98,415 research outputs found

    Quantum and thermal effects in the double exchange ferromagnet

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    The physics of the ferromagnetic phase of the ``double exchange'' model has been widely discussed in the context of the CMR manganites. Usually, the double exchange ferromagnet is treated is classically, by mapping it onto an effective Heisenberg model. However this mapping does not permit a correct treatment of quantum or thermal fluctuation effects, and the results obtained lack many of the interesting features seen in experiments on the manganites. Here we outline a new analytic approach to systematically evaluating quantum and thermal corrections to the magnetic and electronic properties of the double exchange ferromagnet.Comment: 4 pages summary of results for spin excitations in DE model with a few comments on associated electronic physics (from talk given at European Conference on Physics of Magnetism, Poznan 2002

    Entanglement and optimal strings of qubits for memory channels

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    We investigate the problem of enhancement of mutual information by encoding classical data into entangled input states of arbitrary length and show that while there is a threshold memory or correlation parameter beyond which entangled states outperform the separable states, resulting in a higher mutual information, this memory threshold increases toward unity as the length of the string increases. These observations imply that encoding classical data into entangled states may not enhance the classical capacity of quantum channels.Comment: 14 pages, 8 figures, latex, accepted for publication in Physical Review

    Mixed valence on a pyrochlore lattice - LiV2O4 as a geometrically frustrated magnet

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    Above 40K, the magnetic susceptibility of the heavy Fermion spinel LiV2O4 has many features in common with those of geometrically frustrated magnetic insulators, while its room temperature resistivity comfortably exceeds the Mott-Regel limit. This suggests that local magnetic moments, and the underlying geometry of the pyrochlore lattice, play an important role in determining its magnetic properties. We extend a recently introduced tetragonal mean field theory for insulating pyrochlore antiferromagnets to the case where individual tetrahedra contain spins of different lengths, and use this as a starting point to discuss three different scenarios for magnetic and electronic transitions in LiV2O4.Comment: 15 pages latex, 12 eps figures, uses EPJ macro

    Unseen and Unheard: Exploring the Mental Health of Mostly Heterosexual College Students

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    College years have long been understood to be a difficult yet important developmental period in an individual’s life, which may be particularly challenging for sexual minority students who tend to face discrimination on campus, which can undermine their mental health. Research in both college student and non-college student samples has shown that mostly heterosexual is a distinct sexual orientation. However, little is known about the wellbeing of individuals, including college students, who identify as mostly heterosexual. Moreover, among college students, little is known about the intersections between a mostly heterosexual identity and mental health. This study examined the association between sexual orientation and anxiety, depression, and risk for alcohol abuse. Specifically, it compared outcomes between students who identify as mostly heterosexual and students who identify as completely heterosexual. This study also compared outcomes between mostly heterosexual participants and lesbian, gay, bisexual, and queer (LGB+) students (as one group) to investigate potential differences among sexual minority students. In order to attempt to explain why differences exist, the mediating role of discrimination, namely incivility and hostility, were investigated. Several key findings emerged showing that mostly heterosexuals differ significantly from their completely heterosexual and LGB+ peers, in terms of their mental health and the role that forms of discrimination play in explaining disparities. Implications for the field of social work and other allied health professionals are discussed

    Technology Advancement Influence in Accounting and Information System Fields

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    This research serves to relate the accounting and information technology fields. The information in the research documents changes in the accounting and information technology fields, and how the fields are expected to change in the coming years. The research also discuss the relationship between the accounting and information technology fields. The topics on the ideal accounting candidates for employers and the expectation gap between graduates skills and employers’ expectations are also discussed. Careers in accounting and information systems and also similar and different basic skills of both fields are documented in the research. The changes in accounting are influenced by the improvements in technology as time progress. Information technology makes integration and communication possible anywhere in the world between businesses. Information technology systems have created a lot of job opportunities. Accounting and Information Systems are two different fields but combined they create a means of collecting, storing, managing, processing, retrieving and reporting financial data effectively

    Conflicting Commitments: The Politics of Enforcing Immigrant Worker Rights in San Jose and Houston

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    [Excerpt] This book examines how immigrant workers\u27 rights are enforced in practice, how claims are channeled, and why and how advocates take on particular battles. In the chapters that follow, I draw on an in-depth comparative case study of two immigrant-receiving destinations—San Jose, California, and Houston, Texas—to examine the dynamics of enforcing immigrant worker rights. I consider how certain solutions become commonly understood as appropriate responses to a given issue that affects immigrant laborers, and which actors take on responsibility for the advancement of particular worker problems. For example, why does a construction worker who has been cheated of a week\u27s pay in San Jose get funneled to a local legal aid clinic and eventually a state agency to file a formal claim, while his counterpart working in one of Houston\u27s sprawling track developments will struggle to find any lawyer willing to serve him and will perhaps never set foot in a government office to file a claim? Why do the San Jose police have little to offer this worker, while in Houston any police officer is required to make a theft-of-service report when asked? How is it that if this nonunionized worker were to call the South Bay AFL-CIO Labor Council in San Jose, he would be advised to call the California Department of Labor Standards Enforcement or seek out a local legal aid clinic, while in Houston the Harris County AFL-CIO Council would be more likely to encourage him to pay a visit to city hall, the federal building, or perhaps even a worker center to help organize a direct action, depending on his situation? And how do we understand the vastly different support immigrant workers will find from their consulates in these two cities? The goal of this book is to help answer these questions and expand our understanding of how immigrant worker rights are enforced and advanced. I situate the rights of immigrant workers in the space between both labor standards enforcement and immigration control, two conflicting jurisdictions whose implementation can vary widely, depending on their local political context. I then look beyond government bureaucrats to understand how enforcement strategies are influenced by local intermediaries who may have diverse interests in the advancement of immigrant worker rights. These include local elected officials, who can either intensify or mitigate the surveillance of undocumented immigrants and promote or stymie the interests of workers; civil society actors, who have direct knowledge of and access to immigrant workers, and who work in diverse ways to advance their rights; and consular institutions, whose unique combination of political legitimacy, institutionalized resources, and unfettered support for their emigrant population creates a unique pathway for rights enforcement

    Narratives of Deservingness and the Institutional Youth of Immigrant Workers

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    This article speaks to the special issue’s goal of disrupting the deserving/undeserving immigrant narrative by critically examining eligibility criteria available under two arenas of relief for undocumented immigrants: 1) the 2012 Deferred Action for Childhood Arrivals (DACA) program, which provides temporary deportation relief and work authorization for young adults who meet an educational requirement and other criteria, and 2) current and proposed pathways to legal status for those unauthorized immigrants who come forward to denounce workplace injustice, among other crimes. For each of these categories of “deserving migrants,” I illuminate the exclusionary nature each of these requirements, which pose challenges especially for those workers who have limited education. As such, I argue for the importance of an institutional perspective on youth. Specifically, I demonstrate how the educational criteria required by DACA privileges a select few individuals who have access to formal educational institutions as deserving, while ignoring other empowering but non-traditional models of worker education. I also examine those mechanisms that reward workers who come forward to contest employer abuse. These include the current U-Visa program, which opens a path to legal status for those select claimants who have been harmed by employer abuse and aid criminal investigations (e.g. Saucedo, 2010). In a similar vein, some advocates and legal scholars have proposed a pathway to citizenship for those workers involved in collective organizing (e.g. Gordon, 2007, 2011). I weigh the benefits and exclusivity of each pathway for addressing the precarity of the millions of undocumented immigrants currently in the United States. In doing so, I highlight how institutions have unevenly incorporated immigrant workers, creating wide categories of vulnerability that go ignored. That is, demographically young immigrants are often privileged as deserving, as are those institutionally mature workers who have been successfully incorporated by civic organizations and legal bureaucracies. Meanwhile, institutionally young immigrants—those who have been excluded from these spaces—are framed as undeserving. As a result, rather than to see legal status as a pathway to incorporation, it is extended as a reward for those who have surpassed longstanding barriers

    Handel opera presentation, past and present : a thesis presented in partial fulfilment of the requirements for the degree of Master of Music at Massey University, Wellington, New Zealand

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    What differences, if any, exist between the performance of Handel opera during his lifetime, and contemporary performances? To what extent do these differences reflect the need to adapt Handel's operas when performed out of their original context, and how does knowledge of original performance practices enhance the singer's ability to interpret and present characters in performance? This study investigates the ideas outlined above, exploring the social and cultural environment of opera seria, its conventions, and the way in which Handel's operas were presented during his lifetime, later providing a comparison with contemporary productions. It aims to enhance understanding of the production and musical aspects of staging a Handel opera, and to illustrate how this knowledge can assist in performance

    Fruit and Fish: Alison Goodwin’s Reimaging of the Modernist Motif

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    Alison Goodwin’s painting Cantaloupe (2008) at ïŹrst appears, perhaps naively, to depict a still life of fruit and ïŹ‚owers on a table: pomegranate, cantaloupe, sunïŹ‚owers, and a drink. Beneath two rusty red and murky green lines, a diamond pattern demarcates the ïŹ‚oor from the wall above. Next to the mottled green-and-red wall is a view through an open window. Three narrow houses lean precariously to the left; the windows are indicated, almost carelessly, by blocks of watery black paint. Two stylized trees with foliage shaped into bulbous spheres punctuate the row of buildings. Goodwin’s particular style, with its emphasis on a skewed perspective, ïŹ‚attened forms, and broadly applied colors, cannot—and should not—be read as unsophisticated or unknowing. Rather, Goodwin’s paintings reinterpret the work of some of the most important nineteenth- and early twentieth-century painters. She deliberately evokes the style and subjects of European modernists such as Henri Matisse, Paul Gauguin, and Vincent van Gogh. Each of her paintings recalls the implied formal tension between depicted three-dimensional space and the literal ïŹ‚atness of painted planes of color and stylized forms that her predecessors welcomed. Matisse, CĂ©zanne, and others in the late nineteenth century rejected academic norms of picture making (painting realistically through modeling, shade, and one-point perspective). By revisiting these artists’ aesthetic, Goodwin complicates this historical progression and inserts her own mark onto the modernist (and particularly male-dominated) canon. [excerpt
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