Period three actions on lens spaces

We show that a free period three action on a lens space is standard, i.e. the quotient is homeomorphic to a lens space. This is an extension of the result for period three actions on the three-sphere, arXiv:math.GT/0204077, by the author and J. Hyam Rubinstein.Comment: 67 pages, 54 picture

The Capital of Diversity: Difference, Development, and Placemaking in Washington, D.C.

Diversity has long been a part of the urban landscape, both as a demographic fact and as a valuable commodity used to attract development. Both kinds of diversity move through Columbia Heights, the rapidly (re)developing neighborhood in Washington D.C. that serves as my case study. It is home to residents of varying racial, ethnic, sexuality and class-based identifications as well as the rhetoric that selectively values them. In this dissertation, I argue that a rhetorical commitment to diversity has been an integral part of uneven development in Columbia Heights. It is the cornerstone of neoliberal development, a process in which government subsidized, private development benefits middle and upper-middle class (often white) residents, while low-income residents of color are increasingly denied quality housing, employment, and education. This interdisciplinary project draws on urban, cultural, ethnic, and queer studies scholarship to illustrate how representations of difference affect material development. I argue that they create ideological "maps" of the neighborhood that value some markers of difference while erasing and policing others. In turn, these maps guide who invests in the neighborhood and who belongs where. I chart how representations have changed over time, from the appropriation of civil rights rhetoric in the mid to late 20th century, to more recent multicultural imagery and gay-led gentrification narratives used to sell a "new," upscale Columbia Heights. Using a mixed methodology of textual and ethnographic analysis, I examine different sites of discursive production: city planning documents, real estate marketing, and an online neighborhood listserv. I also interview longtime and incoming Columbia Heights residents with various social locations, illustrating how dominant narratives of difference and development are reinforced and/or challenged among residents. This project expands existing development, gentrification, and gay enclave scholarship. It challenges singular analyses of difference and examines how multiple markers of difference affect spaces. All middle-class newcomers are not white, nor are all lesbian, gay, bisexual, and queer residents middle-class. In addition to suggesting policy solutions, I suggest how "contact" between residents of different social locations has the potential to counteract uneven development and the discourse that reinforces it

The Withering of Community Life and the Growth of Emotional Disorders

The architecture of this essay is as follows: I begin by assaying the communitarian crisis of the modern western world. Second, I offer a brief narrative of the social and cultural variables that foster rootlessness and social disintegration in much of urban industrial life. Third, I state a strong case for how this same process may be systematically undermining the nuclear family as a life-long community, threatening the dependence of children on care-giving adults, and, thereafter, the psychological development of children

Archaeological Testing at 31OR281 and 31OR4d on the Mason Farms and Finley Golf Course Property, The University of North Carolina at Chapel Hill

Technical Report No. 25, Research Laboratories of Archaeology, University of North Carolina at Chapel Hill. Reports in this series present the findings of archaeological surveys and test excavations completed by the RLA between 1983 and present

The rise of China : challenges and opportunities for the European Union

China\u2019s growing power and influence raise important and inescapable questions for countries and societies around the world, not least for Europe. A rising China offers opportunities for greater cooperation, both bilaterally and in the context of old and new multilateral institutions, yet also carries inherent risks for the European Union (EU), not least in the way in which it may make it (even) more difficult to manage the relations with other global powers while also maintaining unity among EU member states. This special issue examines Europe\u2019s response to the steady and dramatic rise of China over the past two decades. In particular, it explores the challenges as well as the many instances of engagement that define their relations today across a number of policy areas, including economic, diplomatic, and security relations. The contributions to this special issue demonstrate the varied, multi-faceted and to some extent contradictory nature of EU-China relations. The two sides are in an ever-closer economic embrace, yet they remain distant and occasionally antagonistic with respect to security concerns or normative discourses

Method Effects and the Need for Cognition Scale

Individual differences in the need for cognition are typically assessed using the 18-item Need for cognition scale (NCS) developed by Cacioppo and Petty (1982). However, in contrast to the unidimensional model proposed by the scale developers, recent factor analyses have introduced two -and three- dimensional models of the scale. Confirmatory factor analyses were used in this study to evaluate different measurement models based on data provided by 590 (236 males, 354 females) young adult members of the general public. Although some alternative models showed promise, a single factor model with method effects associated with positively and negatively worded items provided best fit. Implications for the asses sment of need for cognition are considered

Peer‐to‐peer Networks and Complementary Goods: The Impact of Openness and Innovation on Profitable Piracy

File‐sharing is often depicted as detrimental to traditional commercial activities and tends to dissuade official digital goods’ producers from innovating. Meanwhile, evidence shows that producers are likely to provide complementary hardware goods that are compatible with digital goods available both offline and online. This article investigates to what extent the introduction of peer‐to‐peer networks has a positive impact on the level of profits reached by producers.   Our model shows that the file‐sharing activity does not crowd the official digital goods producers and hardware goods producers out of the market. Moreover, we find that there exists suitable quality‐based strategies so that both types of producers benefit from the file‐sharing activity. The utility that peer‐to‐peer networks provide to file‐sharers has to be considered cautiously for commercial firms to gain positive outcomes from the file‐sharing activity

Rectified Gaussian Scale Mixtures and the Sparse Non-Negative Least Squares Problem

In this paper, we develop a Bayesian evidence maximization framework to solve the sparse non-negative least squares (S-NNLS) problem. We introduce a family of probability densities referred to as the Rectified Gaussian Scale Mixture (R- GSM) to model the sparsity enforcing prior distribution for the solution. The R-GSM prior encompasses a variety of heavy-tailed densities such as the rectified Laplacian and rectified Student- t distributions with a proper choice of the mixing density. We utilize the hierarchical representation induced by the R-GSM prior and develop an evidence maximization framework based on the Expectation-Maximization (EM) algorithm. Using the EM based method, we estimate the hyper-parameters and obtain a point estimate for the solution. We refer to the proposed method as rectified sparse Bayesian learning (R-SBL). We provide four R- SBL variants that offer a range of options for computational complexity and the quality of the E-step computation. These methods include the Markov chain Monte Carlo EM, linear minimum mean-square-error estimation, approximate message passing and a diagonal approximation. Using numerical experiments, we show that the proposed R-SBL method outperforms existing S-NNLS solvers in terms of both signal and support recovery performance, and is also very robust against the structure of the design matrix.Comment: Under Review by IEEE Transactions on Signal Processin