This case report describes the presence of autism and Childhood Disintegrative Disorder (CDD) cosegregating within a sibship of half-brothers with the same mother. The report suggests that the rarity of the two conditions suggests a shared transmissible mechanism. (Contains references.) (Author/DB)

Reviews the research on the relationship of autism and pervasive developmental disorders to tuberous sclerosis (TSC). Notes that, among TSC cases, the frequency of autism is 25% and among autistic populations, the frequency of TSC is 1% to 4%. It is thought that an abnormal TSC gene may directly influence the development of autism. (DB)

Describes a series of activities that help students form accurate conceptions of meiosis and how its process and purpose differ greatly from mitosis. Discusses the concept of crossing over. Uses a small plastic egg to engage students in a fertilization activity. (SAH)

Evidence that genetic factors play a significant role in susceptibility for autism is reviewed, especially: (1) chromosomal abnormalities associated with autism; (2) single gene disorders associated with autism; and (3) twin and family studies of autism. However, recent genetic studies have failed to locate any genes having a major effect on…

Describes how seeds contain the information of both the past and future of the world's plants. (CCM)

Makes the case that, contrary to popular belief, Mendel's famous paper about plant breeding announced no major findings. Reports on the paper's rediscovery as a result of a priority dispute between de Vries and Correns. (Author/MM)

Nanotechnology are employed by researchers at Northwestern University to develop a method of labeling disease markers present in blood with unique DNA tags they have dubbed "bio-bar-codes". The preparation of nanoparticle and magnetic microparticle probes and a nanoparticle-based PSR-less DNA amplification scheme are involved by the DNA-BCA assay.

Since the first DNA model was created approximately 50 years ago using molecular models, students and teachers have been building simplified DNA models from various practical materials. A 3D double-helical DNA model, made by placing beads on a wire and stringing beads through holes in plastic canvas, is described. Suggestions are given to enhance…

In this article we show the one-factor model can be rewritten as a quasi-simplex model. Using this result along with addition theorems from time series analysis, we describe a common general model, the nonstationary autoregressive moving average (NARMA) model, that includes as a special case, any latent variable model with continuous indicators…

Industry and mainstream research and policy institutions often suggest that transgenic crop varieties can raise the productivity of poor third world farmers, feed the hungry, and reduce poverty. These claims are critically evaluated by examining global-hunger data, the constraints that affect the productivity of small farmers in the third world,…

In this research, we have demonstrated that a new subdiscipline in the field of Medical Sociology is urgently needed to integrate, interpret, and synthesize the interrelationships and implications of genetic discoveries, treatments, and prognoses upon societal behavior. That subdiscipline in our view is "Genetic Sociology."We applied the…

Increasingly, recent research has identified relatively high rates of autistic types of symptoms in a variety of genetic conditions, such as fragile X (Turk and Graham, 1997), tuberous sclerosis (Bolton and Griffiths, 1997), Angelman syndrome (Trillingsgaard and Ostergaard, this issue) and others (see Gillberg and Coleman, 2000). Detailed…

In this article, the authors argue that the overwhelming portion of the literature on intelligence, race, and genetics is based on folk taxonomies rather than scientific analysis. They suggest that because theorists of intelligence disagree as to what it is, any consideration of its relationships to other constructs must be tentative at best. They…

General intelligence (g) poses a problem for evolutionary psychology's modular view of the human brain. The author advances a new evolutionary psychological theory of the evolution of general intelligence and argues that general intelligence evolved as a domain-specific adaptation for the originally limited sphere of evolutionary novelty in the…

Autism is a heterogeneous neurodevelopmental disorder with a 3-4 times higher sex ratio in males than females. X chromosome genes may contribute to this higher sex ratio through unusual skewing of X chromosome inactivation. We studied X chromosome skewness in 30 females with classical autism and 35 similarly aged unaffected female siblings as…