Science and Technology

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Entry Category: Science and Technology - Starting with M

Main Street Bridge (Little Rock–North Little Rock)

The Main Street Bridge was originally constructed in 1924 as a vehicular structure, replaced in 1973, and altered in 1998; it is one of six bridges linking the downtown areas of Little Rock (Pulaski County) and North Little Rock (Pulaski County). As the downtown areas of Little Rock and Argenta (now North Little Rock) developed in the 1880s, it became apparent that a toll-free bridge independent of the railroad bridges across the Arkansas River was needed. Some people supported the idea of a bridge at the foot of Little Rock’s Main Street, while others thought it should start at Broadway. After years of debate and a series of bridge commissions, the Main Street site was adopted, and the Groton Bridge …

Mammals

Arkansas’s assemblage of mammals contains both domesticated and wild species, as well as humans. The agriculture and pet industries within Arkansas are enhanced by domesticated mammals. Wild mammals can be grouped into two categories: game (species with hunting seasons) and non-game (species without hunting seasons). All mammals are classified into the class Mammalia. Mammals—along with birds, fish, amphibians, and reptiles—belong to a large group known as the vertebrates (animals possessing a backbone). Mammals share common features with each other, including being homeothermic (constant internal body temperature), having hair, having mammary glands (milk-producing structures in females), and being able to give live birth. Some mammals found outside of Arkansas, such as dolphins and whales (order Cetacea), have very small amounts of …

Mantodea

aka: Mantids
aka: Mantises
Mantises belong to the Phylum Arthropoda, Class Insecta, and Order Mantodea. The order contains over 2,400 species within about 430 genera in fifteen families. The largest family is the cosmopolitan Mantidae. Mantises are distributed worldwide in mostly tropical but also temperate habitats. Little has been published on the mantises of Arkansas, although the Carolina mantid, Stagmomantis carolina, has been investigated in the central part of the state. In the fossil history of mantises, fossils of the group are rare. For example, by 2007, only about twenty-five fossil species were known. The earliest, from Siberia, are about 135 million years old. Fossil mantises, from Cretaceous amber, include a specimen from Japan with spines on the front legs, as in modern mantises. …

Maple-Leaf Oak

aka: Quercus acerifolia
Maple-leaf oak (Quercus acerifolia) is a rare tree species commonly agreed to occur at just four sites in the world, all of which are in Arkansas. All of these sites are open, rocky woodlands on sandstone or novaculite substrate and are located at the tops of high-elevation ridges in the Arkansas Valley and Ouachita Mountains: Magazine Mountain in Logan County, Porter Mountain in Polk County, Pryor Mountain in Montgomery County, and Sugarloaf Mountain in Sebastian County. The growth form of maple-leaf oak ranges from short, stunted multi-trunked shrubs to single-trunked trees up to fifty feet tall. It is most easily distinguished by its upper leaves, which are commonly as wide or wider than they are long, with three to five …

Marked Tree Siphons

Constructed in 1939 by the Memphis District Corps of Engineers for Drainage District Number Seven of Poinsett County, the Marked Tree Siphons were an integral part of the St. Francis River Basin Flood Control Project. The siphons were also a unique application of an engineering structure of their type, designed to lift the flow of the St. Francis River over an earthen levee and deposit it in the river channel on the other side of the levee. In 1917, Drainage District Number Seven of Poinsett County was authorized by the Arkansas General Assembly. The St. Francis River meandered from north to south through the district, which encompassed most of the county east of Crowley’s Ridge, and carried a considerable traffic …

Massie, Samuel Proctor, Jr.

Samuel Proctor Massie Jr. overcame racial barriers to become one of America’s greatest chemists in research and teaching. As a doctoral candidate during World War II, he worked on the Manhattan Project with Henry Gilman at Iowa State University in the development of uranium isotopes for the atomic bomb. In 1966, the U.S. Naval Academy appointed him as its first black faculty member. Massie’s research over fifty years led to the development of drugs to treat mental illness, malaria, meningitis, gonorrhea, herpes, and cancer. Chemical and Engineering News in 1998 named him one of the top seventy-five chemists of all time, along with Marie Curie, Linus Pauling, George Washington Carver, and DNA pioneers James Watson and Francis Crick. Samuel Massie …

Mayflies

aka: Ephemeropterans
Mayflies belong to the Phylum Arthropoda, Class Insecta, and Order Ephemeroptera. They are a small, wide-ranging, primitive order of insects that is well known to entomologists, biologists, naturalists, and fly fishermen. There are approximately 3,000 species of mayflies described worldwide; these are grouped into over 400 genera within forty-two families. As of 2019, approximately 676 species within twenty-one families were recognized from North America. The southeastern United States has nearly 400 mayfly species, which is more than half of those known from the United States and almost half of those known from North America alone. No single study summarizing mayflies exists specifically for Arkansas, but an investigation from 2010 noted about 117 species of mayflies reported from the state. The …

Megaloptera

aka: Alderflies
aka: Dobsonflies
aka: Fishflies
Megaloptera is an order that is included within the Phylum Arthropoda and Class Insecta. There are about 300 extant species of megalopterans, and these include the alderflies, dobsonflies, and fishflies. There are six families: Corydalidae, Corydasialidae (extinct), Euchauliodidae (extinct), Nanosialidae (extinct), Parasialidae (extinct), and Sialidae. Megalopterans can be found in several Arkansas counties. The Megaloptera were once regarded as a part of a group of insects called Neuroptera, together with the lacewings and snakeflies; however, they are now generally considered to be separate orders, with Neuroptera only referring to the lacewings and their relatives (formerly Planipennia). The former Neuroptera, particularly the lacewing group, are very closely related to each other, and the new name for this group is Neuropterida. This …

Memphis-Arkansas Memorial Bridge

The Memphis-Arkansas Memorial Bridge on Interstate Highway 55 connects Arkansas with Tennessee at Memphis. Since its opening on the morning of December 17, 1949, the span has served as a vital link for automotive traffic to cross the Mississippi River. When the Frisco Bridge was built for railroads in 1892, automobile traffic was not a factor. The Harahan Bridge, the second bridge linking Arkansas and Tennessee, opened in the summer of 1916. Due to increasing numbers of automobiles on both sides of the river, carriageways were hung off both sides of the Harahan in 1917. These provided a single lane for traffic on either side of the bridge. Although Arkansas cars could cross the Mississippi River at Memphis beginning in …

Meteorites

Meteorites are fragments of rock or metal that fall from space. Except for a few that have come from the moon or Mars, meteorites represent fragments of small non-planetary bodies within the solar system, such as the objects that make up the asteroid belt. Most meteorites are remnants from the formation of the solar system that have drifted in orbits between the primary planets for over 4.5 billion years. Meteorites are some of the most scientifically significant materials on earth. Sample return missions to find and recover these objects from their orbits in space are, in most cases, prohibitively expensive or impossible. It is extraordinarily good fortune for scientists when a new meteorite falls to earth, since each one offers …

Millipedes

There have been around 7,000 species of millipedes (sometimes spelled millipeds) described scientifically, with a projected estimate of possibly 80,000 total species occurring around the globe. Around 900 species have been described from the United States and Canada. However, the family Parajulidae, the largest group from North America, has not been studied thoroughly, suggesting that numerous more species exist in North America. Arkansas has a diverse array of millipede species. Some of them are fairly common, while others are rare. Millipedes—their name meaning “thousand feet”—make up a group of invertebrates (lacking a backbone) in the phylum Arthropoda. Within the Arthropoda phylum, millipedes belong in the subphylum Myriapoda, which includes four classes: Chilopoda (centipedes), Diplopoda (millipedes), Paurapoda (paurapods), and Sumphyla (symphylans). …

Millwood Dam and Lake

Millwood Dam, which impounds Millwood Lake on the Little River, was constructed between 1961 and 1966 at a cost of $46.1 million as part of a U.S. Army Corps of Engineers (USACE) project to control flooding on the lower Red River, into which the Little River empties near the town of Fulton (Hempstead County). The lake created by the dam spills across the borders of four counties—Sevier, Little River, Howard, and Hempstead—and provides a variety of recreational opportunities for southwestern Arkansas. The 3.3-mile-long, earthen Millwood Dam is the longest of its kind in Arkansas. Millwood Dam, located east of Ashdown (Little River County), was made possible by the federal Flood Control Act of 1946, though opposition within the state and …

Miser, Hugh Dinsmore

Hugh Dinsmore Miser was a geologist who spent much of his career with the United States Geological Survey (USGS). Over the course of his career, he produced geologic maps of large parts of many states and oversaw investigations of mineral deposits critical to the national World War II efforts. Hugh Miser was born in Pea Ridge (Benton County) on December 18, 1884. He was the third child of Jordan Stanford Miser, a farmer, and Eliza Caroline Webb. Miser’s ancestors were immigrants of German and English descent who moved from Tennessee to northern Arkansas in the early part of the nineteenth century. Miser attended the Pea Ridge Normal School, an academy organized by Benjamin Harvey Caldwell. He entered the University of …

Mississippi County Community College Solar Power Experiment

In 1976, the Department of Energy and the Solar Energy Research Institute were allotted funds for a Total Energy Solar Photovoltaic Conversion System that would be the largest of its kind in the world. The location chosen for the project was Mississippi County Community College (MCCC), now Arkansas Northeastern College (ANC), in Blytheville (Mississippi County). The project design included the installation of solar panels, as well as additional funding for the college facility. The main purpose of the project was to build an energy-efficient structure and harness solar power from the panels in order to coordinate, monitor, and manage energy production. With the United States facing an energy crisis in the mid-1970s, President Jimmy Carter created a comprehensive energy plan …

Mites

Mites are small arthropods (Phylum Arthropoda) belonging to the Class Arachnida (Subclass Acari) with two or three Superorders as follows: Acariformes (or Actinotrichida), Parasitiformes (or Anactinotrichida), and Opilioacariformes. There are four Orders, Mesostigmata, Prostigmata, Orbatida, and Astigmata. Among the more well-known mites are ticks (Ixodida). There are an estimated 48,200 species of described mites. The phylogeny of the Acari is still debatable, and several different taxonomic schemes have been proposed for their classification. The diversity of the Acari is extraordinary, and its fossil history goes back to at least the early Devonian Period (about 419 million years ago). Mites are very common in Arkansas, with chiggers being a particular pest of humans during warmer months. Historically, references to mites/chiggers go …

Moles

The mammalian family Talpidae includes seventeen genera and forty-two species of moles worldwide in the order Eulipotyphla. Of these, there are four genera and seven species in North America alone. Moles are found in most parts of North America, Asia, and Europe. The family contains all the true moles, and some of their close relatives—including desmans, but these are not normally called “moles” and belong to the subfamily Talpinae. Those species called “shrew moles” denote an intermediate form between the moles and their shrew ancestors. There are three subfamilies of moles, including the Scalopinae (New World moles) with five genera, Talpinae (Old World, desmans, and shrew moles) with nine genera, and Uropsilinae (Asian shrew-like moles) with a single genus. The …

Molluscs

aka: Mollusks
The phylum Mollusca is a major invertebrate group known commonly as “molluscs” (sometimes spelled “mollusks”), which includes about 85,000 living species (although this number varies), with another 60,000 to 100,000 additional fossil species. This phylum is ranked second only to the Phylum Arthropoda in number of living species. Included within the diverse phylum are snails, slugs, cowries, squids, clams, mussels, limpets, oysters, scallops, octopi, cuttlefish, and a myriad of additional groups such as the little-known chitons, monoplacophorans, and tusk shells. Malacology is the scientific study of molluscs, and a specialist who studies them is known as a malacologist. Two classes of molluscs inhabit Arkansas: the Gastropoda and the Bivalvia. Approximately eighty-five species of bivalves are known from the state, while …

Monogeneans

The class Monogenoidea is a fairly large group of parasitic flatworms belonging to the phylum Platyhelminthes. Monogeneans are generally found on bony fishes in freshwater and marine habitats. Although some are endoparasites in the urinary bladder and eyes, most monogeneans are ectoparasites that attach to their host’s skin or gills by a special posteriorly positioned attachment organ called a haptor. The class contains about nine orders, fifty families, and 4,000–5,000 species. The genus Dactylogyrus is one of the largest genera, with nearly 1,000 species. Some taxonomists divide the Monogenoidea into two or three subclasses based on the complexity of their haptor. Those in the subclass Monopisthocotylea have one main part to the haptor, often with hooks or a large attachment …