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"Drama of Life Before Birth" (1965), by Life Magazine and Lennart Nilsson

Life Magazine's 1965 cover story "Drama of Life Before Birth" featured photographs of embryos and fetuses taken by Swedish photojournalist Lennart Nilsson to document the developmental stages of a human embryo. Included in this article was the first published image of a living fetus inside its mother's womb. Prior to this, embryos and fetuses were observed, studied, and photographed outside of women's bodies as non-living specimens.

Format: Articles

Subject: Publications, Outreach, Reproduction

The Pasteur Institute (1887- )

L'Institut Pasteur (The Pasteur Institute) is a non-profit private research institution founded by Louis Pasteur on 4 June 1887 in Paris, France. The Institute's research focuses on the study of infectious diseases, micro-organisms, viruses, and vaccines. As of 2014, ten scientists have received Nobel Prizes in physiology or medicine for the research they have done at the Pasteur Institute.

Format: Articles

Subject: Organizations

Molecular Epigenetics and Development: Histone Conformations, DNA Methylation and Genomic Imprinting

Introduced by Conrad Hal Waddington in 1942, the concept of epigenetics gave scientists a new paradigm of thought concerning embryonic development, and since then has been widely applied, for instance to inheritable diseases, molecular technologies, and indeed the human genome as a whole. A genome contains an embedded intricate coding template that provides a means of genetic expression from the initial steps of embryonic development until the death of the organism. Within the genome there are two prominent components: coding (exons) and non-coding (introns) sequences.

Format: Articles

Subject: Theories

Gastrulation in Gallus gallus (Domestic Chicken)

Gastrulation is an early stage in embryo development in which the blastula reorganizes into three germ layers: the ectoderm, the mesoderm, and the endoderm. Gastrulation occurs after cleavage but before neurulation and organogenesis. Ernst Haeckel coined the term; gaster, meaning stomach in Latin, is the root for gastrulation, as the gut is one of the most unique creations of the gastrula.

Format: Articles

Subject: Processes

Ilya Ilyich Mechnikov (Elie Metchnikoff) (1845-1916)

Ilya Ilyich Mechnikov studied phagocytes, immune function, and starfish embryos in Europe during the late nineteenth and early twentieth centuries. Mechnikov adopted the French form of his name, Élie Metchnikoff, in the last twenty-five years of his life. In 1908, he won the Nobel Prize in Physiology or Medicine with Paul Ehrlich for their contributions to immunology. Mechnikov discovered phagocytes, immune cells that protect organisms by ingesting foreign particles or microorganisms, by conducting experiments on starfish larvae.

Format: Articles

Subject: People

"The Cell-Theory" (1853), by Thomas Henry Huxley

The Cell-Theory was written by Thomas Henry Huxley in Britain and published in 1853 by The British and Foreign Medico-Chirurgical Review. The twenty-two page article reviews twelve works on cell theory, including those in Germany by Caspar Friedrich Wolff in the eighteenth century and by Karl Ernst von Baer in the nineteenth century. Huxley spends much of The Cell-Theory on a cell theory proposed in the late 1830s by Matthias Schleiden and Theodor Schwann in Germany.

Format: Articles

Subject: Publications

Epigenetic Landscape

The epigenetic landscape is a concept representing embryonic development. It was proposed by Conrad Hal Waddington to illustrate the various developmental pathways a cell might take toward differentiation. The epigenetic landscape integrates the connected concepts of competence, induction, and regulative abilities of the genes into a single model designed to explain cellular differentiation, a long standing problem in embryology.

Format: Articles

Subject: Theories

Temperature-Dependent Sex Determination in Reptiles

The sex of a reptile embryo partly results from the production of sex hormones during development, and one process to produce those hormones depends on the temperature of the embryo's environment. The production of sex hormones can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination, also called genetic or chromosomal sex determination, an organism's genes determine which hormones are produced.

Format: Articles

Subject: Experiments

The Carapacial Ridge of Turtles

Two main elements characterize the skeletal morphology of turtles: the carapace and the plastron. For a turtle, the carapacial ridge begins in the embryo as a bulge posterior to the limbs but on both sides of the body. Such outgrowths are the first indication of shell development in turtle embryos. While the exact mechanisms underpinning the formation of the carapacial ridge are still not entirely known, some biologists argue that understanding these embryonic mechanisms is pivotal to explaining both the development of turtles and their evolutionary history.

Format: Articles

Subject: Processes

Christian Peeters and Bert Hölldobler's Experiments on Reproduction in Indian Jumping Ants (1991–1994)

Between 1991 and 1994, Christian Peeters and Bert Hölldobler studied the reproductive behaviors of the Indian jumping ant (Harpegnathos saltator), a species native to southern India. They conducted experiments as part of a larger investigation into conflict and reproductive behavior among ants. Peeters and Hölldobler discovered that Indian jumping ant colonies contained both sexually reproductive workers and egg-laying queens. In most other species of ant, the queens are the only sexually reproductive individuals.

Format: Articles

Subject: Experiments

"The Adaptive Significance of Temperature-Dependent Sex Determination in a Reptile" (2008), by Daniel Warner and Richard Shine

In 2008 researchers Daniel Warner and Richard Shine tested the Charnov-Bull model by conducting experiments on the Jacky dragon (Amphibolurus muricatus), in Australia. Their results showed that temperature-dependent sex determination(TSD) evolved in this species as an adaptation to fluctuating environmental temperatures. The Charnov-Bull model, proposed by Eric Charnov and James Bull in 1977, described the evolution of TSD, although the model was, for many years, untested.

Format: Articles

Subject: Experiments

Edward Charles Dodds (1899-1973)

Edward Charles Dodds researched the function and effects of natural and artificial hormones on the endocrine system in England during the twentieth century. Though he first worked with hormones such as insulin, Dodds focused on the effects of estrogen in the body and how to replicate those effects with artificial substances. In 1938, along with chemist Robert Robinson, Dodds synthesized the first synthetic estrogen called diethylstilbestrol.

Format: Articles

Subject: People

Muriel Wheldale Onslow (1880-1932)

Muriel Wheldale Onslow studied flowers in England with genetic and biochemical techniques in the early twentieth century. Working with geneticist William Bateson, Onslow used Mendelian principles and biochemical analysis together to understand the inheritance of flower colors at the beginning of the twentieth century. Onslow's study of snapdragons, or Antirrhinum majus, resulted in her description of epistasis, a phenomenon in which the phenotypic effect of one gene is influenced by one or more other genes. She discovered several biochemicals related to color formation.

Format: Articles

Subject: People

Stanley Alan Plotkin's Development of a Rubella Vaccine (1969)

In the US during the late 1960s, Stanley Alan Plotkin, John D. Farquhar, Michael Katz, and Fritz Buser isolated a strain of the infectious disease rubella and developed a rubella vaccine with a weakened, or attenuated, version of the virus strain. Rubella, also called German measles, is a highly contagious disease caused by the rubella virus that generally causes mild rashes and fever. However, in pregnant women, rubella infections can lead to developmental defects in their fetuses.

Format: Articles

Subject: Experiments

David Hunter Hubel (1926–2013)

David Hunter Hubel studied the development of the visual system and how the brain processes visual information in the US during the twentieth century. He performed multiple experiments with kittens in which he sewed kitten’s eyes shut for varying periods of time and monitored their vision after reopening them. Hubel, along with colleague Torsten Wiesel, received the 1981 Nobel Prize in Physiology or Medicine for that research.

Format: Articles

Subject: People

History of the Monash IVF Research Program from 1971 to 1989

In 1971, a group of researchers founded the Monash IVF Research Program with the mission to discover how in vitro fertilization, or IVF, techniques could become a treatment for infertility in both men and women. The program included researcher Carl Wood and colleagues John Leeton, Alex Lopata, Alan Trounson, and Ian Johnston at the Queen Victoria Medical Center and Royal Women’s Hospital in Melbourne, Australia. Since the program’s establishment in 1971, the Monash IVF Research Program has helped to develop and implement many IVF technologies still used in clinical practice as of 2020.

Format: Articles

Subject: Organizations, Reproduction

Gail Roberta Martin (1944– )

In the twentieth and early twenty-first centuries, Gail Roberta Martin specialized in biochemistry and embryology, more specifically cellular communication and the development of organs. In 1981, she named any cell taken from inside a human embryo at the blastocyst stage an “embryonic stem cell”. During development, an embryo goes through the blastocyst stage just before it implants in the uterus. Embryonic stem cells are useful for experiments because they are self-renewing and able to develop into almost any cell type in the body.

Format: Articles

Subject: People

Turpin v. Sortini (1982)

The Supreme Court of California reversed the Superior Court of Fresno County's decision to dismiss the Turpins' claims in the case Turpin v. Sortini on 3 May 1982. The case was based upon a wrongful life claim, in which a disabled child sues physicians for neglecting to inform its parents of potential genetic defects, resulting in harm to the child when it is born. The Turpin case determined tha a physician could be liable for failing to inform parents of potential birth defects in the fetus.

Format: Articles

Subject: Legal, Reproduction

Florence Rena Sabin (1871-1953)

Florence Rena Sabin had successful careers as both a researcher and public health reformer. When Johns Hopkins University Medical School opened, accepting women and men on the same basis, Sabin was one of the first to enter. After the successful completion of her MD degree, Sabin went on to become the first female faculty member and later full-time professor at Johns Hopkins.

Format: Articles

Subject: People

"Selective Growth Stimulating Effects of Mouse Sarcoma on the Sensory and Sympathetic Nervous System of the Chick Embryo" (1951), by Rita Levi-Montalcini and Viktor Hamburger

In "Selective Growth Stimulating Effects of Mouse Sarcoma on the Sensory and Sympathetic Nervous System of the Chick Embryo," Rita Levi-Montalcini and Viktor Hamburger explored the effects of two nerve growth stimulating tumors; mouse sarcomas 180 and 37. This experiment led to the discovery that nerve growth factor was a diffusible chemical and later to discoveries that the compound was a protein. Although this paper was an important step in the discovery of nerve growth factor, the term "nerve growth factor" was not used in this paper.

Format: Articles

Subject: Experiments

Mitochondria

All cells that have a nucleus, including plant, animal, fungal cells, and most single-celled protists, also have mitochondria. Mitochondria are particles called organelles found outside the nucleus in a cell's cytoplasm. The main function of mitochondria is to supply energy to the cell, and therefore to the organism. The theory for how mitochondria evolved, proposed by Lynn Margulis in the twentieth century, is that they were once free-living organisms.

Format: Articles

Subject: Organisms, Theories

Early Infantile Autism and the Refrigerator Mother Theory (1943-1970)

In 1943, child psychiatrist Leo Kanner in the US gave the first account of Early Infantile Autism that encouraged psychiatrists to investigate what they called emotionally cold mothers, or refrigerator mothers. In 1949, Kanner published Problems of Nosology and Psychodynamics of Early Infantile Autism. In that article, Kanner described autistic children as reared in emotional refrigerators. US child psychiatrists claimed that some psychological or behavioral conditions might have origins in emotional or mental stress, meaning that they might be psychogenic.

Format: Articles

Subject: Disorders, Theories

Santiago Felipe Ramon y Cajal (1852-1934)

Santiago Felipe Ramon y Cajal investigated brains in the nineteenth and twentieth centuries in Spain. He identified and individuated many components of the brain, including the neuron and the axon. He used chick embryos instead of adult animals, then customary in brain research, to study the development and physiology of the cerebellum, spinal cord, and retina. Ramon y Cajal received the Nobel Prize in Physiology and Medicine in 1906, along with Camillo Golgi, for his work on the structure of the nervous system.

Format: Articles

Subject: People

Jane Elizabeth Hodgson (1915–2006)

Jane Elizabeth Hodgson was a physician who advocated for abortion rights in the twentieth century in the United States. In November of 1970, Hodgson became the first physician in the U.S. to be convicted of performing an illegal abortion in a hospital. Hodgson deliberately performed the abortion to challenge the Minnesota State Statute 617.18, which prohibited non-therapeutic abortions. Following the legalization of abortion in the US Supreme Court case Roe v. Wade (1973), Hodgson focused on promoting accessible abortion, obstetric, and gynecological care throughout Minnesota.

Format: Articles

Subject: People

Cornelia Isabella Bargmann (1961- )

Cornelia Isabella Bargmann studied the relationship between genes, neural circuits, and behavior in the roundworm Caenorhabditis elegans (C. elegans) during the twentieth and twenty-first centuries in the US. Bargmann’s research focused on how the sense of smell (olfaction) in the nematode word Caenorhabditis elegans. She provided a model to study how neural circuits develop and function in the human brain, as the genetic regulatory pathways are similar.

Format: Articles

Subject: People