The United States twenty-dollar bill is a denomination of U. S. currency. The seventh U. S. president, Andrew Jackson, has been featured on the front side of the bill since 1928. As of December 2013, the average circulation life of a $20 bill is 7.9 years before it is replaced due to wear. About 11% of all notes printed in 2009 were $20 bills. Twenty-dollar bills are delivered by Federal Reserve Banks in violet straps. 1861: A demand note with Lady Liberty holding a sword and shield on the front, an abstract design on the back. The back is printed green. 1862: A note, similar, the first $20 United States note. The back is different, with several small variations extant. 1863: A gold certificate $20 note with an Eagle vignette on the face. The reverse has various abstract elements; the back is orange. 1865: A national bank note with "The Battle of Lexington" and Pocahontas's marriage to John Rolfe in black, a green border. 1869: A new United States note design, with Alexander Hamilton on the left side of the front and Victory holding a shield and sword.

The back design is green. 1875: As above, except with a different reverse. 1878: A silver certificate $20 note with a portrait of Stephen Decatur on the right side of the face. The back design is black. 1882: A new gold certificate, with a portrait of James Garfield on the right of the face. The back features an eagle. 1882: A new national bank note. The front is similar. 1886: A new silver certificate $20 note, with Daniel Manning on the center of the face. 1890: A treasury note with John Marshall on the left of the face. Two different backs exist both with abstract designs. 1902: A new national bank note. The front features Hugh McCulloch, the back has a vignette of an allegorical America. 1905: A new gold certificate $20 note, with George Washington on the center of the face. The back design is orange. 1914: A Federal Reserve Note Andrew Jackson first appeared on the $20 bill in 1928. Although 1928 coincides with the 100th anniversary of Jackson's election as president, it is not clear why the portrait on the bill was switched from Grover Cleveland to Jackson..

According to the U. S. Treasury, "Treasury Department records do not reveal the reason that portraits of these particular statesmen were chosen in preference to those of other persons of equal importance and prominence."The placement of Jackson on the $20 bill may be a historical irony. In his farewell address to the nation, he cautioned the public about paper money. 1914: Began as a large-sized note, a portrait of Grover Cleveland on the face, and, on the back, a steam locomotive and an automobile approaching from the left, a steamship approaching from the right. 1918: A federal reserve banknote with Grover Cleveland on the front, a back design similar to the 1914 Federal Reserve Note. 1928: Switched to a small-sized note with a portrait of Andrew Jackson on the face and the south view of the White House on the reverse. The banknote is redeemable in silver at any Federal Reserve Bank. 1933: With the U. S. having abandoned the gold standard, the bill is no longer redeemable in gold, but rather in "lawful money", meaning silver.

1942: A special emergency series, with brown serial numbers and "HAWAII" overprinted on both the front and the back, is issued. These notes are designed to circulate on the islands and be deemed invalid in the event of a Japanese invasion. 1948: The White House picture was updated to reflect renovations to the building itself, including the addition of the Truman Balcony, as well as the passage of time. Most notably, the trees are larger; the change occurred during production of Series 1934C. 1950: Design elements like the serial numbers are reduced in size and moved around subtly for aesthetic reasons. 1963: "Will Pay To The Bearer On Demand" is removed from the front of the bill below the portrait, the legal tender designation is shortened to "This note is legal tender for all debts and private" Also, "In God We Trust" is added above the White House on the reverse. These two acts are coincidental if their combined result is implemented in one redesign. Several design elements are rearranged, less perceptibly than the change in 1950 to make room for the rearranged obligations.

1969: The new treasury seal appears on all denominations, including the $20. 1977: A new type of serial-number press results in a different font. The old presses are retired, old-style serial numbers appear as late as 1981 for this denomination. 1992: Anti-counterfeiting features are added: microprinting around the portrait, a plastic strip embedded in the paper. Though the bills read Series 1990, the first bills were printed in April 1992. 1994: The first notes at the Western Currency Facility are printed in January late during production of Series 1990. September 24, 1998: The Series 1996 $20 note was redesigned for the first time since 1929 to further deter counterfeiting. A larger, off-center portrait of Jackson was used on the front, several anti-counterfeiting features were added, including color-shifting ink, a watermark; the plastic strip now reads "USA 20"

Nyangabgwe Referral Hospital is a health care institution located in Francistown, The hospital was established in 1989. Nyangabgwe Referral Hospital was established in 1989, it is a Government of Botswana health institution. The hospital is located in the second largest city of Botswana called Francistown. Nyangabgwe has beds at the Internal Medicine Department, it is connected to the government of Botswana database system. This department serves several wards at the hospital from the male medical ward, female medical ward, private ward and isolation ward; the hospital's 24-hour emergency department is able to cater for children. The hospital departments include a Rehabilitation Centre, anti-retroviral treatment for patients with HIV infection and AIDS, post-trauma counseling services, occupational services, laundry services, kitchen services and a mortuary. Princess Marina hospital has an annex, consisting of about 550 beds, space with the basic medical equipment for conducting series of diagnostic test.

Botswana Ministry of Health

Tubastraea faulkneri, common name Orange sun coral, is a species of large-polyp stony corals belonging to thr family Dendrophylliidae. Other common names of this coral are Orange Cup Coral, Sun Coral, Orange Polyp Coral, Rose Sun Coral, Golden Cup Coral, Sun Flower Coral, Tube Coral; the species has been named faulkneri by the American paleontologist John West Wells in 1982 in honor of Douglas Faulkner, who collected and illustrated in color the specimen used for the description. This species is present in the Indo-Pacific Ocean, in Australian water and from the Philippines to the Galapagos Islands; these large-polyp stony corals occurs in areas with a strong water flow and a high nutrient content, not related to the reef, at depths of 3 to 5 m. Tubastraea faulkneri is an encrusting coral that can become massive and convex; the corallites of this species are covered with a porous tissue with a vermicular appearance. The calices have a diameter of 8 -- a depth of 5 -- 8 mm, they are spaced of 5 -- 15 rise of 3 -- 8 mm above the coenosteum.

The tentacles of the polyps are bright yellow-orange, while the coenosteum and the center of the polyps are deeper orange. The surface of the coenosteum is swollen between calices, they have four cycles of septa, with vertical internal margins dropping steeply towards the columella. The third cycle of septa reaches the edge of the calice and the fourth cycle is weakly developed incomplete and irregularly fused in the third cycle; the columella is deep and slightly compressed. This species is rather similar to Tubastraea coccinea, but the latter species lacks of spacing between the coralites and they are united only at the base, while in T. faulkneri there is a space between the polyps. These corals do not contribute to coral reef development. Unlike many tropical corals, they are azooxanthellate or non-photosynthetic, meaning that they do not live in symbiosis with zooxanthellae in their tissues, allowing them to grow in complete darkness as long as they can capture enough food, they extend their translucent tentacles during the late erveing and the night, while during the day the tentacles are withdrawn and the coenosteum is visible.

They feed on plankton. Like most corals, Tubastraea faulkneri reproduce asexually, they are hermaphrodites. Mature gametes are spawned through the mouth; the zygote develops into a planktonic planula larva