Boston University

About: Boston University is a education organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 48688 authors who have published 119622 publications receiving 6276020 citations. The organization is also known as: BU & Boston U.

Capture and Governance at Local and National Levels

Abstract: 135 Despite the importance of this issue, not much systematic research appears to have been devoted to assessing the relative susceptibility of national and local governments to interestgroup capture. Here we describe a model of two-party electoral competition with “probabilistic” voting behavior and lobbying by specialinterest groups based on David Baron (1994) and Gene Grossman and Elhanan Helpman (1996) that helps identify determinants of relative capture at different levels of government. These include relative levels of voter awareness and interest-group cohesiveness, electoral uncertainty, electoral competition, heterogeneity of districts with respect to inequality, and the electoral system. While some of these uphold the traditional Madisonian presumption, others are likely to create a tendency for lower capture at the local level, so the net effect is theoretically ambiguous. This suggests that the extent of relative capture may be context-specific and needs to be assessed empirically.

From Quantum Chaos and Eigenstate Thermalization to Statistical Mechanics and Thermodynamics

Abstract: This review gives a pedagogical introduction to the eigenstate thermalization hypothesis (ETH), its basis, and its implications to statistical mechanics and thermodynamics. In the first part, ETH is introduced as a natural extension of ideas from quantum chaos and random matrix theory (RMT). To this end, we present a brief overview of classical and quantum chaos, as well as RMT and some of its most important predictions. The latter include the statistics of energy levels, eigenstate components, and matrix elements of observables. Building on these, we introduce the ETH and show that it allows one to describe thermalization in isolated chaotic systems without invoking the notion of an external bath. We examine numerical evidence of eigenstate thermalization from studies of many-body lattice systems. We also introduce the concept of a quench as a means of taking isolated systems out of equilibrium, and discuss results of numerical experiments on quantum quenches. The second part of the review explores the implications of quantum chaos and ETH to thermodynamics. Basic thermodynamic relations are derived, including the second law of thermodynamics, the fundamental thermodynamic relation, fluctuation theorems, and the Einstein and Onsager relations. In particular, it is shown that quantum chaos allows one to prove these relations for individual Hamiltonian eigenstates and thus extend them to arbitrary stationary statistical ensembles. We then show how one can use these relations to obtain nontrivial universal energy distributions in continuously driven systems. At the end of the review, we briefly discuss the relaxation dynamics and description after relaxation of integrable quantum systems, for which ETH is violated. We introduce the concept of the generalized Gibbs ensemble, and discuss its connection with ideas of prethermalization in weakly interacting systems.

Age at drinking onset and alcohol dependence: age at onset, duration, and severity.

Abstract: Objective To examine whether starting to drink at an early age is associated with developing alcohol dependence at a younger age and chronic relapsing dependence, controlling for respondent demographics, smoking and illicit drug use, childhood antisocial behavior and depression, and family alcoholism history. Design Cross-sectional survey. Setting Nationwide face-to-face survey with a multistage probability sample. Participants A total of 43 093 adults were surveyed in 2001-2002. Main Outcome Measures Based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria, lifetime alcohol dependence, dependence within 10 years of starting drinking, multiple episodes, an alcohol dependence episode in the past year, episodes exceeding 1 year, and meeting 6 or 7 dependence criteria. Results Relative to respondents who began drinking at 21 years or older, those who began drinking before age 14 years were more likely to experience alcohol dependence ever and within 10 years of first drinking (adjusted hazard ratios and 95% confidence intervals [CIs], 1.78 [1.51-2.11] and 1.69 [1.38-2.07], respectively). They also more often experienced past-year dependence and multiple dependence episodes (adjusted odds ratios, 1.93 [95% CI, 1.40-2.64] and 3.09 [95% CI, 2.19-4.35], respectively). Among alcohol-dependent persons, the odds were 2.62 (95% CI, 1.79-3.84) for having at least 1 episode exceeding 1 year and 2.89 (95% CI, 1.97-4.23) for meeting 6 or 7 dependence diagnostic criteria. Conclusion There is a need to screen and counsel adolescents about alcohol use and to implement policies and programs that delay alcohol consumption.

The predictive value of ICD-10 diagnostic coding used to assess Charlson comorbidity index conditions in the population-based Danish National Registry of Patients

Abstract: Background The Charlson comorbidity index is often used to control for confounding in research based on medical databases. There are few studies of the accuracy of the codes obtained from these databases. We examined the positive predictive value (PPV) of the ICD-10 diagnostic coding in the Danish National Registry of Patients (NRP) for the 19 Charlson conditions.