Entry Category: Science and Technology - Starting with H

Haemogregarines are protist parasites that belong to the Phylum Apicomplexa, Class Conoidasida, Order Eucoccidiorina, and Suborder Adeleorina, and include the following seven families: Adeleidae, Dactylosomatidae, Haemogregarinidae, Hepatozoidae, Karyolysidae, Klossiellidae, and Legerellidae. There are two major genera, Haemogregarina and Hepatozoon, in addition to several minor ones, including Babesiosoma, Bartazoon, Cyrilia, Dactylosoma, Desseria, Hemolivia, and Karyolysus. As a group, these parasites are cosmopolitan in their range of infected hosts (such as turtles, crocodiles, birds, reptiles, and mammals) and geographic distribution. In general, haemogregarines sensu lato (meaning, in a broad sense) are elongate to fusiform ovoidal organisms that occur within the erythrocytes (red blood cells) of various animals, mostly poikilothermic vertebrates (animals whose internal temperatures vary widely). They form a group of diverse …

The Handywagon, built in 1964 for the Arkansas Louisiana Gas Company (Arkla), was intended as an economical vehicle for use by the company’s Gaslite and domestic appliance servicers, meter readers, collectors, and meter setters. The small wagon was designed to be easily reparable and average thirty-five miles per gallon. In mid-1963, Arkla board chairman Wilton “Witt” R. Stephens asked company lawyer Raymond Thornton to design a utility vehicle that could operate economically, have a 900-pound load capacity, weigh less than a ton and a half, and be company-built. In 1964, Thornton chose Ed Handy, a company construction engineer, to collaborate with him on the project. After much research, the two men found the power train they needed in Holland. Van …

Arthur McCracken Harding, the first Arkansas-born president of the University of Arkansas (UA) in Fayetteville (Washington County), served his alma mater as a professor and in various administrative positions from 1905 to 1941, and then as president from 1941 to 1947. His teaching was marked by publication of books on mathematics and astronomy, and his administrative service developed new programs and extension of university education throughout Arkansas. As university president, he worked to quell political turmoil and helped UA face changes to the university brought by World War II. Arthur McCracken Harding was born on September 3, 1884, in Pine Bluff (Jefferson County), the eldest of seven sons, to Charles Taylor Harding and Florence May Brewster Harding. (His great-grandfather was …

Ernest James Harris was an accomplished entomologist known for his work on breeding Biosteres arisanus, a species of wasp that parasitizes fruit fly eggs. Thanks to the work done by Harris, B. arisanus has been bred on a large scale for the purposes of pest eradication. More than twenty nations have adopted use of the “Harris strain” of the wasp for fruit fly eradication. Harris was inducted into the Arkansas Black Hall of Fame in 1999. Ernest J. Harris was born on May 24, 1928. His parents had a farm in North Little Rock (Pulaski County), where Harris’s interest in insects first developed. After graduation, he attended Arkansas AM&N (now the University of Arkansas at Pine Bluff). There, he majored …

The U.S. Department of Agriculture Agricultural Research Service (USDA-ARS) actively supports aquaculture through research conducted at the Harry K. Dupree Stuttgart National Aquaculture Research Center (HKDSNARC) in Stuttgart (Arkansas County). The mission of the HKDSNARC is to conduct cutting-edge research that addresses the highest priorities of the U.S. aquaculture industry, as well as serving as a global leader in aquaculture research. The research conducted addresses vital issues that are national in scope and result in new knowledge that informs scientists, farmers, feed mills, pharmaceutical companies, processors, teachers, governmental agencies, and consumers. The HKDSNARC collaborates with universities, international research institutions, government agencies, and private industry. Since the 1970s, aquaculture has been the fastest-growing sector of global food production. Global aquaculture production in …

Harvestmen belong to the Phylum Arthropoda, Subphylum Chelicerata, Class Arachnida, and Order Opiliones. They represent the third most diverse order in Arachnida. The order Opiliones includes five suborders as follows: Cyphophthalmi, Eupnoi, Dyspnoi, Laniatores, and Tetrophthalmi. They are often referred to as “daddy long-legs.” They are found throughout the world (except Antarctica), and there are over 6,650 species. Their common name is derived from the fact that they are common during the harvesting season. They are traditionally akin with the Order Acari (ticks and mites) or the Novogenuata (the Scorpiones, Pseudoscorpiones, and Solifugae); however, others suggest the Opiliones forms a clade with the scorpions and two smaller orders. As such, they are considered the sister group of scorpions. In addition, …

Hemipterans, or true bugs, belong to the Phylum Arthropoda, Superclass Hexapoda, Class Insecta, Order Hemiptera, and four suborders: Auchenorrhyncha, Coleorrhyncha, Sternorrhyncha, and Heteroptera. Hemiptera is the largest order of hemimetabolous insects (those not undergoing complete metamorphosis), although male scale insects (Coccoidea) do undergo a form of complete metamorphosis. The number of species in the order is about 75,000, with a great diversity of forms, including aphids, cicadas, leafhoppers, planthoppers, and shield bugs. The three largest families of Heteroptera are Miridae (plant bugs), Lygaeidae (seed bugs), and Pentatomidae (stink bugs). The largest family, Miridae, contains major insect pests and predatory groups that can be used as biological control agents. Although hemipterans inhabit a wide variety of habitats, most are generally terrestrial, …

Herrings (Order Clupeiformes) belong to a large family (Clupeidae) of about 200 species within fifty-four genera of cosmopolitan ray-finned fishes that are mostly marine; a few inhabit freshwater, and some are anadromous—that is, they migrate up rivers from saltwater habitats for purposes of spawning. The family includes herrings, menhadens, sardines, and shads. Most herrings are small fishes, generally being less than 300 mm (12 in.), but some may reach 750 mm (30 in.). Many are valuable food fishes and are collected for production of fish meal and oil, protein concentrate, and fertilizer. Some commercially important species include Atlantic herring (Clupea harengus) found in the north Atlantic, Pacific sardine (Sardinops sagax), and Atlantic menhaden (Brevortia tyrannus). In the fossil record, clupeid …

Dorothy M. Hoover was a pioneer in the field of aeronautical mathematics and research. The granddaughter of enslaved people, she overcame the significant obstacles facing African-American women in the twentieth century to earn advanced degrees in physics and mathematics. One of her greatest achievements in aeronautical research was her contribution to the development of the “thin sweptback tapered wing,” which revolutionized flight and became the aviation industry standard. Her life story was essentially unknown until she was briefly mentioned in the highly acclaimed book Hidden Figures: The American Dream and the Untold Story of the Black Women Mathematicians Who Helped Win the Space Race (2016), by Margot Lee Shetterly. Hidden Figures, which was made into a major motion picture in …

John Wesley Huddleston is best known as a struggling farmer who found two diamonds on the surface of his field near Murfreesboro (Pike County) in August 1906 and made himself and his state famous. Soon after the discovery, he was recognized as the first person outside South Africa to find diamonds at an original volcanic source. In the process, he also became the controversial subject of numerous folk tales. A native of Pike County, John Huddleston was born in 1862 to David Fielding Huddleston and America White Huddleston. He had seven siblings before his mother’s death in the early 1870s and gained three step-sisters after his father’s remarriage to Francis Carey. In 1886, Huddleston wed Sarah A. Keys, the mother …

Conservationist Carl Glenn Hunter achieved prominence in two branches of the Arkansas outdoors—its fauna and its flora. Activities with wildflowers of the state made him a household name in Arkansas and beyond after his retirement as a wildlife biologist. Carl Hunter was born on August 30, 1923, in Little Rock (Pulaski County). He graduated from Little Rock High School (now Central High School) in 1941 and received a bachelor of science in agriculture degree from the University of Arkansas (UA) in Fayetteville (Washington County) in 1945. In college, Hunter worked part time for the Arkansas Game and Fish Commission (AGFC); he became a full-time employee in July 1945. He was one of the first hires of the agency after it …

Hydroelectric power is the electricity generated by the gravitational force of falling or flowing water through a turbine connected to a power generator. The three major types of hydropower facilities include reservoirs (high dams), in-stream (low dams), and pumped-storage. The most common type is the high dam, which creates significant reservoirs behind the dam (e.g., Hoover Dam). In 1882, the world’s first hydroelectric power station, located in Appleton, Wisconsin, produced 12.5 kilowatts of electrical power. Also in the early 1880s, a similar facility opened in New York City. Since these early facilities, hydroelectric power from the nation’s waterways has proliferated. Hydroelectric development in Arkansas can generally be grouped into three time periods—1924–1930; 1944–1973; and 1988–1999—and under three sponsoring agencies: Arkansas …