4,018 research outputs found
T-Duality and Double Field Theory
The purpose of this thesis is to study a symmetry of string theory known as T-duality. We focus on a particular example establishing the equivalence between a quantized string moving in a circular space of radius R and a dual string moving in a similar space of radius 1/R . We will show that this duality implies that the momentum of the string in one picture becomes the number of times the string is wound around the circle in the dual picture. We present two proofs of T-duality. The first reflects the standard interpretation of T-duality as an isomorphism of quantum theories. The second approach is based on Hull\u27s Double Field Theory
Playoff Uncertainty, Match Uncertainty and Attendance at Australian National Rugby League Matches
This paper develops a new simulation-based measure of playoff uncertainty and investigates its contribution to modelling match attendance compared to other variants of playoff uncertainty in the existing literature. A model of match attendance that incorporates match uncertainty, playoff uncertainty, past home-team performance and other relevant control variables is fitted to Australian National Rugby League data for seasons 2004-2008 using fixed effects estimation. The results suggest that playoff uncertainty and home-team success are more important determinants of match attendance than match uncertainty. Alternative measures of playoff uncertainty based on points behind the leader, although more ad hoc, also appear able to capture the effects of playoff uncertainty.playoff uncertainty, match uncertainty, sports league attendance, Australian National Rugby League, fixed effects estimation
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Ebola, 1995/2014
Nicholas B. King looks back at the dialectics of confidence and paranoia in the Ebola outbreaks of 1995 and 2014
THE IMPACT OF A QUALITY UNDERGRADUATE EDUCATION ON MARINE CORPS OFFICER PERFORMANCE
To meet the demands of future conflicts against increasingly capable adversaries, the Marine Corps must recruit, promote, and retain the most capable officers. Yet, every year money is spent training and educating Marine officers, and each year high performing and capable officers voluntarily separate, resulting in Marine Corps talent loss. The goal of this thesis was to determine if the type of college attended predicts performance of career-level officers. U.S. universities with Naval Reserve Officer Training Corps were grouped by selectivity. Models used ordinary least squares to predict officer retention at 5-, 7-, 10-, and 15-year career milestones and a logit model to study predictive variables for promotion to Major. Our results suggest that graduates of top-ranked public or private universities are less likely to be retained in the first 10 years of service. Graduates of top-ranked private universities who decide to stay in the Marines are more likely to retain at 15 years and promote to Major. Graduates of bottom-ranked public universities are more likely to retain at 7 years of service but are less likely to remain on active duty at 15 years or promote to Major. A Marine’s accession source was not found to be a significant factor in predicting promotion or retention after controlling for gender and race. Since school type retention rates were found to be similar, results do not support any policy changes that emphasize recruitment from a particular college type.Major, United States Marine CorpsApproved for public release. Distribution is unlimited
Deferred Prosecution Agreements in England & Wales: Castles Made of Sand?
Public Law, 2020, Apr, 307-330.
Negotiated settlements are increasingly regarded as an alternative tool against corporate criminality, with numerous countries now embracing such settlements. In England and Wales, amidst concerns relating to corporate criminal liability, the government introduced deferred prosecution agreements (DPAs) in 2014. Five years on from their introduction in England and Wales, it is timely to re-examine the DPA regime, not least given its influence on developments in other jurisdictions.
This article examines three key aspects of the development of the DPA regime to date, that, we argue, have resulted in a weak foundational basis for the regime notwithstanding its robust legal framework. Specifically, we explore: whether a DPA is in the public interest; the requirement of self-reporting; and the terms of a DPA. Even though there are admittedly only five Agreements to date, it is nonetheless useful to reflect upon the lessons to be learnt from these infant years. While DPAs were enacted to overcome obstacles to prosecuting companies and they have been widely lauded, we are not convinced by such contentions. The argument advanced in this article is that practice has been haphazard, rather than tied to any core principles, and lacks a clear underlying purpose. This situation is particularly evident in the three areas discussed in this article, which leads to the conclusion that the DPA regime stands on shaky foundations
Challenges in Minimizing Teacher Authority While Facilitating a Student-Owned Activism Project
Students who take critical sociology courses often report feeling discouraged about their ability to change large-scale social-structural problems. To redress this perceived lack of agency and control, we modified an upper-division sociology of popular culture course to include a studentowned activism project that would entail minimal teacher direction. In this paper we describe our efforts through two iterations of the activism project and reflect on the obstacles and suc- cesses of the project
Moduli spaces for Bondal quivers
Given a sufficiently nice collection of sheaves on an algebraic variety V,
Bondal explained how to build a quiver Q along with an ideal of relations in
the path algebra of Q such that the derived category of representations of Q
subject to these relations is equivalent to the derived category of coherent
sheaves on V. We consider the case in which these sheaves are all locally free
and study the moduli spaces of semistable representations of our quiver with
relations for various stability conditions. We show that V can often be
recovered as a connected component of such a moduli space and we describe the
line bundle induced by a GIT construction of the moduli space in terms of the
input data. In certain special cases, we interpret our results in the language
of topological string theory.Comment: 17 pages, major revisio
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A Difference-in-Differences Approach to Assess the Effect of a Heat Action Plan on Heat-Related Mortality, and Differences in Effectiveness According to Sex, Age, and Socioeconomic Status (Montreal, Quebec).
BackgroundThe impact of heat waves on mortality and health inequalities is well documented. Very few studies have assessed the effectiveness of heat action plans (HAPs) on health, and none has used quasi-experimental methods to estimate causal effects of such programs.ObjectivesWe developed a quasi-experimental method to estimate the causal effects associated with HAPs that allows the identification of heterogeneity across subpopulations, and to apply this method specifically to the case of the Montreal (Quebec, Canada) HAP.MethodsA difference-in-differences approach was undertaken using Montreal death registry data for the summers of 2000-2007 to assess the effectiveness of the Montreal HAP, implemented in 2004, on mortality. To study equity in the effect of HAP implementation, we assessed whether the program effects were heterogeneous across sex (male vs. female), age (≥ 65 years vs. < 65 years), and neighborhood education levels (first vs. third tertile). We conducted sensitivity analyses to assess the validity of the estimated causal effect of the HAP program.ResultsWe found evidence that the HAP contributed to reducing mortality on hot days, and that the mortality reduction attributable to the program was greater for elderly people and people living in low-education neighborhoods.ConclusionThese findings show promise for programs aimed at reducing the impact of extreme temperatures and health inequities. We propose a new quasi-experimental approach that can be easily applied to evaluate the impact of any program or intervention triggered when daily thresholds are reached. Citation: Benmarhnia T, Bailey Z, Kaiser D, Auger N, King N, Kaufman J. 2016. A difference-in-differences approach to assess the effect of a heat action plan on heat-related mortality, and differences in effectiveness according to sex, age, and socioeconomic status (Montreal, Quebec). Environ Health Perspect 124:1694-1699; http://dx.doi.org/10.1289/EHP203
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