar toxins to temporarily raise the eyebrow.
From the 8th century, many Japanese noblewomen practiced hikimayu, shaving or plucking the eyebrow hair and painting smudge-like ones higher on the forehead. Shaving lines in eyebrows is another cosmetic alteration, more common among younger people in the 1990s and 2000s.
Identification
In a study published by MIT, where subjects were asked to identify celebrities with either their eyes or their eyebrows digitally edited out, the subjects were able to recognize the celebrity 46% of the time with their eyebrows edited out, compared to 60% of the time with their eyes edited out. The findings indicate the importance of eyebrows in providing clues to an individual's identity.
Several options exist for removing hair to achieve a thinner or smaller eyebrow, or to "correct" a unibrow, including manual and electronic tweezing, waxing, and threading. The most common method is to use tweezers to thin out and shape the eyebrow. Waxing is becoming more popular.[5] Lastly, there is threading eyebrows, where a cotton thread is rolled over hair to pull it out. Small scissors are sometimes used to trim the eyebrows, either with another method of hair removal or alone. All of these methods can be painful for some seconds or minutes due to the sensitivity of the area around the eye but, often, this pain decreases over time as the individual becomes used to it. In time, hair that has been plucked will stop growing back. Some people wax or shave off their eyebrows and leave them bare, stencil or draw them in with eye liner, or tattoo them on. In Western societies, it has become more common for men to pluck part of their eyebrows.
To create a fuller look, eyebrows can be cloned in an eyebrow transplant: Individual strands of the eyebrow are mimicked to create a natural-looking eyebrow of the desired shape. Eyebrow brushes and shaders are used to further define the eyebrow. A fairly recent trend in eyebrow modification is in eyebrow tinting: Permanent dye, similar to hair color, is used on the eyebrow, often to darken them.
An eyebrow lift, a cosmetic surgery to raise the eyebrow, usually to create a more feminine or youthful appearance, is a new phenomenon. They can be affected during a face lift or an eye lift. More recently, doctors inject patients' eyebrows with botox or similar toxins to temporarily raise the eyebrow.
From the 8th century, many Japanese noblewomen practiced hikimayu, shaving or plucking the eyebrow hair and painting smudge-like ones higher on the forehead. Shaving lines in eyebrows is another cosmetic alteration, more common among younger people in the 1990s and 2000s.
Identification
In a study published by MIT, where subjects were asked to identify celebrities with either their eyes or their eyebrows digitally edited out, the subjects were able to recognize the celebrity 46% of the time with their eyebrows edited out, compared to 60% of the time with their eyes edited out. The findings indicate the importance of eyebrows in providing clues to an individual's identity.
Public hair Removal
Removal
According to the Oxford Companion to the Body, in the 1450s public women would shave their pubic hair for personal hygiene and to combat pubic lice and would then don a merkin or pubic wig where their public line of work would require so. In some Middle Eastern societies, removal of female body hair has been considered proper hygiene, mandatated by local customs, for many centuriesIn Islamic societies removing pubic hair is a religiously endorsed practice known as an act of Sunan al-Fitra. Evidence of pubic hair removal in ancient India is thought to date back to 4000 to 3000 BC. According to ethnologist F. Fawcett, writing in 1901, he had observed the removal of body hair, including pubic hair about the vulva, as a custom of women from the Hindu Nair caste.
Some strippers and pornographic actresses, who always had inherently performed in the nude with more or less strict regulation laws according to the licenses allowed to their job location, began, some time in the late 1980s after the widespread fear of the HIV~AIDS epidemic and other STD's contagions, to a more radical trimming of their pubic hair. The spread of contagious diseases at the time was affecting many in the industry, though it was transmitted by body fluids, not hair. The fashion progressed to the extremes of reducing ever increasing amounts of pubic hair until its full removal of it. The widespread consuming of porn film and its watching, increased by the parallel boom of domestic video use, would catapult the adoption and mimicking of the concurrent fashion by the general public of women of the time. The fashion of such practices would reach cult status, and the growth of a whole industry dedicated to its maintenance after its implanted social acceptance and even some universal projection, it soon acquired the negative connotations of discrimination to any pubic hair in women (and even on men) in a totalitarian turn of social intolerance. Observation of most pornographic or artistic nude material before that decade and from the advent of the filming or photography camera, would show most if not all the performers or models with their own pubic hair differences of growth, with no signs of invested rejection or manipulated discrimination. The presentation is regarded by some as being erotic and aesthetic, while others consider the style as unnatural. Some people remove pubic hairs for erotic and sexual reasons or because they or their sex partner enjoy the feel of a hairless crotch.
According to the Oxford Companion to the Body, in the 1450s public women would shave their pubic hair for personal hygiene and to combat pubic lice and would then don a merkin or pubic wig where their public line of work would require so. In some Middle Eastern societies, removal of female body hair has been considered proper hygiene, mandatated by local customs, for many centuriesIn Islamic societies removing pubic hair is a religiously endorsed practice known as an act of Sunan al-Fitra. Evidence of pubic hair removal in ancient India is thought to date back to 4000 to 3000 BC. According to ethnologist F. Fawcett, writing in 1901, he had observed the removal of body hair, including pubic hair about the vulva, as a custom of women from the Hindu Nair caste.
Some strippers and pornographic actresses, who always had inherently performed in the nude with more or less strict regulation laws according to the licenses allowed to their job location, began, some time in the late 1980s after the widespread fear of the HIV~AIDS epidemic and other STD's contagions, to a more radical trimming of their pubic hair. The spread of contagious diseases at the time was affecting many in the industry, though it was transmitted by body fluids, not hair. The fashion progressed to the extremes of reducing ever increasing amounts of pubic hair until its full removal of it. The widespread consuming of porn film and its watching, increased by the parallel boom of domestic video use, would catapult the adoption and mimicking of the concurrent fashion by the general public of women of the time. The fashion of such practices would reach cult status, and the growth of a whole industry dedicated to its maintenance after its implanted social acceptance and even some universal projection, it soon acquired the negative connotations of discrimination to any pubic hair in women (and even on men) in a totalitarian turn of social intolerance. Observation of most pornographic or artistic nude material before that decade and from the advent of the filming or photography camera, would show most if not all the performers or models with their own pubic hair differences of growth, with no signs of invested rejection or manipulated discrimination. The presentation is regarded by some as being erotic and aesthetic, while others consider the style as unnatural. Some people remove pubic hairs for erotic and sexual reasons or because they or their sex partner enjoy the feel of a hairless crotch.
Pubic hair
Development
The Tanner scale looks at the development of pubic hair. Before the onset of puberty, the genital area of both boys and girls has very fine vellus hair, referred to as Tanner stage 1 hair. As puberty begins, the body produces rising levels of the sex hormones, and in response the skin of the genital area begins to produce thicker and rougher, often curlier, hair with a faster growth rate. The onset of pubic hair development is termed pubarche. The change for each hair follicle is relatively abrupt, but the extent of skin which grows androgenic hair gradually increases over several years.
In males, the first pubic hair appears as a few sparse hairs that are usually thin on the scrotum or at the upper base of the penis (stage 2). Within a year, hairs around the base of the penis are numerous (stage 3). Within 3 to 4 years, hair fills the pubic area (stage 4) and becomes much thicker and darker, and by 5 years extends to the near thighs and upwards on the abdomen toward the umbilicus (stage 5).
Other areas of the skin are similarly, though slightly less, sensitive to androgens and androgenic hair typically appears somewhat later. In rough sequence of sensitivity to androgens and appearance of androgenic hair, are the armpits (axillae), perianal area, upper lip, preauricular areas (sideburns), periareolar areas (nipples), middle of the chest, neck under the chin, remainder of chest and beard area, limbs and shoulders, back, and buttocks.
Although generally considered part of the process of puberty, pubarche is distinct and independent of the process of maturation of the gonads that leads to sexual maturation and fertility. Pubic hair can develop from adrenal androgens alone, and can develop even when the ovaries or testes are defective and nonfunctional. See puberty for details.
There is little if any difference in the capacity of male and female bodies to grow hair in response to androgens. The obvious sex-dimorphic difference in hair distribution in men and women is primarily a result of differences in the levels of androgen reached as maturity occurs.
Pubic hair and axillary (armpit) hair can vary in color considerably from the hair of the scalp. In most people it is darker, although it can also be lighter. In most cases it is most similar in color to the eyebrows of the individual.
Natural female pubic hair varies considerably around the world, ranging from short to long, from sparse to dense, and from straight and soft to wiry and curly. In color, pubic hair does not always match head hair. Many dark-haired women have lighter pubic hair often with a red tinge. Most women have wavy and curly pubic hair, even when their head hair is straight. In the Far East, however, straight black head hair is matched by pubic hair that has been described as 'black, short, straight and not thick but rather sparse...' Hair texture varies from tightly curled to entirely straight. Such variations also appear in men.
The Tanner scale looks at the development of pubic hair. Before the onset of puberty, the genital area of both boys and girls has very fine vellus hair, referred to as Tanner stage 1 hair. As puberty begins, the body produces rising levels of the sex hormones, and in response the skin of the genital area begins to produce thicker and rougher, often curlier, hair with a faster growth rate. The onset of pubic hair development is termed pubarche. The change for each hair follicle is relatively abrupt, but the extent of skin which grows androgenic hair gradually increases over several years.
In males, the first pubic hair appears as a few sparse hairs that are usually thin on the scrotum or at the upper base of the penis (stage 2). Within a year, hairs around the base of the penis are numerous (stage 3). Within 3 to 4 years, hair fills the pubic area (stage 4) and becomes much thicker and darker, and by 5 years extends to the near thighs and upwards on the abdomen toward the umbilicus (stage 5).
Other areas of the skin are similarly, though slightly less, sensitive to androgens and androgenic hair typically appears somewhat later. In rough sequence of sensitivity to androgens and appearance of androgenic hair, are the armpits (axillae), perianal area, upper lip, preauricular areas (sideburns), periareolar areas (nipples), middle of the chest, neck under the chin, remainder of chest and beard area, limbs and shoulders, back, and buttocks.
Although generally considered part of the process of puberty, pubarche is distinct and independent of the process of maturation of the gonads that leads to sexual maturation and fertility. Pubic hair can develop from adrenal androgens alone, and can develop even when the ovaries or testes are defective and nonfunctional. See puberty for details.
There is little if any difference in the capacity of male and female bodies to grow hair in response to androgens. The obvious sex-dimorphic difference in hair distribution in men and women is primarily a result of differences in the levels of androgen reached as maturity occurs.
Pubic hair and axillary (armpit) hair can vary in color considerably from the hair of the scalp. In most people it is darker, although it can also be lighter. In most cases it is most similar in color to the eyebrows of the individual.
Natural female pubic hair varies considerably around the world, ranging from short to long, from sparse to dense, and from straight and soft to wiry and curly. In color, pubic hair does not always match head hair. Many dark-haired women have lighter pubic hair often with a red tinge. Most women have wavy and curly pubic hair, even when their head hair is straight. In the Far East, however, straight black head hair is matched by pubic hair that has been described as 'black, short, straight and not thick but rather sparse...' Hair texture varies from tightly curled to entirely straight. Such variations also appear in men.
Demi and Semi permanents
Demi-permanent
Demi-permanent hair color is hair color that contains an alkaline agent other than ammonia (e.g. ethanolamine, sodium carbonate) and, while always employed with a developer, the concentration of hydrogen peroxide in that developer may be lower than used with a permanent hair color. Since the alkaline agents employed in demi-permanent colors are less effective in removing the natural pigment of hair than ammonia these products provide no lightening of hair's color during dyeing. As the result, they cannot color hair to a lighter shade than it was before dyeing and are less damaging to hair than their permanent counterpart.
Demi-permanents are much more effective at covering gray hair than semi-permanents, but less so than permanents.
Demi-permanents have several advantages as compared with permanent color. Because there is essentially no lifting (i.e., removal) of natural hair color, the final color is less uniform/homogeneous than a permanent and therefore more natural looking; they are gentler on hair and therefore safer, especially for damaged hair; and they wash out over time (typically 20 to 28 shampoos), so root regrowth is less noticeable and if a change of color is desired, it is easier to achieve. Demi-permanent hair colors are not permanent but the darker shades in particular may persist longer than indicated on the packet.
Semi-permanent
Semi-permanent hair color has smaller molecules than temporary dyes. These dyes only partially penetrate the hair shaft. For this reason, the color will survive repeated washing, typically 4–5 shampoos or a few weeks. Semi-permanents contain no, or very low levels of developer, peroxide or ammonia, and are therefore safer for damaged or fragile hair. However, semi-permanents may still contain the possibly carcinogenic compound p-phenylenediamine or other such ingredients. The U.S. Environmental Protection Agency reported that in rats and mice chronically exposed to PPD in their diet, it simply depressed body weights, and no other clinical signs of toxicity were observed in several studies.
The final color of each strand of hair will depend on its original color and porosity, so there will be subtle variations in shade across the whole head. This gives a more natural result than the solid, all over color of a permanent color. However, it also means that gray or white hairs will not appear as the same shade as the rest of the hair. If there are only a few grey/white hairs, the effect will usually be enough for them to blend in, but as the gray spreads, there will come a point where it will not be disguised as well. In this case, the move to permanent color can sometimes be delayed by using the semi-permanent as a base and adding highlights.
Demi-permanent hair color is hair color that contains an alkaline agent other than ammonia (e.g. ethanolamine, sodium carbonate) and, while always employed with a developer, the concentration of hydrogen peroxide in that developer may be lower than used with a permanent hair color. Since the alkaline agents employed in demi-permanent colors are less effective in removing the natural pigment of hair than ammonia these products provide no lightening of hair's color during dyeing. As the result, they cannot color hair to a lighter shade than it was before dyeing and are less damaging to hair than their permanent counterpart.
Demi-permanents are much more effective at covering gray hair than semi-permanents, but less so than permanents.
Demi-permanents have several advantages as compared with permanent color. Because there is essentially no lifting (i.e., removal) of natural hair color, the final color is less uniform/homogeneous than a permanent and therefore more natural looking; they are gentler on hair and therefore safer, especially for damaged hair; and they wash out over time (typically 20 to 28 shampoos), so root regrowth is less noticeable and if a change of color is desired, it is easier to achieve. Demi-permanent hair colors are not permanent but the darker shades in particular may persist longer than indicated on the packet.
Semi-permanent
Semi-permanent hair color has smaller molecules than temporary dyes. These dyes only partially penetrate the hair shaft. For this reason, the color will survive repeated washing, typically 4–5 shampoos or a few weeks. Semi-permanents contain no, or very low levels of developer, peroxide or ammonia, and are therefore safer for damaged or fragile hair. However, semi-permanents may still contain the possibly carcinogenic compound p-phenylenediamine or other such ingredients. The U.S. Environmental Protection Agency reported that in rats and mice chronically exposed to PPD in their diet, it simply depressed body weights, and no other clinical signs of toxicity were observed in several studies.
The final color of each strand of hair will depend on its original color and porosity, so there will be subtle variations in shade across the whole head. This gives a more natural result than the solid, all over color of a permanent color. However, it also means that gray or white hairs will not appear as the same shade as the rest of the hair. If there are only a few grey/white hairs, the effect will usually be enough for them to blend in, but as the gray spreads, there will come a point where it will not be disguised as well. In this case, the move to permanent color can sometimes be delayed by using the semi-permanent as a base and adding highlights.
Modern-day discrimination
Modern-day discrimination
In his 1895 memoir and history The Gurneys of Earlham, Augustus John Cuthbert Hare described an incident of harassment: "The second son, John, was born in 1750. As a boy he had bright red hair, and it is amusingly recorded that one day in the streets of Norwich a number of boys followed him, pointing to his red locks and saying, " Look at that boy ; he's got a bonfire on the top of his head," and that John Gurney was so disgusted that he went to a barber's, had his head shaved, and went home in a wig. He grew up, however, a remarkably attractive-looking young man."
Nonetheless, individuals and families in Britain are targeted for harassment and violence because of their hair colour. In 2003, a 20-year-old was stabbed in the back for "being ginger". In 2007, a UK woman won an award from a tribunal after being sexually harassed and receiving abuse because of her red hair. in the same year, a family in Newcastle upon Tyne, was forced to move twice after being targeted for abuse and hate crime on account of their red hair. In May 2009, a schoolboy committed suicide after being bullied for having red hair. in 2013, a fourteen-year-old boy in Lincoln had his right arm broken and his head stamped on by three men who attacked him "just because he had red hair". The three men were subsequently jailed for a combined total of ten years and one month for the attack.
This prejudice has been satirised on a number of TV shows. The British comedian Catherine Tate (herself a redhead) appeared as a red-haired character in a running sketch of her series The Catherine Tate Show. The sketch saw fictional character Sandra Kemp, who was forced to seek solace in a refuge for ginger people because she had been ostracised from society. The British comedy Bo' Selecta! (starring redhead Leigh Francis) featured a spoof documentary which involved a caricature of Mick Hucknall presenting a show in which celebrities (played by themselves) dyed their hair red for a day and went about daily life being insulted by people. (Hucknall, who says that he has repeatedly faced prejudice or been described as ugly on account of his hair colour, argues that Gingerism should be described as a form of racism. Comedian Tim Minchin, himself a redhead, also covered the topic in his song "Prejudice".
In November 2008 social networking website Facebook received criticism after a 'Kick a Ginger' group, which aimed to establish a "National Kick a Ginger Day" on 20 November, acquired almost 5,000 members. A 14-year-old boy from Vancouver who ran the Facebook group was subjected to an investigation by the Royal Canadian Mounted Police for possible hate crimes.
In October 2010, Harriet Harman, the former Equality Minister in the British government under Labour, faced accusations of prejudice after she described the red-haired Treasury secretary Danny Alexander as a "ginger rodent Alexander responded to the insult by stating that he was "proud to be ginger" Harman was subsequently forced to apologise for the comment, after facing criticism for prejudice against a minority group.
In his 1895 memoir and history The Gurneys of Earlham, Augustus John Cuthbert Hare described an incident of harassment: "The second son, John, was born in 1750. As a boy he had bright red hair, and it is amusingly recorded that one day in the streets of Norwich a number of boys followed him, pointing to his red locks and saying, " Look at that boy ; he's got a bonfire on the top of his head," and that John Gurney was so disgusted that he went to a barber's, had his head shaved, and went home in a wig. He grew up, however, a remarkably attractive-looking young man."
Nonetheless, individuals and families in Britain are targeted for harassment and violence because of their hair colour. In 2003, a 20-year-old was stabbed in the back for "being ginger". In 2007, a UK woman won an award from a tribunal after being sexually harassed and receiving abuse because of her red hair. in the same year, a family in Newcastle upon Tyne, was forced to move twice after being targeted for abuse and hate crime on account of their red hair. In May 2009, a schoolboy committed suicide after being bullied for having red hair. in 2013, a fourteen-year-old boy in Lincoln had his right arm broken and his head stamped on by three men who attacked him "just because he had red hair". The three men were subsequently jailed for a combined total of ten years and one month for the attack.
This prejudice has been satirised on a number of TV shows. The British comedian Catherine Tate (herself a redhead) appeared as a red-haired character in a running sketch of her series The Catherine Tate Show. The sketch saw fictional character Sandra Kemp, who was forced to seek solace in a refuge for ginger people because she had been ostracised from society. The British comedy Bo' Selecta! (starring redhead Leigh Francis) featured a spoof documentary which involved a caricature of Mick Hucknall presenting a show in which celebrities (played by themselves) dyed their hair red for a day and went about daily life being insulted by people. (Hucknall, who says that he has repeatedly faced prejudice or been described as ugly on account of his hair colour, argues that Gingerism should be described as a form of racism. Comedian Tim Minchin, himself a redhead, also covered the topic in his song "Prejudice".
In November 2008 social networking website Facebook received criticism after a 'Kick a Ginger' group, which aimed to establish a "National Kick a Ginger Day" on 20 November, acquired almost 5,000 members. A 14-year-old boy from Vancouver who ran the Facebook group was subjected to an investigation by the Royal Canadian Mounted Police for possible hate crimes.
In October 2010, Harriet Harman, the former Equality Minister in the British government under Labour, faced accusations of prejudice after she described the red-haired Treasury secretary Danny Alexander as a "ginger rodent Alexander responded to the insult by stating that he was "proud to be ginger" Harman was subsequently forced to apologise for the comment, after facing criticism for prejudice against a minority group.
Biochemistry and genetics
The pigment pheomelanin gives red hair its distinctive color. Red hair has far more of the pigment pheomelanin than it has of the dark pigment eumelanin.
The genetics of red hair, discovered in 1997, appear to be associated with the melanocortin-1 receptor (MC1R), which is found on chromosome 16. Red hair is associated with fair skin color because low concentrations of eumelanin throughout the body of those with red hair caused by a MC1R mutation can cause both. The lower melanin concentration in skin confers the advantage that a sufficient concentration of important Vitamin D can be produced under low light conditions. However, when UV-radiation is strong (as in regions close to the equator) the lower concentration of melanin leads to several medical disadvantages, such as a higher risk of skin cancer.
The MC1R recessive variant gene that gives people red hair and non-tanning skin is also associated with freckles, though it is not uncommon to see a redhead without freckles Eighty percent of redheads have an MC1R gene variant, and the prevalence of these alleles is highest in Scotland and Ireland.
Red hair can originate from several changes on the MC1R-gene. If one of these changes is present on both chromosomes then the respective individual is likely to have red hair. This type of inheritance is described as an autosomal recessive mode of inheritance. Even if both parents do not have red hair themselves, both can be carriers for the gene and have a redheaded child.
Genetic studies of dizygotic (fraternal) twins indicate that the MC1R gene is not solely responsible for the red hair phenotype; unidentified modifier genes exist, making variance in the MC1R gene necessary, but not always sufficient, for red hair production.
Origins
Red hair is the rarest natural hair color in humans. The non-tanning skin associated with red hair may have been advantageous in far-northern climates where sunlight is scarce. Studies by Bodmer and Cavalli-Sforza (1976) hypothesized that lighter skin pigmentation prevents rickets in colder climates by encouraging higher levels of Vitamin D production and also allows the individual to retain heat better than someone with darker skin. In 2000, Harding et al. concluded that red hair was not the result of positive selection and instead proposed that it occurs because of a lack of negative selection. In Africa, for example, red hair is selected against because high levels of sun would be harmful to untanned skin. However, in Northern Europe this does not happen, so redheads come about through genetic drift.
Estimates on the original occurrence of the currently active gene for red hair vary from 20,000 to 100,000 years ago.
A DNA study has concluded that some Neanderthals also had red hair, although the mutation responsible for this differs from that which causes red hair in modern humans.
The genetics of red hair, discovered in 1997, appear to be associated with the melanocortin-1 receptor (MC1R), which is found on chromosome 16. Red hair is associated with fair skin color because low concentrations of eumelanin throughout the body of those with red hair caused by a MC1R mutation can cause both. The lower melanin concentration in skin confers the advantage that a sufficient concentration of important Vitamin D can be produced under low light conditions. However, when UV-radiation is strong (as in regions close to the equator) the lower concentration of melanin leads to several medical disadvantages, such as a higher risk of skin cancer.
The MC1R recessive variant gene that gives people red hair and non-tanning skin is also associated with freckles, though it is not uncommon to see a redhead without freckles Eighty percent of redheads have an MC1R gene variant, and the prevalence of these alleles is highest in Scotland and Ireland.
Red hair can originate from several changes on the MC1R-gene. If one of these changes is present on both chromosomes then the respective individual is likely to have red hair. This type of inheritance is described as an autosomal recessive mode of inheritance. Even if both parents do not have red hair themselves, both can be carriers for the gene and have a redheaded child.
Genetic studies of dizygotic (fraternal) twins indicate that the MC1R gene is not solely responsible for the red hair phenotype; unidentified modifier genes exist, making variance in the MC1R gene necessary, but not always sufficient, for red hair production.
Origins
Red hair is the rarest natural hair color in humans. The non-tanning skin associated with red hair may have been advantageous in far-northern climates where sunlight is scarce. Studies by Bodmer and Cavalli-Sforza (1976) hypothesized that lighter skin pigmentation prevents rickets in colder climates by encouraging higher levels of Vitamin D production and also allows the individual to retain heat better than someone with darker skin. In 2000, Harding et al. concluded that red hair was not the result of positive selection and instead proposed that it occurs because of a lack of negative selection. In Africa, for example, red hair is selected against because high levels of sun would be harmful to untanned skin. However, in Northern Europe this does not happen, so redheads come about through genetic drift.
Estimates on the original occurrence of the currently active gene for red hair vary from 20,000 to 100,000 years ago.
A DNA study has concluded that some Neanderthals also had red hair, although the mutation responsible for this differs from that which causes red hair in modern humans.
Evolution of blond hair
Natural
lighter hair colors occur most often in Europe and less frequently in other
areas. In Northern European populations, the occurrence of blond hair is very
frequent. The hair color gene MC1R has at least seven variants in Europe giving
the continent a wide range of hair and eye shades. Based on recent genetic
research carried out at three Japanese universities, the date of the genetic
mutation that resulted in blond hair in Europe has been isolated to about
11,000 years ago during the last ice age.
A typical
explanation found in the scientific literature for the evolution of light hair
is related to the requirement for vitamin D synthesis and northern Europe's
seasonal deficiency of sunlight. Lighter skin is due to a low concentration in
pigmentation, thus allowing more sunlight to trigger the production of vitamin
D. In this way, high frequencies of light hair in northern latitudes are a
result of the light skin adaptation to lower levels of sunlight, which reduces
the prevalence of rickets caused by vitamin D deficiency. The darker
pigmentation at higher latitudes in certain ethnic groups such as the Inuit is
explained by a greater proportion of seafood in their diet. As seafood is high
in vitamin D, vitamin D deficiency would not create a selective pressure for
lighter pigmentation in that population.
An
alternative hypothesis was presented by Canadian anthropologist Peter Frost,
who claims blond hair evolved very quickly in a specific area at the end of the
last ice age by means of sexual selection. According to Frost, the appearance
of blond hair and blue eyes in some northern European women made them stand out
from their rivals at a time of fierce competition for scarce males.
A theory
propounded in The History and Geography of Human Genes (1994), says blond hair
became predominant in Northern Europe beginning about 3,000 BC, in the area now
known as Lithuania, among the recently arrived linguistically
Proto-Indo-European settlers (according to the Kurgan hypothesis), and the
trait spread quickly through sexual selection into Scandinavia. As above, the
theory assumes that men found women with blond hair more attractive.[29]
It is now
hypothesized by researchers that blond hair evolved more than once. Published
in May 2012 in Science, a study of people from the Solomon Islands in Melanesia
found that an amino acid change in TYRP1 produced blonde hair.
Americas
The United
States, Canada, Argentina and Uruguay (along with Australia and New Zealand)
are overall considered as the only countries with a great majority of White
population outside Eurasia because a great majority of their population has
European origins.[46] Because of it, these countries have the highest frequency
of naturally blonds. There are also other American countries with a lower but
noticeable frequency, such as Brazil, Chile, Cuba and Costa Rica. Blonds are
also found (but rarely) in the rest of the American countries, where they
account for 1% or less of the population.
Hair color
Two types of pigment give hair its color: eumelanin and pheomelanin. Pheomelanin colors hair orange and yellow. All humans have some pheomelanin in their hair. Eumelanin, which has two subtypes of black or brown, determines the darkness of the hair color. A low concentration of brown eumelanin results in blond hair, whereas a higher concentration of brown eumelanin will color the hair brown. High amounts of black eumelanin result in black hair, while low concentrations give gray hair.
Pheomelanin is more chemically stable than black eumelanin, but less chemically stable than brown eumelanin, so it breaks down more slowly when oxidized. This is why bleach gives darker hair a reddish tinge during the artificial coloring process. As the pheomelanin continues to break down, the hair will gradually become orange, then yellow, and finally white.
One phenotype (brown/blonde) has a dominant brown allele and a recessive blond allele. A person with a brown allele will have brown hair; a person with no brown alleles will be blond. This explains why two brown-haired parents can produce a blond-haired child. However, this can only be possible if both parent are heterozygous in hair color- meaning that both of them have one dominant brown hair allele and one recessive allele for blond hair but as dominant always wins the parents both have brown hair. In a punnet square it is possible determine the possibility of a certain trait in an offspring.
The other gene pair is a non-red/red pair, where the non-red allele (which suppresses production of pheomelanin) is dominant and the allele for red hair is recessive. A person with two copies of the red-haired allele will have red hair.
The two-gene model does not account for all possible shades of brown, blond, or red (for example, platinum blond versus dark blond/light brown), nor does it explain why hair color sometimes darkens as a person ages. Several gene pairs control the light versus dark hair color in a cumulative effect. A person's genotype for a multifactorial trait can interact with environment to produce varying phenotypes (see quantitative trait locus).
Blonde hair can have almost any proportion of pheomelanin and eumelanin, but has only small amounts of both. More pheomelanin creates a more golden blonde color, and more eumelanin creates an ash blond. Many children born with blonde hair develop darker hair as they age, with the majority of natural blondes developing a hair color of a dark "gunmetal" hue by the time they reach middle age. Pregnancy hormones hasten this process. Natural blonde hair is rare in adulthood, with some reports stating that only about 2% of the world's population is naturally blonde. Blonde hair is most commonly found in Northern and Western Europeans and their descendants but can be found spread around most of Europe. Blonde hair is rare outside of Europe but can also be found in populations in South America, Israel and Australia. Studies in 2012 showed that naturally blonde hair of Melanesians is caused by a recessive mutation in tyrosinase-related protein 1 (TYRP1).
Pheomelanin is more chemically stable than black eumelanin, but less chemically stable than brown eumelanin, so it breaks down more slowly when oxidized. This is why bleach gives darker hair a reddish tinge during the artificial coloring process. As the pheomelanin continues to break down, the hair will gradually become orange, then yellow, and finally white.
One phenotype (brown/blonde) has a dominant brown allele and a recessive blond allele. A person with a brown allele will have brown hair; a person with no brown alleles will be blond. This explains why two brown-haired parents can produce a blond-haired child. However, this can only be possible if both parent are heterozygous in hair color- meaning that both of them have one dominant brown hair allele and one recessive allele for blond hair but as dominant always wins the parents both have brown hair. In a punnet square it is possible determine the possibility of a certain trait in an offspring.
The other gene pair is a non-red/red pair, where the non-red allele (which suppresses production of pheomelanin) is dominant and the allele for red hair is recessive. A person with two copies of the red-haired allele will have red hair.
The two-gene model does not account for all possible shades of brown, blond, or red (for example, platinum blond versus dark blond/light brown), nor does it explain why hair color sometimes darkens as a person ages. Several gene pairs control the light versus dark hair color in a cumulative effect. A person's genotype for a multifactorial trait can interact with environment to produce varying phenotypes (see quantitative trait locus).
Blonde hair can have almost any proportion of pheomelanin and eumelanin, but has only small amounts of both. More pheomelanin creates a more golden blonde color, and more eumelanin creates an ash blond. Many children born with blonde hair develop darker hair as they age, with the majority of natural blondes developing a hair color of a dark "gunmetal" hue by the time they reach middle age. Pregnancy hormones hasten this process. Natural blonde hair is rare in adulthood, with some reports stating that only about 2% of the world's population is naturally blonde. Blonde hair is most commonly found in Northern and Western Europeans and their descendants but can be found spread around most of Europe. Blonde hair is rare outside of Europe but can also be found in populations in South America, Israel and Australia. Studies in 2012 showed that naturally blonde hair of Melanesians is caused by a recessive mutation in tyrosinase-related protein 1 (TYRP1).
Boil
Complications
The most common complications of boils are scarring and infection or abscess of the skin, spinal cord, brain, kidneys, or other organs. Infections may also spread to the bloodstream (bacteremia) and become life-threatening. S. aureus strains first infect the skin and its structures (for example, sebaceous glands, hair follicles) or invade damaged skin (cuts, abrasions). Sometimes the infections are relatively limited (such as a stye, boil, furuncle, or carbuncle), but other times they may spread to other skin areas (causing cellulitis, folliculitis, or impetigo). Unfortunately, these bacteria can reach the bloodstream (bacteremia) and end up in many different body sites, causing infections (wound infections, abscesses, osteomyelitis, endocarditis, pneumonia) that may severely harm or kill the infected person. S. aureus strains also produce enzymes and exotoxins that likely cause or increase the severity of certain diseases. Such diseases include food poisoning, septic shock, toxic shock syndrome, and scalded skin syndrome. Almost any organ system can be infected by S. aureus.
Treatment
A boil may clear up on its own without bursting, but more often it will need to open and drain. This will usually happen spontaneously within two weeks. Regular application of a warm moist compress, both before and after a boil opens, can help speed healing. The area must be kept clean, hands washed after touching it, and any dressings disposed of carefully, in order to avoid spreading the bacteria. A doctor may cut open or "lance" a boil to allow it to drain, but squeezing or cutting should not be attempted at home, as this may further spread the infection. Antibiotic therapy may be recommended for large or recurrent boils or those that occur in sensitive areas (such as the groin, breasts, armpits, around or in the nostrils, or in the ear). Doctors that are not specialists tend to treat boils with antibiotics, a less-than-ideal but common treatment, but this method should not be used for longer than one month, with at least two months (preferably longer) between uses, otherwise it will lose its effectiveness. More severe boils should be treated with intralesional steroid injections. If the patient has chronic (more than two years) boils, removal by plastic surgery is the best treatment, as plastic surgeons have a better understanding of the healing process of skin, especially on the outermost layers.
Furuncles at risk of leading to serious complications should be incised and drained if antibiotics or steroid injections are not effective. These include furuncles that are unusually large, last longer than two weeks, or occur in the middle of the face or near the spine. Fever and chills are signs of sepsis and indicate immediate treatment is needed.
Staphylococcus aureus has the ability to acquire antimicrobial resistance easily, making treatment difficult. Knowledge of the antimicrobial resistance of S. aureus is important in the selection of antimicrobials for treatment.
The most common complications of boils are scarring and infection or abscess of the skin, spinal cord, brain, kidneys, or other organs. Infections may also spread to the bloodstream (bacteremia) and become life-threatening. S. aureus strains first infect the skin and its structures (for example, sebaceous glands, hair follicles) or invade damaged skin (cuts, abrasions). Sometimes the infections are relatively limited (such as a stye, boil, furuncle, or carbuncle), but other times they may spread to other skin areas (causing cellulitis, folliculitis, or impetigo). Unfortunately, these bacteria can reach the bloodstream (bacteremia) and end up in many different body sites, causing infections (wound infections, abscesses, osteomyelitis, endocarditis, pneumonia) that may severely harm or kill the infected person. S. aureus strains also produce enzymes and exotoxins that likely cause or increase the severity of certain diseases. Such diseases include food poisoning, septic shock, toxic shock syndrome, and scalded skin syndrome. Almost any organ system can be infected by S. aureus.
Treatment
A boil may clear up on its own without bursting, but more often it will need to open and drain. This will usually happen spontaneously within two weeks. Regular application of a warm moist compress, both before and after a boil opens, can help speed healing. The area must be kept clean, hands washed after touching it, and any dressings disposed of carefully, in order to avoid spreading the bacteria. A doctor may cut open or "lance" a boil to allow it to drain, but squeezing or cutting should not be attempted at home, as this may further spread the infection. Antibiotic therapy may be recommended for large or recurrent boils or those that occur in sensitive areas (such as the groin, breasts, armpits, around or in the nostrils, or in the ear). Doctors that are not specialists tend to treat boils with antibiotics, a less-than-ideal but common treatment, but this method should not be used for longer than one month, with at least two months (preferably longer) between uses, otherwise it will lose its effectiveness. More severe boils should be treated with intralesional steroid injections. If the patient has chronic (more than two years) boils, removal by plastic surgery is the best treatment, as plastic surgeons have a better understanding of the healing process of skin, especially on the outermost layers.
Furuncles at risk of leading to serious complications should be incised and drained if antibiotics or steroid injections are not effective. These include furuncles that are unusually large, last longer than two weeks, or occur in the middle of the face or near the spine. Fever and chills are signs of sepsis and indicate immediate treatment is needed.
Staphylococcus aureus has the ability to acquire antimicrobial resistance easily, making treatment difficult. Knowledge of the antimicrobial resistance of S. aureus is important in the selection of antimicrobials for treatment.
Pseudofolliculitis
Prevention
The most effective prevention is to let the beard grow. For men who are required or prefer to shave, studies show the optimal length to be about 0.5 mm to 1 mm to prevent their hair growing back into the skin. For most cases, totally avoiding shaving for three to four weeks allows all lesions to subside, and most extrafollicular hairs will resolve themselves in about 10 days. Permanent removal of the hair follicle is the only definitive treatment for PFB. Electrolysis is impractical and ineffective because the needle may not reach the hair follicle. Laser-assisted hair removal is effective. There is a risk of skin discoloration and a very small risk of scarring.
Some men use electric razors to control PFB. Those who use a razor, should use a single blade or special wire-wrapped blade to avoid shaving too closely, with a new blade each shave. Shaving in the direction of hair growth every other day, rather than daily, may improve pseudofolliculitis barbae. If one must use a blade, softening the beard first with a hot, wet washcloth for five minutes or shave while showering in hot water can be helpful. Some use shaving powders (a kind of chemical depilatory) to avoid the irritation of using a blade. Barium sulfide-based depilatories are most effective, but produce an unpleasant smell.
Treatment
The easiest cure is to let the beard grow. Existing razor bumps can often be treated by removal of the ingrown hair. Extrafollicular hairs can usually be pulled gently from under the skin, with tweezers. Complete removal of the hair from its follicle is not recommended. Severe or transfollicular hairs may require removal by a dermatologist.
Medications are also prescribed to speed healing of the skin. Clinical trials have shown glycolic acid-based peels to be an effective and well-tolerated therapy which resulted in significantly fewer PFB lesions on the face and neck. The mechanism of action of glycolic acid is unknown, but it is hypothesized that straighter hair growth is caused by the reduction of sulfhydrylbonds in the hair shaft by glycolic acid, which results in reduced re-entry of the hair shaft into the follicular wall or epidermis. Medications containing Allantoin and Azulene have been shown to reduce swelling, redness and itchiness. Allantoin is a natural soothing skin protectant and moisturizer that increases the water content to provide structure support to skin cells. Azulene is a blue colored oil derived from flowers in the Asteraceae family and can be used to moisturize and soothe irritated skin. Salicylic acid peels are also effective. Prescription antibiotic gels (Benzamycin, Cleocin-T) or oral antibiotics are also used. Retin-A is a potent treatment that helps even out any scarring after a few months. It is added as a nightly application of Retin-A Cream 0.05 - 0.1% to the beard skin while beard is growing out.
Exfoliating the skin before and between shaves using an ingrown hair brush or bump brush effectively frees trapped hair out and teases it away from the skin before the hair has a chance to embed itself.
The most effective prevention is to let the beard grow. For men who are required or prefer to shave, studies show the optimal length to be about 0.5 mm to 1 mm to prevent their hair growing back into the skin. For most cases, totally avoiding shaving for three to four weeks allows all lesions to subside, and most extrafollicular hairs will resolve themselves in about 10 days. Permanent removal of the hair follicle is the only definitive treatment for PFB. Electrolysis is impractical and ineffective because the needle may not reach the hair follicle. Laser-assisted hair removal is effective. There is a risk of skin discoloration and a very small risk of scarring.
Some men use electric razors to control PFB. Those who use a razor, should use a single blade or special wire-wrapped blade to avoid shaving too closely, with a new blade each shave. Shaving in the direction of hair growth every other day, rather than daily, may improve pseudofolliculitis barbae. If one must use a blade, softening the beard first with a hot, wet washcloth for five minutes or shave while showering in hot water can be helpful. Some use shaving powders (a kind of chemical depilatory) to avoid the irritation of using a blade. Barium sulfide-based depilatories are most effective, but produce an unpleasant smell.
Treatment
The easiest cure is to let the beard grow. Existing razor bumps can often be treated by removal of the ingrown hair. Extrafollicular hairs can usually be pulled gently from under the skin, with tweezers. Complete removal of the hair from its follicle is not recommended. Severe or transfollicular hairs may require removal by a dermatologist.
Medications are also prescribed to speed healing of the skin. Clinical trials have shown glycolic acid-based peels to be an effective and well-tolerated therapy which resulted in significantly fewer PFB lesions on the face and neck. The mechanism of action of glycolic acid is unknown, but it is hypothesized that straighter hair growth is caused by the reduction of sulfhydrylbonds in the hair shaft by glycolic acid, which results in reduced re-entry of the hair shaft into the follicular wall or epidermis. Medications containing Allantoin and Azulene have been shown to reduce swelling, redness and itchiness. Allantoin is a natural soothing skin protectant and moisturizer that increases the water content to provide structure support to skin cells. Azulene is a blue colored oil derived from flowers in the Asteraceae family and can be used to moisturize and soothe irritated skin. Salicylic acid peels are also effective. Prescription antibiotic gels (Benzamycin, Cleocin-T) or oral antibiotics are also used. Retin-A is a potent treatment that helps even out any scarring after a few months. It is added as a nightly application of Retin-A Cream 0.05 - 0.1% to the beard skin while beard is growing out.
Exfoliating the skin before and between shaves using an ingrown hair brush or bump brush effectively frees trapped hair out and teases it away from the skin before the hair has a chance to embed itself.
Hair drug testing
Hair drug testing
Hair drug testing is a method that can detect drug use over a much longer period of time, and is often used for highly safety-critical positions where there is zero tolerance of illegal drug use. Standard hair follicle screen covers a period of 30 to 90 days. The growth of hair is usually at the rate of 0.5 inches per month. The hair sample is cut close to the scalp and 80 to 120 strands of hair are needed for the test. In the absence of hair on the head, body hair can be used as an acceptable substitute. This includes facial hair, the underarms, arms, and legs or even pubic hair. Because body hair grows at a different rate than head hair, the timeframe changes, with scientists estimating that drug use can be detected in body hair for up to 12 months. Currently, most entities that use hair testing have prescribed consequences for individuals removing hair to avoid a hair drug test.
The claim that a hair test cannot be tampered with has been shown to be debatable. One study has shown that THC does not readily deposit inside epithelial cells so it is possible for cosmetic and other forms of adulteration to reduce the amount of testable cannabinoids within a hair sample.
Australia
A person conducting a business or undertaking (PCBU - the new term that includes employers) has duties under the work health and safety (WHS) legislation to ensure a worker affected by alcohol or other drugs does not place themselves or other persons at risk of injury while at work. Workplace policies and prevention programs can help change the norms and culture around substance abuse.
All organisations - large and small - can benefit from an agreed policy on alcohol and drug misuse that applies to all workers. Such a policy should form part of an organisations overall health and safety management system. PCBUs are encouraged to establish a policy and procedure, in consultation with workers, to constructively manage alcohol and other drug related hazards in their workplace. A comprehensive workplace alcohol and other drug policy should apply to everyone in the workplace and include prevention, education, counselling and rehabilitation arrangements. In addition, the roles and responsibilities of managers and supervisors should be clearly outlined.
UK
A study in 2004 by the Independent Inquiry into Drug Testing at Work found that attempts by employers to force employees to take drug tests could potentially be challenged as a violation of privacy under the Human Rights Act 1998 and Article 8 of the European Convention of Human Rights. However, this does not apply to industries where drug testing is a matter of personal and public safety or security rather than productivity.
Hair drug testing is a method that can detect drug use over a much longer period of time, and is often used for highly safety-critical positions where there is zero tolerance of illegal drug use. Standard hair follicle screen covers a period of 30 to 90 days. The growth of hair is usually at the rate of 0.5 inches per month. The hair sample is cut close to the scalp and 80 to 120 strands of hair are needed for the test. In the absence of hair on the head, body hair can be used as an acceptable substitute. This includes facial hair, the underarms, arms, and legs or even pubic hair. Because body hair grows at a different rate than head hair, the timeframe changes, with scientists estimating that drug use can be detected in body hair for up to 12 months. Currently, most entities that use hair testing have prescribed consequences for individuals removing hair to avoid a hair drug test.
The claim that a hair test cannot be tampered with has been shown to be debatable. One study has shown that THC does not readily deposit inside epithelial cells so it is possible for cosmetic and other forms of adulteration to reduce the amount of testable cannabinoids within a hair sample.
Australia
A person conducting a business or undertaking (PCBU - the new term that includes employers) has duties under the work health and safety (WHS) legislation to ensure a worker affected by alcohol or other drugs does not place themselves or other persons at risk of injury while at work. Workplace policies and prevention programs can help change the norms and culture around substance abuse.
All organisations - large and small - can benefit from an agreed policy on alcohol and drug misuse that applies to all workers. Such a policy should form part of an organisations overall health and safety management system. PCBUs are encouraged to establish a policy and procedure, in consultation with workers, to constructively manage alcohol and other drug related hazards in their workplace. A comprehensive workplace alcohol and other drug policy should apply to everyone in the workplace and include prevention, education, counselling and rehabilitation arrangements. In addition, the roles and responsibilities of managers and supervisors should be clearly outlined.
UK
A study in 2004 by the Independent Inquiry into Drug Testing at Work found that attempts by employers to force employees to take drug tests could potentially be challenged as a violation of privacy under the Human Rights Act 1998 and Article 8 of the European Convention of Human Rights. However, this does not apply to industries where drug testing is a matter of personal and public safety or security rather than productivity.
Urine drug screen
Urine drug screen
UrinalysisUrine drug tests screen the urine for the presence of a parent drug or its metabolites. The level of drug or its metabolites is not predictive of when the drug was taken or how much the patient used. Rather, it is simply a confirmatory report indicating the presence of the parent drug or its metabolites.
Urine drug testing is an immunoassay based on the principle of competitive binding. Drugs which may be present in the urine specimen compete against their respective drug conjugate for binding sites on their specific antibody.During testing, a urine specimen migrates upward by capillary action. A drug, if present in the urine specimen below its cut-off concentration, will not saturate the binding sites of its specific antibody. The antibody will then react with the drug-protein conjugate and a visible colored line will show up in the test line region of the specific drug strip
When an employer requests a drug test from an employee, or a physician requests a drug test from a patient, the employee or patient is typically instructed to go to a collection site or their home. The urine sample goes through a specified 'chain of custody' to ensure that it is not tampered with or invalidated through lab or employee error. The patient or employee’s urine is collected at a remote location in a specially designed secure cup, sealed with tamper-resistant tape, and sent to a testing laboratory to be screened for drugs (typically the Substance Abuse and Mental Health Services Administration 5 panel). The first step at the testing site is to split the urine into two aliquots. One aliquot is first screened for drugs using an analyzer that performs immunoassay as the initial screen. If the urine screen is positive then another aliquot of the sample is used to confirm the findings by gas chromatography – mass spectrometry (GC-MS) methodology. If requested by the physician or employer, certain drugs are screened for individually; these are generally drugs part of a chemical class that are, for one of many reasons, considered more abuse-prone or of concern. For instance, oxycodone and diamorphine may be tested, both sedative analgesics. If such a test is not requested specifically, the more general test (in the preceding case, the test for opiates) will detect the drugs, but the employer or physician will not have the benefit of the identity of the drug.
Employment-related test results are relayed to a medical review office (MRO) where a medical physician reviews the results. If the result of the screen is negative, the MRO informs the employer that the employee has no detectable drug in the urine, typically within 24 hours. However, if the test result of the immunoassay and GC-MS are non-negative and show a concentration level of parent drug or metabolite above the established limit, the MRO contacts the employee to determine if there is any legitimate reason—such as a medical treatment or prescription.
On-site instant drug testing is a more cost-efficient method of effectively detecting drug abuse amongst employees, as well as in rehabilitation programs to monitor patient progress.These instant tests can be used for both urine and saliva testing. Although the accuracy of such tests varies with the manufacturer, some kits boast extremely high rates of accuracy, correlating closely with laboratory test results.
UrinalysisUrine drug tests screen the urine for the presence of a parent drug or its metabolites. The level of drug or its metabolites is not predictive of when the drug was taken or how much the patient used. Rather, it is simply a confirmatory report indicating the presence of the parent drug or its metabolites.
Urine drug testing is an immunoassay based on the principle of competitive binding. Drugs which may be present in the urine specimen compete against their respective drug conjugate for binding sites on their specific antibody.During testing, a urine specimen migrates upward by capillary action. A drug, if present in the urine specimen below its cut-off concentration, will not saturate the binding sites of its specific antibody. The antibody will then react with the drug-protein conjugate and a visible colored line will show up in the test line region of the specific drug strip
When an employer requests a drug test from an employee, or a physician requests a drug test from a patient, the employee or patient is typically instructed to go to a collection site or their home. The urine sample goes through a specified 'chain of custody' to ensure that it is not tampered with or invalidated through lab or employee error. The patient or employee’s urine is collected at a remote location in a specially designed secure cup, sealed with tamper-resistant tape, and sent to a testing laboratory to be screened for drugs (typically the Substance Abuse and Mental Health Services Administration 5 panel). The first step at the testing site is to split the urine into two aliquots. One aliquot is first screened for drugs using an analyzer that performs immunoassay as the initial screen. If the urine screen is positive then another aliquot of the sample is used to confirm the findings by gas chromatography – mass spectrometry (GC-MS) methodology. If requested by the physician or employer, certain drugs are screened for individually; these are generally drugs part of a chemical class that are, for one of many reasons, considered more abuse-prone or of concern. For instance, oxycodone and diamorphine may be tested, both sedative analgesics. If such a test is not requested specifically, the more general test (in the preceding case, the test for opiates) will detect the drugs, but the employer or physician will not have the benefit of the identity of the drug.
Employment-related test results are relayed to a medical review office (MRO) where a medical physician reviews the results. If the result of the screen is negative, the MRO informs the employer that the employee has no detectable drug in the urine, typically within 24 hours. However, if the test result of the immunoassay and GC-MS are non-negative and show a concentration level of parent drug or metabolite above the established limit, the MRO contacts the employee to determine if there is any legitimate reason—such as a medical treatment or prescription.
On-site instant drug testing is a more cost-efficient method of effectively detecting drug abuse amongst employees, as well as in rehabilitation programs to monitor patient progress.These instant tests can be used for both urine and saliva testing. Although the accuracy of such tests varies with the manufacturer, some kits boast extremely high rates of accuracy, correlating closely with laboratory test results.
Hair testing
Hair testing
Hair analysis to detect drugs of abuse has been used by court systems in the United States, United Kingdom, Canada, and other countries worldwide. In the United States, hair testing has been accepted in court cases as forensic evidence following the Frye Rule, the Federal Rules of Evidence, and the Daubert Rule. As such, hair testing results are legally and scientifically recognized as admissible evidence.
Hair testing is now recognised in both the UK and US judicial systems. There are guidelines for hair testing that have been published by the Society of Hair Testing (a private company in France) that specify the markers to be tested for and the cutoff concentrations that need to be tested. Drugs of abuse that can be detected include Cannabis, Cocaine, Amphetamines and drugs new to the UK such as Mephedrone.
Alcohol
In contrast to other drugs consumed, alcohol is deposited directly in the hair. For this reason the investigation procedure looks for direct products of ethanol metabolism. The main part of alcohol is oxidized in the human body. This means it is released as water and carbon dioxide. One part of the alcohol reacts with fatty acids to produce esters. The sum of the concentrations of four of these fatty acid ethyl esters (FAEEs: ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) are used as indicators of the alcohol consumption. The amounts found in hair are measured in nanograms (one nanogram equals only one billionth of a gram), however with the benefit of modern technology, it is possible to detect such small amounts. In the detection of ethyl glucuronide, or EtG, testing can detect amounts in picograms (one picogram equals 0.001 nanograms).
However, there is one major difference between most drugs and alcohol metabolites in the way in which they enter into the hair: on the one hand like other drugs FAEEs enter into the hair via the keratinocytes, the cells responsible for hair growth. These cells form the hair in the root and then grow through the skin surface taking any substances with them. On the other hand, the sebaceous glands produce FAEEs in the scalp and these migrate together with the sebum along the hair shaft (Auwärter et al., 2001, Pragst et al., 2004). So these glands lubricate not only the part of the hair that is just growing at 0.3 mm per day on the skin surface, but also the more mature hair growth, providing it with a protective layer of fat.
In practice, most hair which is sent for analysis has been cosmetically treated in some way (bleached, permed etc.). It has been proven that FAEEs are not significantly affected by such treatments (Hartwig et al., 2003a). FAEE concentrations in hair from other body sites can be interpreted in a similar fashion as scalp hair (Hartwig et al., 2003b).
Hair analysis to detect drugs of abuse has been used by court systems in the United States, United Kingdom, Canada, and other countries worldwide. In the United States, hair testing has been accepted in court cases as forensic evidence following the Frye Rule, the Federal Rules of Evidence, and the Daubert Rule. As such, hair testing results are legally and scientifically recognized as admissible evidence.
Hair testing is now recognised in both the UK and US judicial systems. There are guidelines for hair testing that have been published by the Society of Hair Testing (a private company in France) that specify the markers to be tested for and the cutoff concentrations that need to be tested. Drugs of abuse that can be detected include Cannabis, Cocaine, Amphetamines and drugs new to the UK such as Mephedrone.
Alcohol
In contrast to other drugs consumed, alcohol is deposited directly in the hair. For this reason the investigation procedure looks for direct products of ethanol metabolism. The main part of alcohol is oxidized in the human body. This means it is released as water and carbon dioxide. One part of the alcohol reacts with fatty acids to produce esters. The sum of the concentrations of four of these fatty acid ethyl esters (FAEEs: ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) are used as indicators of the alcohol consumption. The amounts found in hair are measured in nanograms (one nanogram equals only one billionth of a gram), however with the benefit of modern technology, it is possible to detect such small amounts. In the detection of ethyl glucuronide, or EtG, testing can detect amounts in picograms (one picogram equals 0.001 nanograms).
However, there is one major difference between most drugs and alcohol metabolites in the way in which they enter into the hair: on the one hand like other drugs FAEEs enter into the hair via the keratinocytes, the cells responsible for hair growth. These cells form the hair in the root and then grow through the skin surface taking any substances with them. On the other hand, the sebaceous glands produce FAEEs in the scalp and these migrate together with the sebum along the hair shaft (Auwärter et al., 2001, Pragst et al., 2004). So these glands lubricate not only the part of the hair that is just growing at 0.3 mm per day on the skin surface, but also the more mature hair growth, providing it with a protective layer of fat.
In practice, most hair which is sent for analysis has been cosmetically treated in some way (bleached, permed etc.). It has been proven that FAEEs are not significantly affected by such treatments (Hartwig et al., 2003a). FAEE concentrations in hair from other body sites can be interpreted in a similar fashion as scalp hair (Hartwig et al., 2003b).
Religious and Medical Medical reasons
Religious reasons
Head-shaving is a part of some Buddhist, Christian, Muslim, Jain and Hindu traditions.[citation needed] Buddhist and Christian monks generally undergo some form of head-shaving or tonsure during their induction into monastic life[citation needed]; in Thailand monks shave their eyebrows as well[citation needed]. Brahmin children have their heads ritualistically shaved before beginning school.[citation needed] The Amish religion forbids men from having mustaches, as they are associated with the military.
In some parts of the Theravada Buddhist world, it is common practice to shave the heads of children. Weak or sickly children are often left with a small topknot of hair, to gauge their health and mark them for special treatment. When health improves, the lock is cut off.[citation needed]
In Judaism, there is no obligation to remove hair; nor is there a general prohibition to removing hair. However, there is a prohibition for men using a razor to shave their beards or sideburns; and, by custom, neither men nor women may cut their hair or shave during a 30-day mourning period after the death of an immediate family member.[citation needed]
The Bahá'í Faith recommends against complete and long-term head-shaving outside of medical purposes. It is not currently practiced as a law, contingent upon future decision by the Universal House of Justice, its highest governing body. Sikhs take an even stronger stance, opposing all forms of hair removal. One of the "Five Ks" of Sikhism is Kesh, meaning "hair". To Sikhs, the maintenance and management of long hair is a manifestation of one's piety.[citation needed]
Muslim law (Sharia) puts hair in three categories: that which it is recommended and trim mustache. It is recommended to keep (the beard)[citation needed], and that which is the object of recommendation (foot, hand, back, and chest hair). A Muslim may trim or cut hair on head. The hairs on the chest and the back may be removed. In the 9th century, the use of chemical depilatories for women was introduced by Ziryab in Al-Andalus.
Ancient Egyptian priests also shaved or depilated all over daily, so as to present a "pure" body before the images of the gods.
Medical reasons
The body hair of surgical patients may be removed before surgery. In the past this may have been achieved by shaving, but that is now considered counter-productive, so clippers or chemical depilatories may be used instead. The shaving of hair has sometimes been used in attempts to eradicate lice or to minimize body odor due to accumulation of odor-causing micro-organisms in hair. Some people with trichiasis find it medically necessary to remove ingrown eyelashes. Shaving against the grain can often cause ingrown hairs.
Many forms of cancer require chemotherapy, which often causes severe and irregular hair loss. For this reason, it is common for cancer patients to shave their heads even before starting chemotherapy
Head-shaving is a part of some Buddhist, Christian, Muslim, Jain and Hindu traditions.[citation needed] Buddhist and Christian monks generally undergo some form of head-shaving or tonsure during their induction into monastic life[citation needed]; in Thailand monks shave their eyebrows as well[citation needed]. Brahmin children have their heads ritualistically shaved before beginning school.[citation needed] The Amish religion forbids men from having mustaches, as they are associated with the military.
In some parts of the Theravada Buddhist world, it is common practice to shave the heads of children. Weak or sickly children are often left with a small topknot of hair, to gauge their health and mark them for special treatment. When health improves, the lock is cut off.[citation needed]
In Judaism, there is no obligation to remove hair; nor is there a general prohibition to removing hair. However, there is a prohibition for men using a razor to shave their beards or sideburns; and, by custom, neither men nor women may cut their hair or shave during a 30-day mourning period after the death of an immediate family member.[citation needed]
The Bahá'í Faith recommends against complete and long-term head-shaving outside of medical purposes. It is not currently practiced as a law, contingent upon future decision by the Universal House of Justice, its highest governing body. Sikhs take an even stronger stance, opposing all forms of hair removal. One of the "Five Ks" of Sikhism is Kesh, meaning "hair". To Sikhs, the maintenance and management of long hair is a manifestation of one's piety.[citation needed]
Muslim law (Sharia) puts hair in three categories: that which it is recommended and trim mustache. It is recommended to keep (the beard)[citation needed], and that which is the object of recommendation (foot, hand, back, and chest hair). A Muslim may trim or cut hair on head. The hairs on the chest and the back may be removed. In the 9th century, the use of chemical depilatories for women was introduced by Ziryab in Al-Andalus.
Ancient Egyptian priests also shaved or depilated all over daily, so as to present a "pure" body before the images of the gods.
Medical reasons
The body hair of surgical patients may be removed before surgery. In the past this may have been achieved by shaving, but that is now considered counter-productive, so clippers or chemical depilatories may be used instead. The shaving of hair has sometimes been used in attempts to eradicate lice or to minimize body odor due to accumulation of odor-causing micro-organisms in hair. Some people with trichiasis find it medically necessary to remove ingrown eyelashes. Shaving against the grain can often cause ingrown hairs.
Many forms of cancer require chemotherapy, which often causes severe and irregular hair loss. For this reason, it is common for cancer patients to shave their heads even before starting chemotherapy
Hair removal
With the increased popularity in many countries of women wearing shorter dresses and swimsuits during the 20th century and the consequential exposure of parts of the body on which hair is commonly found, there has been an increase in the practice of women removing unwanted body hair, such as on legs, underarms and elsewhere. In the United States, for example, the vast majority of women regularly shave their legs and armpits, while roughly half also shave their bikini lines.
People may also remove some or all of their pubic hair for aesthetic or sexual reasons. However, some women in Western cultures choose not to remove hair from their bodies, either as a preference or as an act of defiance against what they regard to be an oppressive ritual.
Many men in Western cultures shave their facial hair, so only a minority of men have a beard, even though fast-growing facial hair must be shaved daily to achieve a clean-shaven or hairless look. Some men shave because they cannot grow a "full" beard (generally defined as an even density from cheeks to neck), because their beard color is different from their scalp hair color, or because their facial hair grows in many directions, making a groomed look difficult. Some men shave because their beards are very coarse, causing itchiness and irritation. Some men grow a beard or mustache from time to time to change their appearance.
Some men shave their heads, either as a fashion statement, because they find a shaved head preferable to the appearance of male pattern baldness, or in order to attain enhanced cooling of the skull – particularly for people suffering from hyperhidrosis. A much smaller number of Western women also shave their heads, often as a fashion or political statement.
Within the gay, bi and straight male cultures, some men are known to eliminate or trim the pubic hair especially from their nether region, a practice that is referred to as being a part of manscaping (portmanteau expression for male-specific landscaping). This custom can be motivated by reasons of potentially increased cleanliness and hygiene, heightened enjoyment during fellatio and analingus, and or the desire to take on the appearance of a developing, younger male.
Some women also shave their heads for cultural or social reasons. In India, tradition required widows in some sections of the society to shave their heads as part of being ostracized (see widowhood in Hinduism). The outlawed custom is still infrequently encountered mostly in rural areas. The society at large and the government are working to end the practice of ostracizing widows. In addition, it continues to be common practice for men to shave their heads prior to embarking on a pilgrimage.[citation needed]
People may also remove some or all of their pubic hair for aesthetic or sexual reasons. However, some women in Western cultures choose not to remove hair from their bodies, either as a preference or as an act of defiance against what they regard to be an oppressive ritual.
Many men in Western cultures shave their facial hair, so only a minority of men have a beard, even though fast-growing facial hair must be shaved daily to achieve a clean-shaven or hairless look. Some men shave because they cannot grow a "full" beard (generally defined as an even density from cheeks to neck), because their beard color is different from their scalp hair color, or because their facial hair grows in many directions, making a groomed look difficult. Some men shave because their beards are very coarse, causing itchiness and irritation. Some men grow a beard or mustache from time to time to change their appearance.
Some men shave their heads, either as a fashion statement, because they find a shaved head preferable to the appearance of male pattern baldness, or in order to attain enhanced cooling of the skull – particularly for people suffering from hyperhidrosis. A much smaller number of Western women also shave their heads, often as a fashion or political statement.
Within the gay, bi and straight male cultures, some men are known to eliminate or trim the pubic hair especially from their nether region, a practice that is referred to as being a part of manscaping (portmanteau expression for male-specific landscaping). This custom can be motivated by reasons of potentially increased cleanliness and hygiene, heightened enjoyment during fellatio and analingus, and or the desire to take on the appearance of a developing, younger male.
Some women also shave their heads for cultural or social reasons. In India, tradition required widows in some sections of the society to shave their heads as part of being ostracized (see widowhood in Hinduism). The outlawed custom is still infrequently encountered mostly in rural areas. The society at large and the government are working to end the practice of ostracizing widows. In addition, it continues to be common practice for men to shave their heads prior to embarking on a pilgrimage.[citation needed]
Hair loss
Hair transplantation is a surgical technique that moves individual hair follicles from a part of the body called the donor site to bald or balding part of the body known as the recipient site. It is primarily used to treat male pattern baldness. In this condition, grafts containing hair follicles that are genetically resistant to balding are transplanted to bald scalp. It is also used to restore eyelashes, eyebrows, beard hair, chest hair, and pubic hair and to fill in scars caused by accidents or surgery such as face-lifts and previous hair transplants. Hair transplantation differs from skin grafting in that grafts contain almost all of the epidermis and dermis surrounding the hair follicle, and many tiny grafts are transplanted rather than a single strip of skin.
Since hair naturally grows in follicles in groups of 1 to 4 hairs, transplantation takes advantage of these naturally occurring follicular units. This achieves a more natural appearance by matching hair for hair through Follicular unit transplantation (FUT).
Donor hair can be harvested in two different ways. Small grafts of naturally-occurring units of one to four hairs, called follicular units, can be moved to balding areas of the hair restoration. These follicular units are surgically implanted in the scalp in very close proximity to one another and in large numbers. The grafts are obtained in one or both of the two primary methods of surgical extraction, follicular unit transplantation, colloquially referred to as "strip harvesting", or Follicular Unit Extraction (FUE), in which follicles are transplanted individually.
In FUT, a strip of skin containing many follicular units is extracted from the patient and dissected under stereoscopic microscope. The site of the strip removal is stiched closed. Once divided into follicular unit grafts, the surgeon implants each unit is individually inserted into small recipient sites made by incision in the bald scalp. In newer technique, roots are extracted from the donor area and divided into strips for transplantation. The strip, two to three millimeters thick, is isolated and transplanted to the bald scalp. After surgery, a bandage is worn for two days to protect the stiched strip during healing. A small strip scar remains after healing, which can be covered by scalp hair growing over the scar.
Certain hair shampoos and ointments visually thicken existing hair, without affecting the growth cycle. There have also been developments in the fashion industry with wig design. The fashion accessory has also been shown to be a source of psychological support for women undergoing chemotherapy, with cancer survivors in one study describing their wig as a "constant companion". Other studies in women have demonstrated a more mixed psychosocial impact of hairpiece use.
Specialized scalp tattoos can mimic the appearance of a short buzzed haircut.
Since hair naturally grows in follicles in groups of 1 to 4 hairs, transplantation takes advantage of these naturally occurring follicular units. This achieves a more natural appearance by matching hair for hair through Follicular unit transplantation (FUT).
Donor hair can be harvested in two different ways. Small grafts of naturally-occurring units of one to four hairs, called follicular units, can be moved to balding areas of the hair restoration. These follicular units are surgically implanted in the scalp in very close proximity to one another and in large numbers. The grafts are obtained in one or both of the two primary methods of surgical extraction, follicular unit transplantation, colloquially referred to as "strip harvesting", or Follicular Unit Extraction (FUE), in which follicles are transplanted individually.
In FUT, a strip of skin containing many follicular units is extracted from the patient and dissected under stereoscopic microscope. The site of the strip removal is stiched closed. Once divided into follicular unit grafts, the surgeon implants each unit is individually inserted into small recipient sites made by incision in the bald scalp. In newer technique, roots are extracted from the donor area and divided into strips for transplantation. The strip, two to three millimeters thick, is isolated and transplanted to the bald scalp. After surgery, a bandage is worn for two days to protect the stiched strip during healing. A small strip scar remains after healing, which can be covered by scalp hair growing over the scar.
Certain hair shampoos and ointments visually thicken existing hair, without affecting the growth cycle. There have also been developments in the fashion industry with wig design. The fashion accessory has also been shown to be a source of psychological support for women undergoing chemotherapy, with cancer survivors in one study describing their wig as a "constant companion". Other studies in women have demonstrated a more mixed psychosocial impact of hairpiece use.
Specialized scalp tattoos can mimic the appearance of a short buzzed haircut.
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