Science and Medicine

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Entry Category: Science and Medicine - Starting with N

Narrows Dam

aka: Lake Greeson
Narrows Dam is located six miles north of Murfreesboro (Pike County). Authorized by the Flood Control Act of 1941, it was constructed on the Little Missouri River as a project for flood control and hydroelectric power. The Little Missouri River flows through the Ouachita Mountains and enters Pike County at its northwest upper corner, dropping 1,035 feet before it runs into Lake Greeson. Before the dam was constructed, heavy rains in the mountains often caused the area around Murfreesboro to become flooded, causing damage to houses and resulting in loss of livestock and farm crops. Martin White Greeson, the owner of the Murfreesboro-Nashville Southwest Railroad, urged the development of the watershed in order to control the water of the Little …

Nashville Sauropod Trackway

The Nashville sauropod trackway, which may be the largest dinosaur trackway in the world, was located near Nashville (Howard County). The most unusual thing about the Nashville trackway is its size, but it also represented, for over twenty-five years, the only evidence of sauropods in Arkansas other than bone fragments found nearby. This discovery has greatly informed the scientific study of sauropods and other dinosaur trackways. A trackway is a path of preserved footprints left by dinosaurs. There are between 5,000 and 10,000 assorted tracks on the Nashville trackway, most of which have been identified as having been made by sauropods. Some species of sauropods are the diplodocus and the titansaur. Sauropods had long necks and long tails and walked on all …

Natural Gas

The earliest natural gas find is reported to have been in Scott County in 1887 during an effort to develop a commercial water well. The second recorded gas well was drilled two years later (also in Scott County) by an oil driller, Harry Kelly, to a depth of 1,600 feet. This was recognized as the first recorded effort to find oil in Arkansas, though “only gas was present.” No other efforts to find oil or gas were reported until 1901–1902, when the Mansfield Pool was developed by Choctaw Oil and Gas Company. While no oil was found, this effort did provide large amounts of gas, with some wells producing as much as 5 million cubic feet of gas per day. …

Neel, Margarete Ethel

Margarete Ethel Neel became the symbol of the International Red Cross after World War II. The White County chapter submitted to the national headquarters a wartime photo of Neel guiding the wheelchair of wounded Private Gordon Pyle of California. It was reproduced as a poster for the organization’s post-war fundraising activities. A plaque commemorating Neel’s Red Cross service stands in front of the Searcy American Legion Hut, where the White County chapter of the Red Cross is located. The chapter was dedicated to Neel just after her death in 1971. Neel was among the first women listed on the rolls of the U.S. Women’s Memorial when it was dedicated in Washington DC in 1997. Margarete Neel was born on December …

Nematodes

aka: Roundworms
The phylum Nematoda includes three classes (Anoplea, Chromodorea, and Rhabditida), sixteen to twenty orders, and about 27,000 described species (and possibly up to one million) of mostly dioecious, elongate, bilaterally symmetrical pseudocoelomate worms. They can be found in abundance in nearly every habitat on Earth, with a diverse array of species existing in both marine and terrestrial habitats. Most are free-living, with less than half considered to be parasitic. Nevertheless, many species threaten the health of plants and animals (including humans) on a global scale. Nematodes are variable in size from less than one millimeter to more than one meter in length. They have been in existence for an estimated one billion years, having evolved from simple animals some 400 …

Nematomorpha

aka: Horsehair Worms
aka: Hairworms
Horsehair worms belong to the phylum Nematomorpha and are typically obligate parasites of terrestrial arthropods (e.g., beetles, crickets, cockroaches, locusts, grasshoppers, and mantids). As adults, however, they are free-living in aquatic environments. These worms are sometimes found in coiled clusters termed “Gordian knots” from the intricate legendary knot of Greek mythology. Another myth is related to the common name given these worms, “hairworms” or “horsehair worms,” originating from the idea that horse hairs that fell into water became worms. This belief was not disproved scientifically until American anatomist and paleontologist Joseph Leidy (1823–1891) noted in 1870 that horse hairs placed in water for many months did not come to life. The first published report of a horsehair worm from Arkansas …

Nemertea

aka: Ribbon Worms
The phylum Nemertea is an invertebrate phylum that contains over 1,000 species within 250 genera of mostly marine organisms known variously as ribbon, proboscis, or nemertean worms. Only a few taxa inhabit freshwater, and there are several terrestrial species. Most are free living; however, a few are known to be parasitic. The name means one of “Nereis” (unerring one), which refers to the unerring aim of the proboscis. Ribbon worms are unique in having an eversible muscular proboscis that is used for grasping prey. It lies free inside of a cavity above the alimentary canal known as the rhynchocoel. This muscular tube can be swiftly thrust out to catch prey items. This phylum is also occasionally called the Rhynchocoela, which …

Neuropterans

aka: Net-Winged Insects
Neuropterans belong to the Phylum Arthropoda, Class Insecta, and Order Neuroptera. The Neuroptera (antlions, lacewings, mantidflies, and their relatives) and allied orders Megaloptera (dobsonflies, alderflies) and Raphidioptera (snakeflies) together make up the clade Neuropterida. There are three suborders (Osmyloidea, Hemerobiiformia, and Myrmeleontiformia) and nine extinct and fifteen extant families. There are about 6,400 species in the group worldwide, with about 450 found in the United States and Canada. Neuropterans can be found on all continents except Antarctica. There are several types of neuropterans in Arkansas. In the fossil record, neuropterans first appeared during end of the Permian period (251 million years ago), which ended in the largest mass extinction the Earth ever experienced, as shown by fossils of the Permithonidae …

Nimrod Dam and Lake

Nimrod Dam in western Perry County is the oldest project of the U.S. Army Corps of Engineers in the state of Arkansas, created to control flooding along the Fourche La Fave River. Nimrod Lake, the reservoir created by the dam, stretches across the border of Perry and Yell counties and is a popular attraction for fishermen and duck hunters. The dam and lake take their names from the nearby community of Nimrod (Perry County), itself named after the biblical figure. The construction of Nimrod Dam was authorized by the Flood Control Act of 1938. Damming the Fourche La Fave was considered an economical means of protecting communities and valuable crop land in Yell and Perry counties, as well as lessening …

Nix, Joe Franklin

Joe Nix is a water chemist, environmentalist, naturalist, and educator considered by many to be the watchdog of Arkansas rivers and lakes with respect to water quality and usage patterns. His mission has been to have society use good scientific data in making decisions about environmental matters. Joe Franklin Nix was born on August 28, 1939, the only child of Frank and Era Nix, in Malvern (Hot Spring County). His father was a mechanic; his mother was a homemaker. He was a sickly child, so the doctor advised that he spend a lot of time outdoors. As a youth, he fell under the personal tutelage of family friend and former state geologist Joe Kimzey of Magnet Cove (Hot Spring County). …

Norfork Dam and Lake

Built on the North Fork River, just upstream from its confluence with the White River in Baxter County in north-central Arkansas, Norfork Dam and Lake are named after the nearby town of Norfork (Baxter County). The dam was authorized by Congress in the Flood Control Act of 1938, and construction began in the spring of 1941, making it one of the oldest U.S. Army Corps of Engineers’ multi-purpose concrete structures. The reservoir extends north from the dam site to near Tecumseh, Missouri, and covers portions of Baxter and Fulton counties in Arkansas and Ozark County in Missouri. The drainage area controlled by the reservoir is about 1,806 square miles. The project also contains a powerhouse that houses the generators and …

Northern Snakehead

aka: Channa argus
aka: Snakehead
The northern snakehead (Channa argus) is a modern bony fish belonging to the family Channidae. It is native to China, eastern Russia, and parts of the Korean peninsula. The fish was discovered in Arkansas in 2008, leading to attempts to eradicate it. The northern snakehead has an elongate body, with long dorsal and anal fins, and a truncated tail. Coloration is dark tan to brown with darker spots laterally, extending above and below the midline. The jaws have sharp, pointed teeth. The fish can reach a size of one meter and weigh as much as eight kilograms. The northern snakehead breathes with gills but also possesses a suprabranchial organ, which consists of chambers filled with folded tissue that allow atmospheric …

Novaculite

Novaculite is a hard, dense, white-to-grayish-black sedimentary rock, composed of microcrystalline quartz. It is translucent on its thin, sharp edges and usually breaks with a smooth conchoidal (shell-like) fracture. The word “novaculite” is derived from a Latin word meaning “razor stone.” Novaculite is found in the Ouachita Mountains in formations that are highly resistant to erosion. These formations range from about 250 to 900 feet in thickness. There are two categories of Arkansas novaculite classified by the abrasives industry. The “Washita” stone has the dull luster of unglazed porcelain. It is more porous and less dense than the “Arkansas” stone, which is extremely fine-grained with a waxy luster. There has been recent interest in the fine-grained novaculite as a lapidary …

Nuttall, Thomas

Thomas Nuttall, a preeminent and far-ranging field naturalist, participated in the early scientific exploration of Arkansas and is remembered both for identifying a number of the state’s plants and for his description of early Arkansas life. His notes on people living in the territory—both Native Americans and American settlers—have provided valuable information for historians and researchers ever since they were first published in 1821. Thomas Nuttall was born to James Nuttall and Margaret Hardacre Nuttall on January 5, 1786, in Long Preston, Yorkshire, England. He was the oldest of three siblings; he had two sisters, Susan (Susannah) and Elizabeth. He never married and had no children. After attending the village school, Nuttall worked as a journeyman printer for his uncle …