Joseph G. Hirschberg

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Carotenoid biosynthesis in plants has been described at the molecular level for most of the biochemical steps in the pathway. However, the cis-trans isomerization of carotenoids, which is known to occur in vivo, has remained a mystery since its discovery five decades ago. To elucidate the molecular mechanism of carotenoid isomerization, we have taken a(More)
Proteorhodopsin phototrophy was recently discovered in oceanic surface waters. In an effort to characterize uncultured proteorhodopsin-exploiting bacteria, large-insert bacterial artificial chromosome (BAC) libraries from the Mediterranean Sea and Red Sea were analyzed. Fifty-five BACs carried diverse proteorhodopsin genes, and we confirmed the function of(More)
During recent years genes for more than 20 different carotenogenic enzymes have been cloned from various organisms: bacteria, cyanobacteria, fungi, algae and plants. This accomplishment has provided new molecular tools to study the enzymes and yielded new information on their structure, function and regulation. We describe here the recent progress in the(More)
This paper explores the insight from the application of cluster analysis to the results of a Data Envelopment Analysis of productive behaviour. Cluster analysis involves the identification of groups among a set of different objects (individuals or characteristics). This is done via the definitions of a distance matrix that defines the relationship between(More)
This paper considers the similarity between two measures of air pollution/quality control, on the one hand, and widely used indicators of life quality and welfare in the US, on the other. We use statistical cluster analysis based on information measures of similarity and distance. The results indicate the clusters of the US macroeconomic and quality of life(More)
The interpretation of dummy variables in regressions where the dependent variable is subject to a log transformation has been of continuing interest in economics. However, in the main, these earlier papers do not deal with the inferential aspects of the parameters estimated. In this paper we compare the inference implied by the hypotheses tested on the(More)
It is now widely believed that Foreign Direct Investment (FDI) affects positively the productivity of individual enterprises in the host economy and this is a main argument in favour of FDI. Although China is the largest recipient of FDI after the USA, there has been little empirical research as to whether such productivity effects of FDI are present in(More)
The estimation of regression models subject to exact linear restrictions, is a widely applied technique, however, aside from simple examples, the reparameterization method is rarely employed except in the case of polynomial lags. We believe this is due to the lack of a general transformation method for changing from the definition of restrictions in terms(More)
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