Offspring adoption

The family environment, such as communicational deviancy, is unlikely to contribute to risk, because adoption studies indicate that the risk for schizophrenia in offspring of schizophrenics (i.e. first degree relatives) is unchanged by being adopted into and raised in a family without schizophrenia. Nevertheless, adverse family environments characterized by high levels of expressed emotions negatively affect the course of schizophrenia for those who are already symptomatic. 

There are also cross-fostering studies of children of schizophrenic parents, adopted away by nonschizophrenic foster parents, who were compared with adopted children of normal parents raised by schizophrenic foster parents ( 53, 54). Invariably, those children whose biological parents had schizophrenia developed this disorder more frequently than the offspring of nonschizophrenic parents, even when the latter were reared by schizophrenic foster families. In addition, the concordance rate for the illness in schizophrenic monozygotic twins reared apart was comparable with monozygotic twins reared together. These findings leave little doubt of a hereditary factor in schizophrenia. 

Lidz T, Blatt S, Cook B. 1981. Critique of the Danish-American studies of the adopted-away offspring of schizophrenic parents. Am J Psychiatry 138(8) 1063-1068. Magliano L, Fadden G, Madianos M, de Almeida JM, Held T, et al. 1998. Burden of the families of patients with... 

Rosenthal D, Wender PH, Kety SS, Schulsinger F, Weiner J, et al. 1968. Schizophrenics, offspring reared in adoptive homes. Rosenthal D, Kety SS, editors. The transmission of schizophrenia. Oxford Pergamon. 

Laboratories that perform genetic studies occasionally encounter families in which the laboratory findings are inconsistent with the reported paternity. These situations should be discussed with the clinician or genetic counselor to determine whether specunens were correctly labeled and the family relationships accurately reported on the requisition form. If there is a possibility of a sample mix-up, new samples should be obtained. In cases of demonstrated nonpaternity, it may not be possible to determine the risk of a genetic disease to an offspring and the report should indicate this. The issue of nonpaternity or undisclosed adoption is clearly one that has to be approached with great discretion by the genetic counselor or other professional who is responsible for communication of the test result to the patient or family. 

Since the 1930 s, the rapid adoption of hybrid seed corn has fueled the development of the seed industry. Hybrid sales rose on the same traj ectory as corn yields to around a billion dollars today. Because the offspring of hybrid seed are not reliable, farmers were guaranteed to be repeat customers and profits flowed steadily to the seed industry. As Kloppenburg (33) notes, the sustained profitability of seed companies had brought most of the seed industry into multinational petrochemical and pharmaceutical corporations. Only Pioneer-Hybrid remains an Independent firm. 

In this study, the (/t + A) - evolutionary strategy (ES) was adopted. In contrast to the elitist strategy of genetic algorithms, with the aid of the + A) - ES, parents survive until they are superseded by better offspring (Back et al, 1997). The following notation is used to facilitate the presentation ... 

For the second portion of the chromosome, the traditional gene-alter mutation operator (Bmke and Kendall, 1999) was adopted. For instance, if an offspring... 

A situation that is sometimes encountered is when only two individuals are available, such as a child and putative father. Paternal-specific bands in the child cannot now be identified and the only technique that can be adopted is to compare the two individuals merely on the basis of the numbers of bands that they share. Suppose we have two individuals with a and b bands respectively, of which c bands are shared between them. We can imagine two alternative hypotheses for their relationship, 1 and 2, such as parent-offspring and unrelated. We can calculate, from genetic arguments, the expected proportions of bands that the two individuals share. Let Bi and B2 represent the expected proportions of bands shared under the two hypotheses. If hypothesis 2 is no relationship, then B2 x. It is easy to show that the likelihood ratio under the two hypotheses is ... 

GA is based on a population of individuals. In the present situation, each individual represents a cluster structure. The evolutionary principles are adopted to identify the optimal cluster structure. Then evolutionary operations such as mating, mutation and natural selection are used. The fittest members of a population survive and pass their genetic information onto subsequent generations (offspring) to produce descendants of improved quality. 

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