Science and Technology

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Entry Category: Science and Technology - Starting with R

Ranavirus

Ranaviruses are viral pathogens (double-stranded DNA viruses) that infect a broad diversity of at least 175 ectothermic (cold-blooded) vertebrates across the globe; they belong in the genus Ranavirus (RV) of the family Iridoviridae. The genus is composed of six recognized viral species, three of which—tiger salamander (Ambystoma tigrinum) virus (ATV), Bohle iridovirus (BIV), and the type species, frog virus 3 (FV3)—are known to infect amphibians. There are four additional genera of viruses within this family, but RV is the only one that includes viruses that are infectious not only to amphibians but also reptiles and wild and cultured teleost fishes. A study in 2016 found no occurrence of ranavirus in Arkansas in turtles of the eastern part of the state …

Razorback Hogs

Arkansas was known for its razorback hogs long before the University of Arkansas mascot came into being. These wild boars were called razorbacks because of their high, hair-covered backbone and ill-mannered temper. The razorback hog was considered ruthless and dangerous when backed into a corner. The true wild boar, also called the European or Russian boar, is not native to the United States. Christopher Columbus introduced their domesticated ancestors to the New World in 1493. Wild boars are thought to have arrived with explorer Hernando de Soto, who brought the original thirteen grunting hogs to the new world in 1539, though this theory has lately been cast into doubt by Charles Hudson, who reconstructs de Soto’s path in his book, …

Red-cockaded Woodpeckers

aka: Picoides borealis
With the exception of the recently rediscovered ivory-billed woodpecker, red-cockaded woodpeckers (Picoides borealis) are the rarest of Arkansas’s nesting woodpeckers. A century ago, the bird was common in mature, open pine stands. Its natural range included millions of acres of pine habitat throughout the southeast United States. An estimated ninety-nine percent of suitable habitat was lost because of logging, wildfire suppression, conversion to agricultural lands, and urbanization. Best estimates range-wide indicate an original population numbering over four million. By the time the bird was declared endangered, it had declined to an estimated 10,000. The Arkansas population dwindled to under 400 birds. The red-cockaded woodpecker was designated as endangered on October 13, 1970. It received formal legal protection with the passage …

Remmel Dam

aka: Lake Catherine
Remmel Dam is situated on the Ouachita River at Jones Mills (Hot Spring County). It was constructed in 1924 by Arkansas Power and Light (AP&L), now Entergy, in response to the growing demand for electrical power in southern Arkansas and surrounding states. The dam impounds Lake Catherine and, together with Carpenter Dam in Hot Springs (Garland County), provides hydroelectric power for southern Arkansas. Part of a three-dam project on the Ouachita River along with Carpenter Dam (completed in 1931) and Blakely Mountain Dam (completed in 1953), it played an important role in the early development of AP&L. In 1916, former riverboat captain Flave Carpenter met with Harvey Couch, who founded AP&L in 1913, to discuss the possibility of building dams on …

Reptiles

Arkansas’s reptilian biodiversity includes four groups—turtles, lizards, snakes, and the American alligator—each with a sharply different body morphology. By closely examining the morphology of these varied groups within the class Reptilia, today’s phylogenetic taxonomists (individuals who study the evolutionary relationships among species) have found that members of this class share several recently derived features (such as skull characteristics) with birds. Because of this modern understanding of the evolutionary relationships among reptilian ancestors and their descendents, which include dinosaurs and birds, some taxonomists have proposed a new class (Eureptilia) to include dinosaurs, birds, crocodylians, all of their close diapsid relatives (including lizards and snakes), and a number of extinct groups. However, the classical taxonomic designation for the class Reptilia includes turtles, …

Riddle’s Elephant and Wildlife Sanctuary

Opened in 1990 by Scott and Heidi Riddle, Riddle’s Elephant and Wildlife Sanctuary, located on 330 acres outside of Greenbrier (Faulkner County), provides a permanent home for African and Asian elephants in need of sanctuary for any reason, regardless of age, sex, species, health, or temperament. Elephants come from private owners, circuses, or zoos. The 501(c)(3) nonprofit sanctuary—which raises money through grants and donations—houses up to a dozen elephants at any given time, with three baby elephants born at the facility as of 2010. Maximus, an African elephant born at the sanctuary in 2003, starred in Animal Planet’s television show Growing Up Elephant. Scott and Heidi Riddle met while both were working at the Los Angeles Zoo, and they married …

Rivervale Inverted Siphons

Completed in 1926, the Rivervale Inverted Siphons were a prerequisite to permanent settlement in eastern Poinsett County and adjacent areas in the St. Francis River and Little River basins. The siphons provided relief from overflow and outlet for runoff from Craighead and Mississippi counties and portions of southeastern Missouri. One of the first components in the comprehensive drainage plan devised for Drainage District Number Seven of Poinsett County, the Rivervale Inverted Siphons also permitted the immediate agricultural development and economic exploitation of parts of Poinsett County and those counties in Missouri and Arkansas tributary to District Seven. They were also a necessary response to the proliferation of organized drainage and levee districts in the early twentieth century. The siphons were …

Rock Island Bridge (Little Rock–North Little Rock)

aka: Choctaw Bridge
aka: Clinton Presidential Park Bridge
The Rock Island Bridge is a lift-span bridge crossing the Arkansas River between downtown Little Rock (Pulaski County) and North Little Rock (Pulaski County). One of six bridges linking the two downtowns, the Rock Island Bridge was originally constructed as a railroad bridge in 1899; it was converted to serve as a pedestrian bridge in 2011 to complement the William J. Clinton Presidential Center and Park. In late 1898, the Choctaw and Memphis Railroad was organized with the goal of establishing a railroad into the Indian Territory (modern-day Oklahoma). Congress passed legislation authorizing construction of a new bridge across the Arkansas River in January 1899, and the Little Rock Bridge Company formed that May to develop plans for constructing the …

Rocks and Minerals

There are three basic classes of rocks: igneous, metamorphic, and sedimentary. Igneous rocks are those that solidified from magma (molten rock). Metamorphic rocks are formed from pre-existing rocks in a solid state by heat, pressure, and/or chemical activity. Sedimentary rocks are made up of particles of sediment cemented together. In Arkansas, the overwhelming majority of surface and near-surface rocks are sedimentary rocks. There are a few igneous rocks and some very low-grade metamorphic rocks, but these occupy little area. Out of Arkansas’s total area of 53,179 square miles, only about fifteen square miles are composed of igneous rocks. In the Ozark Plateau and Ouachita Mountains, there are indications of some very low-grade metamorphic effects on the rocks in restricted areas, …

Rotifers

aka: Wheel Animals
The Phylum Rotifera (“wheel animals”) contains over 2,100 nominal taxa of microscopic and near microscopic species of unsegmented, bilaterally symmetrical pseudocoelomate invertebrates. They were originally named in 1696 by Anglican priest John Harris (1666–1719) and studied in 1703 by Antoine van Leeuwenhoek (1632–1723). Several surveys of Rotiferans have been done in Arkansas, although there is no summation of the species as of 2019. Because they are minute and mostly composed of soft bodies, rotifers are not commonly supported for fossilization. Their only hard parts, their jaws, are sometimes preserved in the fossil record, but their size makes detection challenging. However, fossils of Habrotrocha angusticollis have been found in Pleistocene (2.5 million to 11,700 years ago) peat deposits of Ontario, Canada. …