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Norbert Freinkel (1926–1989)

Norbert Freinkel (1926–1989)During the twentieth century, Norbert Freinkel studied hormones and diabetes in the United States. Freinkel conducted many experiments that enabled him to determine the factors that influence hormones of the thyroid gland and how those hormones affect surrounding tissues. Furthermore, Freinkel studied gestational diabetes, which is diabetes that occurs for the first time during a woman’s pregnancy. That type of diabetes is caused by a change in the way a woman’s body responds to insulin, a hormone made in the

“Sierra Leone’s Former Child Soldiers: A Longitudinal Study of Risk, Protective Factors, and Mental Health” (2010), by Theresa S. Betancourt, Robert T. Brennan, Julia Rubin-Smith, Garrett M. Fitzmaurice, and Stephen E. Gilman

“Sierra Leone’s Former Child Soldiers: A Longitudinal Study of Risk, Protective Factors, and Mental Health” (2010), by Theresa S. Betancourt, Robert T. Brennan, Julia Rubin-Smith, Garrett M. Fitzmaurice, and Stephen E. GilmanIn 2010, Theresa S. Betancourt, Robert T. Brennan, Julia Rubin-Smith, Garrett M. Fitzmaurice, and Stephen E. Gliman, published “Sierra Leone’s Former Child Soldiers: A Longitudinal Study of Risk, Protective Factors, and Mental Health” in the Journal of the American Academy of Child and Adolescent Psychiatry. The paper describes the results of a longitudinal study of former Sierra Leone child soldiers that examines how protective and risk factors affect children’s post-conflict mental health outcomes over several years of development. Researchers from Harvard University in Cambridge, Massachusetts, conducted the study in

The Dalkon Shield

The Dalkon ShieldThe Dalkon Shield was an intrauterine contraceptive device (IUD) that women used in the early 1970s and 1980s. Produced by the A.H. Robins Company in the US, the Dalkon Shield was a contraceptive device placed directly into a woman’s uterus that was supposed to prevent pregnancy. In the 1980s, researchers discovered that the Dalkon Shield caused an array of severe injuries, including pelvic infection, infertility, unintended pregnancy, and death. Eventually the A.H. Robins Company took the shield off the market, and the US Food and Drug

Andreas Vesalius (1514–1564)

Andreas Vesalius (1514–1564)Andreas Vesalius, also called Andries van Wesel, studied anatomy during the sixteenth century in Europe. Throughout his career, Vesalius dissected numerous human cadavers, and took detailed notes and drawings of the human anatomy. Compiling his research, Vesalius published an anatomy work titled De humani corporis fabrica libri septem ("On the fabric of the human body in seven books"). The Fabrica included illustrations of male and female anatomy. It also included diagrams of uteruses with intact fetuses. Vesalius was one of the first physicians to accurately record and illustrate human anatomy based on his findings from autopsies and dissections, which led to improved understanding of the human body and enhanced surgery techniques.

Shoukhrat Mitalipov and Masahito Tachibana’s Mitochondrial Gene Replacement in Primate Offspring and Embryonic Stem Cells (2009)

Shoukhrat Mitalipov and Masahito Tachibana’s Mitochondrial Gene Replacement in Primate Offspring and Embryonic Stem Cells (2009) In 2009, at Oregon National Primate Research Center in Beaverton, Oregon, Shoukhrat Mitalipov, Masahito Tachibana, and their team of researchers replaced the mitochondrial genes of primate embryonic stem cells via spindle transfer. Spindle replacement, also called spindle transfer, is the process of removing the genetic material found in the nucleus of one egg cell, or oocyte, and placing it in another egg that

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

The Debate over DNA Replication Before the Meselson-Stahl <a href="/search?text=Experiment" title="" class="lexicon-term">Experiment</a> (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. Many scientists, beginning with Max Delbrück, questioned Watson and Cricks’ model and

David Hunter Hubel (1926–2013)

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. By using kittens as models for human children and sewn eyes as models for congenital vision disorders, Hubel’s research demonstrated how vision impairments can affect the development of the visual system in humans. Furthermore, Hubel’s research has informed

Experiments on the Reproductive Costs of a Pure Capital Breeder, the Children’s Python (Antaresia childreni) (2013), by Olivier Lourdais, Sophie Lorioux, and Dale F. DeNardo

Experiments on the Reproductive Costs of a Pure Capital Breeder, the Children’s Python (Antaresia childreni) (2013), by Olivier Lourdais, Sophie Lorioux, and Dale F. DeNardoIn 2013, Olivier Lourdais, Sophie Lorioux, and Dale DeNardo conducted a study on the impact of the reproductive effort on the muscle size and the constriction strength of female Children’s pythons. Children’s pythons are pure capital breeders, meaning that they do not eat during vitellogenesis, a process in which egg-laying or oviparous species allocate bodily resources including fat, water, and protein to follicles in the ovary that develop into eggs.

“Of Pregnancy and Progeny” (1980), by Norbert Freinkel

“Of Pregnancy and Progeny” (1980), by Norbert FreinkelNorbert Freinkel’s lecture “Of Pregnancy and Progeny” was published by the American Diabetes Association’s journal Diabetes in December of 1980. In the lecture, Freinkel argued that pregnancy changes the way that the female body breaks down and uses food. Through experiments that involved pregnant women as well as infants, Freinkel established the body’s maternal metabolism and how it affects both the mother and the infant. Freinkel’s main focus of research in the latter part of his life was diabetes, specifically in pregnant women. Diabetes occurs in around one to three percent of all pregnancies, which is 30,000 to 90,000 women

Ponseti's Treatment for Congenital Clubfoot (1963)

Ponseti's Treatment for Congenital Clubfoot (1963)In 1963, Ignacio Ponseti and Eugene Smoley experimentally determined an effective and minimally invasive method of treating congenital clubfoot. Congenital clubfoot is a disorder in which a newborn’s foot is rigidly turned inwards and upwards. During the early 1960s, orthopedists often relied on invasive surgical procedures to treat clubfoot. In Ponseti and Smoley’s experiment, Ponseti and Smoley had a team of physicians treat patients with clubfoot using the Ponseti method, which consisted of manually manipulating each patient’s foot into a more desirable position and subsequently casting each foot to heal in place. After following up with the patients for several years, Ponseti and Smoley concluded that the Ponseti method is an effective alternative to the more invasive surgical procedures that orthopedists had often

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