Two kinds of modification theory of light: Some new observations on the Newton-Hooke controversy of 1672 concerning the nature of light

It has not been sufficiently emphasized that there existed two kinds of modification theory of colours, Aristotle's modification theory and Descartes-Hook's modification theory. This seems to have caused some confusion in the interpretation of the optical controversy between Newton and Hooke in 1672. The aim of the present paper is to prove that these two kinds of modification theory really coexisted, and on that basis to present a new interpretation of the optical controversy of 1672. The characteristics and the historical role of each of these theories will be described. Newton's colour theory was formed under the influence of Aristotle's modification theory, which had been disseminated through the work of an English Gassendist, Walter Charleton. Newton's optical theories were created not only under the influence of Descartes, as we have been often told, but also under the conspicuous influence of corpuscular philosophers.     

Some new data on the chromosomes ofCatarrhina

Riassunto L'autore sta conducendo uno studio comparativo sui cromosomi dei Primati. Nella presente nota riferisce sulle variazioni numeriche riscontrate nelle Scimmie Catarrine.     

Some new data concerning effect of actinomycin D on early chick embryos

Zusammenfassung Actinomycin D führte beim Hühnerembryo zu einer deutlichen Hemmung der Herzentwicklung nach Inkubation im Nährmedium während der Entwicklungsstadien 3 und 3⁺. Nach Vorbehandlung der Stadien 3–7 und anschliessender Kultur in actinomycin D-freiem Medium fanden sich Fehlbildungen von Herz, ZNS und Somiten, die in ihrer Häufigkeit von den betroffenen Entwicklungsphasen abhängig sind.

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This study was supported by a grant from the Rutgers University Research Council No. 07-2189.     

The impact of climate change on human health: Some international implications

The objective of this study is to discuss the potential impact of a global warming on various aspects of human health. Changes in heat-related mortality are estimated for four countries: the United States, Canada, the People's Republic of China and Egypt. In addition, the potential confounding impact of increased air pollution is considered. Finally, a framework to analyze two vector-borne diseases, onchocerciasis and malaria, which may spread if temperatures increase, is discussed. Our findings suggest that heat-related mortality is estimated to rise significantly in all four countries if the earth warms, with the greatest impacts in China and Egypt. The most sensitive areas are those with intense but irregular heat waves. In the United States, air pollution does not appear to impact daily mortality significantly when severe weather is present, although it seems to have a slight influence when weather conditions are not stressful.     

The ovicidal activity ofcis-dehydromatricaria ester: time-dependance of its enhancement by UV light

Summary Freshly laid eggs ofDrosophila melanogaster were treated with the polyacetylenic compoundcis-dehydromatricaria ester. The toxicity of the chemical was enhanced by treatments with long-wavelength ultraviolet light, and the maximum effect was observed when the UV irradiation was performed 4–5 h after the initial contact of the eggs with the chemical.We are grateful to Professor E. Spiess for advice and assistance, and to the National Institutes of Health (GM 24144) for financial support.     

The subventricular zone: new molecular and cellular developments

The subventricular zone (SVZ), which lines the lateral walls of the lateral ventricle, persists as a neurogenic zone into adulthood and functions as the largest site of neurogenesis in the adult brain. In recent years, with the acceptance of the concept of postembryonic mammalian neurogenesis, neurogenesis in the adult SVZ has been an area of active research. With the rapid accumulation of new information on the SVZ, some of which is contradictory, summarizing existing knowledge on the SVZ and outlining future research directions in this area become important. In this review, we will cover recent molecular and cellular investigations that characterize the SVZ niche, SVZ neurogenesis, and SVZ cell migration within the adult brain.     

The exotoxin ofBacillus thuringiensis: A new C-mitotic agent

Summary Thuringiensin A, an exotoxin fromBacillus thuringiensis, a constituent of the microbial insecticide thuricide has been found to inhibit mitotic spindle, condense and scatter chromosomes. It may therefore be a promizing tool in future cell biological studies.We thank Prof.H. Sharatchandra for facilities. CBSR is a National Associate of the University Grants Commission, New Delhi.     

The ovicidal activity of cis-dehydromatricaria ester: time-dependance of its enhancement by UV light

Freshly laid eggs of Drosophila melanogaster were treated with the polyacetylenic compound cis-dehydromatricaria ester. The toxicity of the chemical was enhanced by treatments with long-wavelength ultraviolet light, and the maximum effect was observed when the UV irradiation was performed 4-5 h after the initial contact of the eggs with the chemical.