Articles

Displaying 921 - 930 of 1065 items.

"Experiments on Artificial Parthenogenesis in Annelids (Chaetopterus) and the Nature of the Process of Fertilization" (1901), by Jacques Loeb

By Steve Elliott

Jacques Loeb showed that scientists could achieve artificial parthenogenesis with some types of annelid worm eggs through a series of experiments in 1900. Loeb published the results of his experiments in 1901 as "Experiments on Artificial Parthenogenesis in Annelids (Chaetopterus) and the Nature of the Process of Fertilization," in The American Journal of Physiology. Loeb 's results broadened the range of animals to which artificial parthenogenesis applied beyond sea urchins.

Format: Articles

Subject: Experiments

Jacques Loeb (1859-1924)

By Steve Elliott

Jacques Loeb experimented on embryos in Europe and the United States at the end of the nineteenth and beginning of the twentieth centuries. Among the first to study embryos through experimentation, Loeb helped found the new field of experimental embryology. Notably, Loeb showed scientists how to create artificial parthenogenesis, thus refuting the idea that spermatozoa alone were necessary to develop eggs into embryos and confirming the idea that the chemical constitution of embryos environment affected their development.

Format: Articles

Subject: People

Translational Developmental Biology

By Mary E. Sunderland

Translational developmental biology is a growing approach to studying biological phenomena that explicitly aims to develop medical therapies. When discussing the generation of new therapies it is often argued that they will emerge as a "translation" from "fundamental biology." Although translational research is not a new term, "translational developmental biology" has been steadily gaining popularity as discoveries in cell and developmental biology, particularly those involving stem cells, provide a basis for regenerative medicine.

Format: Articles

Subject: Theories

Dictyostelium discoideum

By Mary E. Sunderland

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

Ricardo Hector Asch (1947- )

By Hilary Gilson

Ricardo Hector Asch was born 26 October 1947 in Buenos Aires, Argentina, to a lawyer and French professor, Bertha, and a doctor and professor of surgery, Miguel. Asch's middle-class family lived among the largest Jewish community in Latin America, where a majority of males were professionals. After his graduation from National College No. 3 Mariano Moreno in Buenos Aires, Asch worked as a teaching assistant in human reproduction and embryology at the University of Buenos Aires School of Medicine where he received his medical degree in 1971.

Format: Articles

Subject: Ethics, People

Thomas Hunt Morgan's Definition of Regeneration: Morphallaxis and Epimorphosis

By Mary E. Sunderland

For Thomas Hunt Morgan clarity was of utmost importance. He was therefore frustrated with the many disparate, disconnected terms that were used to refer to similar, if not the same, regenerative processes within organisms. When Morgan wrote Regeneration in 1901 there had been many different terms developed and adopted by various investigators to describe their observations. As a result there were many inconsistencies making it difficult to discuss results comparatively and also making it more challenging to generalize. Defining terms was a priority for Morgan.

Format: Articles

Subject: Theories

"Mechanistic Science and Metaphysical Romance" (1915), by Jacques Loeb

By Steve Elliott

Jacques Loeb published "Mechanistic Science and Metaphysical Romance" in 1915. His goal for the article was to outline his conception of mechanistic science and its relation to other methods of inquiry. Loeb argued that mechanistic science was the foundation of knowledge and humanity's progress depended on it. Loeb's argument altered the account of science he offered in The Mechanistic Conception of Life insofar as scientists no longer aimed merely to control nature, but also to understand nature s underlying elements and their mechanical relations.

Format: Articles

Subject: Publications

Assisted Human Reproduction Canada (AHRC)

By Katherine Brind'Amour

Established under the Assisted Human Reproduction (AHR) Act of 2004, Assisted Human Reproduction Canada (AHRC), also known as the Assisted Human Reproduction Agency of Canada, was created in 2006 to oversee research related to reproductive technologies and to protect the reproductive rights and interests of Canadian citizens. AHRC serves as a regulatory body for the development and use of such research and technology while enforcing the guidelines and restrictions laid out by the AHR Act.

Format: Articles

Subject: Organizations, Reproduction

Edwin Grant Conklin (1863-1952)

By D. Brian Scheurmann

Edwin Grant Conklin was born in Waldo, Ohio, on 24 November 1863 to parents Nancy Maria Hull and Dr. Abram V. Conklin. Conklin's family was very religious and he seriously considered a theistic path before choosing a career in academics. Conklin's scientific work was primarily in the areas of embryology, cytology, and morphology, though many questions regarding the relationships between science, society, and philosophy had an influence on both his writings and academic lectures.

Format: Articles

Subject: People

Charles Otis Whitman (1842-1910)

By D. Brian Schuermann

Charles Otis Whitman was an extremely curious and driven researcher who was not content to limit himself to one field of expertise. Among the fields of study to which he made significant contributions were: embryology; morphology, or the form of living organisms and the relationships between their structures; natural history; and behavior.

Format: Articles

Subject: People