Search

Displaying 176 - 200 of 270 items.

The Mechanistic Conception of Life (1912), by Jacques Loeb

Jacques Loeb published The Mechanistic Conception of Life in 1912. Loeb's goal for the book was to further disseminate his explanations of organic processes, such as embryonic development and organisms orientations to their environments, which relied on physics and chemistry. Loeb also wanted to provide an alternative explanatory framework to vitalism and what he called romantic evolutionism, then both widespread.

Format: Articles

Subject: Publications

Hartsoeker's Homunculus Sketch from Essai de Dioptrique

This embryology image is a pencil sketch by Nicolaas Hartsoeker, published as part of his 1694 French-language paper entitled Essai de Dioptrique, a semi-speculative work describing the sorts of new scientific observations that could be done using magnifying lenses. Dioptrique was published in Paris by the publishing house of Jean Anisson. The image depicts a curled up infant-like human, now referred to as a homunculus, inside the head of a sperm cell.

Format: Articles

Subject: Theories, Processes

Hermann Joseph Muller's Study of X-rays as a Mutagen, (1926-1927)

Hermann Joseph Muller conducted three experiments in 1926 and 1927 that demonstrated that exposure to x-rays, a form of high-energy radiation, can cause genetic mutations, changes to an organism's genome, particularly in egg and sperm cells. In his experiments, Muller exposed fruit flies (Drosophila) to x-rays, mated the flies, and observed the number of mutations in the offspring. In 1927, Muller described the results of his experiments in "Artificial Transmutation of the Gene" and "The Problem of Genic Modification".

Format: Articles

Subject: Experiments

The People of the State of New York v. Margaret H. Sanger (1918)

In 1918, the New York State Court of Appeals in Albany broadened the justification physicians could use to prescribe contraceptives to married patients in the case The People of the State of New York v. Margaret H. Sanger (People v. Sanger). The presiding judge of People v. Sanger, Frederick Crane, ruled that under Section 1145 of the New York Penal Code physicians could provide contraceptives to married couples for the prevention of disease.

Format: Articles

Subject: Legal

China's One-Child Policy

In September 1979, China's Fifth National People's Congress passed a policy that encouraged one-child families. Following this decision from the Chinese Communist Party (CCP), campaigns were initiated to implement the One-Child Policy nationwide. This initiative constituted the most massive governmental attempt to control human fertility and reproduction in human history. These campaigns prioritized reproductive technologies for contraception, abortion, and sterilization in gynecological and obstetric medicine, while downplaying technologies related to fertility treatment.

Format: Articles

Subject: Ethics, Legal, Reproduction

Epithelium

Frederik Ruysch, working in the Netherlands, introduced the term epithelia in the third volume of his Thesaurus Anatomicus in 1703. Ruysch created the term from the Greek epi, which means on top of, and thele, which means nipple, to describe the type of tissue he found when dissecting the lip of a cadaver. In the mid nineteenth century, anatomist Albrecht von Haller adopted the word epithelium, designating Ruysch's original terminology as the plural version. In modern science, epithelium is a type of animal tissue in which cells are packed into neatly arranged sheets.

Format: Articles

Subject: Theories, Processes

Wilhelm Friedrich Phillip Pfeffer (1845-1920)

Wilhelm Friedrich Phillip Pfeffer studied plants in Germany during the late nineteenth and early twentieth centuries. He started his career as an apothecary, but Pfeffer also studied plant physiology, including how plants move and react to changes in light, temperature, and osmotic pressure. He created the Pfeffer Zelle apparatus, also known as the Pfeffer Cell, to study osmosis in plants. PfefferÕs experiments led to new theories about the structure and development of plants.

Format: Articles

Subject: People

Harry Hamilton Laughlin (1880-1943)

Harry Hamilton Laughlin helped lead the eugenics
movement in the United States during the early twentieth century.
The US eugenics movement of the early twentieth century sought to
reform the genetic composition of the United States population through
sterilization and other restrictive reproductive measures. Laughlin
worked as superintendent and assistant director of the Eugenics
Research Office (ERO) at Cold Spring Harbor Laboratory in Cold
Spring Harbor, New York, alongside director Charles Davenport.

Format: Articles

Subject: People, Reproduction

Human Fertilisation and Embryology Act (1990)

The Human Fertilisation and Embryology Act 1990 established the legal framework that governs infertility treatment, medical services ancillary to infertility treatment such as embryo storage, and all human embryological research performed in the UK. The law also defines a legal concept of the parent of a child conceived with assisted reproductive technologies.

Format: Articles

Subject: Legal, Reproduction, Ethics

“The Stein-Leventhal Syndrome: A Curable Form of Sterility” (1958), by Irving Freiler Stein Sr.

In 1958, Irving Freiler Stein Sr. published “The Stein-Leventhal Syndrome: A Curable Form of Sterility” documenting his findings on the diagnosis and surgical treatment of Stein-Leventhal syndrome. Stein-Leventhal syndrome, later called polycystic ovarian syndrome (PCOS), affects the reproductive health of women. Common symptoms include excess body hair, a lack of menstrual cycle or amenorrhea, and infertility. As of 2017, polycystic ovarian syndrome is considered the most common reproductive health disorder among women in the United States.

Format: Articles

Subject: Publications

Abortion

Abortion is the removal of the embryo or fetus from the womb, before birth can occur-either naturally or by induced labor. Prenatal development occurs in three stages: the zygote, or fertilized egg; the embryo, from post-conception to eight weeks; and the fetus, from eight weeks after conception until the baby is born. After abortion, the infant does not and cannot live. Spontaneous abortion is the loss of the infant naturally or accidentally, without the will of the mother. It is more commonly referred to as miscarriage.

Format: Articles

Subject: Processes, Ethics, Reproduction

Biological Clocks and the Formation of Human Tooth Enamel

Tooth enamel contains relics of its formation process, in the form of microstructures, which indicate the incremental way in which it forms. These microstructures, called cross-striations and striae of Retzius, develop as enamel-forming cells called ameloblasts, whcih cyclically deposit enamel on developing teeth in accordance with two different biological clocks. Cross-striations result from a twenty-four hour cycle, called a Circadian rhythm, in the enamel deposition process, while striae of Retzius have a longer periodicity.

Format: Articles

Subject: Processes

Boris Ephrussi (1901-1979)

Boris Ephrussi studied fruit flies, yeast, and mouse genetics and development while working in France and the US during the twentieth century. In yeast, Ephrussi studied how mutations in the cytoplasm persisted across generations. In mice he studied the genetics of hybrids and the development of cancer. Working with George Wells Beadle on the causes of different eye colors in fruit flies, Ephrussi's research helped establish the one-gene-one-enzyme hypothesis. Ephrussi helped create new embryological techniques and contributed the theories of genetics and development.

Format: Articles

Subject: People

Beadle and Ephrussi's Transplantation Technique for Drosophila

Boris Ephrussi and George Wells Beadle developed a transplantation technique on flies, Drosophila melanogaster, which they described in their 1936 article A Technique of Transplantation for Drosophila. The technique of injecting a tissue from one fly larva into another fly larva, using a micropipette, to grow that tissue in the second larvae, was a means for investigating development of Drosophila. Through this technique, Beadle and Ephrussi studied the role of genes in embryological processes.

Format: Articles

Subject: Technologies

Margaret Higgins Sanger (1879-1966)

Margaret Higgins Sanger advocated for birth control in the United States and Europe during the late nineteenth and early twentieth centuries. Although people used contraceptives prior to the twentieth century, in the US the 1873 Comstock Act made the distribution of information relating to the use of contraceptives illegal, and similar state-level Comstock laws also classified discussion and dissemination of contraceptives as illegal.

Format: Articles

Subject: People, Reproductive Health Arizona, Reproduction, Outreach

Roberto Caldeyro-Barcia (1921–1996)

Roberto Caldeyro-Barcia studied fetal health in Uruguay during the second half of the twentieth century. Caldeyro-Barcia developed Montevideo units, which are used to quantify intrauterine pressure, or the force of contractions during labor. Intrauterine pressure is a useful measure of the progression of labor and the health of a fetus.

Format: Articles

Subject: People

“Elective Induction of Labor” (1955), by Edward Bishop

In 1955, obstetrician Edward Bishop, a physician specializing in childbirth, published the article “Elective Induction of Labor,” in which he proposed the best conditions for pregnant women to elect to induce, or begin, labor. Elective induction of labor requires an obstetrician to administer a drug to help a pregnant woman to start her contractions, and to rupture the fluid-filled sac surrounding the fetus called the amniotic sac.

Format: Articles

Subject: Reproduction, Publications

Dorothy Andersen (1901–1963)

Dorothy Andersen studied cystic fibrosis in the United States during the early 1900s. In 1935, Andersen discovered lesions in the pancreas of an infant during an autopsy, which led her to classify a condition she named cystic fibrosis of the pancreas. In 1938, Andersen became the first to thoroughly describe symptoms of the medical condition cystic fibrosis.

Format: Articles

Subject: People

Intrauterine Pressure Catheter

An intrauterine pressure catheter (IUPC) is a device placed inside a pregnant woman’s uterus to monitor uterine contractions during labor. During labor, a woman’s uterus contracts to dilate, or open, the cervix and push the fetus into the birth canal. The catheter measures the pressure within the amniotic space during contractions and allows physicians to evaluate the strength, frequency, and duration of contractions.

Format: Articles

Subject: Technologies

Carl Gottfried Hartman (1879-1968)

Carl Gottfried Hartman researched the reproductive physiology of opossums and rhesus monkeys. He was the first to extensively study the embryology and physiology of reproduction in opossums when little was known about this mammal. Hartman worked in Texas where opossums, the only marsupial that lives in North America, were abundant. The female opossum delivers her fetal opossums in her pouch, where one can easily observe their development. After studying opossums for thirteen years, Hartman investigated the reproductive physiology of rhesus monkeys, also known as macaques.

Format: Articles

Subject: People

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

Betty Friedan (1921–2006)

Betty Friedan advocated for the advancement of women's rights in the twentieth century in the United States. In 1963, Friedan wrote The Feminine Mystique, which historians consider a major contribution to the feminist movement. Friedan also helped establish two organizations that advocated for women's right, the National Organization for Women (NOW) in 1963 and, in 1969 the National Association for the Repeal of Abortion Laws (NAARL). Friedan argued for legalizing access to abortion and contraception, and her advocacy helped advance women's reproductive rights.

Format: Articles

Subject: People

Alfred Henry Sturtevant (1891–1970)

Alfred Henry Sturtevant studied heredity in fruit flies in the US throughout the twentieth century. From 1910 to 1928, Sturtevant worked in Thomas Hunt Morgan’s research lab in New York City, New York. Sturtevant, Morgan, and other researchers established that chromosomes play a role in the inheritance of traits. In 1913, as an undergraduate, Sturtevant created one of the earliest genetic maps of a fruit fly chromosome, which showed the relative positions of genes along the chromosome.

Format: Articles

Subject: People

On the Generation of Animals, by Aristotle

Aristotle's On the Generation of Animals is referred to in Latin as De Generatione animalium. As with many of Aristotle's writings, the exact date of authorship is unknown, but it was produced in the latter part of the fourth century B.C. This book is the second recorded work on embryology that is treated as a subject of philosophy, being preceded by contributions in the Hippocratic corpus by about a century.

Format: Articles

Subject: Publications

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