Electoral device for choosing a party's candidates for public office. The formal primary system is peculiar to the U.S., where it came into widespread use in the early 20th century. Most U.S. states use it for elections to statewide offices and to the national presidency; in presidential elections, delegates are selected to attend a national convention, where they vote for the candidate to whom they are pledged. A closed-vote primary is restricted to party members; an open-vote primary is open to all voters in the district. Names can be placed on a ballot by an eligible citizen's declaration of candidacy, by nomination at a pre-primary convention, or by a petition signed by a required number of voters. In the late 20th and early 21st centuries political parties in some countries (e.g., the United Kingdom and Israel) adopted similar procedures for the election of the national party leader. Seealso electoral system; party system.
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Traditionally, the first stage of formal education, beginning at age 5–7 and ending at age 11–13. Often preceded by some form of preschool, it usually includes middle school, or junior high school (ages 11–13), though this is sometimes regarded as part of secondary education. Nearly all nations are committed to some form of elementary education, though in many developing countries many children are unable to continue full-time studies past the age of 10 or 11. The elementary curriculum usually emphasizes reading and writing, arithmetic, social studies, and science. A basic teaching strategy involves moving the student from the immediate and familiar to the distant and unfamiliar, an approach first formulated by Johann Heinrich Pestalozzi.
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Disease in which gradual atrophy of the adrenal cortex causes the adrenal glands to produce insufficient quantities of the steroid hydrocortisone while causing the pituitary gland to produce excess quantities of pituitary hormones. Most of the cortex tissue is destroyed by the time symptoms (including weakness, abnormal coloration, weight loss, and hypotension) appear. Hydrocortisone-replacement therapy is often successful, usually given with other hormones to stabilize sodium levels. More than half of cases are believed to be due to an autoimmune reaction (see autoimmune disease); the remainder are caused by destruction of the adrenal gland by granuloma (e.g., tuberculosis).
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