Is there reciprocal influence between siblings' educational attainments or a predominant influence of older on younger siblings? A reanalysis of Benin and Johnson's (1984) Nebraska data shows no unusually high level of resemblance between brothers, but there is an unusually low similarity between older sisters and younger brothers. We model reciprocal effects between brothers' educational attainments using Olneck's (1976) data from Kalamazoo, Michigan. We find evidence of reciprocal influence of brothers' levels of educational attainment, net of the common effects of family background and the effect of each brother's mental ability on his schooling. The unconstrained effect of older brother's schooling on younger brother's schooling is larger than the reciprocal effect, but a model of equal reciprocal effects fits almost as well. This leaves open the questions of whether reciprocal influence occurs in other types of sibling pairs and whether there is a predominant effect of older on younger siblings. It is a sociological truism that the family is initiated modern studies of sibling resemblance one of the important stratifying agents in the in their discussions of the effects of "family transmission of social and economic inequal-climate" on achievement and the possibility of ity. This was well stated many decades ago cross-sibling influence, the emphasis in reby Charles Horton Cooley (quoted in Blau search has been on between-family differences and Duncan 1967, u. vii): in easily measured social and economic charac-. A teristici, rather than on differences within the There is a certain opposition between the ideal family in resources or social support, on typical of equal opportunity and that of family responsibility. Responsibility involves autonomy, which patterns of activity of interaction, or on mutual will produce divergence among families, which, influences among members. For examin turn, will mean divergent conditions for the ple, the classic status-attainment model, introchildren; that is, unequal opportunities. duced by Blau and Duncan (1967) and then elaborated as the Wisconsin model (Hauser, Well-known models of the stratification pro-Tsai. and Sewell 1983: Sewell. Haller. and cess represent family characteristics through a handful of variables-race, education, occupation, earnings, female headship, size of sibship, and the like-that cannot very well represent the full variety or influence of family environments. Although Blau and Duncan (1967)

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This study investigated the cognitive and metacognitive aspects of writing problems in learning disabled adolescents. Twenty-one learning disabled eighth and eleventh graders constituted the target population. The comparison groups included 15 normally achieving eighth graders and a reading-age control group of 23 normally achieving sixth graders. The participants wrote two reportive essays and one argument essay, and answered a questionnaire designed to probe their metacognition about the writing process. Results indicated that normally achieving eighth graders consistently and clearly surpassed their learning disabled counterparts in both quality and quantity of essay writing. Adult judges rated normally achieving eighth graders' essays to be substantially more interesting, much clearer in communicating the goals, and to contain a substantially more felicitous word choice than those of learning disabled eighth and eleventh graders. Moreover, they wrote longer essays with much fewer spelling errors than learning disabled eighth and eleventh graders. Finally, they possessed more mature and articulate conceptions of the writing task, and were more aware of the relevance of planning and audience in writing. In striking contrast, the learning disabled eighth and eleventh graders were comparable to the normally achieving sixth graders in their performances across a broad front. This comparability occurred in the three categories of holistic ratings of essays (interestingness, clarity in communication of goals, and word choice), structural ratings of paragraphs, and metacognition about the writing process. Interestingly, learning disabled eighth and eleventh graders were superior to normally achieving sixth graders in length of essays. However, the consistent, broad picture was that the learning disabled adolescents performed at a very similar level to that of younger normally achieving children. These findings permit the conclusion that the learning disabled adolescents in this study showed a developmental delay in the cognitive and metacognitive aspects of writing.

Metallic carcinogenicity is generally thought to generate of free radicals, and thus some metals were reported to play a role in lung tumorigenesis. In order to verify the role of heavy metals in the development of Taiwanese lung cancer, a case-control study was conducted to compare heavy metal contents between 60 tumor and 42 normal lung tissues surgically resected from lung cancer and noncancer patients. The tissue concentration of heavy metals, including cadmium (Cd), chromium (Cr), cobalt (Co), lead (Pb), and nickel (Ni), was measured using by atomic absorption spectrometry (AAS). Our results indicated that Cr and Ni contents in lung tumors of lung cancer patients were significantly higher than those in normal lung tissue of noncancer controls, but Co content was markedly lower in lung tumors. Additionally, Pb content in lung tumors was associated with nodal involvement, and Co amounts in squamous-cell carcinomas were relatively higher than those in adenocarcinomas. Data suggest that accumulation of Cr and Ni in lung tumors may play a role, at least in part, in the development of lung cancer in Taiwan.

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