Experiments

"The Development of the Pronephros during the Embryonic and Early Larval Life of the Catfish (Ictalurus punctatus)" (1932), by Rachel L. Carson

By Karen Wellner

Rachel L. Carson studied biology at Johns Hopkins University in Maryland and graduated in 1933 with an MA upon the completion of her thesis, The Development of the Pronephros during the Embryonic and Early Larval Life of the Catfish (Ictalurus punctatus). The research that Carson conducted for this thesis project grounded many of the claims and observations she presented in her 1962 book, Silent Spring.

Created 2014-02-28

Last modified 2 years 7 months ago

Format: Articles

"Cellular death in morphogenesis of the avian wing" (1962), by John W. Saunders Jr., et al.

By Lijing Jiang

In the early 1960s, John W. Saunders Jr., Mary T. Gasseling, and Lilyan C. Saunders in the US investigated how cells die in the developing limbs of chick embryos. They studied when and where in developing limbs many cells die, and they studied the functions of cell death in wing development. At a time when only a few developmental biologists studied cell death, or apoptosis, Saunders and his colleagues showed that researchers could use embryological experiments to uncover the causal mechanisms of apotosis.

Created 2014-03-07

Last modified 3 years 4 months ago

Format: Articles

Frank Rattray Lillie's Study of Freemartins (1914-1920)

By Mary Drago

Frank Rattray Lillie's research on freemartins from 1914 to 1920 in the US led to the theory that hormones partly caused for sex differentiation in mammals. Although sometimes applied to sheep, goats, and pigs, the term freemartin most often refers to a sterile cow that has external female genitalia and internal male gonads and was born with a normal male twin.

Created 2014-03-14

Last modified 3 years 4 months ago

Format: Articles

Embryonic Sex Differentiation and Sex Hormones (1947), by Carl R. Moore

By Mary Drago

In 1947, Carl Richard Moore, a researcher at the University of Chicago, in Chicago, Illinois, wrote Embryonic Sex Differentiation and Sex Hormones, which was published in the same year as a first-edition monograph. In the book, Moore argues that regulation of sex differentiation in mammals is not controlled by sex hormones secreted by embryonic sex organs (gonads), but is controlled by non-hormonal genetic factors.

Created 2014-05-03

Last modified 3 years 2 months ago

Format: Articles

"Genetic Control of Biochemical Reactions in Neurospora" (1941), by George W. Beadle and Edward L. Tatum

By Divyash Chhetri

George Wells Beadle and Edward Lawrie Tatum's 1941 article Genetic Control of Biochemical Reactions in Neurospora detailed their experiments on how genes regulated chemical reactions, and how the chemical reactions in turn affected development in the organism. Beadle and Tatum experimented on Neurospora, a type of bread mold, and they concluded that mutations to genes affected the enzymes of organisms, a result that biologists later generalized to proteins, not just enzymes.

Created 2014-06-11

Last modified 3 years 1 month ago

Format: Articles

"Maternal Thyroid Deficiency During Pregnancy and Subsequent Neuropsychological Development of the Child" (1999), by James E. Haddow et al.

By Jennifer R. Craer

From 1987 to the late 1990s, James Haddow and his team of researchers at the Foundation for Blood Research in Scarborough, Maine, studied children born to women who had thyroid deficiencies while pregnant with those children. Haddow's team focused the study on newborns who had normal thyroid function at the time of neonatal screening. They tested the intelligence quotient, or IQ, of the children, ages eight to eleven years, and found that all of the children born to thyroid-hormone deficient mothers performed less well than the control group.

Created 2014-07-11

Last modified 9 months 3 weeks ago

Format: Articles

Robert Geoffrey Edwards's Study of in vitro Mammalian Oocyte Maturation, 1960 to 1965

By Lijing Jiang

In a series of experiments between 1960 and 1965, Robert Geoffrey Edwards discovered how to make mammalian egg cells, or oocytes, mature outside of a female's body. Edwards, working at several research institutions in the UK during this period, studied in vitro fertilization (IVF) methods. He measured the conditions and timings for in vitro (out of the body) maturation of oocytes from diverse mammals including mice, rats, hamsters, pigs, cows, sheep, and rhesus monkeys, as well as humans.

Created 2014-08-18

Last modified 2 years 11 months ago

Format: Articles

"Human Factor IX Transgenic Sheep Produced by Transfer of Nuclei from Transfected Fetal Fibroblasts" (1997), by Angelika E. Schnieke, et al.

By Zane Bartlett

In the 1990s, researchers working at the Roslin Institute in Edinburgh, Scotland, performed cloning experiments in collaboration with PPL Therapeutics in Roslin, Scotland, on human coagulation factor IX, a protein. The team of scientists used the methods identified during the Dolly experiments to produce transgenic livestock capable of producing milk containing human blood clotting factor IX, which helps to treat a type of hemophilia.

Created 2014-08-19

Last modified 2 years 11 months ago

Format: Articles

"Sheep Cloned by Nuclear Transfer from a Cultured Cell Line" (1996), by Keith Campbell, Jim McWhir, William Ritchie, and Ian Wilmut

By Zane Bartlett

In 1995 and 1996, researchers at the Roslin Institute in Edinburgh, Scotland, cloned mammals for the first time. Keith Campbell, Jim McWhir, William Ritchie, and Ian Wilmut cloned two sheep, Megan and Morag, using sheep embryo cells. The experiments indicated how to reprogram nuclei from differentiated cells to produce live offspring, and that a single population of differentiated cells could produce multiple offspring. They reported their results in the article 'Sheep Cloned by Nuclear Transfer from a Cultured Cell Line' in March 1996.

Created 2014-09-19

Last modified 2 years 10 months ago

Format: Articles

Lysogenic Bacteria as an Experimental Model at the Pasteur Institute (1915-1965)

By Valerie Racine

Lysogenic bacteria, or virus-infected bacteria, were the primary experimental models used by scientists working in the laboratories of the Pasteur Institute in Paris, France, during the 1950s and 1960s. Historians of science have noted that the use of lysogenic bacteria as a model in microbiological research influenced the scientific achievements of the Pasteur Institute's scientists.

Created 2014-10-10

Last modified 2 years 9 months ago

Format: Articles

"Viable Offspring Derived from Fetal and Adult Mammalian Cells" (1997), by Ian Wilmut et al.

By Zane Bartlett

In the 1990s, Ian Wilmut, Jim McWhir, and Keith Campbell performed experiments while working at the Roslin Institute in Roslin, Scotland. Wilmut, McWhir, and Campbell collaborated with Angelica Schnieke and Alex J. Kind at PPL Therapeutics in Roslin, a company researching cloning and genetic manipulation for livestock. Their experiments resulted in several sheep being born in July 1996, one of which was a sheep named Dolly born 5 July 1996.

Created 2014-10-10

Last modified 2 years 9 months ago

Format: Articles

"Transfer of Fetal Cells with Multilineage Potential to Maternal Tissue" (2004), by Kiarash Khosrotehrani et al.

By Alexis Abboud

In 2004, a team of researchers at Tufts-New England
Medical Center in Boston, Massachusetts, investigated the fetal
cells that remained in the maternal blood stream after pregnancy.
The results were published in Transfer of Fetal Cells with
Multilineage Potential to Maternal Tissue. The team working on that
research included Kiarash Khosrotehrani, Kirby L. Johnson, Dong
Hyun Cha, Robert N. Salomon, and Diana W. Bianchi. The researchers
reported that the fetal cells passed to a pregnant woman during

Created 2014-11-14

Last modified 2 years 8 months ago

Format: Articles

Paul Kammerer (1880-1926)

By Federica Turriziani Colonna

Paul Kammerer conducted experiments on amphibians and marine animals at the Vivarium, a research institute in Vienna, Austria, in the early twentieth century. Kammerer bred organisms in captivity, and he induced them to develop particular adaptations, which Kammerer claimed the organismss offspring would inherit. Kammerer argued that his results demonstrated the inheritance of acquired characteristics, or Lamarckian inheritance. The Lamarckian theory of inheritance posits that individuals transmit acquired traits to their offspring.

Created 2014-11-25

Last modified 2 years 7 months ago

Format: Articles

Experimental Studies on Germinal Localization (1904), by Edmund B. Wilson

By James Lowe

At the turn of the twentieth century, Edmund B. Wilson
performed experiments to show where germinal
matter was located in molluscs. At Columbia University in New York City,
New York, Wilson studied what causes cells to differentiate during
development. In 1904 he conducted his experiments on molluscs, and he modified the
theory about the location of germinal matter in the succeeding years. Wilson and others modified the
theory of germinal localization to accommodate results that showed

Created 2014-12-22

Last modified 2 years 7 months ago

Format: Articles

Paul Kammerer's Experiments on Salamanders (1903-1912)

By Federica Turriziani Colonna

In the early twentieth century, Paul Kammerer conducted a series of experiments to demonstrate that organisms could transmit characteristics acquired in their lifetimes to their offspring. In his 1809 publication, zoologist Jean-Baptiste Lamarck had hypothesized that living beings can inherit features their parents or ancestors acquired throughout life. By breeding salamanders, as well as frogs and other organisms, Kammerer tested Lamarck's hypothesis in an attempt to provide evidence for Lamarck's theory of the inheritance of acquired characteristics.

Created 2014-12-30

Last modified 2 years 6 months ago

Format: Articles

Paul Kammerer's Experiments on the Midwife Toad (1905-1910)

By Federica Turriziani Colonna

In the first decade of the twentieth century, Paul Kammerer, a zoologist working at the Vivarium in Vienna, Austria, conducted research on developmental mechanisms, including a series of breeding experiments on toads (Alytes obstetricans). Kammerer claimed that his results demonstrated that organisms could transmit acquired characteristics to their offspring.

Created 2014-12-30

Last modified 2 years 6 months ago

Format: Articles

A plant genetically modified that accumulates Pb is especially promising for phytoremediation (2003), by Carmina Gisbert et al.

By Ernest Nkansah-Dwamena

In 2003, Carmina Gisbert and her research team produced a tobacco plant that could remove lead from soil. To do so, they inserted a gene from wheat plants that produces phytochelatin synthase into a shrub tobacco plant (Nicotiana glauca) to increase N. glauca's absorption and tolerance of toxic metals, particularly lead and cadmium. Gisbert and her team aimed to genetically modify a plant so that it could be used for phytoremediation- using plants to remove toxic substances from the soil.

Created 2014-12-30

Last modified 2 years 6 months ago

Format: Articles

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

By Zane Bartlett

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.

Created 2015-03-24

Last modified 9 months 3 weeks ago

Format: Articles

Amphioxus, and the Mosaic Theory of Development (1893), by Edmund Beecher Wilson

By James Lowe

Edmund Beecher Wilson experimented with Amphioxus (Branchiostoma) embryos in 1892 to identify what caused their cells to differentiate into new types of cells during the process of development. Wilson shook apart the cells at early stages of embryonic development, and he observed the development of the isolated cells. He observed that in the normal development of Amphioxus, all three main types of symmetry, or cleavage patterns observed in embryos, could be found. Wilson proposed a hypothesis that reformed the Mosaic Theory associated with Wilhelm Roux in Germany.

Created 2015-03-31

Last modified 2 years 3 months ago

Format: Articles

Paul Kammerer's Experiments on Sea-squirts in the Early Twentieth Century

By Federica Turriziani Colonna

In the early twentieth century, Paul Kammerer, a zoologist working at the Vivarium in Vienna, Austria, experimented on sea-squirts (Ciona intestinalis). Kammerer claimed that results from his experiments demonstrated that organisms could transmit characteristics that they had acquired in their lifetimes to their offspring. Kammerer conducted breeding experiments on sea-squirts and other organisms at a time when Charles Darwin's 1859 theory of evolution lacked evidence to explain how offspring inherited traits from their parents.

Created 2015-04-13

Last modified 2 years 3 months ago

Format: Articles

Digit Regeneration Is Regulated by Msx1 and BMP4 in Fetal Mice (2003), by Manjong Han et al.

By Joe Brinkman

In the early 2000s, Manjong Han, Xiaodang Yang, Jennifer Farrington, and Ken Muneoka investigated how genes and proteins in fetal mice (Mus musculus) influenced those fetal mice to regenerate severed toes at Tulane University in New Orleans, Louisiana. The group used hind limbs from mice to show how the gene Msx1 (Homeobox 7) functions in regenerating amputated digits.

Created 2015-04-13

Last modified 2 years 3 months ago

Format: Articles

The Genetic Control and Cytoplasmic Expression of 'Inducibility' in the synthesis of B-galactosidase" (1959), by Arthur B. Pardee, Francois Jacob, and Jacques Monod

By Abhinav Mishra

Between 1957 and 1959, Arthur Pardee, Francois Jacob, and Jacques Monod conducted a set of experiments at the Pasteur Institute in Paris, France, that was later called the PaJaMa Experiments, a moniker derived from the researchers' last names. In these experiments, they described how genes of a species of single-celled bacteria, called Escherichia coli (E. coli), controlled the processes by which enzymes were produced in those bacteria.

Created 2015-05-28

Last modified 2 years 1 month ago

Format: Articles

Induced Pluripotent Stem Cell Experiments by Kazutoshi Takahashi and Shinya Yamanaka in 2006 and 2007

By Zane Bartlett

In 2006, Kazutoshi Takahashi and Shinya Yamanaka reprogrammed mice fibroblast cells, which can produce only other fibroblast cells, to become pluripotent stem cells, which have the capacity to produce many different types of cells. Takahashi and Yamanaka also experimented with human cell cultures in 2007. Each worked at Kyoto University in Kyoto, Japan. They called the pluripotent stem cells that they produced induced pluripotent stem cells (iPSCs) because they had induced the adult cells, called differentiated cells, to become pluripotent stem cells through genetic manipulation.

Created 2015-06-01

Last modified 2 years 1 month ago

Format: Articles

"Human Toxoplasmosis: Occurrence in Infants as an Encephalomyelitis Verification of Transmission to Animals" (1939), by Abner Wolf et al.

By Jesse Potestas

In a series of experiments during mid 1930s, a team of researchers in New York helped establish that bacteria of the species Toxoplasma gondii can infect humans, and in infants can cause toxoplasmosis, a disease that inflames brains, lungs, and hearts, and that can organisms that have it. The team included Abner Wolf, David Cowen, and Beryl Paige. They published the results of their experiment in Human Toxoplasmosis: Occurrence in Infants as an Encephalomyelitis Verification of Transmission to Animals.

Created 2015-06-11

Last modified 1 year 1 month ago

Format: Articles

Beadle and Ephrussi’s Technique to Transplant Optic Discs between Fruit Fly Larvae

By Amy Pribadi

Object is a digital image of fruit fly larvae. There are three panes. In the first, a micropipette sucks the optic disc from a fruit fly larva. In the second, the micropipette pushes the optic disc into the abdomen of another fruit fly larva. The third pane shows the adult fruit fly from the second pane with an eye that has developed in its abdomen.

In 1935, George Beadle and Boris Ephrussi developed a technique to transplant optic discs between fruit fly larvae. They developed it while at the California Institute of Technology in Pasedena, California. Optic discs are tissues from which the adult eyes develop. Beadle and Ephrussi used their technique to study the development of the eye and eye pigment. (1) The experimenter dissects a donor larva, which is in the third instar stage of development, and removes the optic disc (colored red) with a micropipette.

Created 2016-10-11

Last modified 1 month 4 days ago

Format: Graphics

Beadle and Ephrussi Show that Something Besides Eye Tissue Determines Eye Color in Fruit Flies

By Amy Pribadi

Object is a digital image of fruit flies, and it has three panes. The first pane shows two fruit fly larvae, with one having its optic disc removed and the other getting that disc inserted in its abdomen. The second pane shows an adult fruit fly, a donee, which has a normal colored eye in its abdomen. The third pane shows an adult fruit fly, a donee, which has an abnormally colored eye in its abdomen.

In the 1930s, George Beadle and Boris Ephrussi discovered factors that affect eye colors in developing fruit flies. They did so while working at the California Institute of Technology in Pasadena, California. (1) They took optic discs (colored fuchsia in the image) from fruit fly larvae in the third instar stage of development. Had the flies not been manipulated, they would have developed into adults with vermilion eyes.

Created 2016-10-11

Last modified 1 month 5 days ago

Format: Graphics

Beadle and Tatum's 1941 Experiments with Neurospora Revealed that Genes Produce Enzymes

By Amy Pribadi

Object is a digital image that depicts four stages in Beadle and Tatum's Neurospora experiments. Each stage is depicted in a separate section, with different test tubes in each section.

This illustration shows George Beadle and Edward Tatum's experiments with Neurospora crassa that indicated that single genes produce single enzymes. The pair conducted the experiments at Stanford University in Palo Alto, California. Enzymes are types of proteins that can catalyze reactions inside cells, reactions that produce a number of things, including nutrients that the cell needs. Neurospora crassa is a species of mold that grows on bread.

Created 2016-10-12

Last modified 1 month 5 days ago

Format: Graphics

Barbara McClintock's Transposon Experiments in Maize (1931–1951)

By Federica Turriziani Colonna

Barbara McClintock conducted experiments on corn (Zea mays) in the United States in the mid-twentieth century to study the structure and function of the chromosomes in the cells. McClintock researched how genes combined in corn and proposed mechanisms for how those interactions are regulated. McClintock received the Nobel Prize in Physiology or Medicine in 1983, the first woman to win the prize without sharing it. McClintock won the award for her introduction of the concept of transposons, also called jumping genes.

Created 2017-02-09

Last modified 2 months 2 weeks ago

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"The Limited In Vitro Lifetime of Human Diploid Cell Strains" (1964), by Leonard Hayflick

By Zane Bartlett

Leonard Hayflick in the US during the early 1960s showed that normal populations of embryonic cells divide a finite number of times. He published his results as 'The Limited In Vitro Lifetime of Human Diploid Cell Strains' in 1964. Hayflick performed the experiment with WI-38 fetal lung cells, named after the Wistar Institute, in Philadelphia, Pennsylvania, where Hayflick worked. Frank MacFarlane Burnet, later called the limit in capacity for cellular division the Hayflick Limit in 1974.

Created 2017-02-11

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The Effects of Gene Regulation on Aging in Caenorhabditis elegans (2003)

By Dasia Garcia

In 2003, molecular biology and genetics researchers Coleen T. Murphy, Steven A. McCarroll, Cornelia I. Bargmann, Andrew Fraser, Ravi S. Kamath, Julie Ahringer, Hao Li, and Cynthia Kenyon conducted an experiment that investigated the cellular aging in, Caenorhabditis elegans (C. elegans) nematodes. The researchers investigated the interactions between the transcription factor DAF-16 and the genes that regulate the production of an insulin-like growth factor 1 (IGF-1-like) protein related to the development, reproduction, and aging in C. elegans.

Created 2017-02-16

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Gene Transfer Strategy Used to Treat Tay - Sachs Disease (2005), by Sabata Martino’s Research Group

By Tiffany Nardi

In the early 2000s, Sabata Martino and a team of researchers in Italy and Germany showed that they could reduce the symptoms of Tay-Sachs in afflicted mice by injecting them with a virus that infected their cells with a gene they lacked. Tay-Sachs disease is a fatal degenerative disorder that occurs in infants and causes rapid motor and mental impairment, leading to death at the ages of three to five. In gene therapy, researchers insert normal genes into cells that have missing or defective genes in order to correct genetic disorders.

Created 2017-02-21

Last modified 2 months 2 weeks ago

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The Effectiveness of Phototherapy in Premature Infants (1968)

By Arianna Bradley

In 1968, pediatric researchers Jerold Lucey, Mario Ferreiro, and Jean Hewitt conducted an experimental trial that determined that exposure to light effectively treated jaundice in premature infants. The three researchers published their results in 'Prevention of Hyperbilirubinemia of Prematurity by Phototherapy' that same year in Pediatrics. Jaundice is the yellowing of the skin and eyes due to the failure of the liver to break down excess bilirubin in the blood, a condition called hyperbilirubinemia.

Created 2017-02-23

Last modified 2 months 2 weeks ago

Format: Articles

Edgar Allen and Edward A. Doisy's Extraction of Estrogen from Ovarian Follicles, (1923)

By Brendan Van Iten

In the early 1920s, researchers Edgar Allen and Edward Adelbert Doisy conducted an experiment that demonstrated that ovarian follicles, which produce eggs in mammals, also contain and produce what they called the primary ovarian hormone, later renamed estrogen. In their experiment, Doisy and Allen extracted estrogen from the ovarian follicles of hogs and proved that they had isolated estrogen by using a measurement later renamed the Allen-Doisy test.

Created 2017-03-02

Last modified 2 months 2 weeks ago

Format: Articles

Julia Barlow Platt's Embryological Observations on Salamanders' Cartilage (1893)

By Karina Ramirez

In 1893, Julia Barlow Platt published her research on the origins of cartilage in the developing head of the common mudpuppy (Necturus maculosus) embryo. The mudpuppy is an aquatic salamander commonly used by embryologists because its large embryonic cells and nuclei are easy to see. Platt followed the paths of cells in developing mudpuppy embryos to see how embryonic cells migrated during the formation of the head. With her research, Platt challenged then current theories about germ layers, the types of cells in an early embryo that develop into adult cells.

Created 2017-03-06

Last modified 4 months 2 weeks ago

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"Presence of Fetal DNA in Maternal Plasma and Serum" (1997), by Dennis Lo, et al.

By Cassidy Possehl

In the late 1990s researchers Yuk Ming Dennis Lo and his colleagues isolated fetal DNA extracted from pregnant woman’s blood. The technique enabled for more efficient and less invasive diagnoses of genetic abnormalities in fetuses, such as having too many copies of chromosomes.

Created 2017-03-07

Last modified 2 months 2 weeks ago

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

By Kevin M. Gleason

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".

Created 2017-03-07

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Harald zur Hausen's Experiments on Human Papillomavirus Causing Cervical Cancer (1976–1987)

By Grace Kim

From 1977 to 1987, Harald zur Hausen led a team of researchers across several institutions in Germany to investigate whether the human papillomavirus (HPV) caused cervical cancer. Zur Hausen's first experiment tested the hypothesis that HPV caused cervical cancer rather than herpes simplex virus type 2 (HSV-2), the then accepted cause. His second and third experiments detailed methods to identify two previously unidentified HPV strains, HPV 16 and HPV 18, in cervical cancer tumor samples. The experiments showed that HPV 16 and 18 DNA were present in cervical tumor samples.

Created 2017-03-09

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Ginger as a Treatment for Nausea and Vomiting in Pregnancy by Teraporn Vutyavanich, Theerajana Kraisarin, and Rung-Aroon Ruangsri (1998–2001)

By Cecilia Chou

In 1998 and 1999, Teraporn Vutyavanich, Theerajana Kraisarin, and Rung-Aroon Ruangsri in Thailand showed that ginger alleviated nausea in pregnant women. Vutyavanich and his colleagues found that the group of pregnant women who took ginger capsules reported significantly fewer nausea symptoms and vomiting episodes than the group who only received the placebo. Vutyavanich and his team’s study at Chiang Mai University in Chiang Mai, Thailand, was one of the earliest to investigate and support the use of ginger as an effective treatment for relieving pregnancy-related nausea and vomiting.

Created 2017-03-14

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"Congenital Club Foot in the Human Fetus" (1980), by Ernesto Ippolito and Ignacio Ponseti

By Katherine Gandee

In 1980, Ernesto Ippolito and Ignacio Ponseti published their results on a histological study they performed on congenital club foot in human fetuses. The researchers examined the feet of four aborted fetuses and compared the skeletal tissues from healthy feet to those affected by congenital club foot. Infants born with club foot are born with one or both feet rigidly twisted inwards and upwards, making typical movement painful and challenging.

Created 2017-03-16

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"The Familial Factor in Toxemia of Pregnancy" (1968), by Leon C. Chesley, et al.

By Sarah Patel

In the 1950s and 1960s, researchers Leon Chesley, John Annitto, and Robert Cosgrove investigated the possible familial factor for the conditions of preeclampsia and eclampsia in pregnant women. Preeclampsia and eclampsia, which are related to high blood pressure, have unknown causes and affect at least five percent of all pregnancies.

Created 2017-03-16

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"The Developmental Capacity of Nuclei Taken from Intestinal Epithelium Cells of Feeding Tadpoles" (1962), by John B. Gurdon

By Giselle Lee

In 1962 researcher John Bertrand Gurdon at the University of Oxford in Oxford, England, conducted a series of experiments on the developmental capacity of nuclei taken from intestinal epithelium cells of feeding tadpoles. In the experiments, Gurdon conducted nuclear transplantation, or cloning, of differentiated cells, or cells that have already specialized to become one cell type or another, in tadpoles. Gurdon's experiment showed that differentiated adult cells could be induced to an undifferentiated state, where they could once again become multiple cell types.

Created 2017-03-16

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

By Kelle Dhein

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.

Created 2017-03-23

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Infant Mortality: Results of a Field Study in Johnstown, PA., Based on Births in One Calendar Year (1915), by Emma Duke

By Katherine Madgett

The book Infant Mortality: Results of a Field Study in Johnstown, PA., Based on Births in One Calendar Year (1915), written by Emma Duke, detailed one of the first infant mortality field studies conducted by the US Children's Bureau. In the study, Duke and her colleagues collected information about over one thousand infants in the city of Johnstown, Pennsylvania. They used that information, along with interviews conducted with the families of the infants, to identify factors that affected infant mortality rates in the community.

Created 2017-03-23

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

By Brendan Van Iten

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.

Created 2017-04-06

Last modified 3 months 2 weeks ago

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Jeffrey Weinzweig's Experiments on In Utero Cleft Palate Repair in Goats (1999-2002)

By Jillian R. Kersten

Jeffrey Weinzweig and his team, in the US at the turn of the twenty-first century, performed a series of experiments on fetal goats to study the feasibility of repairing cleft palates on organisms still in the womb. Weinzweig , a plastic surgeon who specialized in cleft palate repair, and his team developed a method to cause cleft palates in fetal goats that are similar to clefts that occur in human fetuses. Using their goat congenital model, the team developed a method to repair a congenital cleft palate in utero, or in the womb.

Created 2017-04-07

Last modified 3 months 1 week ago

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"The Association between Depressive Symptoms and Social Support in Taiwanese Women During the Month" (2004), by Shu-Shya Heh et al.

By Cecilia Chou

In 2004, Shu-Shya Heh, Lindsey Coombes, and Helen Bartlett studied the association between Chinese postpartum (post-childbirth) practices and postpartum depression in Taiwanese women. The researchers surveyed Taiwanese women about the social support they received after giving birth and then evaluated the depression rates in the same women. Heh and her colleagues focused on the month following childbirth, which according to traditional Chinese medicine, is an important period that warrants a set of specialized practices to aid the woman's recovery.

Created 2017-04-11

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“A Linkage Between DNA Markers on the X Chromosome and Male Sexual Orientation” (1993), by Dean H. Hamer and Charles A. Thomas.

By Christina Nguyen

In 1993, Dean H. Hamer and colleagues in the US published results from their research that indicated that men with speicifc genes were more likely to be homosexual than were men without those genes. The study hypothesized that some X chromosomes contain a gene, Xq28, that increases the likelihood of an individual to be homosexual. Prior to those results, researchers had argued that the cause of homosexuality was environmental and that homosexuality could be altered or reversed. Hamer’s research suggested a possible genetic cause of homosexuality.

Created 2017-04-13

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The Meselson-Stahl Experiment (1957–1958), by Matthew Meselson and Franklin Stahl

By Victoria Hernandez

In an experiment later named for them, Matthew Stanley Meselson and Franklin William Stahl in the US demonstrated during the 1950s the semi-conservative replication of DNA, such that each daughter DNA molecule contains one new daughter subunit and one subunit conserved from the parental DNA molecule. The researchers conducted the experiment at California Institute of Technology (Caltech) in Pasadena, California, from October 1957 to January 1958.

Created 2017-04-18

Last modified 3 months 1 week ago

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Treatment of Anemia during Pregnancy (1931), by Lucy Wills

By Lauren Lynch

In 1931, physician Lucy Wills conducted a study of nutritional deficiencies that caused anemia in pregnant women in Bombay, India, later renamed Mumbai. Anemia is a lack of healthy red blood cells in the blood. Wills published the results of her study in the medical article 'Treatment of ‘Pernicious Anaemia of Pregnancy' and 'Tropical Anaemia'' in the British Medical Journal in 1931. Wills's research contributed to knowledge of anemia and the possible causes associated with the disease, such as the symptoms of fatigue and irritability.

Created 2017-04-20

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Serial Cultivation of Human Diploid Cells in the Lab (1958–1961) by Leonard Hayflick and Paul S. Moorhead

By Christian H. Ross

From 1958 to 1961, Leonard Hayflick and Paul Moorhead in the US developed a way in the laboratory to cultivate strains of human cells with complete sets of chromosomes. Previously, scientists could not sustain cell cultures with cells that had two complete sets of chromosomes like normal human cells (diploid). As a result, scientists struggled to study human cell biology because there was not a reliable source of cells that represented diploid human cells. In their experiments, Hayflick and Moorhead created lasting strains of human cells that retained both complete sets of chromosomes.

Created 2017-04-27

Last modified 2 months 2 weeks ago

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