|
1940 In Science
The year 1940 in science and technology involved some significant events, listed below. Biochemistry * August 24 – Howard Florey and a team including Ernst Chain, Arthur Duncan Gardner, Norman Heatley, M. Jennings, J. Orr-Ewing and G. Sanders at the Sir William Dunn School of Pathology, University of Oxford, publish their laboratory results showing the ''in vivo'' bactericidal action of penicillin. They have also purified the drug. On December 25 they seed their first batch of culture with spores of penicillin to grow it in medicinal quantity. * The antibiotic dactinomycin (actinomycin D) is first isolated by Selman Waksman and H. Boyd Woodruff at Rutgers University. Biology * February 2 – The first transposons are discovered in maize (''Zea mays'', aka corn) by Barbara McClintock. * March 11 – Ed Ricketts, John Steinbeck and six others leave Monterey for the Gulf of California on a marine invertebrate collecting expedition. Chemistry * February 27 – The ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposon
A transposable element (TE), also transposon, or jumping gene, is a type of mobile genetic element, a nucleic acid sequence in DNA that can change its position within a genome. The discovery of mobile genetic elements earned Barbara McClintock a Nobel Prize in 1983. There are at least two classes of TEs: Class I TEs or retrotransposons generally function via reverse transcription, while Class II TEs or DNA transposons encode the protein transposase, which they require for insertion and excision, and some of these TEs also encode other proteins. Discovery by Barbara McClintock Barbara McClintock discovered the first TEs in maize (''Zea mays'') at the Cold Spring Harbor Laboratory in New York. McClintock was experimenting with maize plants that had broken chromosomes. In the winter of 1944–1945, McClintock planted corn kernels that were self-pollinated, meaning that the silk (style) of the flower received pollen from its own anther. These kernels came from a long lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stocking
Stockings (also known as hose, especially in a historical context) are close-fitting, variously elastic garments covering the leg from the foot up to the knee or possibly part or all of the thigh. Stockings vary in color, design, and transparency. Today, stockings are primarily worn for fashion and aesthetics, usually in association with mid-length or short skirts. History Historically, even though the word ''sock'' is at least as ancient in origin, what men normally wore in the medieval period were referred to as hose. The word ''stock'' used to refer to the bottom "stump" part of the body, and by analogy the word was used to refer to the one-piece covering of the lower trunk and limbs of the 15th century—essentially tights consisting of the ''upper-stocks'' (later to be worn separately as knee breeches) and ''nether-stocks'' (later to be worn separately as ''stockings''). (See Hose.) In 1560, the merchant Thomas Gresham tried to buy silk hose ("sylke howsse") for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after the Anglo-Irish philosopher George Berkeley, it is the state's first land-grant university and is the founding campus of the University of California system. Berkeley has an enrollment of more than 45,000 students. The university is organized around fifteen schools of study on the same campus, including the UC Berkeley College of Chemistry, College of Chemistry, the UC Berkeley College of Engineering, College of Engineering, UC Berkeley College of Letters and Science, College of Letters and Science, and the Haas School of Business. It is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". Lawrence Berkeley National Laboratory was originally founded as par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sam Ruben
Samuel Ruben (born Charles Rubenstein; November 5, 1913 – September 28, 1943) was an American chemist who with Martin Kamen co-discovered the synthesis of the isotope carbon-14 in 1940. Early life Ruben was the son of Herschel and Frieda Penn Rubenstein – the name was officially shortened to Ruben in 1930. Young Sam developed a friendship with neighbor Jack Dempsey and became involved with a local boys' boxing club and later, when the family moved across the Bay to Berkeley, he was a successful basketball player at Berkeley High School (Berkeley, California). After achieving his B.S. in chemistry at the University of California, Berkeley, he continued his studies there and was awarded a Ph.D. in physical chemistry in May 1938. He was immediately appointed instructor in the chemistry department, and became an assistant professor in 1941. Research Ruben and colleague Martin Kamen, a University of Chicago Ph.D. and researcher in chemistry and nuclear physics working under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martin Kamen
Martin David Kamen (August 27, 1913, Toronto – August 31, 2002, Montecito, California) was an American chemist who, together with Sam Ruben, co-discovered the synthesis of the isotope carbon-14 on February 27, 1940, at the University of California Radiation Laboratory, Berkeley. He also confirmed that all of the oxygen released in photosynthesis comes from water, not carbon dioxide, in 1941. Kamen was the first to use carbon-14 to study a biochemical system, and his work revolutionized biochemistry and molecular biology, enabling scientists to trace a wide variety of biological reactions and processes. Despite being blacklisted for nearly a decade on suspicion of being a security risk, Kamen went on to receive the Albert Einstein World Award of Science in 1989, and the U.S. Department of Energy's 1995 Enrico Fermi award for lifetime scientific achievement. Early life and education Kamen was born on August 27, 1913, in Toronto, the son of Russian Jewish immigrants. He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon-14
Carbon-14, C-14, C or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic matter is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California. Its existence had been suggested by Franz Kurie in 1934. There are three naturally occurring isotopes of carbon on Earth: carbon-12 (C), which makes up 99% of all carbon on Earth; carbon-13 (C), which makes up 1%; and carbon-14 (C), which occurs in trace amounts, making up about 1-1.5 atoms per 10 atoms of carbon in the atmosphere. C and C are both stable; C is unstable, with half-life years. Carbon-14 has a specific activity of 62.4 mCi/mmol (2.31 GBq/mmol), or 164.9 GBq/g. Carbon-14 decay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotope
Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemical element), but different nucleon numbers (mass numbers) due to different numbers of neutrons in their nuclei. While all isotopes of a given element have similar chemical properties, they have different atomic masses and physical properties. The term isotope is derived from the Greek roots isos (wikt:ἴσος, ἴσος "equal") and topos (wikt:τόπος, τόπος "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table. It was coined by Scottish doctor and writer Margaret Todd (doctor), Margaret Todd in a 1913 suggestion to the British chemist Frederick Soddy, who popularized the term. The number of protons within the atomic nuc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered ''radioactive''. Three of the most common types of decay are Alpha decay, alpha, Beta decay, beta, and Gamma ray, gamma decay. The weak force is the Fundamental interactions, mechanism that is responsible for beta decay, while the other two are governed by the electromagnetic force, electromagnetic and nuclear forces. Radioactive decay is a randomness, random process at the level of single atoms. According to quantum mechanics, quantum theory, it is impossible to predict when a particular atom will decay, regardless of how long the atom has existed. However, for a significant number of identical atoms, the overall decay rate can be expressed as a decay constant or as a half-life. The half-lives of radioactive atoms have a huge range: f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of California
The Gulf of California (), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Vermejo''), is a marginal sea of the Pacific Ocean that separates the Baja California peninsula from the Mexico, Mexican mainland. It is bordered by the states of Baja California, Baja California Sur, Sonora, and Sinaloa with a coastline of approximately . Rivers that flow into the Gulf of California include the Colorado River, Colorado, Fuerte River, Fuerte, Mayo River (Mexico), Mayo, Sinaloa River, Sinaloa, Sonora River, Sonora, and the Yaqui River, Yaqui. The surface of the gulf is about . Maximum depths exceed because of the complex geology, linked to plate tectonics. The gulf is thought to be one of the most diverse seas on Earth and is home to more than 5,000 species of micro-invertebrates. Parts of the Gulf of California are a UNESCO World Heritage Site. Geography History The marine expeditions of Fortún Ximénez, Hernán Cort� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monterey, California
Monterey ( ; ) is a city situated on the southern edge of Monterey Bay, on the Central Coast (California), Central Coast of California. Located in Monterey County, California, Monterey County, the city occupies a land area of and recorded a population of 30,218 in the 2020 United States census, 2020 census. The city was founded by the Spanish Empire, Spanish in 1770, when Gaspar de Portolá and Junípero Serra established the Presidio of Monterey, California, Presidio of Monterey and the Cathedral of San Carlos Borromeo (Monterey, California), Cathedral of San Carlos Borromeo. Monterey was elevated to capital of the the Californias, Province of the Californias in 1777, servings as the administrative and military headquarters of both Alta California and Baja California, as well as its only official port of entry. Following the Mexican War of Independence, Monterey continued as the capital of the Mexican The_Californias#Department_of_Mexico, Department of the Californias. During t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Steinbeck
John Ernst Steinbeck ( ; February 27, 1902 – December 20, 1968) was an American writer. He won the 1962 Nobel Prize in Literature "for his realistic and imaginative writings, combining as they do sympathetic humor and keen social perception". He has been called "a giant of American letters." During his writing career, he authored 33 books, with one book coauthored alongside Edward Ricketts, including 16 novels, six non-fiction books, and two collections of short stories. He is widely known for the comic novels ''Tortilla Flat'' (1935) and ''Cannery Row (novel), Cannery Row'' (1945), the multigeneration epic ''East of Eden (novel), East of Eden'' (1952), and the novellas ''The Red Pony'' (1933) and ''Of Mice and Men'' (1937). The Pulitzer Prize–winning ''The Grapes of Wrath'' (1939) is considered Steinbeck's masterpiece and part of the Western canon, American literary canon. By the 75th anniversary of its publishing date, it had sold 14 million copies. Much of Steinbec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
