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Displaying 201 - 225 of 1169 items.

The Hedgehog Signaling Pathway in Vertebrates 

The hedgehog signaling pathway is a mechanism that regulates cell growth and differentiation during embryonic development, called embryogenesis, in animals. The hedgehog signaling pathway works both between cells and within individual cells.

Format: Articles

Subject: Theories

The Roslin Institute (1993- )

The Roslin Institute was established in 1993 in the village of Roslin, Scotland, as an independent research center by the Biotechnology and Biological Sciences Research Council (BBSRC), and as of 2014 is part of the University of Edinburgh in Edinburgh, Scotland. Researchers at the Roslin Institute cloned the Dolly the sheep in 1996. According to the Roslin Institute, Dolly was the first mammal to develop into an adult from the transfer of the nucleus of an adult sheep cell into an ovum with the nucleus removed.

Format: Articles

Subject: Organizations

The Inheritance of Acquired Characteristics (1924), by Paul Kammerer

The Inheritance of Acquired Characteristics is a book published in 1924, written by Paul Kammerer, who studied developmental biology in Vienna, Austria, in the early twentieth century. The Inheritance of Acquired Characteristics summarizes Kammerer's experiments, and explains their significance. In his book, Kammerer aims to explain how offspring inherit traits from their parents. Some scholars criticized Kammerer's reports and interpretations, arguing that they were inaccurate and misleading, while others supported Kammerer's work.

Format: Articles

Subject: Publications, Theories

Tomorrow's Children (1934)

Tomorrow's Children is a film that tells the story of Alice Mason, a young woman whom the US government forcibly sterilizes because she comes from a family with a history of alcoholism, mental illnesses, and physical disabilities, traits that they considered biologically determined and inferior. The film, released in 1934, was directed by Crane Wilbur, produced by Bryan Foy, written by Wilbur and Wallace Thurman, and released by Foy Productions Ltd.

Format: Articles

Subject: Publications

Sexual Hygiene (1902), by the Alkaloidal Clinic

In 1902, editors of the medical journal Alkaloidal Clinic Wallace C. Abbott and William Francis Waugh published Sexual Hygiene, a book about normal sexual physiology and behavior in Chicago, Illinois. Though the book includes a collection of passages from other books, articles, speeches, and documents surrounding sexual physiology and behavior, it does not include text regarding sexual hygiene.

Format: Articles

Subject: Publications

Epidermal Growth Factor

Epidermal growth factor is a signaling molecule that stimulates the growth of epidermal tissues during development and throughout life. Stanley Cohen discovered epidermal growth factor (EGF) during studies of nerve growth factor as a side effect of other experiments. EGF stimulates tissue growth by initiating a variety of cellular mechanisms. This work led to the 1986 Nobel Prize in Physiology or Medicine awarded to Cohen and Rita Levi-Montalcini.

Format: Articles

Subject: Processes

"In vitro Experiments on the Effects of Mouse Sarcomas 180 and 37 on the Spinal and Sympathetic Ganglia of the Chick Embryo" (1954), by Rita Levi-Montalcini, Viktor Hamburger, and Hertha Meyer

"In vitro Experiments on the Effects of Mouse Sarcomas 180 and 37 on the Spinal and Sympathetic Ganglia of the Chick Embryo" were experiments conducted by Rita Levi-Montalcini in conjunction with Viktor Hamburger and Hertha Meyer and published in Cancer Research in 1954. In this series of experiments, conducted at the University of Brazil, Levi-Montalcini demonstrated increased nerve growth by introducing specific tumors (sarcomas) to chick ganglia. Ganglia are clusters of nerve cells, from which nerve fibers emerge.

Format: Articles

Subject: Experiments

Christiane Nusslein-Volhard (1942- )

Christiane Nusslein-Volhard studied how genes control embryonic development in flies and in fish in Europe during the twentieth and twenty-first centuries. In the 1970s, Nusslein-Volhard focused her career on studying the genetic control of development in the fruit fly Drosophila melanogaster. In 1988, Nusslein-Volhard identified the first described morphogen, a protein coded by the gene bicoid in flies. In 1995, along with Eric F. Wieschaus and Edward B.

Format: Articles

Subject: People

"The Role of Urethra in Female Orgasm" (1950), by Ernst Gräfenberg

In 1950, physician and researcher Ernst Gräfenberg published “The Role of Urethra in Female Orgasm,” in the International Journal of Sexology. The article was one of the first to mention the area in the anterior, or front, vaginal wall colloquially called the G-spot. In the article, Gräfenberg acknowledges that many females experience problems related to sexual satisfaction, and he argues that researchers and physicians of the time did not know enough information about the anatomical mechanisms and localization of the female orgasm to help them.

Format: Articles

Subject: Publications, Reproduction, Processes

The China-US Study on the Prevention of Neural Tube Defects using Folic Acid (1999)

From 1993 to 1995 researchers led by Robert J. Berry from the US Centers for Disease Control headquartered in Atlanta, Georgia, and Zhu Li from Beijing Medical University in Beijing, China, conducted a collaborative study in China on the prevention of neural tube defects or NTDs using folic acid supplements. NTDs are birth defects in which openings in the spinal cord or the brain that occur during early development remain after birth. Neural-tube formation occurs in early pregnancy, often before a woman knows she is pregnant and therefore before she has begun taking prenatal vitamins.

Format: Articles

Subject: Experiments

“Labor and Delivery Outcomes among Young Adolescents” (2015), by Ana J. Torvie, Lisa S. Callegari, Melissa A. Schiff, Katherine E. Debiec

In July 2015, Ana J. Torvie, Lisa S. Callegari, Melissa A. Schiff, and Katherine E. Debiec published “Labor and Delivery Outcomes Among Young Adolescents,” hereafter “Labor and Delivery Outcomes,” in the American Journal for Obstetrics and Gynecology. The authors conducted a study using birth certificate data and hospital records in the state of Washington to compare the frequency and outcomes of cesarean and surgically assisted vaginal births among different age groups of pregnant people.

Format: Articles

Subject: Publications, Reproduction

“Female Ejaculation: A Case Study” (1981), by Frank Addiego, Edwin G. Belzer Jr., Jill Comolli, William Moger, John D. Perry, and Beverly Whipple

In 1981, Frank Addiego and colleagues published “Female Ejaculation: A Case Study” in The Journal of Sex Research. In the article, the authors find that female ejaculation, or the expulsion of fluid from a female’s urethra during or before orgasm, is a legitimate phenomenon that can occur when one stimulates an area in the vaginal wall that the team names the Gräfenberg-spot. According to the authors, at the time of publication, many individuals believed that if a female expelled fluid during orgasm, the fluid was urine and, thus, improper bladder control caused the expulsions.

Format: Articles

Subject: Publications, Processes, Reproduction

“All-fours Maneuver for Reducing Shoulder Dystocia During Labor” (1999), by Joseph P. Bruner, Susan B. Drummond, Anna L. Meenan, and Ina May Gaskin

In 1999, Joseph Bruner, Susan B. Drummond, Anna L. Meenan, and Ina May Gaskin published, “All-fours Maneuver for Reducing Shoulder Dystocia During Labor,” in the medical journal, Obstetrical and Gynecological Survey. In the article, the authors described a birthing technique named the all-fours maneuver, or the Gaskin maneuver, and explained its effectiveness in treating fetal shoulder dystocia as compared to other maneuvers.

Format: Articles

Subject: Publications, Processes

"Health Status of Vietnam Veterans III. Reproductive Outcomes and Child Health" (1988), by the US Centers for Disease Control

In 1988, the US Centers for Disease Control published 'Health Status of Vietnam Veterans III. Reproductive Outcomes and Child Health,' which summarized part of the results of the Vietnam Experience Study commissioned by US Congress to assess the health of US Vietnam veterans. They published the article in the Journal of the American Medical Association. The most heavily used herbicide in the Vietnam, Agent Orange, had previously been found to contain a contaminant linked to birth defects in rats.

Format: Articles

Subject: Publications

"A Diffusible Agent of Mouse Sarcoma, Producing Hyperplasia of Sympathetic Ganglia and Hyperneurotization of Viscera in the Chick Embryo" (1953), by Rita Levi-Montalcini and Viktor Hamburger

"A Diffusible Agent of Mouse Sarcoma, Producing Hyperplasia of Sympathetic Ganglia and Hyperneurotization of Viscera in the Chick Embryo," by Rita Levi-Montalcini and Viktor Hamburger, appeared in 1953 in the Journal of Experimental Zoology. The paper provided the first evidence that nerve growth factor is a diffusible substance. Nerve growth promoting tumors were implanted into developing embryos to determine whether the tumors stimulated growth by direct contact or by a diffusible substance.

Format: Articles

Subject: Experiments

“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

In 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 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.

Format: Articles

Subject: Publications

"Comfortably, Safely, and Without Shame: Defining Menstrual Hygiene Management as a Public Health Issue" (2015), by Marni Sommer, Jennifer S. Hirsch, Constance Nathanson, and Richard G. Parker

In July 2015, Marni Sommer and colleagues published “Comfortably, Safely, and Without Shame: Defining Menstrual Hygiene Management as a Public Health Issue,” hereafter “Defining MHM,” in American Journal of Public Health. The authors discuss that growing interest in the gender gap in education raised awareness about girls’ obstacles to managing menstruation, especially in low-income countries. Increased focus on MHM pushed menstruation to be redefined as a public issue rather than a private one.

Format: Articles

Subject: Publications

“Maternal and Perinatal Outcomes Associated with a Trial of Labor after Prior Cesarean Delivery” (2004), Mark B. Landon et al.

In 2004 Mark Landon and his colleagues in the United States published “Maternal and Perinatal Outcomes Associated with a Trial of Labor after Prior Cesarean Delivery,” which compared the risks of vaginal delivery and cesarean section for delivery of a fetus after a previous cesarean delivery. During a cesarean section, a physician surgically removes a fetus from a pregnant woman through an incision in her abdomen. By the late 1900s, most clinical guidelines viewed attempting a vaginal birth after a previous cesarean delivery as a reasonable option for most women.

Format: Articles

Subject: Publications

Elizabeth Blackburn, Carol Greider and Jack Szostak's Telomere and Telomerase Experiments (1982-1989)

Experiments conducted by Elizabeth Blackburn, Carol Greider, and Jack Szostak from 1982 to 1989 provided theories of how the ends of chromosomes, called telomeres, and the enzyme that repairs telomeres, called telomerase, worked. The experiments took place at the Sidney Farber Cancer Institute and at Harvard Medical School in Boston, Massachusetts, and at the University of California in Berkeley, California. For their research on telomeres and telomerase, Blackburn, Greider, and Szostak received the Nobel Prize in Physiology or Medicine in 2009.

Format: Articles

Subject: Experiments

Edwin Grant Conklin (1863-1952)

Edwin Grant Conklin was born in Waldo, Ohio, on 24 November 1863 to parents Nancy Maria Hull and Dr. Abram V. Conklin. Conklin's family was very religious and he seriously considered a theistic path before choosing a career in academics. Conklin's scientific work was primarily in the areas of embryology, cytology, and morphology, though many questions regarding the relationships between science, society, and philosophy had an influence on both his writings and academic lectures.

Format: Articles

Subject: People

"How do Embryos Assess Risk? Vibrational Cues in Predator-Induced Hatching of Red-Eyed Treefrogs" (2005), by Karen Warkentin

In 'How do Embryos Assess Risk? Vibrational Cues in Predator-Induced Hatching of Red-Eyed Treefrogs' (2005), Karen Warkentin reported on experiments she conducted to see how red-eyed treefrog embryos, Agalychnis callidryas, can distinguish between vibrations due to predator attacks and other environmental occurrences, such as storms. Though the ability of red-eyed treefrogs to alter their hatch timing had been documented, the specific cues that induce early hatching were not well understood.

Format: Articles

Subject: Experiments, Organisms

American Eugenics Society (1926-1972)

The American Eugenics Society (AES) was established in the US by
Madison Grant, Harry H. Laughlin, Henry Crampton, Irving Fisher, and
Henry F. Osborn in 1926 to promote eugenics education programs for
the US public. The AES described eugenics as the study of improving
the genetic composition of humans through controlled reproduction of
different races and classes of people. The AES aided smaller eugenic
efforts such as the Galton Society in New York, New York, and the

Format: Articles

Subject: Organizations

“Maternal Stress Responses and Anxiety During Pregnancy: Effects on Fetal Heart Rate” (2000), by Catherine Monk, William Fifer, Michael Myers, Richard Sloan, Leslie Trien, and Alicia Hurtado

In 2000, Catherine Monk, William Fifer, Michael Myers, Richard Sloan, Leslie Trien, and Alicia Hurtado published “Maternal stress responses and anxiety during pregnancy: Effects on fetal heart rate,” in which the authors conducted a study on how pregnant women’s stress and anxiety affects the health of their fetuses. Previous studies had shown that stress and anxiety during pregnancy could cause fetal abnormalities.

Format: Articles

Subject: Publications, Disorders

Revive & Restore’s Woolly Mammoth Revival Project

In 2015, Revive & Restore launched the Woolly Mammoth Revival Project with a goal of engineering a creature with genes from the woolly mammoth and introducing it back into the tundra to combat climate change. Revive & Restore is a nonprofit in California that uses genome editing technologies to enhance conservation efforts in sometimes controversial ways.

Format: Articles

Subject: Theories, Technologies, Organizations, Ethics

Wilhelm Johannsen's Genotype-Phenotype Distinction

Wilhelm Johannsen in Denmark first proposed the distinction between genotype and phenotype in the study of heredity in 1909. This distinction is between the hereditary dispositions of organisms (their genotypes) and the ways in which those dispositions manifest themselves in the physical characteristics of those organisms (their phenotypes). This distinction was an outgrowth of Johannsen's experiments concerning heritable variation in plants, and it influenced his pure line theory of heredity.

Format: Articles

Subject: Theories