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Displaying 26 - 50 of 251 items.

J. R. Schramm

Format: Photographs

Subject: People

Embryonic Sex Differentiation and Sex Hormones (1947), by Carl R. Moore

In 1947, Carl Richard Moore, a researcher at the University of Chicago, in Chicago, Illinois, wrote Embryonic Sex Differentiation and Sex Hormones, which was published in the same year as a first-edition monograph. In the book, Moore argues that regulation of sex differentiation in mammals is not controlled by sex hormones secreted by embryonic sex organs (gonads), but is controlled by non-hormonal genetic factors.

Format: Articles

Subject: Publications, Experiments

"The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme" (1979), by Stephen J. Gould and Richard C. Lewontin

The Spandrels of San Marco and the Panglossian Paradigm:
A Critique of the Adaptationist Programme, hereafter called
The Spandrels, is an article written by Stephen J. Gould and
Richard C. Lewontin published in the Proceedings of the Royal
Society of London in 1979. The paper emphasizes issues with
what the two authors call adaptationism or the adaptationist
programme as a framework to explain how species and traits evolved. The paper
is one in a series of works in which Gould emphasized the

Format: Articles

Subject: Publications, Theories

"Behavioral Thermoregulation by Turtle Embryos" (2011), by Wei-Guo Du, Bo Zhao, Ye Chen, and Richard Shine

In "Behavioral Thermoregulation by Turtle Embryos," published in Proceedings of the National Academy of Sciences in April, 2011, Wei-Guo Du, Bo Zhao, Ye Chen, and Richard Shine report that turtle embryos can move towards warmer temperatures within the egg when presented with a small, 0.8 degrees Celsius gradient. This behavioral thermoregulation may benefit the embryo's fitness by accelerating the rate of development enough to decrease the incubation period by up to four and a half days. Embryos are generally thought to have little control over their surroundings.

Format: Articles

Subject: Publications

"Programmed Cell Death-II. Endocrine Potentiation of the Breakdown of the Intersegmental Muscles of Silkmoths" (1964), by Richard A. Lockshin and Carroll M. Williams

Richard A. Lockshin's 1963 PhD dissertation on cell death in insect metamorphosis was conducted under the supervision of Harvard insect physiologist Carroll M. Williams. Lockshin and Williams used this doctoral research as the basis for five articles, with the main title "Programmed Cell Death," that were published between 1964 and 1965 in the Journal of Insect Physiology. These articles examine the cytological processes, neuronal and endocrinal controls, and the influence of drugs on the mechanism of cell death observed in pupal muscle structures of the American silkmoth.

Format: Articles

Subject: Experiments, Publications

The British Doctors’ Study (1951–2001)

From 1951 to 2001, researchers at the University of Oxford in Oxford, England, conducted the British Doctors’ Study, a study that examined the smoking habits, disease rates, and mortality rates of physicians in Britain. Two epidemiologists, scientists who study occurrence and distribution of disease, Richard Doll and Austin Bradford Hill, initiated the study, and statistician Richard Peto joined the team in 1971. The objective of the study was to assess the risks associated with tobacco use, and its relationship to lung cancer.

Format: Articles

Subject: Experiments

"Gene Regulation for Higher Cells: A Theory" (1969), by Roy J. Britten and Eric H. Davidson

In 1969, Roy J. Britten and Eric H. Davidson published Gene Regulation for Higher Cells: A Theory, in Science. A Theory proposes a minimal model of gene regulation, in which various types of genes interact to control the differentiation of cells through differential gene expression. Britten worked at the Carnegie Institute of Washington in Washington, D.C., while Davidson worked at the California Institute of Technology in Pasadena, California. Their paper was an early theoretical and mechanistic description of gene regulation in higher organisms.

Format: Articles

Subject: Publications

Hermaphrodites and the Medical Invention of Sex (1998), by Alice Domurat Dreger

Hermaphrodites and the Medical Invention of Sex, by historian of science Alice Domurat Dreger, was published in 1998 by Harvard University Press. In the book, Dreger describes how many doctors and scientists treated human hermaphrodites from the late nineteenth century to the early twentieth century. She states that during this time period, many physicians and scientists struggled to determine the nature sex, and to support a classification of sex as male or female, many physicians and scientists resorted to viewing a person's gonads for identification of his or her sex.

Format: Articles

Subject: Publications, Theories, Disorders

Ernest Everett Just (1883-1941)

Ernest Everett Just was an early twentieth century American experimental embryologist involved in research at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, and the Stazione Zoologica in Naples, Italy. Just was known for simple but elegant experiments that supported the "fertilizing" theory of Frank R. Lillie and served as an antagonist to Jacques Loeb's work with artificial parthenogenesis.

Format: Articles

Subject: People

Stephen Jay Gould (1941-2002)

Stephen Jay Gould studied snail fossils and worked at Harvard University in Cambridge, Massachusetts during the latter half of the twentieth century. He contributed to philosophical, historical, and scientific ideas in paleontology, evolutionary theory, and developmental biology. Gould, with Niles Eldredge, proposed the theory of punctuated equilibrium, a view of evolution by which species undergo long periods of stasis followed by rapid changes over relatively short periods instead of continually accumulating slow changes over millions of years.

Format: Articles

Subject: People

Wilhelm August Oscar Hertwig (1849-1922)

Wilhelm August Oscar Hertwig contributed to embryology through his studies of cells in development and his discovery that only one spermatozoon is necessary to fertilize an egg. He was born 21 April 1849 to Elise Trapp and Carl Hertwig in Hessen, Germany. After his brother Richard was born the family moved to Muhlhausen in Thuringen where the boys were educated. The two brothers later attended the university in Jena from 1868 to 1888 and studied under Ernst Haeckel, who later convinced Hertwig to leave chemistry and pursue medicine.

Format: Articles

Subject: People

Alec Jeffreys’s Experiments to Identify Individuals by Their Beta-globin Genes (1977-1979)

In a series of experiments in the late 1970s, Alec J. Jeffreys in the UK and Richard A. Flavell in the Netherlands developed a technique to detect variations in the DNA of different individuals. They compared fragments of DNA from individuals’ beta-globin genes, which produce a protein in hemoglobin. Previously, to identify biological material, scientists focused on proteins rather than on genes. But evidence about proteins enabled scientists only to exclude, but not to identify, individuals as the sources of the biological samples.

Format: Articles

Subject: Experiments

Mitochondria

All cells that have a nucleus, including plant, animal, fungal cells, and most single-celled protists, also have mitochondria. Mitochondria are particles called organelles found outside the nucleus in a cell's cytoplasm. The main function of mitochondria is to supply energy to the cell, and therefore to the organism. The theory for how mitochondria evolved, proposed by Lynn Margulis in the twentieth century, is that they were once free-living organisms.

Format: Articles

Subject: Organisms, Theories

"The Environment and Disease: Association or Causation?" (1965), by Austin Bradford Hill

In 1965, Austin Bradford Hill published the article “The Environment and Disease: Association or Causation?” in the Proceedings of the Royal Society of Medicine. In the article, Hill describes nine criteria to determine if an environmental factor, especially a condition or hazard in a work environment, causes an illness. The article arose from an inaugural presidential address Hill gave at the 1965 meeting of the Section of Occupational Medicine of the Royal Society of Medicine in London, England.

Format: Articles

Subject: Publications

Title X Family Planning Program (1970–1977)

The Family Planning Services and Public Research Act of 1970, often called Title X Family Planning Program, is a US federal law that provides federal funding for family planning services to low income or uninsured families. The US federal government passed the law, Public Law 91-572, in 1970 as an amendment to the Public Health Services Act of 1944. The Act created the Office of Population Affairs (OPA) under the Secretary of Health, Education, and Welfare (here called the Secretary).

Format: Articles

Subject: Reproduction, Legal

Frazer v. Schlegel (2007)

On 20 August 2007, in Frazer v. Schlegel, the United States Court of Appeals for the Federal Circuit decided that researchers Ian Frazer and Jian Zhou owned the rights to the vaccine patent for Human Papillomavirus, or HPV, instead of a research team led by Richard Schlegel. Frazer v. Schlegel reversed the decision that the Board of Patent Appeals and Interferences had previously made, awarding the patent to Schlegel on the basis that Frazer’s patent application contained inaccurate science.

Format: Articles

Subject: Legal, Technologies

Austin Bradford Hill (1897-1991)

During the twentieth century, Austin Bradford Hill researched diseases and their causes in England and developed the Bradford Hill criteria, which comprise the minimal requirements that must be met for a causal relationship to be established between a factor and a disease. Hill also suggested that researchers should randomize clinical trials to evaluate the effects of a drug or treatment by monitoring large groups of people.

Format: Articles

Subject: People

Alec John Jeffreys (1950–)

Alec John Jeffreys created a process called DNA fingerprinting in the UK during the twentieth century. For DNA fingerprinting, technicians identify a person as the source of a biological sample by comparing the genetic information contained in the person's DNA to the DNA contained in the sample. Jeffreys developed the technique in the 1980s while at the University of Leicester in Leicester, UK. Jeffreys's technique had immediate applications. In forensic science, DNA fingerprinting enabled police to identify suspects of crimes based on their genetic identities.

Format: Articles

Subject: People

Mitochondrial DNA (mtDNA)

Mitochondrial DNA (mtDNA) is located outside the nucleus in the liquid portion of the cell (cytoplasm) inside cellular organelles called Mitochondria. Mitochondria are located in all complex or eukaryotic cells, including plant, animal, fungi, and single celled protists, which contain their own mtDNA genome. In animals with a backbone, or vertebrates, mtDNA is a double stranded, circular molecule that forms a circular genome, which ranges in size from sixteen to eighteen kilo-base pairs, depending on species. Each mitochondrion in a cell can have multiple copies of the mtDNA genome.

Format: Articles

Subject: Theories

Charles Bradlaugh (1833–1891)

Charles Bradlaugh was as a political and social activist in the seventeenth century in England. He held leadership positions in various organizations focused on social and political activism including the Reform League, the London Secular Society, the newspaper National Reformer, and the National Secular Society. Throughout his career, Bradlaugh advocated for better conditions for the working poor, and for the separation of government and religion.

Format: Articles

Subject: People

Transposition of the Great Arteries (TGA)

Transposition of the great arteries or TGA is a potentially fatal congenital heart malformation where the pulmonary artery and the aorta are switched. The switch means that the aorta, which normally carries oxygenated blood, carries deoxygenated blood. There are two types of the malformation, d-TGA where no oxygen reaches the body and l-TGA where some oxygenated blood circulates. In the US, the Centers for Disease Control estimate that about 1,901 infants are born each year with TGA, or about one for every 2,000 births.

Format: Articles

Subject: Disorders

Apoptosis in Embryonic Development

Apoptosis, or programmed cell death, is a mechanism in embryonic development that occurs naturally in organisms. Apoptosis is a different process from cell necrosis, which is uncontrolled cell death usually after infection or specific trauma. As cells rapidly proliferate during development, some of them undergo apoptosis, which is necessary for many stages in development, including neural development, reduction in egg cells (oocytes) at birth, as well as the shaping of fingers and vestigial organs in humans and other animals. Sydney Brenner, H. Robert Horvitz, and John E.

Format: Articles

Subject: Theories

"Autistic Disturbances of Affective Contact" (1943), by Leo Kanner

Leo Kanner published Autistic Disturbances of Affective Contact in 1943 in the journal Nervous Child. This article described the cases of eleven children with autism. Kanner described the behavior and upbringing of each child, aged two to eight, as well as the educational backgrounds of the children's.

Format: Articles

Subject: Publications

Dissertation: Lessons from Embryos: Haeckel’s Embryo Drawings, Evolution, and Secondary Biology Textbooks

Haeckel believed that the development of an embryo revealed the adult stages of the organism’s ancestors. Haeckel represented this idea with drawings of vertebrate embryos at similar developmental stages. This is Haeckel’s embryo grid, the most common of all illustrations in biology textbooks. Yet, Haeckel’s embryo grids are much more complex than any textbook explanation. I examined 240 high school biology textbooks, from 1907 to 2010, for embryo grids.

Format: Essays and Theses

Subject: Publications, People

Dissertation: Degeneration in Miniature: History of Cell Death and Aging Research in the Twentieth Century

Once perceived as an unimportant occurrence in living organisms, cell degeneration was reconfigured as an important biological phenomenon in development, aging, health, and diseases in the twentieth century. This dissertation tells a twentieth-century history of scientific investigations on cell degeneration, including cell death and aging.

Format: Essays and Theses

Subject: Processes, Organisms