Yale University

About: Yale University is a education organization based out in New Haven, Connecticut, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 89824 authors who have published 220665 publications receiving 12834776 citations. The organization is also known as: Yale & Collegiate School.

Mitochondrial dysfunction and type 2 diabetes.

Abstract: Maintenance of normal blood glucose levels depends on a complex interplay between the insulin responsiveness of skeletal muscle and liver and glucose-stimulated insulin secretion by pancreatic β cells. Defects in the former are responsible for insulin resistance, and defects in the latter are responsible for progression to hyperglycemia. Emerging evidence supports the potentially unifying hypothesis that both of these prominent features of type 2 diabetes are caused by mitochondrial dysfunction.

A general theory of bibliometric and other cumulative advantage processes

Abstract: A Cumulative Advantage Distribution is proposed which models statistically the situation in which success breeds success. It differs from the Negative Binomial Distribution in that lack of success, being a non-event, is not punished by increased chance of failure. It is shown that such a stochastic law is governed by the Beta Function, containing only one free parameter, and this is approximated by a skew or hyperbolic distribution of the type that is widespread in bibliometrics and diverse social science phenomena. In particular, this is shown to be an appropriate underlying probabilistic theory for the Bradford Law, the Lotka Law, the Pareto and Zipf Distributions, and for all the empirical results of citation frequency analysis. As side results one may derive also the obsolescence factor for literature use. The Beta Function is peculiarly elegant for these manifold purposes because it yields both the actual and the cumulative distributions in simple form, and contains a limiting case of an inverse square law to which many empirical distributions conform.

A Review of IPO Activity, Pricing, and Allocations

Abstract: We review the theory and evidence on IPO activity: why firms go public, why they reward first-day investors with considerable underpricing, and how IPOs perform in the long run. Our perspective is threefold: First, we believe that many IPO phenomena are not stationary. Second, we believe research into share allocation issues is the most promising area of research in IPOs at the moment. Third, we argue that asymmetric information is not the primary driver of many IPO phenomena. Instead, we believe future progress in the literature will come from nonrational and agency conf lict explanations. We describe some promising such alternatives. From 1980 to 2001, the number of companies going public in the United States exceeded one per business day. The number of initial public offerings ~IPOs! has varied from year to year, however, with some years seeing fewer than 100 IPOs, and others seeing more than 400. These IPOs raised $488 billion ~in 2001 dollars! in gross proceeds, an average of $78 million per deal. At the end of the first day of trading, their shares traded on average at 18.8 percent above the price at which the company sold them. For an investor buying shares at the first-day closing price and holding them for three years, IPOs returned 22.6 percent. Still, over three years, the average IPO underperformed the CRSP value-weighted market index by 23.4 percent and underperformed seasoned companies with the same market capitalization and book-to-market ratio by 5.1 percent. In a nutshell, these numbers summarize the patterns in issuing activity, underpricing, and long-run underperformance, which have been the focus of a large theoretical and empirical literature. We survey this literature, focusing on recent papers. Space constraints force us to take a U.S.-centric point of view and to omit a description of the institutional aspects of going public. The interested reader can consult Ellis, Michaely, and O’Hara ~2000!,

Membrane Fusion: Grappling with SNARE and SM Proteins

Abstract: The two universally required components of the intracellular membrane fusion machinery, SNARE and SM (Sec1/Munc18-like) proteins, play complementary roles in fusion. Vesicular and target membrane-localized SNARE proteins zipper up into an alpha-helical bundle that pulls the two membranes tightly together to exert the force required for fusion. SM proteins, shaped like clasps, bind to trans-SNARE complexes to direct their fusogenic action. Individual fusion reactions are executed by distinct combinations of SNARE and SM proteins to ensure specificity, and are controlled by regulators that embed the SM-SNARE fusion machinery into a physiological context. This regulation is spectacularly apparent in the exquisite speed and precision of synaptic exocytosis, where synaptotagmin (the calcium-ion sensor for fusion) cooperates with complexin (the clamp activator) to control the precisely timed release of neurotransmitters that initiates synaptic transmission and underlies brain function.