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David Starr Jordan (1851-1931)

David Starr Jordan studied fish and promoted eugenics in the US during the late nineteenth and early twentieth centuries. In his work, he embraced Charles Darwin s theory of evolution and described the importance of embryology in tracing phylogenic relationships. In 1891, he became the president of Stanford University in Stanford, California. Jordan condemned war and promoted conservationist causes for the California wilderness, and he advocated for the eugenic sterilization of thousands of Americans.

Format: Articles

Subject: People, Reproduction

Karl Landsteiner (1868-1943)

Karl Landsteiner studied blood types in Europe and in the United States in the late nineteenth and early twentieth centuries. Landsteiner won the Nobel Prize in Physiology or Medicine in 1930 for detailing immunological reactions in the ABO blood group system. The ABO blood group system divides human blood into one of four types based on the antibodies that are present on each cell. Landsteiner's work with blood types led physicians to safely perform blood transfusions and organ transplants.

Format: Articles

Subject: People

“The History of Twins, As a Criterion of the Relative Powers of Nature and Nurture” (1875), by Francis Galton

In the article “The History of Twins, As a Criterion of the Relative Powers of Nature and Nurture,” Francis Galton describes his study of twins. Published in 1875 in Fraser’s Magazine in London, England, the article lays out Galton’s use of twins to examine and distinguish between the characteristics people have at birth and the characteristics they receive from the circumstances of life and experience. Galton calls those factors nature and nurture. Based on his study, Galton concluded that nature has a larger effect than nurture on development.

Format: Articles

Subject: Publications

Preformationism in the Enlightenment

Preformationism was a theory of embryological development used in the late seventeenth through the late eighteenth centuries. This theory held that the generation of offspring occurs as a result of an unfolding and growth of preformed parts. There were two competing models of preformationism: the ovism model, in which the location of these preformed parts prior to gestation was the maternal egg, and the spermism model, in which a preformed individual or homunculus was thought to exist in the head of each sperm.

Format: Articles

Subject: Theories

Richard Woltereck's Concept of Reaktionsnorm

Richard Woltereck first described the concept of Reaktionsnorm (norm of reaction) in his 1909 paper 'Weitere experimentelle Untersuchungen uber Art-veranderung, speziell uber das Wesen quantitativer Artunterschiede bei Daphniden' ('Further investigations of type variation, specifically concerning the nature of quantitative differences between varieties of Daphnia'). This concept refers to the ways in which the environment can alter the development of an organism, and its adult characteristics.

Format: Articles

Subject: Theories

David Hunter Hubel (1926–2013)

David Hunter Hubel studied the development of the visual system and how the brain processes visual information in the US during the twentieth century. He performed multiple experiments with kittens in which he sewed kitten’s eyes shut for varying periods of time and monitored their vision after reopening them. Hubel, along with colleague Torsten Wiesel, received the 1981 Nobel Prize in Physiology or Medicine for that research.

Format: Articles

Subject: People

Alejandro Sánchez Alvarado (1964- )

Alejandro Sánchez Alvarado is a Professor of Neurobiology and Anatomy at the University of Utah School of Medicine and is also a Howard Hughes Medical Institute Investigator. Born in Caracas, Venezuela, 24 February 1964, Sánchez Alvarado left his home to pursue education in the United States, where he received a Bachelor of Science in molecular biology and chemistry from Vanderbilt University in 1986 and a Doctorate in pharmacology and cell biophysics at the University of Cincinnati College of Medicine in 1992.

Format: Articles

Subject: People

A Child Is Born (1965), by Lennart Nilsson

Dell Publishing in New York City, New York, published Lennart Nilsson's A Child Is Born in 1966. The book was a translation of the Swedish version called Ett barn blir till, published in 1965. It sold over a million copies in its first edition, and has translations in twelve languages. Nilsson, a photojournalist, documented a nine-month human pregnancy using pictures and accompanying text written by doctors Axel Ingelman-Sundberg, Claes Wirsen and translated by Britt and Claes Wirsen and Annabelle MacMillian.

Format: Articles

Subject: Outreach, Publications

Alan Mathison Turing (1912-1954)

Alan Mathison Turing was a British mathematician and computer scientist who lived in the early twentieth century. Among important contributions in the field of mathematics, computer science, and philosophy, he developed a mathematical model of morphogenesis. This model describing biological growth became fundamental for research on the process of embryo development.

Format: Articles

Subject: People

The Jackson Laboratory

The Roscoe B. Jackson Laboratory, known commonly in the scientific field as the Jackson Laboratory, was founded by Clarence Cook Little in May 1929. The lab has been pivotal in research with in vitro fertilization, teratomas, gene replacement therapy for birth defects, and more because its researchers have focused from the beginning on developing the mouse as a model organism. Mice were chosen by researchers at Jackson as the best available model for genetic research, and today genetically uniform strains of mice developed at the lab are used in laboratories all over the world.

Format: Articles

Subject: Organizations

Cornelia Isabella Bargmann (1961- )

Cornelia Isabella Bargmann studied the relationship between genes, neural circuits, and behavior in the roundworm Caenorhabditis elegans (C. elegans) during the twentieth and twenty-first centuries in the US. Bargmann’s research focused on how the sense of smell (olfaction) in the nematode word Caenorhabditis elegans. She provided a model to study how neural circuits develop and function in the human brain, as the genetic regulatory pathways are similar.

Format: Articles

Subject: People

“Annual Research Review: Prenatal Stress and the Origins of Psychopathology: An Evolutionary Perspective” (2011), by Vivette Glover

In 2011, fetal researcher Vivette Glover published “Annual Research Review: Prenatal Stress and the Origins of Psychopathology: An Evolutionary Perspective,” hereafter, “Prenatal Stress and the Origins of Psychopathology,” in the Journal of Child Psychology and Psychiatry. In that article, Glover explained how an evolutionary perspective may be useful in understanding the effects of fetal programming. Fetal programming is a hypothesis that attempts to explain how factors during pregnancy can affect fetuses after birth.

Format: Articles

Subject: Theories, Reproduction, Disorders

Temperature-Dependent Sex Determination in Reptiles

The sex of a reptile embryo partly results from the production of sex hormones during development, and one process to produce those hormones depends on the temperature of the embryo's environment. The production of sex hormones can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination, also called genetic or chromosomal sex determination, an organism's genes determine which hormones are produced.

Format: Articles

Subject: Experiments

“Child Development in the Context of Disaster, War, and Terrorism: Pathways of Risk and Resilience” (2012), by Ann S. Masten and Angela J. Narayan

In 2012 Ann S. Masten and Angela J. Narayan published the article “Child Development in the Context of Disaster, War, and Terrorism: Pathways of Risk and Resilience” in Annual Reviews in Psychology. The authors conducted their study at the Institute of Child Development at the University of Minnesota in Minneapolis, Minnesota. In the article, Masten and Narayan review a number of articles to examine and compile the research made since the twenty-first century on the psychological impact of mass trauma, such as war, terrorism, and disasters, on children.

Format: Articles

Subject: Publications

"National Institutes of Health Consensus Development Conference Statement September 22–24, 1980” (1980), by the National Institutes of Health

In 1980 the US National Institutes of Health (NIH) and the US National Institute of Child Health and Human Development (NICHD) released a report titled, “National Institutes of Health Consensus Development Conference Statement September 22–24, 1980.” The report lists recommendations for birth delivery through cesarean sections, a surgical procedure used to deliver the fetus via the pregnant woman’s abdomen. The recommendations arose from the 1980 Consensus Development Conference on Cesarean Childbirth in Bethesda, Maryland.

Format: Articles

Subject: Publications

"The Adaptive Significance of Temperature-Dependent Sex Determination in a Reptile" (2008), by Daniel Warner and Richard Shine

In 2008 researchers Daniel Warner and Richard Shine tested the Charnov-Bull model by conducting experiments on the Jacky dragon (Amphibolurus muricatus), in Australia. Their results showed that temperature-dependent sex determination(TSD) evolved in this species as an adaptation to fluctuating environmental temperatures. The Charnov-Bull model, proposed by Eric Charnov and James Bull in 1977, described the evolution of TSD, although the model was, for many years, untested.

Format: Articles

Subject: Experiments

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

Ilya Ilyich Mechnikov (Elie Metchnikoff) (1845-1916)

Ilya Ilyich Mechnikov studied phagocytes, immune function, and starfish embryos in Europe during the late nineteenth and early twentieth centuries. Mechnikov adopted the French form of his name, Élie Metchnikoff, in the last twenty-five years of his life. In 1908, he won the Nobel Prize in Physiology or Medicine with Paul Ehrlich for their contributions to immunology. Mechnikov discovered phagocytes, immune cells that protect organisms by ingesting foreign particles or microorganisms, by conducting experiments on starfish larvae.

Format: Articles

Subject: People

David Baltimore (1938– )

David Baltimore studied viruses and the immune system in the US during the twentieth century. In 1975, Baltimore was awarded the Nobel Prize in Physiology or Medicine for discovering reverse transcriptase, the enzyme used to transfer information from RNA to DNA. The discovery of reverse transcriptase contradicted the central dogma of biology at the time, which stated that the transfer of information was unidirectional from DNA, RNA, to protein.

Format: Articles

Subject: People

Oliver Allison Ryder III (1946– )

Oliver Allison Ryder studied chromosomal evolution and endangered species in efforts for wildlife conservation and preservation at the San Diego Zoo in San Diego, California. Throughout his career, Ryder studied breeding patterns of endangered species. He collected and preserved cells, tissues, and DNA from endangered and extinct species to store in the San Diego Frozen Zoo, a center for genetic research and development in San Diego, California.

Format: Articles

Subject: People

Nicolaas Hartsoeker (1656-1725)

Nicolaas Hartsoeker, a Dutch astronomer, optics manufacturer, and naturalist, was born 26 March 1656 in Gouda, Netherlands, and died 10 December 1725. His mother was Anna van der Mey and his father was Christiaan Hartsoeker, a prominent evangelical minister. His major contribution to embryology was his observations of human sperm cells, which he claimed to be the first to see under a microscope. His sketch of the homunculus, a tiny preformed human he believed to exist in the head of spermatazoa, is his lasting scientific legacy in the field of embryology.

Format: Articles

Subject: People

Ian Hector Frazer (1953– )

Ian Hector Frazer studied the human immune system and vaccines in Brisbane, Australia, and helped invent and patent the scientific process and technology behind what later became the human papillomavirus, or HPV, vaccinations. According to the Centers for Disease Control and Prevention of the US, or CDC, HPV is the most common sexually transmitted infection, and can lead to genital warts, as well as cervical, head, mouth, and neck cancers.

Format: Articles

Subject: People

Reduction of Maternal-Infant Transmission of Human Immunodeficiency Virus with Zidovudine Treatment

In 1994, Edward M. Connor and colleagues published “Reduction of Maternal-Infant Transmission of Human Immunodeficiency Virus Type 1 with Zidovudine Treatment.” Their study summarized how to reduce the transfer of human immunodeficiency virus, or HIV, from pregnant women to their fetuses with Zidovudine, otherwise known as AZT. HIV is a virus that weakens the immune system by destroying white blood cells, a part of the body’s immune system. Fifteen to forty percent of infants born to HIV-positive mothers become infected during fetal development, labor and delivery, or breast-feeding.

Format: Articles

Subject: Publications

"Experiments in Transplanting Limbs and Their Bearing Upon the Problems of the Development of Nerves" (1907), by Ross Granville Harrison

In his 1907 paper, "Experiments in Transplanting Limbs and Their Bearing Upon the Problems of the Development of Nerves," in the Journal of Experimental Zoology that he edited, Ross Granville Harrison tested the development of nerves in transplanted tissue. He studied neural development by examining two competing theories. Victor Hensen proposed a syncytial theory as a way to explain neural development, suggesting that all the nerves of an embryo were connected directly by cytoplasm laid down early in development, and leaving no room for later modification.

Format: Articles

Subject: Experiments

"A Series of Normal Stages in the Development of the Chick Embryo" (1951), by Viktor Hamburger and Howard L. Hamilton

The developmental stages of the chick embryo were examined by Viktor Hamburger and Howard L. Hamilton in "A Series of Normal Stages in the Development of the Chick Embryo," published in the Journal of Morphology in 1951. These stages were published to standardize the development of the chick based on varying laboratory conditions and genetic differences. The stages Hamburger and Hamilton assigned were determined by the visible features of the chick embryo.

Format: Articles

Subject: Experiments