Foundations of Portfolio Theory

Prize Lecture to the memory of Alfred Nobel, December 7, 1990.Portfolio Theory;

Appropriate Antibiotic Therapy for Urinary Tract Infections

It was stated years ago that physicians pour medicines about which they know little, for diseases about which they know less, into human beings about whom they know nothing. Although as a prophet this wag may have overstated the case as it concerns the therapy of urinary tract infections (UTI), the character of contemporary infectious diseases is, in part, due to the use and abuse of anti-infective agents. One has only to look at the rising incidence of gram-negative bacteremia and the emergence of multiple antibiotic-resistant organisms over the past several decades to appreciate the impact physicians have made with these agents. Despite the drawbacks, the benefits resulting from the use of antibiotics far outweigh the deleterious effects, a fact perhaps realized most vividly by physicians whose careers reach back to the pre-chemotherapeutic era. The enthusiasm for antibiotics makes them one of the most prescribed groups of drugs in the United States, accounting for 15% to 20% of all new and refill prescriptions. Undoubtedly many of the prescriptions are used to treat persons with UTIs, in light of the fact that UTIs are said to rank second only to upper respiratory infections as the most common infections in the western hemisphere

Gravitational Wave Burst Source Direction Estimation using Time and Amplitude Information

In this article we study two problems that arise when using timing and amplitude estimates from a network of interferometers (IFOs) to evaluate the direction of an incident gravitational wave burst (GWB). First, we discuss an angular bias in the least squares timing-based approach that becomes increasingly relevant for moderate to low signal-to-noise ratios. We show how estimates of the arrival time uncertainties in each detector can be used to correct this bias. We also introduce a stand alone parameter estimation algorithm that can improve the arrival time estimation and provide root-sum-squared strain amplitude (hrss) values for each site. In the second part of the paper we discuss how to resolve the directional ambiguity that arises from observations in three non co-located interferometers between the true source location and its mirror image across the plane containing the detectors. We introduce a new, exact relationship among the hrss values at the three sites that, for sufficiently large signal amplitudes, determines the true source direction regardless of whether or not the signal is linearly polarized. Both the algorithm estimating arrival times, arrival time uncertainties, and hrss values and the directional follow-up can be applied to any set of gravitational wave candidates observed in a network of three non co-located interferometers. As a case study we test the methods on simulated waveforms embedded in simulations of the noise of the LIGO and Virgo detectors at design sensitivity.Comment: 10 pages, 14 figures, submitted to PR

Understanding Public Opinion in Debates over Biomedical Research: Looking beyond Political Partisanship to Focus on Beliefs about Science and Society

As social scientists have investigated the political and social factors influencing public opinion in science-related policy debates, there has been growing interest in the implications of this research for public communication and outreach. Given the level of political polarization in the United States, much of the focus has been on partisan differences in public opinion, the strategies employed by political leaders and advocates that promote those differences, and the counter-strategies for overcoming them. Yet this focus on partisan differences tends to overlook the processes by which core beliefs about science and society impact public opinion and how these schema are often activated by specific frames of reference embedded in media coverage and popular discourse. In this study, analyzing cross-sectional, nationally representative survey data collected between 2002 and 2010, we investigate the relative influence of political partisanship and science-related schema on Americans' support for embryonic stem cell research. In comparison to the influence of partisan identity, our findings suggest that generalized beliefs about science and society were more chronically accessible, less volatile in relation to media attention and focusing events, and an overall stronger influence on public opinion. Classifying respondents into four unique audience groups based on their beliefs about science and society, we additionally find that individuals within each of these groups split relatively evenly by partisanship but differ on other important dimensions. The implications for public engagement and future research on controversies related to biomedical science are discussed