Search

Displaying 176 - 200 of 279 items.

Annie Wood Besant (1847–1933)

Annie Wood Besant was a social activist who advocated for women’s access to birth control as well as marriage reform, labor reform, and Indian Nationalism in the nineteenth century in England and India. In her early career, Besant was involved in various social and political advocacy organizations including the National Secular Society, the Malthusian League, and the Fabian Society. Besant gave many public lectures and authored various articles in support of secularism, workers’ rights and unionization, and women’s rights.

Format: Articles

Subject: People

Martius Flap Procedure to Repair Obstetric Fistulas

The Martius flap procedure is a surgical procedure used to treat obstetric fistulas in women. Heinrich Martius developed the procedure in twentieth century Germany to treat women with urinary incontinence caused by stress, and later doctors used it to repair obstetric fistulas. Fistulas occur in pregnant women when a hole is torn between the vagina and the urinary tract (called vesicovaginal) or the vagina and the rectum (called rectovaginal). The hole, or fistula, occurs in the tissue separating two organs and therefore obstetric fistulas result in either urinary or fecal incontinence.

Format: Articles

Subject: Technologies, Disorders

John Philip Trinkaus (1918-2003)

John Philip Trinkaus studied the processes of cell migration and gastrulation, especially in teleost fish, in the US during the twentieth century. Called Trink by his friends, his social confidence and work ethic combined to make him a prolific and decorated developmental biologist. His scientific contributions included investigations of several different aspects of embryology.

Format: Articles

Subject: People

Warren Harmon Lewis (1870-1964)

As one of the first to work at the Carnegie Institution of Washington Department of Embryology, Warren Harmon Lewis made a number of contributions to the field of embryology. In addition to his experimental discoveries on muscle development and the eye, Lewis also published and revised numerous works of scientific literature, including papers in the Carnegie Contributions to Embryology and five editions of Gray's Anatomy.

Format: Articles

Subject: People

Leo Loeb (1869-1959)

Leo Loeb developed an experimental approach to studying cancer and pioneered techniques for tissue culture and in vitro tissue transplantation which impacted early-to-mid twentieth century experimental embryology. Loeb received his medical degree from the University of Zurich in 1897. As part of his doctorate, he completed a thesis on the outcomes of tissue transplantation in guinea pigs. Loeb's thesis inspired a life-long interest in tissue transplantation.

Format: Articles

Subject: People

"Further Experiments on Artificial Parthenogenesis and the Nature of the Process of Fertilization" (1900), by Jacques Loeb

Jacques Loeb broadened and corrected his earlier claims concerning artificial parthenogenesis in sea urchins in a series of experiments in 1900. He published these findings, "Further Experiments on Artificial Parthenogenesis and the Nature of The Process of Fertilization," in a 1900 issue of The American Journal of Physiology.

Format: Articles

Subject: Experiments

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

Amphioxus, and the Mosaic Theory of Development (1893), by Edmund Beecher Wilson

Edmund Beecher Wilson experimented with Amphioxus (Branchiostoma) embryos in 1892 to identify what caused their cells to differentiate into new types of cells during the process of development. Wilson shook apart the cells at early stages of embryonic development, and he observed the development of the isolated cells. He observed that in the normal development of Amphioxus, all three main types of symmetry, or cleavage patterns observed in embryos, could be found. Wilson proposed a hypothesis that reformed the Mosaic Theory associated with Wilhelm Roux in Germany.

Format: Articles

Subject: Experiments

Elinor Catherine Hamlin (1924- )

Elinor Catherine Hamlin founded and helped fund centers in Ethiopia to treat women affected by fistulas from obstetric complications. Obstetric fistulas develop in women who experience prolonged labor, as the pressure placed on the pelvis by the fetus during labor causes a hole, or fistula, to form between the vagina and the bladder (vesicovaginal fistula) or between the vagina and the rectum (rectovaginal fistula). Both of those conditions result in urinary or fecal incontinence, which often impacts womenÍs social status within their communities.

Format: Articles

Subject: People, Reproduction

Ross Granville Harrison (1870-1959)

A pioneer in experimental embryology, Ross Granville Harrison made numerous discoveries that advanced biology. One of the most significant was his adaptation of the hanging drop method from bacteriology to carry out the first tissue culture. This method allowed for further studies in embryology as well as experimental improvements in oncology, virology, genetics, and a number of other fields.

Format: Articles

Subject: People

Theophilus Shickel Painter (1889-1969)

Theophilus Shickel Painter studied the structure and
function of chromosomes in the US during in the early to mid-twentieth century. Painter worked at
the University of Texas at Austin in Austin, Texas. In the 1920s
and 1930s, Painter studied the chromosomes of the salivary gland
giant chromosomes of the fruit fly (Drosophila
melanogaster), with Hermann J. Muller. Muller and Painter
studied the ability of X-rays to cause changes in the chromosomes
of fruit flies. Painter also studied chromosomes in mammals.

Format: Articles

Subject: People

Meselson, Stahl, and the Replication of DNA: A History of "The Most Beautiful Experiment in Biology" (2001), by Frederic Lawrence Holmes

In 2001, Yale University Press published Frederic Lawrence Holmes' book, Meselson, Stahl, and the Replication of DNA: A History of "The Most Beautiful Experiment in Biology" (Replication of DNA), which chronicles the 1950s debate about how DNA replicates. That experiment verified that DNA replicates semi-conservatively as originally proposed by Watson and Crick. Rather than focusing solely on experiments and findings, Holmes's book presents the investigative processes of scientists studying DNA replication.

Format: Articles

Subject: Publications

Edmund Beecher Wilson (1856-1939)

Edmund Beecher Wilson contributed to cell biology, the study of cells, in the US during the end of the nineteenth and the beginning of the twentieth centuries. His three editions of The Cell in Development and Inheritance (or Heredity) in 1896, 1900, and 1925 introduced generations of students to cell biology. In The Cell, Wilson described the evidence and theories of his time about cells and identified topics for future study. He helped show how each part of the cell works during cell division and in every step of early development of an organism.

Format: Articles

Subject: People

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

Hamlin Fistula Ethiopia (1974- )

Hamlin Fistula Ethiopia is a nonprofit organization that began in 1974 as a joint endeavor by Reginald and Catherine Hamlin and the Addis Ababa Fistula Hospital in Addis Ababa, Ethiopia. Hamlin Fistula Ethiopia promotes reproductive health in Ethiopia by raising awareness and implementing treatment and preventive services for women affected by obstetric fistulas. It also aims to restore the lives of women afflicted with obstetric fistulas in Ethiopia and eventually to eradicate the condition.

Format: Articles

Subject: Organizations, Reproduction, Outreach

Jane Maienschein (1950- )

Jane Maienschein is the daughter of Joyce Kylander and Fred Maienschein, and was born in Oak Ridge, Tennessee, on 23 September 1950. She attended MIT as a freshman and then transferred to Yale University in 1969 when Yale decided to admit women undergraduates. In 1972 she graduated with an honors degree in History, the Arts, and Letters having written a thesis on the history of science. She then attended Indiana University and studied with historian of embryology Frederick B.

Format: Articles

Subject: People

The Gradient Theory

The gradient theory is recognized as Charles Manning Child's most significant scientific contribution. Gradients brought together Child's interest in development and his fascination with the origins of individuality and organization. The gradient theory grew from his studies of regeneration, which were largely based on work he conducted with marine invertebrates, such as the ascidian flat worm, planaria and the hydroid, tubularia.

Format: Articles

Subject: Theories