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Displaying 326 - 350 of 1038 items.

Rosalyn Sussman Yalow (1921-2011)

Rosalyn Sussman Yalow co-developed the radioimmunoassay (RIA), a method used to measure minute biological compounds that cause immune systems to produce antibodies. Yalow and research partner Solomon A. Berson developed the RIA in the early 1950s at the Bronx Veterans Administration (VA) Hospital, in New York City, New York. Yalow and Berson's methods expanded scientific research, particularly in the medical field, and contributed to medical diagnostics. For this achievement, Yalow received the Nobel Prize in Physiology or Medicine in 1977.

Format: Articles

Subject: People

Intraspecies Chimeras Produced in Laboratory Settings (1960-1975)

When cells-but not DNA-from two or more genetically distinct individuals combine to form a new individual, the result is called a chimera. Though chimeras occasionally occur in nature, scientists have produced chimeras in a laboratory setting since the 1960s. During the creation of a chimera, the DNA molecules do not exchange genetic material (recombine), unlike in sexual reproduction or in hybrid organisms, which result from genetic material exchanged between two different species. A chimera instead contains discrete cell populations with two unique sets of parental genes.

Format: Articles

Subject: Organisms, Processes

“Delayed Breastfeeding Initiation Increases Risk of Neonatal Mortality” (2006), by Karen Edmond Charles Zandoh, Maria Quigley, Seeba Amenga-Etego, Seth Oqusi-Agyei, and Betty Kirkwood

In March 2006, scientists from Ghana and the UK Karen Edmond, Charles Zandoh, Maria Quigley, Seeba Amenga-Etego, Seth Oqusi-Agyei, and Betty Kirkwood published their findings that early, consistent breastfeeding habits for mothers in Ghana resulted in better survival outcomes for their infants. The authors communicated those results in the paper “Delayed Breastfeeding Initiation Increases Risk of Neonatal Mortality,” or “Delayed Breastfeeding,” published in The American Academy of Pediatrics.

Format: Articles

Subject: Publications

Samuel Randall Detwiler (1890-1957)

Samuel Randall Detwiler was an embryologist who studied neural development in embryos and vertebrate retinas. He discovered evidence for the relationship between somites and spinal ganglia, that transplanted limbs can be controlled by foreign ganglia, and the plasticity of ganglia in response to limb transplantations. He also extensively studied vertebrate retinas during and after embryonic development.

Format: Articles

Subject: People

Susceptibility Assay

Charles Manning Child designed an experimental test, the susceptibility assay, to measure the effects of different toxins on developmental processes. The susceptibility assay measured an organism s vulnerability to death when it was submerged in a noxious solution. The assay involved immersing an organism in a solution that contained a depressant or inhibitory substance, such as alcohol, and then measuring the responses of the organism. Child interpreted these measurements as revealing information about the relative levels of metabolic activity within the organism.

Format: Articles

Subject: Technologies

Libbie Henrietta Hyman (1888-1969)

Libbie Henrietta Hyman was born into a recently immigrated Jewish family on 6 December 1888 in Des Moines, Iowa. One of many siblings and daughter to parents Sabina Neumann and Joseph Hyman, who did not particularly support her interests in science, Hyman excelled in school and indulged her interests in biology in her free time. From a young age, Hyman collected and cataloged flora around her home. Despite being valedictorian of her high school class, Hyman's first job was labeling cereal boxes in a local factory.

Format: Articles

Subject: People

Edmund Beecher Wilson (1856-1939)

Edmund Beecher Wilson contributed to cell biology, the study of cells, in the US during the end of the nineteenth and the beginning of the twentieth centuries. His three editions of The Cell in Development and Inheritance (or Heredity) in 1896, 1900, and 1925 introduced generations of students to cell biology. In The Cell, Wilson described the evidence and theories of his time about cells and identified topics for future study. He helped show how each part of the cell works during cell division and in every step of early development of an organism.

Format: Articles

Subject: People

California Proposition 71 (2004)

The California Stem Cell Research and Cures Act, also called Proposition 71, was a ballot
initiative proposed by California voters in 2004 to allocate three billion dollars of state
funds for stem cell research over ten years. Endorsed by California scientists and
patient-advocates, Prop 71 passed on 2 November 2004, amending the state constitution to make
stem cell research a constitutional right. In addition, Prop 71 led to the creation of the
California Institute for Regenerative Medicine (CIRM), in San Francisco, California to allocate

Format: Articles

Subject: Legal

Theodora (Theo) Emily Colborn (1927-2014)

Theodora Colborn studied how chemicals affect organisms as they develop and reproduce during the twentieth and twenty first centuries in the US. By the 1940s, researchers had reported that chemicals from agricultural and industrial processes affected how wild organisms developed, but in 1991, Colborn organized the Wingspread Conference in Racine, Wisconsin, at which a group of scientists classed these chemicals as environmentally harmful substances. Colborn and her colleagues called those chemicals endocrine disruptors, as they mimic or block the body's endocrine system.

Format: Articles

Subject: People

China's First Baby Conceived through In Vitro Fertilization-Embryonic Transfer, by Zhang Lizhu's Research Team

On 10 March 1988, China's first baby conceived through human in vitro fertilization (IVF) and embryo transfer (ET), commonly referred to as a test-tube baby, was born at the Peking Hospital (PUTH) in Beijing. This birth was reported in numerous media reports as a huge step forward in China's long march to keep pace with global advances in science and technology. Led by gynecologist Zhang Lizhu, the PUTH research team had devoted more than four years to the human IVF-ET project.

Format: Articles

Subject: Experiments, Reproduction

Human Papillomavirus (HPV) Strains 16 and 18

The Human Papillomavirus (HPV) strains 16 and 18 are the two most common HPV strains that lead to cases of genital cancer. HPV is the most commonly sexually transmitted disease, resulting in more than fourteen million cases per year in the United States alone. When left untreated, HPV leads to high risks of cervical, vaginal, vulvar, anal, and penile cancers. In 1983 and 1984 in Germany, physician Harald zur Hausen found that two HPV strains, HPV-16 and HPV-18, caused cervical cancer in women. In the early twenty first century, pharmaceutical companies Merck & Co.

Format: Articles

Subject: Theories

Human Papillomavirus (HPV) Strains 16 and 18

The Human Papillomavirus (HPV) strains 16 and 18 are the two most common HPV strains that lead to cases of genital cancer. HPV is the most commonly sexually transmitted disease, resulting in more than fourteen million cases per year in the United States alone. When left untreated, HPV leads to high risks of cervical, vaginal, vulvar, anal, and penile cancers. In 1983 and 1984 in Germany, physician Harald zur Hausen found that two HPV strains, HPV-16 and HPV-18, caused cervical cancer in women. In the early twenty first century, pharmaceutical companies Merck & Co.

Format: Articles

Subject: Theories

The Comstock Law (1873)

The Comstock Law was a controversial law because it limited the reproductive rights of women and violated every person's right to privacy. This federal law was the beginning of a long fight over the reproductive rights of women which is still being waged. Reproductive rights are important to embryology because they lead to the discussions regarding the morality of abortion, contraceptives, and ultimately the moral status of the embryo.

Format: Articles

Subject: Legal, Reproduction

August Karl Gustav Bier (1861–1949)

In the late nineteenth century, August Karl Gustav Bier was a surgeon in Germany who studied spinal cord anesthesia, later called spinal block. Bier found that, depending upon the amount of anesthesia introduced into the spinal cord, a large area of the human body could be numbed to various degrees. Bier established a procedure to numb individuals from the lower legs to the upper abdomen, with the individual’s numbness ranging from them feeling pressure on their body to them feeling nothing at all.

Format: Articles

Subject: People

Robert William Briggs (1911-1983)

Robert William Briggs was a prolific developmental biologist. However, he is most identified with the first successful cloning of a frog by nuclear transplantation. His later studies focused on the problem of how genes influence development.

Format: Articles

Subject: People

John Tyler Bonner (1920- )

The establishment and growth of developmental-evolutionary biology owes a great debt to the work of John Tyler Bonner. Bonner's studies of cellular slime molds have shed light on some of the big questions of biology including the origins of multicellularity and the nature of morphogenesis. The second child of Lilly Marguerite Stehli and Paul Bonner, John Tyler was born 12 May 1920 in New York City and spent his early years in Locust Valley, Long Island (late 1920s), France (1930), and London (1932).

Format: Articles

Subject: People

Thomas Joseph King Jr. (1921-2000)

Thomas Joseph King Jr. was a developmental biologist who, with fellow scientist Robert Briggs, pioneered a method of transplanting nuclei from blastula cells into fresh egg cells lacking nuclei. This method, dubbed nuclear transplantation, facilitated King's studies on cancer cell development. King's work was instrumental for the development of cloning of fish, insects, and mammals.

Format: Articles

Subject: People

Ernst Heinrich Philipp August Haeckel (1834-1919)

Ernst Heinrich Philipp August Haeckel was a prominent comparative anatomist and active lecturer in the late nineteenth and early twentieth centuries. He is most well known for his descriptions of phylogenetic trees, studies of radiolarians, and illustrations of vertebrate embryos to support his biogenetic law and Darwin's work with evolution. Haeckel aggressively argued that the development of an embryo repeats or recapitulates the progressive stages of lower life forms and that by studying embryonic development one could thus study the evolutionary history of life on earth.

Format: Articles

Subject: People

Sir Graham Collingwood Liggins (1926-2010)

Sir Graham Collingwood Liggins devoted much of his professional life to obstetric research. Liggins demonstrated that hormones created by the fetus helped initiate labor, rather than hormones originating solely from the mother. Liggins also discovered that cortisol given to pregnant mothers helped delay premature labor, and that it increased the likelihood that premature infants would breathe normally after birth. Prior to cortisol treatment, premature infants often died of respiratory distress syndrome characterized by the inability to inflate immature lungs.

Format: Articles

Subject: People, Reproduction

Charles Benedict Davenport (1866-1944)

Charles Benedict Davenport was an early twentieth-century experimental zoologist. Davenport founded both the Station for Experimental Evolution and the Eugenics Record Office at Cold Spring Harbor in New York. Though he was a talented statistician and skilled scientist, Davenport's scientific achievements are eclipsed by his lasting legacy as the scientific leader of the eugenics movement in the US.

Format: Articles

Subject: People, Reproduction

The Hayflick Limit

The Hayflick Limit is a concept that helps to explain the
mechanisms behind cellular aging. The concept states that a normal human
cell can only replicate and divide forty to sixty times before it
cannot divide anymore, and will break down by programmed cell death
or apoptosis. The concept of the Hayflick Limit revised Alexis
Carrel's earlier theory, which stated that cells can replicate
themselves infinitely. Leonard Hayflick developed the concept while
at the Wistar Institute in Philadelphia,

Format: Articles

Subject: Theories

Lydia Estes Pinkham (1819–1883)

Lydia Estes Pinkham invented and sold Lydia Pinkham’s Vegetable Compound, a medicinal tonic used to treat menstrual discomfort and promote female reproductive health in general, in the US during the nineteenth century. Pinkham also founded Mrs. Lydia E. Pinkham Medicine Company, a business that sold natural remedies for women’s health issues. Throughout her life, Pinkham acted as an authority on female wellness, writing medical pamphlets about female anatomy and reproductive processes.

Format: Articles

Subject: People

Beadle and Ephrussi's Transplantation Technique for Drosophila

Boris Ephrussi and George Wells Beadle developed a transplantation technique on flies, Drosophila melanogaster, which they described in their 1936 article A Technique of Transplantation for Drosophila. The technique of injecting a tissue from one fly larva into another fly larva, using a micropipette, to grow that tissue in the second larvae, was a means for investigating development of Drosophila. Through this technique, Beadle and Ephrussi studied the role of genes in embryological processes.

Format: Articles

Subject: Technologies

Advanced Cell Technology, Inc.

Advanced Cell Technology, Inc. (ACT) is a biotechnology company that uses stem cell technology to develop novel therapies in the field of regenerative medicine. Formed in 1994, ACT grew from a small agricultural cloning research facility located in Worcester, Massachusetts, into a multi-locational corporation involved in using both human embryonic stem cells (hESC) and human adult stem cells as well as animal cells for therapeutic innovations.

Format: Articles

Subject: Organizations, Reproduction

Hematopoietic Stem Cells

The discovery of hematopoietic stem cells (HSCs) provided a pioneering step in stem cell research. HSCs are a type of multipotent adult stem cell, characterized by their ability to self-renew and differentiate into erythrocyte (red blood cell) and leukocyte (white blood cell) cell lineages. In terms of function, these cells are responsible for the continual renewal of the erythrocytes, leukocytes, and platelets in the body through a process called hematopoiesis. They also play an important role in the formation of vital organs such as the liver and spleen during fetal development.

Format: Articles

Subject: Processes