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Displaying 851 - 875 of 881 items.

Allan Charles Wilson (1934-1991)

Allan C. Wilson studied genes, proteins, and body structures of animals and humans in the US during the second half of the twentieth century. Wilson also studied human evolution. Although morphology and behaviors of humans (Homo sapiens) and great apes differ, Wilson found that they have biochemical and genetic similarities. Wilson and his colleagues calculated the time period of humans' and African apes' common ancestor.

Format: Articles

Subject: People

Neurocristopathies

Neurocristopathies are a class of pathologies in vertebrates,
including humans, that result from abnormal expression, migration,
differentiation, or death of neural crest cells (NCCs) during embryonic development. NCCs are cells
derived from the embryonic cellular structure called the neural crest.
Abnormal NCCs can cause a neurocristopathy by chemically affecting the
development of the non-NCC tissues around them. They can also affect the
development of NCC tissues, causing defective migration or

Format: Articles

Subject: Theories

"Altruism and the Origin of the Worker Caste" from The Ants (1990), by Bert Hölldobler and Edward Osborne Wilson

In 'Altruism and the Origin of the Worker Caste,' Bert Hölldobler and Edward Osborne Wilson explore the evolutionary origins of worker ants. 'Altruism and the Origin of the Worker Caste' is the fourth chapter of Hölldobler and Wilson's book, The Ants, which was published by The Belknap Press of Harvard University in Cambridge, Massachusetts, in 1990. In 'Altruism and the Origin of the Worker Caste,' Hölldobler and Wilson evaluate various explanations for how a non-reproductive caste of ant evolved.

Format: Articles

Subject: Publications

Regeneration

Regeneration is a fascinating phenomenon. The fact that many organisms have the capacity to regenerate lost parts and even remake complete copies of themselves is difficult to fathom; so difficult, in fact, that for a very long time people were reluctant to believe regeneration actually took place. It seemed unbelievable that some organisms could re-grow lost limbs, organs, and other body parts. If only we could do the same!

Format: Articles

Subject: Processes

State v. New Times, INC (1973)

In the 1973 case State v. New Times, INC, the Arizona Court of Appeals in Phoenix, Arizona, ruled that Arizona Revised Statutes 13-211, 13-212, and 13-213, collectively called the Arizona abortion statutes, were unconstitutional. The statues made it illegal for anyone to receive, provide, or advertise abortion services. The Arizona Court of Appeals reviewed a case in which a city court in Tempe, Arizona, convicted the New Times, a newspaper headquartered in Phoenix, Arizona, of advertising abortion.

Format: Articles

Subject: Legal, Outreach

Progestin: Synthetic Progesterone

Progestin is a synthetic form of progesterone, a naturally occurring hormone, which plays an important role in the female reproductive cycle. During the 1950s two types of progestin that were later used in birth control pills were created, norethindrone and norethynodrel. In 1951 Carl Djerassi developed norethindrone at Syntex, S.A. laboratories located in Mexico City, receiving a patent on 1 May 1956. In 1953 Frank Colton developed norethynodrel at G.D. Searle and Company laboratories located in Chicago, receiving a patent on 29 November 1955.

Format: Articles

Subject: Technologies, Reproduction

Cystic Fibrosis

Cystic fibrosis (CF) is a fatal, inherited disease found in humans and characterized by buildup of thick, sticky mucus, particularly in the respiratory and digestive tracts. The abnormally thick mucus prevents the pancreas from functioning normally; it often leads to digestive problems and chronic lung infections. Cystic fibrosis is most prevalent in Caucasian individuals, and approximately 1 in every 29 individuals in the US is a carrier for the mutated CF gene.

Format: Articles

Subject: Disorders

45 CFR 46: Protection of Human Subjects under United States Law (1974)

In the United States, the Code of Federal Regulations Title 45: Public Welfare, part 46 (45 CFR 46) provides protection for human subjects in research carried out or supported by most federal departments and agencies. 45 CFR 46 created a common federal policy for the protection of such human subjects that was accepted by the Office of Science and Technology Policy and issued by each of the departments and agencies listed in the document.

Format: Articles

Subject: Legal

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

"Apoptosis: A Basic Biological Phenomenon with Wide-Ranging Implications in Tissue Kinetics" (1972), by John F. R. Kerr, Andrew H. Wyllie and Alastair R. Currie

"Apoptosis: A Basic Biological Phenomenon with Wide-Ranging Implications in Tissue Kinetics" (hereafter abbreviated as "Apoptosis") was published in the British Journal of Cancer in 1972 and co-authored by three pathologists who collaborated at the University of Aberdeen, Scotland. In this paper the authors propose the term apoptosis for regulated cell death that proceeds through active, controlled morphological changes. This is in contrast to necrosis, a passive mode of cell death that results from uncontrolled cellular reactions to injury or stress.

Format: Articles

Subject: Publications

The Source-Sink Model

The source-sink model, first proposed by biologist Francis Crick in 1970, is a theoretical system for how morphogens distribute themselves across small fields of early embryonic cells. A morphogen is a substance that determines the fate and phenotype of a group of cells through a concentration gradient of itself across that group. Crick’s theory has been experimentally confirmed with several morphogens, most notably with the protein bicoid , the first discovered morphogen. The model provides a theoretical structure for the understanding of some features of early embryonic development.

Format: Articles

Subject: Theories

Sir D'Arcy Wentworth Thompson (1860-1948)

Known by many for his wide-reaching interests and keen thinking, D'Arcy Wentworth Thompson was one of Britain's leading scientific academics in the first few decades of the twentieth century. A prodigious author, Thompson published some 300 papers, books, and articles in the biological sciences, classics, oceanography, and mathematics. He was a famous lecturer and conversationalist-a true "scholar-naturalist," as his daughter wrote in her biography of her father.

Format: Articles

Subject: People

Gonzales v. Carhart (2007)

In Gonzales v. Carhart (2007), the US Supreme Court held in a five-to-four decision that the 2003 Partial-Birth Abortion Ban Act passed by the US Congress was constitutional. Although the Court previously ruled in Stenberg v. Carhart (2000) that a Nebraska law that prohibited partial-birth abortions was unconstitutional, Gonzales reversed this decision. Gonzales created the precedent that anyone who delivers and kills a living fetus could be subject to legal consequences, unless he or she performed the procedure to save the life of the mother.

Format: Articles

Subject: Legal, Reproduction

"On the Permanent Life of Tissues outside of the Organism" (1912), by Alexis Carrel

'On the Permanent Life of Tissues outside of the Organism' reports Alexis Carrel's 1912 experiments on the maintenance of tissue in culture media. At the time, Carrel was a French surgeon and biologist working at the Rockefeller Institute in New York City. In his paper, Carrel reported that he had successfully maintained tissue cultures, which derived from connective tissues of developing chicks and other tissue sources, by serially culturing them.

Format: Articles

Subject: Experiments

Roman v. Roman (2006)

In the case Randy M. Roman v. Augusta N. Roman (2006), the Court of Appeals of Texas followed courts in other states and upheld the validity and enforceability of in vitro fertilization (IVF) consent agreements. The Romans, a divorced couple, each sought different outcomes for their cryopreserved preembryos created during their marriage. Randy Roman sought to have them destroyed, and Augusta Roman sought to implant them in an attempt to have biological children.

Format: Articles

Subject: Legal

In the Womb (2005), by Toby Mcdonald and National Geographic Channel

Written, produced, and directed by Toby Mcdonald, the 2005 National Geographic Channel film In the Womb uses the most recent technology to provide an intricate glimpse into the prenatal world. The technologies used, which include advanced photography, computer graphics, and 4-D ultrasound imaging, help to realistically illustrate the process of development and to answer questions about the rarely seen development of a human being.

Format: Articles

Subject: Outreach, Reproduction

Sonja Vernes, et al.'s Experiments On the Gene Networks Affected by the Foxp2 Protein (2011)

In 2011, Sonja Vernes and Simon Fisher performed a series of experiments to determine which developmental processes are controlled by the mouse protein Foxp2. Previous research showed that altering the Foxp2 protein changed how neurons grew, so Vernes and Fisher hypothesized that Foxp2 would affect gene networks that involved in the development of neurons, or nerve cells. Their results confirmed that Foxp2 affected the development of gene networks involved in the growth of neurons, as well as networks that are involved in cell specialization and cell communication.

Format: Articles

Subject: Experiments

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.

Format: Articles

Subject: Experiments

Planned Parenthood Center of Tucson, Inc., v. Marks (1972)

In the 1972 case Planned Parenthood Center of Tucson, Inc., v. Marks, the Arizona Court of Appeals required the Arizona Superior Court to rehear the case Planned Parenthood Association v. Nelson (1971) and issue a decision on the constitutionality of Arizona's abortion laws. In 1971, the Planned Parenthood Center of Tucson filed the case Planned Parenthood Association v. Nelson asking for the US District Court to rule on the constitutionality of the Arizona Revised Statutes 13-211, 13-212, and 13-213, which made it illegal for anyone to advertise, provide, or receive an abortion.

Format: Articles

Subject: Legal

“Elective Induction of Labor” (1955), by Edward Bishop

In 1955, obstetrician Edward Bishop, a physician specializing in childbirth, published the article “Elective Induction of Labor,” in which he proposed the best conditions for pregnant women to elect to induce, or begin, labor. Elective induction of labor requires an obstetrician to administer a drug to help a pregnant woman to start her contractions, and to rupture the fluid-filled sac surrounding the fetus called the amniotic sac.

Format: Articles

Subject: Reproduction, Publications

"Predictors of Postpartum Depression: An Update” (2001), by Cheryl Tatano Beck

In her 2001 paper “Predictors of Postpartum Depression: An Update,” researcher Cheryl Tatano Beck presents the most common risk factors associated with postpartum depression in women. Postpartum depression occurs when women experience symptoms such as tearfulness, extreme mood changes, and loss of appetite for a lengthened period after giving birth. At the University of Connecticut in Storrs, Connecticut, nursing professor Beck updated a previous study of hers by analyzing literature about postpartum depression published in the 1990s.

Format: Articles

Subject: Publications

The Arterial Switch Operation (1954-1975)

The arterial switch operation, also called the Jatene procedure, is an operation in which surgeons redirect the flow of blood through abnormal hearts. In 1975, Adib Jatene conducted the first successful arterial switch operation on a human infant. The arterial switch operation corrects a condition called transposition of the great arteries, abbreviated TGA, also called transposition of the great vessels, abbreviated TGV. TGA occurs when the pulmonary artery, which supplies deoxygenated blood to the lungs, and the aorta, which takes oxygenated blood to the body, are switched, or transposed.

Format: Articles

Subject: Technologies

The People of the State of New York v. Margaret H. Sanger (1918)

In 1918, the New York State Court of Appeals in Albany broadened the justification physicians could use to prescribe contraceptives to married patients in the case The People of the State of New York v. Margaret H. Sanger (People v. Sanger). The presiding judge of People v. Sanger, Frederick Crane, ruled that under Section 1145 of the New York Penal Code physicians could provide contraceptives to married couples for the prevention of disease.

Format: Articles

Subject: Legal

Beatrice Mintz (1921- )

Beatrice Mintz is a brilliant researcher who has developed techniques essential for many aspects of research on mouse development. She produced the first successful mouse chimeras and meticulously characterized their traits. She has worked with various cancers and produced viable mice from the cells of a teratoma. Mintz participated in the development of transgenic mice by the incorporation of foreign DNA into a mouse genome.

Format: Articles

Subject: People

Embryo Blotting Paper Models

Anatomical models have always been a mainstay of descriptive embryology. As the training of embryologists grew in the late 1800s, so too did the need for large-scale teaching models. Embryo wax models, such as those made by Adolf Ziegler and Gustav Born, were popular in the latter part of the nineteenth century and the early twentieth century as a way to visualize, in three dimensions, the fine detail of embryos without the aid of a microscope.

Format: Articles

Subject: Technologies