University of Rochester

About: University of Rochester is a education organization based out in Rochester, New York, United States. It is known for research contribution in the topics: Population & Laser. The organization has 63915 authors who have published 112762 publications receiving 5484122 citations. The organization is also known as: Rochester University.

cDNA cloning and functional activity of a glucocorticoid-regulated inflammatory cyclooxygenase

Abstract: The antiinflammatory glucocorticoids are potent inhibitors of cyclooxygenase, a key regulator of prostaglandin synthesis; yet, the mechanism(s) by which this occurs is not fully understood. We have cloned a 4.1-kilobase (kb) cDNA, distinct from the previously cloned cyclooxygenase (2.8 kb), that confers cyclooxygenase activity to transfected cells. The mRNA for this newly discovered cyclooxygenase is unique for its long 3' untranslated region containing many AUUUA repeats. Levels of the 4.1-kb cyclooxygenase mRNA are rapidly increased by serum or interleukin 1 beta in mouse fibroblasts and human monocytes, respectively, and decreased by glucocorticoids, whereas levels of the 2.8-kb cyclooxygenase mRNA do not change. Similar effects are seen in the presence of cycloheximide where the 4.1-kb, but not the 2.8-kb, mRNA is greatly superinduced. Thus, there are both constitutive (2.8 kb) and regulated (4.1 kb) cyclooxygenase species, the latter most likely being a major mediator of inflammation.

Risk, The Pricing of Capital Assets, and The Evaluation of Investment Portfolios

Abstract: THE MAIN PURPOSE of this study is to develop a model for evaluating the performance of portfolios of risky assets. The model begins from the Sharpe-Lintner theory of capital-asset prices, but allows explicitly for the effects of differential degrees of "risk" on the returns of portfolios-a problem which has never been satisfactorily solved. The Sharpe-Lintner results (originally detived in the context of a singleperiod model under the assumption of identical investor horizons) are extended to a multi-period world. In this model investors' horizons may be of different lengths and assets may be traded continuously. In addition, the Sharpe-Lintner ex ante model is extended to include ex post relationships. The resulting model expresses the expected returns on a security (or portfolio) as a function of its level of systematic risk, the risk-free return, and the actual realized returns (instead of the expected future return) on the "market portfolio" over any holding period. Given these results, a measure of portfolio "performance" (which measures only a manager's ability to forecast security prices) is defined as the difference between the actual returns on a portfolio in any particular holding period and the expected returns on that portfolio conditional on the riskless rate, its level of "systematic risk," and the actual returns on the market portfolio. Criteria for judging a portfolio's performance to be neutral, superior, or inferior are established. A measure of a portfolio's efficiency is also derived, and criteria for judging a portfolio to be efficient, superefficient, or inefficient are defined. It is also shown that it is strictly impossible to define a measure of efficiency solely in terms of ex post observable variables. In addition it is shown that there exists a natural relationship between the measure of portfolio performance and the measure of efficiency. The model is then applied to the evaluation of the portfolios of 115 open-end mutual funds in the period 1945-1964. The main results are:

Functional and evolutionary insights from the genomes of three parasitoid Nasonia species.

Abstract: We report here genome sequences and comparative analyses of three closely related parasitoid wasps: Nasonia vitripennis, N. giraulti, and N. longicornis. Parasitoids are important regulators of arthropod populations, including major agricultural pests and disease vectors, and Nasonia is an emerging genetic model, particularly for evolutionary and developmental genetics. Key findings include the identification of a functional DNA methylation tool kit; hymenopteran-specific genes including diverse venoms; lateral gene transfers among Pox viruses, Wolbachia, and Nasonia; and the rapid evolution of genes involved in nuclear-mitochondrial interactions that are implicated in speciation. Newly developed genome resources advance Nasonia for genetic research, accelerate mapping and cloning of quantitative trait loci, and will ultimately provide tools and knowledge for further increasing the utility of parasitoids as pest insect-control agents.