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The Shettles Method of Sex Selection

In the 1960s in the United States Landrum B. Shettles developed the Shettles method, which is a procedure for couples to use prior to and during an intercourse to increase their chances of conceiving a fetus of their desired sex. Shettles, a physician, who specialized in obstetrics and gynecology, found a difference in the size and shape of male sperm cells that he correlated with the different sex chromosomes they carry.

Format: Articles

Subject: Technologies, Reproduction

Using Digital PCR to Detect Fetal Chromosomal Aneuploidy in Maternal Blood (2007)

In 2007, Dennis Lo and his colleagues used digital polymerase chain reaction or PCR to detect trisomy 21 in maternal blood, validating the method as a means to detect fetal chromosomal aneuploidies, or an abnormal number of chromosomes in a cell. The team conducted their research at the Chinese University of Hong Kong in Hong Kong, Hong Kong, and at the Boston University in Boston, Massachusetts.

Format: Articles

Subject: Experiments

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

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.

Format: Articles

Subject: Experiments

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

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.

Format: Articles

Subject: Experiments

Wolbachia

Bacteria of the genus Wolbachia are
bacteria that live within the cells of their hosts. They infect a
wide range of arthropods (insects, arachnids, and crustaceans) and
some nematodes (parasitic roundworms). Scientists estimate that
Wolbachia exist in between seventeen percent and seventy-six percent of
arthropods and nematodes. The frequency of the bacteria makes them
one of the most widespread parasites. In general, they are divided
into five groups, from A to E, depending of the species of their

Format: Articles

Subject: Organisms

Preformationism in the Enlightenment

Preformationism was a theory of embryological development used in the late seventeenth through the late eighteenth centuries. This theory held that the generation of offspring occurs as a result of an unfolding and growth of preformed parts. There were two competing models of preformationism: the ovism model, in which the location of these preformed parts prior to gestation was the maternal egg, and the spermism model, in which a preformed individual or homunculus was thought to exist in the head of each sperm.

Format: Articles

Subject: Theories

"Experimental Chimeras' Removal of Reproductive Barrier Between Sheep and Goat" (1984), by Sabine Meinecke-Tillmann and Burkhard Meinecke

In 1984 Sabine Meinecke-Tillmann and Burkhard Meinecke published their article "Experimental Chimeras - Removal of Reproductive Barrier Between Sheep and Goat" in Nature. Their study conquered the reproductive barrier between sheep and goats through embryo manipulation. Their article appeared in Nature on the same day that a similar experiment, conducted by Carole Fehilly, Steen Willadsen, and Elizabeth Tucker was published regarding reproductive barriers between sheep and goats.

Format: Articles

Subject: Experiments

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

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.

Format: Articles

Subject: Processes, Experiments

Torsten Wiesel (1924– )

Torsten Nils Wiesel studied visual information processing and development in the US during the twentieth century. He performed multiple experiments on cats in which he sewed one of their eyes shut and monitored the response of the cat’s visual system after opening the sutured eye. For his work on visual processing, Wiesel received the Nobel Prize in Physiology or Medicine in 1981 along with David Hubel and Roger Sperry.

Format: Articles

Subject: People

Edward Stuart Russell (1887-1954)

Edward Stuart Russell was born 23 March 1887 to Helen Cockburn Young and the Reverend John N. Russell in Port Glasgow, Scotland. Friends and co-workers alike knew Russell as a quiet and focused, though always kind and helpful person. Trained in classics and biology, Russell's interests drew him to the study of historical and philosophical issues in the biological sciences, particularly morphology and animal behavior. According to Nils Roll-Hansen, Russell was one of the most influential philosophers of biology in the second third of the twentieth century.

Format: Articles

Subject: People

Catherine DeAngelis (1940– )

In the late-twentieth century in the United States, Catherine DeAngelis was a pediatric physician, researcher, and editor of multiple medical journals. During her time with the Journal of the American Medical Association, DeAngelis became the journal’s first female editor. At Johns Hopkins University in Baltimore, Maryland, she studied how physician-nurse interactions affected patient care, how immunizations and adolescent pregnancy affected children, and how medications affected men and women differently.

Format: Articles

Subject: People

Mizuko Kuyo

Mizuko Kuyo is a Japanese Buddhist ceremony that focuses on a deceased fetus or stillborn child. This ceremony was originally developed to honor Jizo, a god believed to be responsible for transporting dead fetuses or children to the other world. The practice has become more popular in the last half century due to the growing number of abortions taking place and the particular views that Japanese Buddhists have about fetuses and abortion.

Format: Articles

Subject: Religion, Reproduction

History of the Monash IVF Research Program from 1971 to 1989

In 1971, a group of researchers founded the Monash IVF Research Program with the mission to discover how in vitro fertilization, or IVF, techniques could become a treatment for infertility in both men and women. The program included researcher Carl Wood and colleagues John Leeton, Alex Lopata, Alan Trounson, and Ian Johnston at the Queen Victoria Medical Center and Royal Women’s Hospital in Melbourne, Australia. Since the program’s establishment in 1971, the Monash IVF Research Program has helped to develop and implement many IVF technologies still used in clinical practice as of 2020.

Format: Articles

Subject: Organizations, Reproduction

“The Stein-Leventhal Syndrome: A Curable Form of Sterility” (1958), by Irving Freiler Stein Sr.

In 1958, Irving Freiler Stein Sr. published “The Stein-Leventhal Syndrome: A Curable Form of Sterility” documenting his findings on the diagnosis and surgical treatment of Stein-Leventhal syndrome. Stein-Leventhal syndrome, later called polycystic ovarian syndrome (PCOS), affects the reproductive health of women. Common symptoms include excess body hair, a lack of menstrual cycle or amenorrhea, and infertility. As of 2017, polycystic ovarian syndrome is considered the most common reproductive health disorder among women in the United States.

Format: Articles

Subject: Publications

Corticosteroids' Effect on Fetal Lung Maturation (1972), by Sir Graham Collingwood Liggins and Ross Howie

In a clinical trial from 1969 to 1972, Sir Graham Collingwood Liggins and Ross Howie showed that if doctors treat pregnant women with corticosteroids before those women deliver prematurely, then those women's infants have fewer cases of respiratory distress syndrome than do similarly premature infants of women not treated with corticosteroids. Prior to the study, premature infants born before 32 weeks of gestation often died of respiratory distress syndrome, or the inability to inflate immature lungs.

Format: Articles

Subject: Experiments

"The Development of the Turtle Carapace" (1989), by Ann Campbell Burke

Ann Campbell Burke examines the development and evolution of vertebrates, in particular, turtles. Her Harvard University experiments, described in Development of the Turtle Carapace: Implications for the Evolution of a Novel Bauplan, were published in 1989. Burke used molecular techniques to investigate the developmental mechanisms responsible for the formation of the turtle shell.

Format: Articles

Subject: Experiments, Publications

Niemann-Pick Disease

In 1914 Albert Niemann, a German pediatrician who primarily studied infant metabolism, published a description of an Ashkenazi Jewish infant with jaundice, nervous system and brain impairments, swollen lymph nodes (lymphadenopathy), and an enlarged liver and spleen (hepatosplenomegaly). He reported that these anatomical disturbances resulted in the premature death of the child at the age of eighteen months. After extensively studying the abnormal characteristics of the infant, Niemann came to the conclusion that the disease was a variant of Gaucher's disease.

Format: Articles

Subject: Disorders

Mechanistic Realization of the Turtle Shell

Turtle morphology is unlike that of any other vertebrate. The uniqueness of the turtle's bodyplan is attributed to the manner in which the turtle's ribs are ensnared within its hard upper shell. The exact embryological and genetic mechanisms underpinning this peculiar anatomical structure are still a matter of debate, but biologists agree that the evolution of the turtle shell lies in the embryonic development of the turtle.

Format: Articles

Subject: Processes

The Hershey-Chase Experiments (1952), by Alfred Hershey and Martha Chase

In 1951 and 1952, Alfred Hershey and Martha Chase conducted a series of experiments at the Carnegie Institute of Washington in Cold Spring Harbor, New York, that verified genes were made of deoxyribonucleic acid, or DNA. Hershey and Chase performed their experiments, later named the Hershey-Chase experiments, on viruses that infect bacteria, also called bacteriophages. The experiments followed decades of scientists’ skepticism about whether genetic material was composed of protein or DNA.

Format: Articles

Subject: Experiments

"Genetic Programming: Artificial Nervous Systems, Artificial Embryos and Embryological Electronics" (1991), by Hugo de Garis

In 1991, Hugo de Garis' article "Genetic Programming: Artificial Nervous Systems, Artificial Embryos and Embryological Electronics" was published in the book Parallel Problem Solving from Nature. With this article de Garis hoped to create what he envisioned as a new branch of artificial embryology called embryonics (short term for "embryological electronics"). Embryonics is based on the idea of adapting the processes found in embryonic development to build artificial systems.

Format: Articles

Subject: Publications

Wilhelm Roux (1850-1924)

Wilhelm Roux was a nineteenth-century experimental embryologist who was best known for pioneering Entwicklungsmechanik, or developmental mechanics. Roux was born in Jena, Germany, on 9 June 1850, the only son of Clotilde Baumbach and a university fencing master, F. A. Wilhelm Ludwig Roux. Roux described himself as an aloof child, but when he was fourteen he cultivated a passion for science that was encouraged by the director at Oberrealschule in Meiningen.

Format: Articles

Subject: People

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, such as in artificial insemination. The researchers examined the effects of freezing conditions on bull sperm and how well they produce fertilized embryos once thawed.

Format: Articles

Subject: Experiments

Bernadine Healy (1944–2011)

During the twentieth century in the United States, Bernadine Patricia Healy was a cardiologist who served as the first female director of the National Institutes of Health or NIH and the president of both the American Heart Association and the American Red Cross. Healy conducted research on the different manifestations of heart attacks in women compared to men. At the time, many physicians underdiagnosed and mistreated coronary heart disease in women. Healy's research illustrated how coronary heart disease affected women.

Format: Articles

Subject: People

Dictyostelium discoideum

Dictyostelium discoideum is a cellular slime mold that serves as an important model organism in a variety of fields. Cellular slime molds have an unusual life cycle. They exist as separate amoebae, but after consuming all the bacteria in their area they proceed to stream together to form a multicellular organism. These features make it a valuable tool for studying developmental processes and also for investigating the evolution of multicellularity. Long thought to be a type of fungus, it has recently been shown that slime molds in fact bear no relation to fungi.

Format: Articles

Subject: Organisms