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Displaying 226 - 250 of 1032 items.

Hans Adolf Eduard Driesch (1867-1941)

Although educated as a scientist who studied with both August Weismann and Ernst Heinrich Haeckel, Hans Adolf Eduard Driesch was first employed as a professor of philosophy and became a strong proponent of vitalism. Driesch was born on 28 October 1867, the only child of Josefine Raudenkolb and Paul Driesch. He grew up in a wealthy merchant family in Hamburg, Germany, where he was educated at the humanistic Gymnasium Gelehrtenschule des Johanneums that had been founded by a friend of Martin Luther.

Format: Articles

Subject: People

Landrum Brewer Shettles (1909-2003)

Landrum Brewer Shettles is remembered as an important contributor to early in vitro fertilization research in the United States as well as a prolific author on the subject of choosing a child's sex before conception. Shettles was born in Pontotoc County, Mississippi on 21 November 1909 to Sue Mounce and Brazil Manly. Shettles trained and worked as a gynecologist at Columbia University Presbyterian Medical Center, after receiving his MD in 1943 from Johns Hopkins University.

Format: Articles

Subject: People, Reproduction

Jennifer Doudna and Emmanuelle Charpentier’s Experiment About the CRISPR/cas 9 System’s Role in Adaptive Bacterial Immunity (2012)

In 2012, Jennifer Doudna, Emmanuelle Charpentier from the University of California, Berkeley, in Berkeley, California, and Umeå University in Umeå, Sweden, along with their colleagues discovered how bacteria use the CRISPR/cas 9 system to protect themselves from viruses. The researchers also proposed the idea of using the CRISPR/cas 9 system as a genome editing tool.

Format: Articles

Subject: Experiments

"Alternative Sources of Human Pluripotent Stem Cells" (2005), by Leon Kass and the President’s Council on Bioethics

Human pluripotent stem cells are valued for their potential to form numerous specialized cells and for their longevity. In the US, where a portion of the population is opposed to destruction of human embryos to obtain stem cells, what avenues are open to scientists for obtaining pluripotent cells that do not offend the moral sensibilities of a significant number of citizens?

Format: Articles

Subject: Publications, Ethics

"On the Induction of Embryonic Primordia by Implantation of Organizers from Different Species" (1924), Hilde Mangold's Dissertation

Hilde Proscholdt Mangold was a doctoral student at the Zoological Institute at the University of Freiburg in Freiburg, Germany, from 1920-1923. Mangold conducted research for her dissertation 'On the Induction of Embryonic Primordia by Implantation of Organizers from Different Species' ('Ueber Induktion von Embryonanlagen durch Implantation artfremder Organisatoren'), under the guidance of Hans Spemann, a professor of zoology at the University of Freiburg.

Format: Articles

Subject: Experiments, Publications

A History of Embryology (1959), by Joseph Needham

In 1931 embryologist and historian Joseph Needham published a well-received three-volume treatise titled Chemical Embryology. The first four chapters from this work were delivered as lectures on Speculation, Observation, and Experiment, as Illustrated by the History of Embryology at the University of London. The same lectures were later released as a book published in 1934 titled A History of Embryology.

Format: Articles

Subject: Publications

Roy John Britten (1919-2012)

Roy John Britten studied DNA sequences in the US in the second
half of the twentieth century, and he helped discover repetitive
elements in DNA sequences. Additionally, Britten helped propose
models and concepts of gene regulatory networks. Britten studied the
organization of repetitive elements and, analyzing data from the
Human Genome Project, he found that the repetitive elements in DNA
segments do not code for proteins, enzymes, or cellular parts.
Britten hypothesized that repetitive elements helped cause cells to

Format: Articles

Subject: People

Diana W. Bianchi

Diana W. Bianchi studied the medical treatment of premature and newborn infants in the US during the twentieth and twenty-first centuries. Bianchi helped develop non-invasive prenatal genetic tests that use cell-free fetal DNA found within maternal blood to diagnose genetic abnormalities of the fetus during pregnancy. The test provides a means to test fetuses for chromosomal and genetic abnormalities.

Format: Articles

Subject: People

Leon Richard Kass (1939- )

A PhD and medical doctor turned ethicist, Leon Kass calls himself an unlicensed humanist. Throughout his unique career he has sought to impact others and engage important cultural issues. This he has accomplished over the course of many years by studying biochemistry, teaching humanities, writing articles and books on ethics, and serving as chair of the President's Council on Bioethics.

Format: Articles

Subject: People, Ethics, Reproduction

45 CFR 46: Protection of Human Subjects under United States Law (1974)

In the United States, the Code of Federal Regulations Title 45: Public Welfare, part 46 (45 CFR 46) provides protection for human subjects in research carried out or supported by most federal departments and agencies. 45 CFR 46 created a common federal policy for the protection of such human subjects that was accepted by the Office of Science and Technology Policy and issued by each of the departments and agencies listed in the document.

Format: Articles

Subject: Legal

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

Stanley Cohen (1922- )

Stanley Cohen is a biochemist who participated in the discovery of nerve growth factor (NGF) and epidermal growth factor (EGF). He shared the 1986 Nobel Prize in Physiology or Medicine with Rita Levi-Montalcini for their work on the discovery of growth factors. His work led to the discovery of many other growth factors and their roles in development.

Format: Articles

Subject: People

Hans Asperger (1906-1980)

Hans Asperger studied mental abnormalities in children in
Vienna, Austria, in the early twentieth century. Asperger was one of
the early researchers who studied the syndrome that was later named
after him, Asperger's Syndrome. Asperger described the syndrome in
his 1944 publication Die Autistischen Psychopathen im
Kindesalter (Autistic Psychopathy in Childhood). At that time,
the syndrome was called autistic psychopathy, and Asperger noted
that characteristics of the syndrome included lack of sympathy,

Format: Articles

Subject: People

Elizabeth Maplesden Ramsey (1906-1993)

Physician and pathologist Elizabeth Maplesden Ramsey was a member of the Carnegie Institution of Washington (CIW) for thirty-nine years. The affiliation began in 1934, when Ramsey discovered what was assumed to be the youngest-known embryo at the time, and donated it to CIW's massive embryo collection. After studying embryos, Ramsey focused her research on placental circulation in primates.

Format: Articles

Subject: People

Barack Obama Executive Order 13505, November 2008

On 20 November 2009 Democrat Barack Obama replaced Republican George W. Bush as president of the United States. Obama soon initiated changes to Bush's 2001 executive order concerning scientific research involving human stem cells. Stem cell research remains a controversial issue in the US. Some individuals consider it immoral to experiment with an embryo because they regard embryos as human beings from the moment of conception, while others believe stem cell research could lead to great scientific advancements.

Format: Articles

Subject: Legal

George W. Bush Executive Order 13455, June 2007

On 20 January 2001, Republican George W. Bush was sworn in as the forty-third president of the United States, replacing Democrat William J. Clinton. During his eight years in office, Bush issued many executive orders, often altering previous policy. By signing Order 13435 on 22 June 2007, he changed how stem cell research would be performed in America.

Format: Articles

Subject: Legal

Images of Embryos in Life Magazine in the 1950s

Embryonic images displayed in Life magazine during the mid-twentieth century serve as a representation of technological advances and the growing public interest in the stages of embryological development. These black-and-white photographs portray skeletal structures and intact bodies of chicken embryos and human embryos and fetuses obtained from collections belonging to universities and medical institutions.

Format: Articles

Subject: Outreach, Publications, Reproduction

Lynn Petra Alexander Sagan Margulis (1938-2011)

Lynn Petra Alexander Sagan Margulis was an American biologist, whose work in the mid-twentieth century focused on cells living together in a mutually advantageous relationship, studied cells and mitochondria in the US during the second half of the twentieth century. She developed a theory for the origin of eukaryotic cells, that proposed two kinds of structures found in eukaryotic cells mitochondria in animals, and plastids in plantsÑwere once free-living bacteria that lived harmoniously and in close proximity to larger cells, a scenario called symbiosis.

Format: Articles

Subject: People, Theories

Karl Ernst von Baer's Laws of Embryology

In 1828, while working at the University of Konigsberg in Konigsberg, Germany Karl Ernst von Baer proposed four laws of animal development, which came to be called von Baer's laws of embryology. With these laws, von Baer described the development (ontogeny) of animal embryos while also critiquing popular theories of animal development at the time.

Format: Articles

Subject: Theories

Jan Swammerdam (1637-1680)

Jan Swammerdam, known as the founder of the preformation theory based on his extensive research on insect development, was born on 12 February 1637 in Amsterdam, the Netherlands, to Baertje Jans Corvers and Jan Jacobszoon Swammerdam. He began medical school on 11 October 1661 at the University of Leiden. A few of his classmates included Regnier de Graaf, Frederik Ruysch, Niels Stensen (Nicolaus Steno), and Robertus Padtbrugge. Padtbrugge would later join the East India Company and send Swammerdam exotic animals.

Format: Articles

Subject: People

The French Flag Model

The French flag model represents how embryonic cells receive and respond to genetic information and subsequently differentiate into patterns. Created by Lewis Wolpert in the late 1960s, the model uses the French tricolor flag as visual representation to explain how embryonic cells can interpret genetic code to create the same pattern even when certain pieces of the embryo are removed. Wolpert's model has provided crucial theoretical framework for investigating universal mechanisms of pattern formation during development.

Format: Articles

Subject: Processes, Theories

"The Development of the Turtle Carapace" (1989), by Ann Campbell Burke

Ann Campbell Burke examines the development and evolution of vertebrates, in particular, turtles. Her Harvard University experiments, described in Development of the Turtle Carapace: Implications for the Evolution of a Novel Bauplan, were published in 1989. Burke used molecular techniques to investigate the developmental mechanisms responsible for the formation of the turtle shell.

Format: Articles

Subject: Experiments, Publications

Barbara McClintock (1902-1992)

Barbara McClintock worked on genetics in corn (maize) plants and spent most of her life conducting research at the Cold Spring Harbor Laboratory in Laurel Hollow, New York. McClintock's research focused on reproduction and mutations in maize, and described the phenomenon of genetic crossover in chromosomes. Through her maize mutation experiments, McClintock observed transposons, or mobile elements of genes within the chromosome, which jump around the genome. McClintock received the Nobel Prize for Physiology or Medicine in 1983 for her research on chromosome transposition.

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

Cocaine as a Teratogen

Cocaine use by pregnant women has a variety of effects on the embryo and fetus, ranging from various gastro-intestinal and cardiac defects to tissue death from insufficient blood supply. Thus, cocaine has been termed a teratogen, or an agent that causes defects in fetuses during prenatal development. Cocaine is one of the most commonly used drugs in the US and it has a history of both medical and illegal recreational use. It is a drug capable of a wide array of effects on physical and mental health.

Format: Articles

Subject: Reproduction, Disorders