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Displaying 201 - 225 of 1058 items.

"The Effects of Wing Bud Extirpation on the Development of the Central Nervous System in Chick Embryos" (1934), by Viktor Hamburger

German embryologist Viktor Hamburger came to the US in 1932 with a fellowship provided by the Rockefeller Foundation. Hamburger started his research in Frank Rattray Lillie's laboratory at the University of Chicago. His two-year work on the development of the central nervous system (CNS) in chick embryos was crystallized in his 1934 paper, "The Effects of Wing Bud Extirpation on the Development of the Central Nervous System in Chick Embryos," published in The Journal of Experimental Zoology.

Format: Articles

Subject: Publications, Experiments

Golden Rice

Golden Rice was engineered from normal rice by Ingo Potrykus and Peter Beyer in the 1990s to help improve human health. Golden Rice has an engineered multi-gene biochemical pathway in its genome. This pathway produces beta-carotene, a molecule that becomes vitamin A when metabolized by humans. Ingo Potrykus worked at the Swiss Federal Institute of Technology in Zurich, Switzerland, and Peter Beyer worked at University of Freiburg, in Freiburg, Germany. The US Rockefeller Foundation supported their collaboration.

Format: Articles

Subject: Organisms, Legal

Hwang Woo-suk's Use of Human Eggs for Research 2002-2005

Hwang Woo-suk, a geneticist in South Korea, claimed in Science magazine in 2004 and 2005 that he and a team of researchers had for the first time cloned a human embryo and that they had derived eleven stem cell lines from it. Hwang was a professor at Seoul National University in Seoul, South Korea. In the Science articles, Hwang stated that all of the women who donated eggs to his laboratory were volunteers who donated their eggs (oocytes) without receiving any compensation in return. In 2006, Hwang admitted that many of the results were fabricated.

Format: Articles

Subject: Legal, Ethics, Reproduction

"Altruism and the Origin of the Worker Caste" from The Ants (1990), by Bert Hölldobler and Edward Osborne Wilson

In 'Altruism and the Origin of the Worker Caste,' Bert Hölldobler and Edward Osborne Wilson explore the evolutionary origins of worker ants. 'Altruism and the Origin of the Worker Caste' is the fourth chapter of Hölldobler and Wilson's book, The Ants, which was published by The Belknap Press of Harvard University in Cambridge, Massachusetts, in 1990. In 'Altruism and the Origin of the Worker Caste,' Hölldobler and Wilson evaluate various explanations for how a non-reproductive caste of ant evolved.

Format: Articles

Subject: Publications

Inducing Fertilization and Development in Sand Dollars

Sand dollars are common marine invertebrates in the phylum Echinodermata and share the same class (Echinoidea) as sea urchins. They have served as model laboratory organisms for such embryologists as Frank Rattray Lillie and Ernest Everett Just. Both Lillie and Just used Echinarachnius parma for their studies of egg cell membranes and embryo development at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, in the early 1900s.

Format: Articles

Subject: Processes

San Diego Zoo Institute for Conservation Research

The San Diego Zoo Institute for Conservation Research (SDZICR) in San Diego, California, is a research organization that works to generate, use, and share information for the conservation of wildlife and their habitats. In 1975, Kurt Benirschke, a researcher at the University of California, San Diego (UCSD) who studied human and animal reproduction, and Charles Bieler, the director of the San Diego Zoo, collaborated to form the Center for Reproduction of Endangered Species (CRES).

Format: Articles

Subject: Organizations

"Predictors of Postpartum Depression: An Update” (2001), by Cheryl Tatano Beck

In her 2001 paper “Predictors of Postpartum Depression: An Update,” researcher Cheryl Tatano Beck presents the most common risk factors associated with postpartum depression in women. Postpartum depression occurs when women experience symptoms such as tearfulness, extreme mood changes, and loss of appetite for a lengthened period after giving birth. At the University of Connecticut in Storrs, Connecticut, nursing professor Beck updated a previous study of hers by analyzing literature about postpartum depression published in the 1990s.

Format: Articles

Subject: Publications

“Traditional postpartum practices and rituals: a qualitative systematic review” (2007), by Cindy-Lee Dennis, Kenneth Fung, Sophie Grigoriadis, Gail Erlick Robinson, Sarah Romans and Lori Ross

In the 2007 paper “Traditional postpartum practices and rituals: a qualitative systematic review,” Toronto-based researchers showed that women from different cultures around the world follow similar postpartum practices after giving birth. At the University of Toronto in Toronto, Canada, Cindy-Lee Dennis, Kenneth Fung, Sophie Grigoriadis, Gail Erlick Robinson, Sarah Romans, and Lori Ross examined fifty-one studies from over twenty countries that focused on traditional postpartum practices.

Format: Articles

Subject: Publications

Hormone Releasing Intrauterine Devices

Hormone releasing intrauterine devices or hormonal IUDs are contraceptive devices placed in a woman’s uterus to prevent pregnancy by continuously releasing a low dose of certain hormones. Jouri Valter Tapani Luukkainen, a medical researcher at the University of Helsinki, introduced the first hormonal IUD in 1976. Luukkainen’s IUD was a plastic device shaped like a capital T.

Format: Articles

Subject: Technologies

Carol Widney Greider (1961-)

Carol Widney Greider studied telomeres and telomerase in the US at the turn of the twenty-first century. She worked primarily at the University of California, Berkeley in Berkeley, California.
She received the Nobel Prize in Physiology or Medicine in 2009, along with Elizabeth Blackburn and Jack Szostak, for their research on telomeres and telomerase. Telomeres are repetitive sequences of

Subject: People

Max Ludwig Henning Delbruck (1906–1981)

Max Ludwig Henning Delbrick applied his knowledge of theoretical physics to biological systems such as bacterial viruses called bacteriophages, or phages, and gene replication during the twentieth century in Germany and the US. Delbrück demonstrated that bacteria undergo random genetic mutations to resist phage infections. Those findings linked bacterial genetics to the genetics of higher organisms. In the mid-twentieth century, Delbrück helped start the Phage Group and Phage Course in the US, which further organized phage research.

Format: Articles

Subject: People

Barbara McClintock's Transposon Experiments in Maize (1931–1951)

Barbara McClintock conducted experiments on corn (Zea mays) in the United States in the mid-twentieth century to study the structure and function of the chromosomes in the cells. McClintock researched how genes combined in corn and proposed mechanisms for how those interactions are regulated. McClintock received the Nobel Prize in Physiology or Medicine in 1983, the first woman to win the prize without sharing it. McClintock won the award for her introduction of the concept of transposons, also called jumping genes.

Format: Articles

Subject: Experiments

The Debate over DNA Replication Before the Meselson-Stahl Experiment (1953–1957)

Between 1953 and 1957, before the Meselson-Stahl experiment verified semi-conservative replication of DNA, scientists debated how DNA replicated. In 1953, James Watson and Francis Crick proposed that DNA was composed of two helical strands that wound together in a coil. Their model suggested a replication mechanism, later termed semi-conservative replication, in which parental DNA strands separated and served as templates for the replication of new daughter strands.

Format: Articles

Subject: Theories

Nuclear Magnetic Resonance Imaging to Visualize Fetal Abnormalities

Nuclear magnetic resonance imaging (MRI) is a technique to create a three-dimensional image of a fetus. Doctors often use MRIs to image a fetuses after an ultrasound has detected an, or has been inconclusive about an, abnormality. In 1983 researchers in Scotland first used MRI to visualize a fetus. MRIs showed a greater level of fetal detail than ultrasound images, and researchers recognized the relevance of this technique as a means to gather information about fetal development and growth.

Format: Articles

Subject: Technologies, Technologies, Reproduction

Nancy Goodman Brinker (1946– )

Nancy Goodman Brinker founded the largest breast cancer organization in the US, Susan G. Komen for the Cure, during the twentieth century. In 1982, Brinker created the organization, Susan G. Komen for the Cure, in memory of her sister, who had died of breast cancer two years earlier. During the early twentieth century, breast cancer was socially stigmatized, very few people discussed the disease, and there were limited treatment options available for those diagnosed with the disease.

Format: Articles

Subject: People

Truman William Brophy (1848–1928)

Truman William Brophy developed a cleft palate surgical repair, later called the Brophy Operation, in the late nineteenth century US. The procedure improved facial aesthetics and speech in cleft palate patients. A cleft palate occurs during development when the palatal bones in the roof of the mouth don't completely fuse, leaving an opening, or cleft, in the upper lip and mouth. Brophy's cleft repair used compression inside and outside of the mouth to push the palatal bones into normal alignment shortly after birth.

Format: Articles

Subject: People, Disorders

Margaret Ann Bulkley (James Barry) (1789−1865)

Margaret Ann Bulkley, under the male pseudonym James Barry, was one of the first female obstetricians in early nineteenth century British Empire. She was the first person to perform a cesarean section in South Africa. Cesarean section is a procedure in which a doctor cuts into the uterus of a pregnant woman to retrieve the fetus during complicated births. Bulkley hid her gender and lived life as the male Barry to practice medicine, an opportunity not allowed to women at the time.

Format: Articles

Subject: People

Frank Rattray Lillie (1870-1947)

Frank R. Lillie was born in Toronto, Canada, on 27 June 1870. His mother was Emily Ann Rattray and his father was George Waddell Little, an accountant and co-owner of a wholesale drug company. While in high school Lillie took up interests in entomology and paleontology but went to the University of Toronto with the aim of studying ministry. He slowly became disillusioned with this career choice and decided to major in the natural sciences. It was during his senior year that he developed his lifelong interest in embryology.

Format: Articles

Subject: People

Benjamin Harrison Willier (1890-1972)

Benjamin Harrison Willier is considered one of the most versatile embryologists to have ever practiced in the US. His research spanned most of the twentieth century, a time when the field of embryology evolved from being a purely descriptive pursuit to one of experimental research, to that of incorporating molecular biology into the research lab. Willier was born on 2 November 1890 near Weston, Ohio to Mary Alice Ricard. He spent his childhood doing farming chores and running the farm while his father, David Willier worked as a banker.

Format: Articles

Subject: People

The Meckel-Serres Conception of Recapitulation

Johann Friedrich Meckel and Antoine Etienne Reynaud Augustin Serres developed in the early 1800s the basic principles of what later became called the Meckel-Serres Law. Meckel and Serres both argued that fetal deformities result when development prematurely stops, and they argued that these arrests characterized lower life forms, through which higher order organisms progress during normal development. The concept that the embryos of higher order organisms progress through successive stages in which they resemble lower level forms is called recapitulation.

Format: Articles

Subject: Theories

Jane Marion Oppenheimer (1911-1966)

Jane Marion Oppenheimer, embryologist and historian of science and medicine, was born on 19 September 1911 in Philadelphia, Pennsylvania, to Sylvia Stern and James H. Oppenheimer. After studying zoology at Bryn Mawr College, Oppenheimer received her AB degree in 1932. Oppenheimer received her PhD in embryology at Yale University in 1935 and worked as a research fellow from 1935-1936. While at Yale she was influenced by the work of Ross Granville Harrison and John Spangler Nicholas, the latter of whom was Oppenheimer's PhD advisor.

Format: Articles

Subject: People

Frank Rattray Lillie's Study of Freemartins (1914-1920)

Frank Rattray Lillie's research on freemartins from 1914 to 1920 in the US led to the theory that hormones partly caused for sex differentiation in mammals. Although sometimes applied to sheep, goats, and pigs, the term freemartin most often refers to a sterile cow that has external female genitalia and internal male gonads and was born with a normal male twin.

Format: Articles

Subject: Experiments

Ian Wilmut (1944- )

British embryologist Sir Ian Wilmut, best known for his work in the field of animal genetic engineering and the successful cloning of sheep, was born 7 July 1944 in Hampton Lucy, England. The family later moved to Scarborough, in the north of the country, to allow his father to accept a teaching position. There Wilmut met Gordon Whalley, head of the biology department at Scarborough High School for Boys, which Wilmut attended.

Format: Articles

Subject: People

Leonardo da Vinci (1452-1519)

Leonardo da Vinci was born on 15 April 1452, the illegitimate son of a young peasant girl by the name of Caterina and Ser Piero da Vinci, a well-renowned Florentine notary. Leonardo lived in Italy in the town of Vinci until his late teens and received a simple education in reading and writing as well as some training in mathematics and engineering. Although he was socially excluded by birthright from almost every profession and prohibited from attending any formal university, Leonardo went on to become a celebrated scientist, artist, and engineer.

Format: Articles

Subject: People