University of Iowa

About: University of Iowa is a education organization based out in Iowa City, Iowa, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 49229 authors who have published 109171 publications receiving 5021465 citations. The organization is also known as: UI & The University of Iowa.

The operating performance of firms conducting seasoned equity offerings

Abstract: Recent studies have documented that firms conducting seasoned equity offerings have inordinately low stock returns during the five years after the offering, following a sharp run-up in the year prior to the offering. This article documents that the operating performance of issuing firms shows substantial improvement prior to the offering, but then deteriorates. The multiples at the time of the offering, however, do not reflect an expectation of deteriorating performance. Issuing firms are disproportionately high-growth firms, but issuers have much lower subsequent stock returns than nonissuers with the same growth rate. SEVERAL RECENT EMPIRICAL STUDIES have documented the poor stock market performance of firms conducting seasoned equity offerings (SEOs) in the United States and other countries.1 Loughran and Ritter (1995) report that the average raw return for issuing firms is only 7 percent per year during the five years after the offering, compared to 15 percent per year for nonissuing firms of the same market capitalization. These low postissue returns follow extremely high returns in the year prior to the offering: 72 percent on average.2 This article links the stock price performance of these issuing firms to their operating performance, and in so doing, addresses four questions: 1) Does the postissue operating performance of issuers deteriorate relative to comparable nonissuing firms? 2) Are the patterns for large issuers different from those for small issuers? 3) Do the capital expenditure decisions of issuers suggest that the managers are just as overoptimistic as investors are? 4) Given that issuing firms tend to be rapidly growing, and rapidly growing firms display strong

Variation in factor B (BF) and complement component 2 (C2) genes is associated with age-related macular degeneration

Abstract: Age-related macular degeneration (AMD) is the most common form of irreversible blindness in developed countries. Variants in the factor H gene (CFH, also known as HF1), which encodes a major inhibitor of the alternative complement pathway, are associated with the risk for developing AMD. Here we test the hypothesis that variation in genes encoding other regulatory proteins of the same pathway is associated with AMD. We screened factor B (BF) and complement component 2 (C2) genes, located in the major histocompatibility complex class III region, for genetic variation in two independent cohorts comprising approximately 900 individuals with AMD and approximately 400 matched controls. Haplotype analyses identify a statistically significant common risk haplotype (H1) and two protective haplotypes. The L9H variant of BF and the E318D variant of C2 (H10), as well as a variant in intron 10 of C2 and the R32Q variant of BF (H7), confer a significantly reduced risk of AMD (odds ratio = 0.45 and 0.36, respectively). Combined analysis of the C2 and BF haplotypes and CFH variants shows that variation in the two loci can predict the clinical outcome in 74% of the affected individuals and 56% of the controls. These data expand and refine our understanding of the genetic risk for AMD.

A comparison of warfarin and aspirin for the prevention of recurrent ischemic stroke.

Abstract: Background Despite the use of antiplatelet agents, usually aspirin, in patients who have had an ischemic stroke, there is still a substantial rate of recurrence. Therefore, we investigated whether warfarin, which is effective and superior to aspirin in the prevention of cardiogenic embolism, would also prove superior in the prevention of recurrent ischemic stroke in patients with a prior noncardioembolic ischemic stroke. Methods In a multicenter, double-blind, randomized trial, we compared the effect of warfarin (at a dose adjusted to produce an international normalized ratio of 1.4 to 2.8) and that of aspirin (325 mg per day) on the combined primary end point of recurrent ischemic stroke or death from any cause within two years. Results The two randomized study groups were similar with respect to base-line risk factors. In the intention-to-treat analysis, no significant differences were found between the treatment groups in any of the outcomes measured. The primary end point of death or recurrent ischemi...

Overview of the SDSS-IV MaNGA Survey: Mapping nearby Galaxies at Apache Point Observatory

Abstract: We present an overview of a new integral field spectroscopic survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) that began on 2014 July 1. MaNGA will investigate the internal kinematic structure and composition of gas and stars in an unprecedented sample of 10,000 nearby galaxies. We summarize essential characteristics of the instrument and survey design in the context of MaNGA's key science goals and present prototype observations to demonstrate MaNGA's scientific potential. MaNGA employs dithered observations with 17 fiber-bundle integral field units that vary in diameter from 12'' (19 fibers) to 32'' (127 fibers). Two dual-channel spectrographs provide simultaneous wavelength coverage over 3600-10300 A at R ~ 2000. With a typical integration time of 3 hr, MaNGA reaches a target r-band signal-to-noise ratio of 4-8 (A–1 per 2'' fiber) at 23 AB mag arcsec–2, which is typical for the outskirts of MaNGA galaxies. Targets are selected with M * 109 M ☉ using SDSS-I redshifts and i-band luminosity to achieve uniform radial coverage in terms of the effective radius, an approximately flat distribution in stellar mass, and a sample spanning a wide range of environments. Analysis of our prototype observations demonstrates MaNGA's ability to probe gas ionization, shed light on recent star formation and quenching, enable dynamical modeling, decompose constituent components, and map the composition of stellar populations. MaNGA's spatially resolved spectra will enable an unprecedented study of the astrophysics of nearby galaxies in the coming 6 yr.