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Displaying 226 - 250 of 353 items.

The Aschheim-Zondek Test for Pregnancy

Throughout history many different methods have been devised for the early detection of pregnancy. From the time of the Ancient Egyptians, inspection of the urine has been a popular place to start. However, it was not until the discovery of hormones in the early twentieth century that the development of truly reliable pregnancy tests occurred. Prior to 1978, when the first home pregnancy tests became available in the United States, pregnancy testing was done in hospital laboratories using various methods, one of them being the Aschheim-Zondek, or A-Z test.

Format: Articles

Subject: Technologies, Reproduction

Sterilization Act of 1924

The passage of the Virginia Sterilization Act of 1924 demonstrates how science has been used to drive policy throughout history. In the case of the Virginia sterilization law, the science used to draft the law was based on the principles of eugenics. With the help of Harry Laughlin's Model Sterilization Law, the state of Virginia was able to pass its own law allowing sterilization of the feebleminded, expressing sterilization as a health issue that needed to be protected from the public.

Format: Articles

Subject: Legal, Reproduction

Clifford Grobstein (1916-1998)

Clifford Grobstein was a traditional, influential, and highly innovative biologist of the mid-twentieth century, gifted with many character facets and pragmatic talents. His early adulthood passion of linking classical embryology with developmental anatomy and medicine was joined by his later pursuit of combining research ethics and science education with public policy.

Format: Articles

Subject: People

John Tyler Bonner (1920- )

The establishment and growth of developmental-evolutionary biology owes a great debt to the work of John Tyler Bonner. Bonner's studies of cellular slime molds have shed light on some of the big questions of biology including the origins of multicellularity and the nature of morphogenesis. The second child of Lilly Marguerite Stehli and Paul Bonner, John Tyler was born 12 May 1920 in New York City and spent his early years in Locust Valley, Long Island (late 1920s), France (1930), and London (1932).

Format: Articles

Subject: People

Process of Eukaryotic Embryonic Development

All sexually reproducing, multicellular diploid eukaryotes begin life as embryos. Understanding the stages of embryonic development is vital to explaining how eukaryotes form and how they are related on the tree of life. This understanding can also help answer questions related to morphology, ethics, medicine, and other pertinent fields of study. In particular, the field of comparative embryology is concerned with documenting the stages of ontogeny.

Format: Articles

Subject: Processes

John von Neumann (1903-1957)

John von Neumann was a Hungarian mathematician who made important contributions to mathematics, physics, computer science, and the area of artificial life. He was born in Budapest, Hungary, on 28 December 1903. His mother was Margit von Neumann and his father was Max von Neumann. His work on artificial life focused on the problem of the self-reproduction of machines. Von Neumann initially discussed self-reproducing machines in his Hixon Symposium paper "The General and Logical Theory of Automata" published in 1948.

Format: Articles

Subject: People

Rita Levi-Montalcini (1909-2012)

Rita Levi-Montalcini is a Nobel Laureate recognized for her work in the discovery and characterization of nerve growth factor. Nerve growth factor (NGF) promotes the growth and maintenance of the nervous system in a developing system. The majority of her career has been devoted to investigating the many aspects of NGF.

Format: Articles

Subject: People

The Effects of Thalidomide on Embryonic Development

Embryogenesis is an intricate process that can easily be disrupted by means of teratogenic agents. Some of these agents target the embryonic period's "window of susceptibility," three to eight weeks after a pregnant woman's last menstruation, when the highest degree of sensitivity to embryonic cell differentiation and organ formation occurs. The embryonic period or critical period is when most organ systems form, whereas the fetal period, week eight to birth, involves the growth and modeling of the organ systems.

Format: Articles

Subject: Processes, Disorders

Osborne Overton Heard (1890-1983)

Osborne O. Heard was a noted Carnegie embryological model maker for the Department of Embryology at The Carnegie Institute of Washington (CIW), Baltimore, Maryland. Heard was born in Frederick, Maryland, on 21 November 1890. His father died while Heard and his three brothers were quite young. Heard attended night school at the Maryland Institute of Art and Design where he studied sculpting and patternmaking. While working as a patternmaker for the Detrick and Harvey Machine Company, Heard made models of tools using a variety of materials such as wood, plastic, and plaster of Paris.

Format: Articles

Subject: People

James David Ebert (1921-2001)

James David Ebert studied the developmental processes of chicks and of viruses in the US during the twentieth century. He also helped build and grow many research institutions, such as the Department of Embryology in the Carnegie Institution of Washington in Baltimore, Maryland and the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts. When few biologists studied the biochemistry of embryos, Ebert built programs and courses around the foci of biochemistry and genetics, especially with regards to embryology.

Format: Articles

Subject: People

Bowen v. American Hospital Association (1986)

The 1986 US Supreme Court decision Bowen v. American Hospital Association rejected the federal government's use of Section 504 of the Rehabilitation Act of 1973 to intervene in a hospital's treatment for neonates born with severe congenital defects. This case set a precedent for the role of government involvement in cases where parents refused consent for care of disabled newborns.

Format: Articles

Subject: Legal, Reproduction

Circulatory Changes at Birth

When placental mammals are born their circulatory systems undergo radical changes as the newborns are prepared for independent life. The lungs are engaged, becoming the primary source of fresh oxygen, replacing the placental barrier as a means for blood-gas exchange.

Format: Articles

Subject: Processes

Sir D'Arcy Wentworth Thompson (1860-1948)

Known by many for his wide-reaching interests and keen thinking, D'Arcy Wentworth Thompson was one of Britain's leading scientific academics in the first few decades of the twentieth century. A prodigious author, Thompson published some 300 papers, books, and articles in the biological sciences, classics, oceanography, and mathematics. He was a famous lecturer and conversationalist-a true "scholar-naturalist," as his daughter wrote in her biography of her father.

Format: Articles

Subject: People

Dictyostelium discoideum

Dictyostelium discoideum is a cellular slime mold that serves as an important model organism in a variety of fields. Cellular slime molds have an unusual life cycle. They exist as separate amoebae, but after consuming all the bacteria in their area they proceed to stream together to form a multicellular organism. These features make it a valuable tool for studying developmental processes and also for investigating the evolution of multicellularity. Long thought to be a type of fungus, it has recently been shown that slime molds in fact bear no relation to fungi.

Format: Articles

Subject: Organisms

Leonardo da Vinci's Embryological Annotations

Among his myriad scientific and artistic contributions, Leonardo da Vinci's work in embryology was groundbreaking. He observed and diagramed the previously undemonstrated position of the fetus in the womb with detailed accompanying annotations of his observations. Leonardo was highly paranoid of plagiarism and wrote all of his notes in mirror-like handwriting laden with his own codes, making his writing difficult to discern and delaying its impact.

Format: Articles

Subject: Publications

David Wildt's Domestic Cat and Cheetah Experiments (1978-1983)

David Wildt's cheetah (Acinonyx jubatus) research from 1978-1983 became the foundation for the use of embryological techniques in endangered species breeding programs. The cheetah is a member of the cat family (Felidae), which includes thirty-seven species. According to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) all Felidae species are currently threatened or endangered, with the exception of the domestic cat (Felinus catus).

Format: Articles

Subject: Experiments

Smith v. Cote (1986)

The case of Smith v. Cote (1986) answered two important questions concerning law and childbirth: does the State of New Hampshire recognize a cause of action for what is defined as wrongful birth, and does the State recognize a cause of action for what is classified as wrongful life? In the case of Smith v. Cote, damages were permitted for wrongful birth, but not for the action of wrongful life.

Format: Articles

Subject: Legal, Disorders

"The Cell-Theory" (1853), by Thomas Henry Huxley

The Cell-Theory was written by Thomas Henry Huxley in Britain and published in 1853 by The British and Foreign Medico-Chirurgical Review. The twenty-two page article reviews twelve works on cell theory, including those in Germany by Caspar Friedrich Wolff in the eighteenth century and by Karl Ernst von Baer in the nineteenth century. Huxley spends much of The Cell-Theory on a cell theory proposed in the late 1830s by Matthias Schleiden and Theodor Schwann in Germany.

Format: Articles

Subject: Publications

"Experiments in Plant Hybridization" (1866), by Johann Gregor Mendel

During the mid-nineteenth century, Johann Gregor Mendel experimented with pea plants to develop a theory of inheritance. In 1843, while a monk in the Augustian St Thomas's Abbey in Brünn, Austria, now Brno, Czech Repubic, Mendel examined the physical appearance of the abbey's pea plants (Pisum sativum) and noted inconsistencies between what he saw and what the blending theory of inheritance, a primary model of inheritance at the time, predicted.

Format: Articles

Subject: Experiments

"Congenital Cataract following German Measles in the Mother" (1941), by Norman McAlister Gregg

In Australia in the 1940s, Norman McAlister Gregg observed a connection between pregnant women who contracted the rubella virus, or German measles, and cataract formation in their children's eyes. Gregg published his findings in the 1941 article Congenital Cataract following German Measles in the Mother in Transactions of the Ophthalmological Society of Australia. In the article, Gregg analyzed seventy-eight cases of congenital cataracts and suggested that the mothers' environmental factors could cause birth defects, otherwise known as teratogenic effects.

Format: Articles

Subject: Publications

"Maternal consumption of peanut during pregnancy is associated with peanut sensitization in atopic infants" (2010), by Scott Sicherer, et al.

In 2010, a team of US researchers concluded that the more peanuts a pregnant woman ate during her pregnancy, the more likely her newborn was to be sensitive to peanuts. They published their results in 2010's "Maternal consumption of peanut during pregnancy is associated with peanut sensitization in atopic infants." The work resulted from the collaboration of Scott Sicherer and Hugh Sampson, both from the Jaffe Food Allergy Institute, Mount Sinai School of Medicine, in New York, New York along with other colleagues.

Format: Articles

Subject: Experiments, Reproduction

Johann Gregor Mendel (1822-1884)

Johann Gregor Mendel studied plants and their patterns of inheritance in Austria during the nineteenth century. Mendel experimented with the pea plant, Pisum, and his publication, 'Versuche uber Pflanzenhybriden' (“Experiments on Plant Hybridization”), published in 1866, revolutionized theories of trait inheritance. Mendel’s discoveries relating to factors, traits, and how they pass between generations of organisms enabled scientists in the twentieth century to build theories of genetics.

Format: Articles

Subject: People

Solomon A. Berson (1918-1972)

Solomon A. Berson helped develop the radioimmunoassay (RIA) technique in the US during the twentieth century. Berson made many scientific contributions while working with research partner Rosalyn Yalow at the Bronx Veterans Administration (VA) hospital, in New York City, New York. In the more than twenty years that Berson and Yalow collaborated, they refined the procedures for tracing diagnostic biological compounds using isotope labels.

Format: Articles

Subject: People

The Discovery of The Dikika Baby Fossil as Evidence for Australopithecine Growth and Development

When scientists discovered a 3.3
million-year-old skeleton of a child of the human lineage (hominin) in
2000, in the village of Hadar, Ethiopia, they were able to study growth
and development of Australopithecus
afarensis, an extinct hominin species. The team of researchers,
led by Zeresenay Alemseged of the Max Planck Institute for Evolutionary
Anthropology in Leipzig, Germany, named the fossil DIK 1-1 and nicknamed
it Dikika baby after the Dikika research site. The Dikika fossil

Format: Articles

Subject: Theories

St. George Jackson Mivart (1827-1900)

St. George Jackson Mivart studied animals and worked in England during the nineteenth century. He also proposed a theory of organismal development that he called individuation, and he critiqued Charles Darwin's argument for evolution by natural selection. His work on prosimians, a group of primates excluding apes and monkeys, helped scientists better investigate the Primate group.

Format: Articles

Subject: People