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Displaying 251 - 275 of 281 items.

"The Premenstrual Syndrome" (1953), by Raymond Greene and Katharina Dalton

In 1953, Raymond Greene and Katharina Dalton, who were doctors in the UK, published The Premenstrual Syndrome in the British Medical Journal. In their article, Dalton and Greene established the term premenstrual syndrome (PMS). The authors defined PMS as a cluster of symptoms that include bloating, breast pain, migraine-headache, fatigue, anxiety, depression, and irritability. The article states that the symptoms begin one to two weeks before menstruation during the luteal phase of the menstrual cycle, and they disappear upon the onset of the menstrual period.

Format: Articles

Subject: Publications, Reproduction

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

“Family Limitations” (1914), by Margaret Higgins Sanger

In 1914, Margaret Sanger published “Family Limitations,” a pamphlet describing six different types of contraceptive methods. At the time Sanger published the pamphlet, the federal Comstock Act of 1873 had made distributing contraceptive and abortion information through the US postal service illegal. The Comstock Act classified contraceptive information as obscene and limited the amount of information available to individuals about preventing pregnancies.

Format: Articles

Subject: Publications

Endoderm

Endoderm is one of the germ layers-- aggregates of cells that organize early during embryonic life and from which all organs and tissues develop. All animals, with the exception of sponges, form either two or three germ layers through a process known as gastrulation. During gastrulation, a ball of cells transforms into a two-layered embryo made of an inner layer of endoderm and an outer layer of ectoderm. In more complex organisms, like vertebrates, these two primary germ layers interact to give rise to a third germ layer, called mesoderm.

Format: Articles

Subject: Processes

Charles Darwin's Theory of Pangenesis

In 1868 in England, Charles Darwin proposed his pangenesis theory to describe the units of inheritance between parents and offspring and the processes by which those units control development in offspring. Darwin coined the concept of gemmules, which he said referred to hypothesized minute particles of inheritance thrown off by all cells of the body. The theory suggested that an organism's environment could modify the gemmules in any parts of the body, and that these modified gemmules would congregate in the reproductive organs of parents to be passed on to their offspring.

Format: Articles

Subject: Theories

Germ Layers

A germ layer is a group of cells in an embryo that interact with each other as the embryo develops and contribute to the formation of all organs and tissues. All animals, except perhaps sponges, form two or three germ layers. The germ layers develop early in embryonic life, through the process of gastrulation. During gastrulation, a hollow cluster of cells called a blastula reorganizes into two primary germ layers: an inner layer, called endoderm, and an outer layer, called ectoderm.

Format: Articles

Subject: Theories, Processes

Birth Defects Caused by Agent Orange

During the Vietnamese War between 1961 and 1971 the United States armed forces engaged in a massive defoliation and crop destruction campaign named Operation Ranch Hand. Agent Orange, an herbicide so named because of the orange color of its storage barrels, was the most heavily used herbicide of the campaign. In addition to military personnel from Australia, New Zealand, South Korea, North Vietnam, South Vietnam, and the United States, an estimated 4.8 million Vietnamese civilians were exposed to herbicides during the war.

Format: Articles

Subject: Disorders, Reproduction

Etienne Geoffroy Saint-Hilaire (1772-1844)

Etienne Geoffroy Saint-Hilaire, commonly known as Geoffroy, studied animals, their anatomy and their embryos, and teratogens at the National Museum of Natural History in Paris, France in the eighteenth and nineteenth centuries. Geoffroy also helped develop several specialized fields in the life sciences, including experimental embryology. In his efforts to experimentally demonstrate the theory of recapitulation, Geoffroy developed techniques to intervene in the growth of embryos to see whether they would develop into different kinds of organisms.

Format: Articles

Subject: People

August Friedrich Leopold Weismann (1834-1914)

August Friedrich Leopold Weismann studied how the traits of organisms developed and evolved in a variety of organisms, mostly insects and aquatic animals, in Germany in the late nineteenth and early twentieth centuries. Weismann proposed the theory of the continuity of germ-plasm, a theory of heredity. Weismann postulated that germ-plasm was the hereditary material in cells, and parents transmitted to their offspring only the germ-plasm present in germ-cells (sperm and egg cells) rather than somatic or body cells.

Format: Articles

Subject: People

The e-Mouse Atlas Project (1992- )

The Edinburgh Mouse Atlas, also called the e-Mouse Atlas Project (EMAP), is an online resource comprised of the e-Mouse Atlas (EMA), a detailed digital model of mouse development, and the e-Mouse Atlas of Gene Expression (EMAGE), a database that identifies sites of gene expression in mouse embryos. Duncan Davidson and Richard Baldock founded the project in 1992, and the Medical Research Council (MRC) in Edinburgh, United Kingdom, funds the project.

Format: Articles

Subject: Technologies

The Role of the Notch signaling pathway in Somitogenesis

Among other functions, the Notch signaling pathway contributes to the development of somites in animals. It involves a cell signaling mechanism with a wide range of functions, including cellular differentiation, and the formation of the embryonic structures (embryogenesis). All multicellular animals use Notch signaling, which is involved in the development, maintenance, and regeneration of a range of tissues. The Notch signaling pathways spans two cells, and consists of receptor proteins, which cross one cell's membrane and interacts with proteins on adjacent cells, called ligands.

Format: Articles

Subject: Theories, Processes

Neural Crest

Early in the process of development, vertebrate embryos develop a fold on the neural plate where the neural and epidermal ectoderms meet, called the neural crest. The neural crest produces neural crest cells (NCCs), which become multiple different cell types and contribute to tissues and organs as an embryo develops. A few of the organs and tissues include peripheral and enteric (gastrointestinal) neurons and glia, pigment cells, cartilage and bone of the cranium and face, and smooth muscle.

Format: Articles

Subject: Theories

"Mitochondrial DNA and Human Evolution" (1987), by Rebecca Louise Cann, Mark Stoneking, and Allan Charles Wilson

In 1987 Rebecca Louise Cann, Mark Stoneking, and Allan Charles Wilson published Mitochondrial DNA and Human Evolution in the journal Nature. The authors compared mitochondrial DNA from different human populations worldwide, and from those comparisons they argued that all human populations had a common ancestor in Africa around 200,000 years ago. Mitochondria DNA (mtDNA) is a small circular genome found in the subcellular organelles, called mitochondria.

Format: Articles

Subject: Publications, Theories

The Germ-Plasm: a Theory of Heredity (1893), by August Weismann

Friedrich Leopold August Weismann published Das
Keimplasma: eine Theorie der Vererbung (The Germ-Plasm: a
Theory of Heredity, hereafter The Germ-Plasm) while
working at the University of Freiburg in Freiburg, Germany in 1892.
William N. Parker, a professor in the University College of South
Wales and Monmouthshire in Cardiff, UK, translated The
Germ-Plasm into English in 1893. In The Germ-Plasm,
Weismann proposed a theory of heredity based on the concept of the

Format: Articles

Subject: Publications, Theories

Hermaphrodites and the Medical Invention of Sex (1998), by Alice Domurat Dreger

Hermaphrodites and the Medical Invention of Sex, by historian of science Alice Domurat Dreger, was published in 1998 by Harvard University Press. In the book, Dreger describes how many doctors and scientists treated human hermaphrodites from the late nineteenth century to the early twentieth century. She states that during this time period, many physicians and scientists struggled to determine the nature sex, and to support a classification of sex as male or female, many physicians and scientists resorted to viewing a person's gonads for identification of his or her sex.

Format: Articles

Subject: Publications, Theories, Disorders

Clinical Tests of Estrogen Injections on Women with Abnormal Menstrual Cycles During the Early 1920s by Jean Paul Pratt and Edgar Allen

In the early twentieth century US, Jean Paul Pratt and Edgar Allen conducted clinical experiments on women who had abnormal menstrual cycles. During the clinical tests, researchers injected the hormone estrogen into their patients to alleviate their menstrual ailments, which ranged from irregular cycles to natural menopause. The hormone estrogen plays a prominent role in the menstrual cycle by signaling the tissue lining the uterus (endometrium) to thicken in preparation for possible pregnancy.

Format: Articles

Subject: Experiments

The Malthusian League (1877–1927)

The Malthusian League, founded in London, England, in 1877 promoted the use of contraception to limit family size. Activists Charles Bradlaugh and Annie Besant established the Malthusian League after they were arrested and exonerated for publishing a pamphlet describing techniques to prevent pregnancy. Founders based the league on the principles of Thomas Malthus, a British nineteenth century economist, who wrote on the perils of a population growing beyond the resources available to support it.

Format: Articles

Subject: Organizations, Outreach, Reproduction

Katharina Dorothea Dalton (1916–2004)

Katharina Dorothea Dalton was a physician in England in the twentieth century who defined premenstrual syndrome (PMS) as a cluster of symptoms suspected to begin one to two weeks before menstruation and disappear upon the onset of a new menstrual cycle. Prior to Dalton, there was little research on pre-menstrual issues and those that existed linked the problem to excessive water retention or estrogen. Dalton hypothesized that PMS resulted from a deficiency in the hormone progesterone and advocated for hormone replacement therapy to lessen the symptoms of the syndrome.

Format: Articles

Subject: People

Where Are My Children? (1916)

Where Are My Children? is an anti-abortion silent film released in the United States on 16 April 1916. The film was directed by Lois Weber and Phillips Smalley and produced by Universal Film Manufacturing Company/Lois Weber Productions in Universal City, California. In the film, Weber tells a story of an attorney who wants to have children and raise a family, but his wife chooses to abort her pregnancies, fearing that having children will ruin her social activities. In the early 1900s, information about contraception was not freely available or legal to obtain.

Format: Articles

Essay: Review of Icons of Life: A Cultural History of Human Embryos

To Lynn M. Morgan, the Mary E. Woolley Professor of Anthropology at Mt. Holyoke College, nothing says life more than a dead embryo. In her easily readable book, Icons of Life: A Cultural History of Human Embryos, Morgan brings together cultural phenomena, ethics, and embryology to show that even dead embryos and fetuses have their own stories to tell. As an anthropologist, Morgan is interested in many things, including the science of embryology and its history. But she also wants to know how culture influences our views on embryos and the material practices that accompany their study.

Format: Essays

Subject: Publications

Diethylstilbestrol (DES) in the US

Diethylstilbestrol (DES) is an artificially created hormone first synthesized in the late 1930s. Doctors widely prescribed DES first to pregnant women to prevent miscarriages, and later as an emergency contraceptive pill and to treat breast cancer. However, in 1971, physicians showed a link between DES and vaginal cancer during puberty in the children of women who had taken DES while pregnant. Consequently, the US Food and Drug Administration (FDA) banned its use during pregnancy.

Format: Articles

Subject: Reproduction, Technologies

Mary Coffin Ware Dennett (1872-1947)

Mary Coffin Ware Dennett advocated for social reform in the United States in the early twentieth century, particularly regarding sex education and women's rights to access contraception. Dennett authored several publications on sex education and birth control laws. She also worked to repeal the Comstock Act, a federal law that made it illegal to distribute obscene materials through the US Postal Services.

Format: Articles

Subject: People, Reproduction

Aristotle (384-322 BCE)

Aristotle studied developing organisms, among other things, in ancient Greece, and his writings shaped Western philosophy and natural science for greater than two thousand years. He spent much of his life in Greece and studied with Plato at Plato's Academy in Athens, where he later established his own school called the Lyceum. Aristotle wrote greater than 150 treatises on subjects ranging from aesthetics, politics, ethics, and natural philosophy, which include physics and biology. Less than fifty of Aristotle's treatises persisted into the twenty-first century.

Format: Articles

Subject: People

Planned Parenthood Committee of Phoenix (1942-1978)

The Planned Parenthood Committee of Phoenix was established in 1942 to expand Arizona women's access to family planning resources. The Planned Parenthood Committee of Phoenix was formed through the merging of The Mother's Health Clinic in Phoenix, Arizona, with the national Planned Parenthood Federation of America. The clinic was primarily based within the Phoenix Memorial Hospital campus but expanded to other locations in the late 1960s.

Format: Articles

Subject: Organizations, Reproduction, Outreach

Nelson v. Planned Parenthood Center of Tucson (1973)

The 1973 case Nelson v. Planned Parenthood Center of Tucson established the legality of abortion in Arizona. The Arizona Court of Appeals ruled that the Arizona Revised Statutes 13-211, 13-212, and 13-213, collectively called the Arizona abortion statutes, were unconstitutional. The statutes had made illegal receiving, providing, or advertising abortions. After the Arizona Appeals Court heard the case, it decided that the Arizona abortion statutes were constitutional. However, two weeks later the US Supreme Court decided in Roe v.

Format: Articles

Subject: Legal