Roger Sperry’s Split Brain Experiments (1959–1968)

Roger Sperry’s Split Brain Experiments (1959–1968) Roger Sperry’s Split Brain Experiments (1959–1968)In the 1950s and 1960s, Roger Sperry performed experiments on cats, monkeys, and humans to study functional differences between the two hemispheres of the brain in the United States. To do so he studied the corpus callosum, which is a large bundle of neurons that connects the two hemispheres of the brain. Sperry severed the corpus callosum in cats and monkeys to study the function of each side of the brain. He found that if hemispheres were not connected, they functioned independently of one another, which he called a split-brain.

"RNA-Guided Human Genome Engineering via Cas 9" (2013), by Prashant Mali, Luhan Yang, Kevin M. Esvelt, John Aach, Marc Guell, James E. DiCarlo, Julie E. Norville, and George M. Church

"RNA-Guided Human Genome Engineering via Cas 9" (2013), by Prashant Mali, Luhan Yang, Kevin M. Esvelt, John Aach, Marc Guell, James E. DiCarlo, Julie E. Norville, and George M. ChurchIn 2013, George Church and his colleagues at Harvard University in Cambridge, Massachusetts published "RNA-Guided Human Genome Engineering via Cas 9," in which they detailed their use of RNA-guided Cas 9 to genetically modify genes in human cells. Researchers use RNA-guided Cas 9 technology to modify the genetic information of organisms, DNA, by targeting specific sequences of DNA and subsequently replacing those targeted sequences with different DNA sequences. Church and his team used RNA-guided Cas 9 technology to edit

David Baltimore (1938– )

David Baltimore (1938– )David Baltimore studied viruses and the immune system in the US during the twentieth century. In 1975, Baltimore was awarded the Nobel Prize in Physiology or Medicine for discovering reverse transcriptase, the enzyme used to transfer information from RNA to DNA. The discovery of reverse transcriptase contradicted the central dogma of biology at the time, which stated that the transfer of information was unidirectional from DNA, RNA, to protein. Baltimore’s research on reverse transcriptase led to the discovery of retroviruses, which accelerated the development of treatments for human immunodeficiency virus or HIV and cancer vaccines. Baltimore also influenced public policy and opinion on genetic engineering. In 1975, he helped organize the Asilomar Conference in Pacific Grove, California, which discussed

Equilibrium Density Gradient Centrifugation in Cesium Chloride Solutions Developed by Matthew Meselson and Franklin Stahl

Equilibrium Density Gradient Centrifugation in Cesium Chloride Solutions Developed by Matthew Meselson and Franklin StahlMatthew Meselson, Franklin Stahl, and Jerome Vinograd, developed cesium chloride, or CsCl, density gradient centrifugation in the 1950s at the California Institute of Technology, or Caltech, in Pasadena, California. Density gradient centrifugation enables scientists to separate substances based on size, shape, and density. Meselson and Stahl invented a specific type of density gradient centrifugation, called isopycnic centrifugation that used a solution of cesium chloride to separate DNA molecules based on density alone.

Annie Dodge Wauneka (1910-1997)

Annie Dodge Wauneka (1910-1997) Annie Dodge Wauneka, a member of the Navajo Tribal Council in Window Rock, Arizona, from 1951 to 1978, advocated for improved lifestyle, disease prevention, and access to medical knowledge in the Navajo Indian Reservation, later renamed the Navajo Nation. Wauneka served as chair of the Health and Welfare Committee of the Navajo Tribal Council and as a member of the US Surgeon General’s Advisory Committee on Indian Health. Wauneka advocated for initiatives aimed at promoting education, preventing tuberculosis, and reducing the infant mortality rate. In 1963, she was awarded the Presidential Medal of Freedom. Wauneka’s initiatives to educate mothers about child health and increase hospital births reduced infant mortality rates in the Navajo Indian Reservation during the twentieth century.

Elizabeth Blackwell (1821–1910)

Elizabeth Blackwell (1821–1910)In the nineteenth century, Elizabeth Blackwell was a women’s healthcare reformer and the first woman to receive her medical degree in the United States. She practiced medicine as a primary care physician in both the United States and the United Kingdom. Blackwell graduated medical school from Geneva Medical College in Geneva, New York, where she was the first woman to receive a medical degree in the US. Throughout her career, Blackwell focused on her patients’ rights to access healthcare and education pertaining to healthcare, particularly the rights of women and children, whom she treated in a hospital she cofounded. Blackwell influenced the medical care during the Civil War in the United States by training nurses to treat soldiers injured in battle.

“The History of Twins, As a Criterion of the Relative Powers of Nature and Nurture” (1875), by Francis Galton

“The History of Twins, As a Criterion of the Relative Powers of Nature and Nurture” (1875), by <a href="/search?text=Francis%20Galton" title="" class="lexicon-term">Francis Galton</a>In the article “The History of Twins, As a Criterion of the Relative Powers of Nature and Nurture,” Francis Galton describes his study of twins. Published in 1875 in Fraser’s Magazine in London, England, the article lays out Galton’s use of twins to examine and distinguish between the characteristics people have at birth and the characteristics they receive from the circumstances of life and experience. Galton calls those factors nature and nurture. Based on his study, Galton concluded that nature has a larger effect than nurture on development.

Christopher Polge and Lionel Edward Aston Rowson’s Experiments on the Freezing of Bull Spermatozoa (1950–1952)

Christopher Polge and Lionel Edward Aston Rowson’s Experiments on the Freezing of Bull Spermatozoa (1950–1952)In 1952, researchers Christopher Polge and Lionel Edward Aston Rowson, who worked at the Animal Research Center in Cambridge, England, detailed several experiments on protocols for freezing bull semen for use in the artificial insemination of cows. Freezing sperm extends the life of a viable sperm sample and allows it to be used at later times,

Symptoms Associated with Polycystic Ovarian Syndrome (PCOS)

Symptoms Associated with Polycystic Ovarian Syndrome (PCOS)Polycystic ovarian syndrome or PCOS is one of the most common reproductive conditions in women, and its symptoms include cystic ovaries, menstrual irregularities, and elevated androgen or male sex hormone levels. During the 1930s, Irving Freiler Stein and Michael Leventhal identified the syndrome and its symptoms. Women who experience symptoms of PCOS may also experience secondary symptoms, including infertility and diabetes. Though estimates vary and the causes of the syndrome are not clear as of 2017, PCOS affects approximately ten percent of women of reproductive age. Women who suspect they have symptoms of PCOS should see a doctor, as early

Nancy Goodman Brinker (1946– )

Nancy Goodman Brinker (1946– )Nancy Goodman Brinker founded the largest breast cancer organization in the US, Susan G. Komen for the Cure, during the twentieth century. In 1982, Brinker created the organization, Susan G. Komen for the Cure, in memory of her sister, who had died of breast cancer two years earlier. During the early twentieth century, breast cancer was socially stigmatized, very few people discussed the disease, and there were limited treatment options available for those diagnosed with the disease. Breast cancer is one of the most prevalent forms of cancer and it affects almost 12 percent of women worldwide. In 1983, Brinker created the Susan G. Komen Race for Cure, a fundraising and awareness event for breast cancer.