The Eleventh International Latin American Symposium is an important mile stone reflecting the rapid development of basic biochemistry in Latin America. The topic "Gene Expression and Its Regulation" was received enthusiastically, and, thanks to the vision of our Argentine colleagues, the program developed rapidly under the leadership of Dr. Gabriel Favelukes as General Secretary of the Symposium. It is interesting to note the tremendous progress that has been made in basic and applied sciences in Latin America over the past few years. The increasing initiative and leadership being...

The present volume developed from a symposium entitled "Enhancing Biological Production of Ammonia From Atmospheric Nitrogen and Soil Nitrate" that was held at Lake Tahoe, California in June, 1980. The meeting was supported by the National Science Foundation, Division of Engineering and Applied Sciences and by the College of Agricultural and Environmental Sciences, University of California, Davis. A total of 99 scientists from 41 insti tutions participated. Plants capture solar energy in photosynthesis and use mineral nutrients to produce human food and fiber products. The extent to which...

Concern is often expressed that our environment may include an increasingly large variety of mutagens, but the extent of the potential hazard they pose has yet to be fully evaluated. A variety of empirical procedures has been devised with which to estimate the mutagenic potency of suspect agents, and the relative merits of different tests are currently under debate. Although such tests are of great value, and are indeed indispensable, they are not, nevertheless, sufficient. In the long term, accurate estimation of hazard will also require a better understanding of the various mechanisms of...

Allen I. Laskin Biosciences Research Exxon Research and Engineering Company Linden, New Jersey I was contacted in the Fall of 1981 by Professors Martin Dworkin and Palmer Rogers, of the University of Minnesota and asked to participate in the orgnization of the 1983 conference in the series, "Interface Between Biology and Medicine." They and the other members of the advisory committee had the vision to realize that this was a time to depart somewhat from the traditional theme, since one of the major areas of interest in the biological and related sciences these days is that of biotechnology in...

The aim of the editors of this volume is to use basic and ap- plied studies in the field of mutagenesis to approach a problem of especial concern. The problem is that of the usage of toxic chemi- cals, particularly agricultural chemicals, in ever-increasing quan- tities in those parts of the world that feed the most people. Agri- cultural chemicals that are in use in Pakistan are emphasized here. These are the same chemicals that are in use throughout the develop- ing world, although the quantities of the different types that are used may vary from country to country, and from region to...

J. Warren Evans Department of Animal Science Texas A&M University College Station, Texas 77843 In the near future, improvement of domestic animals for the production of food and fiber is poised to undergo a revolution by the utilization of recent breakthroughs and advances in molecular genetics, embryo manipula- tions, and gene transfer systems. Utilization of these techniques will have a wide impact on animal agriculture by improvement of production effi- ciency via manipulation and control of many physiological systems. The end result will be to decrease production costs, increase food...

The human race has enormous he terogenei ty, founded on genetic and environmental sources. Variability, therefore, is a vital dimension in any consideration of human risk assessment. In the estimation of risks, current methods of extrapolation based upon converting the response of a median man are inadequate, as they ignore phenotypic variation and there- fore, susceptible subgroups. There is a growing literature defining the extent of human variation in normal populations; thus, the normal young adult population may have 10-20% known hyperreactors. How far can we ignore human variability in...

For this Workshop, the organizers have attempted to invite experts from all known centers which are engaged in neutron beam development for neutron capture therapy. The Workshop was designed around a series of nineteen invited papers which dealt with neutron source design and development and beam characterization and performance. Emphasis was placed on epithermal beams because they offer clinical advantages and are more challenging to implement than thermal beams. Fission reactor sources were the basis for the majority of the papers; however three papers dealt with accelerator neutron...

Elucidating the structures of biopolymers as they exist in nature has long been a goal of biochemists and biologists. Understanding how these substances interact with themselves, other solutes, and solvents can provide useful insights into many areas of biochemistry, agriculture, food science and medicine. Knowledge of the structure of a protein or complex carbohydrate in its native form provides guidelines for the chemical or genetic modifications often desired to optimize these compounds to specific needs and applications. For example, in the pharmaceutical industry, structure-function...