Embryo Project Encyclopedia Articles

"Induction and Patterning of the Primitive Streak, an Organizing Center of Gastrulation in the Amniote," (hereafter referred to as "Induction") examines the mechanisms underlying early amniote gastrulation and the formation of the primitive streak and midline axis. The review, authored by Takashi Mikawa and colleagues at Cornell University Medical College, was published in Developmental Dynamics in 2004. The article primarily discusses chick embryos as a model organism for nonrodent amniote gastrulation, although it intermittently touches on nonamniote gastrulation for comparative purposes. "Induction" attempts to explain the initiation of cell differentiation and embryo organization, one of the most intriguing processes of embryology.

On March 28, 1978, in Stump v. Sparkman, hereafter Stump, the United States Supreme Court held, in a five-to-three decision, that judges have absolute immunity from lawsuits involving any harm their judicial decisions cause. Linda Sparkman, who was unknowingly sterilized when she was fifteen years old in 1971, sued Harold Stump, the county circuit court judge who signed the petition to allow Sparkman’s mother to have her sterilized. Sparkman’s mother stated to Stump that she wanted her daughter sterilized because of Sparkman’s alleged mental deficiencies and sexual promiscuity. Sparkman argued that Stump violated her Fourteenth Amendment rights to due process because nobody informed her about the nature of the procedure and because Stump did not perform typical court proceedings. Stump argued that, because he was acting within his role as a judge, the doctrine of judicial immunity prevented his liability from lawsuit. Stump strengthened the impunity with which judges can act, including acts found to be unconstitutional, regardless of any rights upon which such actions may infringe.

In 1990, the United States Congress passed the Americans with Disabilities Act, or the ADA, which prohibits discrimination against people with disabilities by employers, governments, or public accommodations. Following gains made during the civil rights movements of the 1900s, people with disabilities sought similar anti-discrimination legislation. The ADA was the culmination of decades of protest and advocacy from the disability rights movement. After the ADA, federal law protected people with an impairment that limited major life functions like sight or mobility from discrimination. The ADA changed the lives of millions of Americans with disabilities by expanding the opportunities they had to work, travel, and participate in their communities legally protected from discrimination.

In United States v. Georgia, the United States Supreme Court held, in a unanimous decision, that the rights protected under the Americans with Disabilities Act, or the ADA, extended to inmates held in state prisons. The Court also abolished sovereign immunity in cases where the Eighth Amendment is involved. The case came about as a result of Tony Goodman, a paraplegic man in a Georgia state prison, who attempted to sue the state under Title II of the ADA. The state of Georgia argued that they were immune to civil suits based on sovereign immunity under the Eleventh Amendment that holds that Congress cannot pass laws that allow non-consenting states to be sued by their people, except for specific circumstances. The US federal government interceded on Goodman's behalf, with the case then being taken up by the Supreme Court. US v. Georgia partially determined the extent to which the ADA covers disabled Americans, improved the situation of disabled individuals in state prison systems, and further eroded the sovereign immunity claimed by states in cases where ADA violations are alleged.

In the 1999 case Olmstead v. L.C., hereafter Olmstead, the United States Supreme Court held in a six to three decision that the forced segregation of people based on disability violated the Americans with Disabilities Act. Two women with mental and intellectual disabilities, Lois Curtis and Elaine Wilson, referred to as L.C. and E.W. in case documents, sued the state of Georgia and Tommy Olmstead, the Commissioner of Georgia who headed the Department of Human Resources, for alleged violations of the Americans with Disabilities Act. The two women each voluntarily admitted themselves to treatment in the state-run Georgia Regional Hospital in Atlanta, Georgia, in 1990. After doctors cleared Curtis and Wilson for transfer into a community-based health setting with non-disabled people, the hospital denied them treatment in a community-based setting due to the financial costs of such treatment and the lack of space. Olmstead protected the rights of people with disabilities outlined in the Americans with Disabilities Act by finding the unjustified segregation of disabled people unconstitutional.

In 1975, the United States Congress passed the Individuals with Disabilities Education Act, referred to as the IDEA, which codified the right of all American children to a free and appropriate public education regardless of disability status. The IDEA requires all public schools that accept federal funds to provide education that meets the needs of students with disabilities at the public expense. Prior to IDEA, many students with disabilities went without any educational opportunities, and many faced confinement in institutions. The IDEA enshrined the right to education for children with disabilities, allowing millions of children to learn in a public-school classroom by setting guidelines for accessibility and the instruction of students with disabilities in American public schools.

Meiosis, the process by which sexually-reproducing organisms generate gametes (sex cells), is an essential precondition for the normal formation of the embryo. As sexually reproducing, diploid, multicellular eukaryotes, humans rely on meiosis to serve a number of important functions, including the promotion of genetic diversity and the creation of proper conditions for reproductive success. However, the primary function of meiosis is the reduction of the ploidy (number of chromosomes) of the gametes from diploid (2n, or two sets of 23 chromosomes) to haploid (1n or one set of 23 chromosomes). While parts of meiosis are similar to mitotic processes, the two systems of cellular division produce distinctly different outcomes. Problems during meiosis can stop embryonic development and sometimes cause spontaneous miscarriages, genetic errors, and birth defects such as Down syndrome.

In 1972, the United States District Court for the Eastern District of Pennsylvania decided the case of Pennsylvania Association for Retarded Citizens (PARC) v. Commonwealth of Pennsylvania, hereafter PARC v. Pennsylvania. The court ruled that the state could not deny an individual's right to equal access to education based on an intellectual or developmental disability status. PARC brought the case against the state of Pennsylvania on behalf of fourteen families with intellectually disabled children who were unable to access to public schools based on their child’s disability. PARC challenged state laws that permitted schools to deny education to children who do not reach the mental age of five, or the average intelligence of people aged five, by the time they begin first grade. Both sides settled following the testimony of expert witnesses on PARC's behalf, and the US District Court approved the consent decree. PARC v. Pennsylvania was one of the first cases to establish that people born with an intellectual disability should have the same access to education as the rest of the population.

In Mills v. Board of Education of District of Columbia (1972), the United States District Court for the District of Columbia held that students with disabilities are entitled to an education, and that education cannot be denied based on the accommodations’ additional cost to the school. Mills was a class action lawsuit brought to the court on behalf of seven children denied public education by the District of Columbia School District because of their disabilities and the cost of accommodations the school would incur to educate them. US District Court Judge Joseph Cornelius Waddy presided over the case and ruled in favor of the students, finding that they were not given due process prior to expulsion from the school. Mills was one of the first cases in the US that guaranteed the right of students with any disability to a public education, regardless of the cost to the school system, and led to comprehensive federal legislation protecting disabled children's right to free public education.

The Public Broadcasting Station (PBS) documentary Life's Greatest Miracle (abbreviated Miracle, available at http://www.pbs.org/wgbh/nova/miracle/program.html), is arguably one of the most vivid illustrations of the making of new human life. Presented as part of the PBS television series NOVA, Miracle is a little less than an hour long and was first aired 20 November 2001. The program was written and produced by Julia Cort and features images by renowned Swedish photographer Lennart Nilsson. It comes as a sequel to the award-winning 1983 NOVA production, The Miracle of Life, which exhibits Nilsson's photography as well. The program showcases a combination of graphic animation, endoscopic and microscopic footage, as well as the story of a couple who are expecting a child. It features a number of new technological and scientific developments not present in its prequel, providing additional relevant information. By depicting human development in a clear and fresh manner, Miracle helps shed light on this indispensible aspect of life. Following is a description of the documentary, highlighting the key points of the film and explaining images featured in it.