Vitiligo is a long-term skin condition characterized by patches of the skin losing their pigment. The patches of skin affected become white and have sharp margins; the hair from the skin may become white. The inside of the mouth and nose may be involved. Both sides of the body are affected; the patches begin on areas of skin that are exposed to the sun. It is more noticeable in people with dark skin. Vitiligo may result in psychological stress and those affected may be stigmatized; the exact cause of vitiligo is unknown. It is believed to be due to genetic susceptibility, triggered by an environmental factor such that an autoimmune disease occurs; this results in the destruction of skin pigment cells. Risk factors include a family history of the condition or other autoimmune diseases, such as hyperthyroidism, alopecia areata, pernicious anemia, it is not contagious. Vitiligo is classified into two main types: non-segmental. Most cases are non-segmental. About 10% of cases are segmental, meaning they involve one side of the body.

Diagnosis can be confirmed by tissue biopsy. There is no known cure for vitiligo. For those with light skin and makeup are all, recommended. Other treatment options may phototherapy to darken the light patches. Alternatively, efforts to lighten the unaffected skin, such as with hydroquinone, may be tried. Several surgical options are available for those. A combination of treatments has better outcomes. Counselling to provide emotional support may be useful. Globally about 1% of people are affected by vitiligo. In some populations it affects as many as 2–3%. Males and females are affected. About half show the disorder before age 20 and most develop it before age 40. Vitiligo has been described since ancient history; the only sign of vitiligo is the presence of pale patchy areas of depigmented skin which tend to occur on the extremities. Some people may experience itching; the patches are small, but grow and change shape. When skin lesions occur, they are most prominent on the face and wrists; the loss of skin pigmentation is noticeable around body orifices, such as the mouth, nostrils and umbilicus.

Some lesions have increased skin pigment around the edges. Those affected by vitiligo who are stigmatized for their condition may experience depression and similar mood disorders. Although multiple hypotheses have been suggested as potential triggers that cause vitiligo, studies imply that changes in the immune system are responsible for the condition. Vitiligo has been proposed to be a multifactorial disease with genetic susceptibility and environmental factors both thought to play a role; the TYR gene encodes the protein tyrosinase, not a component of the immune system, but is an enzyme of the melanocyte that catalyzes melanin biosynthesis, a major autoantigen in generalized vitiligo. The National Institutes of Health states that some believe that sunburns can cause or exacerbate the condition, but that this idea is not well-supported by good evidence. Variations in genes that are part of the immune system or part of melanocytes have both been associated with vitiligo, it is thought to be caused by the immune system attacking and destroying the melanocytes of the skin.

A genome wide association study found 36 independent susceptibility loci for generalized vitiligo. Vitiligo is sometimes associated with autoimmune and inflammatory diseases such as Hashimoto's thyroiditis, rheumatoid arthritis, type 1 diabetes mellitus, Addison's disease, pernicious anemia, alopecia areata, systemic lupus erythematosus, celiac disease. Among the inflammatory products of NALP1 are caspase 1 and caspase 7, which activate the inflammatory cytokine interleukin-1β. Interleukin-1β and interleukin-18 are expressed at high levels in people with vitiligo. In one of the mutations, the amino acid leucine in the NALP1 protein was replaced by histidine; the original protein and sequence is conserved in evolution, is found in humans, rhesus monkey, the bush baby. Addison's disease may be seen in individuals with vitiligo. An ultraviolet light can be used in the early phase of this disease for identification and to determine the effectiveness of treatment. Using a Wood's light, skin will change colour when it is affected by certain bacteria and changes to pigmentation of the skin.

Classification attempts to quantify vitiligo have been analyzed as being somewhat inconsistent, while recent consensus have agreed to a system of segmental vitiligo and non-segmental vitiligo. NSV is the most common type of vitiligo. In non-segmental vitiligo, there is some form of symmetry in the location of the patches of depigmentation. New patches appear over time and can be generalized over large portions of the body or localized to a particular area. Extreme cases of vitiligo, to the extent that little pigmented skin remains, are referred to as vitiligo universalis. NSV can come about at any age. Classes of non-segmental vitiligo include the following: Generalized vitiligo: the most common pattern and randomly distributed areas of depigmentation Universal vitiligo: depigmentation encompasses most of the body Focal vitiligo: one or a few scattered macules in one area, most commo

Yanshiping, Tibet

Yanshiping is a small town physically situated in the southwest of Qinghai province, China. However, it is under the jurisdiction of Amdo County in the Nagqu Prefecture of the Tibet Autonomous Region. At an elevation of 4,720 metres, it is one of the highest year-round settlements in the world; the town is situated on the Qinghai-Tibet Highway. The principal industries include animal husbandry and tourism; the township-level division contains seven village committees and one neighborhood which are as follows: Yanshiping Neighborhood Zhukouma Village Naqianma Village Bumadai Village Menlie Sangma Village Longyama Village Oubudong Village Buka Rida Village List of towns and villages in Tibet

Sigma I-66 war game

The Sigma I-66 war game was one of a series of classified high level war games played in The Pentagon during the 1960s to strategize the conduct of the burgeoning Vietnam War. Sigma I-66 was based on the unrealistic scenario of a famine-stricken and militarily diminished North Vietnam agreeing to de-escalate its war efforts, it ended with a hypothetical force of 100,000 Viet Cong still in South Vietnam. These war game simulations were designed to replicate then-current conditions in Indochina, with an aim toward predicting future foreign affairs events, they were staffed with high-ranking officials standing in to represent both domestic and foreign characters. The games were supervised by a Control appointed to oversee both sides; the opposing Blue and Red Teams customary in war games were designated the friendly and enemy forces as was usual. Over the course of the games, the Red Team at times contained the Yellow Team for the People's Republic of China, the Brown Team for the Democratic Republic of Vietnam, the Black Team for the Viet Cong, Green for the USSR.

Preparation for these simulations was quite extensive. A game staff of as many as 45 people developed the scenarios; the actual play of the war game involved 30 to 35 participants. There are four or five simulations per year, solicited secretively from the State Department, the Central Intelligence Agency, major military commands. Sigma I-66 was staged in September 1966, its focus was managing de-escalation of the war if the communists were willing to begin negotiating instead of fighting. In the video-taped summary of the game, a briefer notes that it was believed that the Vietnamese communist insurrection would dwindle into nothingness as they had in Greece and Malaya; the basis for Sigma I-66 was an imagined North Vietnam suffering from food shortages caused by a typhoon destroying the rice crop. The People's Army of Vietnam were being defeated in South Vietnam. American air strikes had beggared the north. Ho Chi Minh secretly passess a private message to the Americans, he proposes withdrawal of northern troops from the south, a ceasefire from the Viet Cong.

In return, he wants a ceasefire from the Americans, a halt to the bombing campaign, a graduated withdrawal of American forces, free elections in South Vietnam. This scenario was played out in an aura of disbelief. Game Control forced Blue Team to cease the air attacks on the north. Control has to rule out a Red Chinese invasion of the north; as the simulation ended, the Viet Cong representative in the game noted: "That's like the cops giving up shooting in shooting in agreement with the robbers. You're turning the countryside back over to the Viet Cong. You have not you are going to get rid of a hundred thousand...armed Viet Cong...."General Earle Wheeler ended the exercise with the comment: "I'm afraid some cynics might be tempted to rediscover that there are worse things than war." Sigma war games Sigma I-62 war game Sigma I-63 war game Sigma I-64 war game Sigma II-64 war game Sigma I-65 war game Sigma II-65 war game Sigma II-66 war game Sigma I-67 and II-67 war games Allen, Thomas B.

War Games: The Secret World of the Creators and Policy Makers Rehearsing World War III Today. McGraw-Hill. ISBNs 0070011958, 9780070011953. Gibbons, William Conrad The U. S. Government and the Vietnam War. Princeton University Press. ISBNs 0691006350, 978-0691006352