Melatonin Biosynthesis in Drosophila: Its Nature and Its Effects

Drosophila melanogaster homogenates incubated with tritiated 5-hydroxytryptophan, 5-hydroxytryptamine, or N-acetylserotonin have the ability of converting them into labelled indolamines, including melatonin. All these compounds were characterized by two-dimensional thin-layer chromatography by comparison with nonradiolabelled standards, and melatonin by mass spectrometry and radioimmunoassay. On the other hand, the injection of pharmacological doses of melatonin into 2-day-old female flies diminishes the mating speed and the oviposition rate.     

Report from the President the Biological Stain Commission: Its Goals, Its Past and Its Present Status

This is a brief overview of the goals, evolution, and present status of the Biological Stain Commission. The main function of the Commission is the testing and certification of dye batches intended for biological applications. The testing is supported by charges made for batch testing and by the sale of certification labels affixed to individual dye containers. Submission of dyes for testing is voluntary, depending on the cooperation of the companies who sell them and the consumers who buy them. The supportive role of the University of Rochester School of Medicine and Dentistry—both past and present—is not well known and should be. Increasingly federal regulations affect the production, availability, and cost of dyes. Commission income from the sale of labels has decreased in recent years. Continuation of its work requires changes that will produce more income. Much dye is now sold in solutions instead of dry powders. The value of using Stain Commission certified dyes whenever possible is illustrated by the case of basic fuchsin. Years ago this dye was a mixture. Most basic fuchsin now marketed consists mainly of either pararosanilin (Colour Index No. 42500) or rosanilin (C.I. No. 42510). The Biological Stain Commission discovered that some certified batches of both pararosanilin and rosanilin sold as “basic fuchsin” had incorrect C.I. numbers on the labels. Sometimes that caused failure of the aldehyde fuchsin stain. Unless made with pararosanilin, aldehyde fuchsin does not stain pancreatic islet B-cells, elastic fibers, and hepatitis B surface antigen in unoxidized sections. Mislabelling by packagers may interfere with other applications of pararosanilin and rosanilin. The Commission acted to publicize and correct this problem. Biological Stain Commission publications help educate microscopists and histotechnologists about dyes and their best use. Stain Commission representatives from member scientific societies provide valuable input about changes in the availability and quality of such dyes as hematoxylin and others; they also provide useful feedback to their societies about dye problems. Each new generation of biologists and histotechnologists should be taught the importance of using only Stain Commission certified stains when available. They should be taught also to notify the Stain Commission whenever they experience problems with any certified dye.     

Utopia and Its Discontents: The Kibbutz and Its Historical Vicissitudes

Following an explication of "utopianism," this article describes the social and cultural systems of the original utopian communes comprising the Israeli kibbutz movement. It then describes the radical changes that have been made in those systems. After accounting for these changes, it assesses their implications for the utopian and cultural determinist theories of human nature.     

纤维素酶及其应用

文章介绍了纤维素酶的组成、来源及生产方法。论述了纤维素酶在饲料工业、食品加工、纺织工业、发酵食品行业的应用,并对其发展前景作了展望。