A new method generates specific predictions concerning the expected frequencies of aphasia after unilateral injury to the brain in the left- and right-handed. These predictions are then compared with the observed data for all known studies between 1935 and 1973 to derive the best-fitting model of hemispheric speech lateralization in the left- and…

Examines new directions in ecological research in which ecologists are analyzing systems with theoretical models and are using descriptive studies to confirm and extend their studies. The development of a model relating to species equilibriums on islands is now being applied to problems of conservation of wildlife in national parks. (JR)

The expected thrust for theoretical chemistry in the next decade will be to combine knowledge of fundamental chemical steps/interactions with advances in chemical dynamics, irreversible statistical mechanics, and computer technology to produce simulations of chemical systems with reaction site competition. A sample simulation (using the enzyme…

Discussed is the discovery which may help to explain epidermal growth factor effects on the cell skeleton. The role of a protein called profilin in the regulation of the microfilament system is described. (CW)

An energy input-output model was used to investigate energy and employment in the construction industry. (Author/BB)

Despite the abundance, persistence, and worldwide distribution of DDT residues, they are not as freely available to the biota as might be assumed....Mere good fortune has protected man and the rest of the biota from much higher concentrations." (Author/AL)

Discusses the optimality of natural selection, ways of testing for optimum solutions to problems of time - or energy-allocation in nature, optimum patterns in spatial distribution and diet breadth, and how best to travel over a feeding area so that food intake is maximized. (JR)

Discusses existing and possible models for the promotion of cooperative research between industry and universities, some of which also involve state and federal funding of basic research. Urges experiementation to determine the effectiveness of the models as large scale industrial laboratories are eliminated. (AL)

A model estimating the contributions of sulfur compounds by natural and human activities, and the rate of removal of sulfur from the atmosphere, is based on a review of the existing literature. Areas requiring additional research are identified. (AL)

Major consequences of present and additional environmental quantities of DDT pesticide are predictable by mathematical models of transport, accumulation and concentration mechanisms in the Wisconsin regional ecosystem. High solubility and stability produce increased DDT concentrations at high organism trophic levels within world biosphere…

Discusses prevailing ideas of how children learn language and addresses the argument of rules versus analogies in learning to form the past tense of verbs. Cites cases involving connectionist models. (ML)

This study discusses the behavior of the females of the parasitic wasp Nasonia vitripennis, which adjust the sex ratio of their broods according to whether or not they are the first or second wasp to parasitize a host. The results provide a quantitative test of sex ratio theory. (Author/SA)

The National Academy of Sciences suggests models for biomedical research which include a biology-wide information system with computerized database accessible from a multitude of dimensions. Links could help discover whether toxic chemicals have effects similar to hormones. Commonalities from molecules to ecosystems might restructure available…

Describes a classification system based on interpersonal and economic resources which provides insight into the social problems of modern culture. Concreteness versus symbolism and particularism versus universalism are the coordinate pairs into which six categories of resources--love, services, goals, money, information, and status--are plotted.…