Matching Items (105)
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The development of the vertebrate musculoskeletal system is a highly dynamic process, requiring tight control of the specification and patterning of myogenic, chondrogenic and tenogenic cell types. Development of the diverse musculoskeletal lineages from a common embryonic origin in the paraxial mesoderm indicates the presence of a regulatory network of

The development of the vertebrate musculoskeletal system is a highly dynamic process, requiring tight control of the specification and patterning of myogenic, chondrogenic and tenogenic cell types. Development of the diverse musculoskeletal lineages from a common embryonic origin in the paraxial mesoderm indicates the presence of a regulatory network of transcription factors that direct lineage decisions. The basic helix-loop-helix transcription factor, PARAXIS, is expressed in the paraxial mesoderm during vertebrate somitogenesis, where it has been shown to play a critical role in the mesenchymal-to-epithelial transition associated with somitogenesis, and the development of the hypaxial skeletal musculature and axial skeleton. In an effort to elucidate the underlying genetic mechanism by which PARAXIS regulates the musculoskeletal system, I performed a microarray-based, genome-wide analysis comparing transcription levels in the somites of Paraxis-/- and Paraxis+/+ embryos. This study revealed targets of PARAXIS involved in multiple aspects of mesenchymal-to-epithelial transition, including Fap and Dmrt2, which modulate cell-extracellular matrix adhesion. Additionally, in the epaxial dermomyotome, PARAXIS activates the expression of the integrin subunits a4 and a6, which bind fibronectin and laminin, respectively, and help organize the patterning of trunk skeletal muscle. Finally, PARAXIS activates the expression of genes required for the epithelial-to-mesenchymal transition and migration of hypaxial myoblasts into the limb, including Lbx1 and Met. Together, these data point to a role for PARAXIS in the morphogenetic control of musculoskeletal patterning.
ContributorsRowton, Megan (Author) / Rawls, Alan (Thesis advisor) / Wilson-Rawls, Jeanne (Committee member) / Kusumi, Kenro (Committee member) / Gadau, Juergen (Committee member) / Arizona State University (Publisher)
Created2013
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This project focuses on the history of how teratogens, or agents which have the potential to cause birth defects, have been understood and tested for teratogenic potential in the US over the twentieth century. Prior to this time, teratogen studies were primarily concerned with cataloguing defects rather than exploring possible

This project focuses on the history of how teratogens, or agents which have the potential to cause birth defects, have been understood and tested for teratogenic potential in the US over the twentieth century. Prior to this time, teratogen studies were primarily concerned with cataloguing defects rather than exploring possible causes. At the turn of the twentieth century, experimental teratogen studies with the aim of elucidating mechanisms commenced. However, these early studies did not aim to discover human pregnancy outcomes and ways to prevent them, but simply focused on the results of exposing pregnant mammals to various physical and chemical insults. My project documents the change in understanding of teratogens over the twentieth century, the advancement of testing methods, and the causes of these advancements. Through the Embryo Project at Arizona State University (embryo.asu.edu), a digital encyclopedia for topics related to embryology, development, and reproductive medicine, I wrote ten encyclopedic articles that focused on chemical mechanisms of various teratogens, testing limitations in animal models, and legal and regulatory responses to well-known teratogens. As an extension of my previous work, this project bridges the current gap in research and focuses on contextualizing major events in the field of teratology to determine how these events led to various shifts in the understanding of birth defects and their causes, and how those conceptual shifts led to the creation of teratological testing guidelines. Results show that throughout the twentieth century, there are four distinct shifts in the understanding of teratogens: the first being 1900-1945, the second being 1946-1960, the third being 1961-1980, and the fourth being 1981-2000.
ContributorsTantibanchachai, Chanapa (Author) / Maienschein, Jane (Thesis director) / Laubichler, Manfred (Committee member) / O'Neil, Erica (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2014-05
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The Embryo Project (EP) Encyclopedia is an online database that has consolidated hundreds of development-related research articles, with subcategories addressing the context of such research. These articles are written by undergraduate students, graduate students, and professionals in the fields of biology, history, and other fields, and are intended for a

The Embryo Project (EP) Encyclopedia is an online database that has consolidated hundreds of development-related research articles, with subcategories addressing the context of such research. These articles are written by undergraduate students, graduate students, and professionals in the fields of biology, history, and other fields, and are intended for a diverse audience of readers from both biology and non-biology related backgrounds. As the EP addresses a public audience, it is imperative to utilize all possible means to share the information that each article covers. Until 2013, the EP Encyclopedia did not present images in articles as no formal protocol for image development existed. I have created an image style guide that outlines the basic steps of creating and submitting an image that can complement an EP article and can enhance a reader's understanding of the discussed concept. In creating this style guide, I investigated similar protocols used by other scientific journals and medical professionals. I also used different programs and based my style guide off of the procedures I used in Adobe Illustrator CS6.
ContributorsHamidi, Neekta (Author) / Maienschein, Jane (Thesis director) / Crowe, Nathan (Committee member) / O'Neil, Erica (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
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Endocrine-disrupting chemicals (EDCs) are substances that disrupt the function of the endocrine system by blocking or mimicking hormones. Over the years, these substances have been identified as responsible for producing adverse reproductive effects in freshwater vertebrate populations. Freshwater vertebrates include reptiles, amphibians, and fish living in bodies of water such

Endocrine-disrupting chemicals (EDCs) are substances that disrupt the function of the endocrine system by blocking or mimicking hormones. Over the years, these substances have been identified as responsible for producing adverse reproductive effects in freshwater vertebrate populations. Freshwater vertebrates include reptiles, amphibians, and fish living in bodies of water such as lakes or streams and are exposed when concentrations of EDCs enter their habitats. With over 800 known or potential EDCs identified, ample studies can be conducted on the effects of EDCs on freshwater vertebrates; however, studies can be costly. Since studies are costly, I have developed a methodology to prioritize EDC studies. I analyzed ten EDCs to determine their impact on freshwater vertebrates. I specified four criteria and EDCs that passed all four criteria were considered significant. The four criteria I utilized were population decreases, routes of exposure, adverse reproductive effects, and environmental persistence. I analyzed research studies as evidence for the pass or fail of each criterion, where I considered the EDC "ambiguous" if there was not enough information to make a judgment. I then assessed the research available for each EDC. Only one EDC had adequate information to pass or fail each criterion. The one with adequate information passed all criteria. Two EDCs lacked adequate information for three of the four criteria, three EDCs lacked adequate information for two of the four criteria, and four EDCs lacked adequate information for one of the four criteria. I assessed the EDCs based on whether there was adequate information available in each criterion in order to provide researchers direction for future research endeavors. The results indicate either there is much research that remains to be conducted or that researchers are not making existing results of studies available. Companies producing EDCs that are released into the environment can use the information in this report as a basis for determining strategies to minimize the impacts of EDCs on freshwater vertebrates.
ContributorsCooper, Samantha Lynn (Author) / Rittmann, Bruce (Thesis director) / Valentine, Teresa A. (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2015-05
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Biology textbooks are everybody's business. In accepting the view that texts are created with specific social goals in mind, I examined 127 twentieth-century high school biology textbooks for representations of animal development. Paragraphs and visual representations were coded and placed in one of four scientific literacy categories: descriptive, investigative, nature

Biology textbooks are everybody's business. In accepting the view that texts are created with specific social goals in mind, I examined 127 twentieth-century high school biology textbooks for representations of animal development. Paragraphs and visual representations were coded and placed in one of four scientific literacy categories: descriptive, investigative, nature of science, and human embryos, technology, and society (HETS). I then interpreted how embryos and fetuses have been socially constructed for students. I also examined the use of Haeckel's embryo drawings to support recapitulation and evolutionary theory. Textbooks revealed that publication of Haeckel's drawings was influenced by evolutionists and anti-evolutionists in the 1930s, 1960s, and the 1990s. Haeckel's embryos continue to persist in textbooks because they "safely" illustrate similarities between embryos and are rarely discussed in enough detail to understand comparative embryology's role in the support of evolution. Certain events coincided with changes in how embryos were presented: (a) the growth of the American Medical Association (AMA) and an increase in birth rates (1950s); (b) the Biological Sciences Curriculum Study (BSCS) and public acceptance of birth control methods (1960s); (c) Roe vs. Wade (1973); (d) in vitro fertilization and Lennart Nilsson's photographs (1970s); (e) prenatal technology and fetocentrism (1980s); and (f) genetic engineering and Science-Technology-Society (STS) curriculum (1980s and 1990s). By the end of the twentieth century, changing conceptions, research practices, and technologies all combined to transform the nature of biological development. Human embryos went from a highly descriptive, static, and private object to that of sometimes contentious public figure. I contend that an ignored source for helping move embryos into the public realm is schoolbooks. Throughout the 1900s, authors and publishers accomplished this by placing biology textbook embryos and fetuses in several different contexts--biological, technological, experimental, moral, social, and legal.
ContributorsWellner, Karen L (Author) / Maienschein, Jane (Thesis advisor) / Ellison, Karin D. (Committee member) / Robert, Jason S. (Committee member) / Arizona State University (Publisher)
Created2010
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Edwin Carlyle Wood, also known as Carl Wood, was a physician who helped develop in vitro fertilization, or IVF, treatments. From 1964 to 1992, Wood worked as a professor of obstetrics and gynecology at Monash University in Melbourne, Australia, where he was one of the first in the world to

Edwin Carlyle Wood, also known as Carl Wood, was a physician who helped develop in vitro fertilization, or IVF, treatments. From 1964 to 1992, Wood worked as a professor of obstetrics and gynecology at Monash University in Melbourne, Australia, where he was one of the first in the world to lead a team of physicians to establish IVF as a proven treatment for infertility. IVF refers to a medical procedure in which scientists inseminate an egg cell with a sperm cell outside of the body, such as in a glass dish in a clinical setting. Wood helped establish some of the first successful IVF pregnancies and births, and his findings throughout his years of practice helped to standardize the procedure. Wood also advocated for the right for women to have an abortion, and co-founded the Family Planning Association of Victoria in Australia at a time when there were not many abortion clinics in operation. Through his early contributions to IVF, Wood provided new options for people to have offspring, which as of 2021, has up to a 21.3 percent chance of producing a live birth.

Created2021-04-01
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On 29 September 1973, researchers David De Kretzer, Peter Dennis, Bryan Hudson, John Leeton, Alexander Lopata, Ken Outch, James Talbot, and Carl Wood published “Transfer of a Human Zygote,” in The Lancet. In the article, the authors describe an experiment that resulted in one of the first pregnancies established via

On 29 September 1973, researchers David De Kretzer, Peter Dennis, Bryan Hudson, John Leeton, Alexander Lopata, Ken Outch, James Talbot, and Carl Wood published “Transfer of a Human Zygote,” in The Lancet. In the article, the authors describe an experiment that resulted in one of the first pregnancies established via in vitro fertilization, or IVF. Prior to the article’s publication in 1973, there was no published evidence demonstrating whether IVF treatment would work in humans, although evidence existed showing that IVF worked in other mammals for breeding purposes. At the end of the article, the authors state that the embryo failed to implant into the wall of the patient’s uterus, leading to a miscarriage less than a week after the authors found evidence of pregnancy in the patient. The authors of “Transfer of a Human Zygote” were some of the first researchers to perform IVF, although unsuccessfully, which contributed to the overall understanding of IVF as an emerging technology.

Created2021-03-25
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Between February 1969 and August 1970 Edward Kollar and Grace Baird, from the University of Chicago in Chicago, Illinois, published three papers that established the role of the mesenchyme in tooth induction. Drawing upon a history of using tissue interactions to understand differentiation, Kollar and Baird designed their experiments to

Between February 1969 and August 1970 Edward Kollar and Grace Baird, from the University of Chicago in Chicago, Illinois, published three papers that established the role of the mesenchyme in tooth induction. Drawing upon a history of using tissue interactions to understand differentiation, Kollar and Baird designed their experiments to understand how differentiated structures become specified. Their work overturned a widely accepted model that epithelium controls the identity of the structure, a phenomenon called structural specificity. Interactions between epithelium and mesenchyme control the development and differentiation of many parts during embryonic development, including structures like the gastrointestinal tract and hair. Thus, the realization that mesenchyme drives induction and differentiation during epithelio-mesenchymal interactions had far-reaching effects.

Created2013-03-15
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In 1616 in Padua, Italy, Fortunio Liceti, a professor of natural philosophy and medicine, wrote and published the first edition of De Monstruorum Causis, Natura et Differentiis (On the Reasons, Nature, and Differences of Monsters), hereafter De monstruorum. In De monstruorum, Liceti chronologically documented cases of human and animal monsters

In 1616 in Padua, Italy, Fortunio Liceti, a professor of natural philosophy and medicine, wrote and published the first edition of De Monstruorum Causis, Natura et Differentiis (On the Reasons, Nature, and Differences of Monsters), hereafter De monstruorum. In De monstruorum, Liceti chronologically documented cases of human and animal monsters from antiquity to the seventeenth century. During the seventeenth century, many people considered such monsters as frightening signs of evil cursed by spiritual or supernatural entities. Liceti categorized monsters based on their potential causes, several of which he claimed were unrelated to the supernatural. Historians later noted that some documented monsters were infants with birth defects. In De monstruorum, Liceti elevated the status of monsters to potential subjects of scientific inquiry and provided an early model for the study of birth defects, a field later called teratology.

Created2018-11-29
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Sir John Bertrand Gurdon further developed nuclear transplantation, the technique used to clone organisms and to create stem cells, while working in Britain in the second half of the twentieth century. Gurdon's research built on the work of Thomas King and Robert Briggs in the United States, who in 1952

Sir John Bertrand Gurdon further developed nuclear transplantation, the technique used to clone organisms and to create stem cells, while working in Britain in the second half of the twentieth century. Gurdon's research built on the work of Thomas King and Robert Briggs in the United States, who in 1952 published findings that indicated that scientists could take a nucleus from an early embryonic cell and successfully transfer it into an unfertilized and enucleated egg cell. Briggs and King also concluded that a nucleus taken from an adult cell and similarly inserted into an unfertilized enucleated egg cell could not produce normal development. In 1962, however, Gurdon published results that indicated otherwise. While Briggs and King worked with Rana pipiens frogs, Gurdon used the faster-growing species Xenopus laevis to show that nuclei from specialized cells still held the potential to be any cell despite its specialization. In 2012, the Nobel Prize Committee awarded Gurdon and Shinya Yamanaka its prize in physiology and medicine for for their work on cloning and pluripotent stem cells.

Created2012-10-11