5,657 research outputs found

    Extinction in a branching process: Why some of the fittest strategies cannot guarantee survival

    Get PDF
    The fitness of a biological strategy is typically measured by its expected reproductive rate, the first moment of its offspring distribution. However, strategies with high expected rates can also have high probabilities of extinction. A similar situation is found in gambling and investment, where strategies with a high expected payoff can also have a high risk of ruin. We take inspiration from the gambler's ruin problem to examine how extinction is related to population growth. Using moment theory we demonstrate how higher moments can impact the probability of extinction. We discuss how moments can be used to find bounds on the extinction probability, focusing on s-convex ordering of random variables, a method developed in actuarial science. This approach generates "best case" and "worst case" scenarios to provide upper and lower bounds on the probability of extinction. Our results demonstrate that even the most fit strategies can have high probabilities of extinction.Comment: Best case extrema adde

    On connectivity-dependent resource requirements for digital quantum simulation of dd-level particles

    Full text link
    A primary objective of quantum computation is to efficiently simulate quantum physics. Scientifically and technologically important quantum Hamiltonians include those with spin-ss, vibrational, photonic, and other bosonic degrees of freedom, i.e. problems composed of or approximated by dd-level particles (qudits). Recently, several methods for encoding these systems into a set of qubits have been introduced, where each encoding's efficiency was studied in terms of qubit and gate counts. Here, we build on previous results by including effects of hardware connectivity. To study the number of SWAP gates required to Trotterize commonly used quantum operators, we use both analytical arguments and automatic tools that optimize the schedule in multiple stages. We study the unary (or one-hot), Gray, standard binary, and block unary encodings, with three connectivities: linear array, ladder array, and square grid. Among other trends, we find that while the ladder array leads to substantial efficiencies over the linear array, the advantage of the square over the ladder array is less pronounced. These results are applicable in hardware co-design and in choosing efficient qudit encodings for a given set of near-term quantum hardware. Additionally, this work may be relevant to the scheduling of other quantum algorithms for which matrix exponentiation is a subroutine.Comment: Accepted to QCE20 (IEEE Quantum Week). Corrected erroneous circuits in Figure

    Corporate Capitalism and Racial (In)Justice: Teaching The Colonel’s Dream

    Get PDF
    Growing up in Cleveland after the Civil War and during the brutal rollback of Reconstruction and the onset of Jim Crow, Charles W. Chesnutt could have passed as white but chose to identify himself as black. An intellectual and activist involved with the NAACP who engaged in debate with Booker T. Washington and W. E. B. Du Bois, he wrote fiction and essays that addressed issues as various as segregation, class among both blacks and whites, Southern nostalgia, and the Wilmington coup d’état of 1898. The portrayals of race, racial violence, and stereotyping in Chesnutt’s works challenge teachers and students to contend with literature as both a social and an ethical practice. In part 1 of this volume, “Materials,” the editors survey the critical reception of Chesnutt’s works in his lifetime and after, along with the biographical, critical, and archival texts available to teachers and students. The essays in part 2, “Approaches,” address such topics in teaching Chesnutt as his use of dialect, the role of intertextuality and genre in his writing, irony, and his treatment of race, economics, and social justice. Winner of the Sylvia Lyons Render Award from the Charles W. Chesnutt Associationhttps://scholarworks.wm.edu/asbookchapters/1017/thumbnail.jp

    Negative And Positive Attention Bias In Anhedonia And Anxious Arousal: Can Depression And Anxiety Be Distinguished By Patterns Of Engagement And Disengagement Bias?

    Get PDF
    Negative and positive attention bias (AB) is the preferential allocation of attentional resources to negative and positive stimuli in the environment, respectively. AB has been studied in various clinical and non-clinical populations and the process has been linked to symptoms of depression and anxiety. Findings so far suggest that negative AB is a trait-based factor that predisposes individuals to anxiety and depression. Positive AB appears specific to a depressed state, yet findings generally remain mixed. Measures of AB have been recently critiqued for their poor psychometric properties. This study addresses three gaps in the literature to further our understanding of the relationship between AB and psychopathology. The aims of this study were to determine whether 1) the core symptoms of depression (anhedonia) and anxiety (anxious arousal) are related to differential patterns of negative and positive AB, 2) anhedonia and anxious arousal have incremental utility in predicting AB over and above negative affectivity, 3) AB predicts group membership (clinical vs non-clinical). The dot-probe paradigm was administered to 144 participants from various settings. Mixed effects modeling was used to predict the relationship between Type of Trial (negative or positive vs neutral), Congruence (congruent vs incongruent), and Group (anhedonia, anxious arousal, comorbid, control) on response rate or error rate. Results from random effects analysis showed that inter-subject variability was significant. Fixed effects analyses showed that the present study failed to capture positive and negative AB. Between group differences in raw reaction times were observed. Implications of the findings with regards to methodological differences across studies are discussed

    We Other Victorians: Domesticity and Modern Professionalism

    Get PDF
    Focusing on literary authors, social reformers, journalists, and anthropologists, Francesca Sawaya demonstrates how women intellectuals in early twentieth-century America combined and criticized ideas from both the Victorian cult of domesticity and the modern culture of professionalism to shape new kinds of writing and new kinds of work for themselves. Sawaya challenges our long-standing histories of modern professional work by elucidating the multiple ways domestic discourse framed professional culture. Modernist views of professionalism typically told a racialized story of a historical break between the primitive, feminine, and domestic work of the Victorian past and the modern, masculine, professional expertise of the present. Modern Women, Modern Work historicizes this discourse about the primitive labor of women and racial others and demonstrates how it has been adopted uncritically in contemporary accounts of professionalism, modernism, and modernity. Seeking to recuperate black and white women\u27s contestations of the modern professions, Sawaya pairs selected novels with a broad range of nonfiction writings to show how differing narratives about the transition to modernity authorized women\u27s professionalism in a variety of fields. Among the figures considered are Jane Addams, Ruth Benedict, Willa Cather, Pauline Hopkins, Zora Neale Hurston, Sarah Orne Jewett, Josephine St. Pierre Ruffin, and Ida Tarbell. In mapping out the constraints women faced in their writings and their work, and in tracing the slippery compromises they embraced and the brilliant adaptations they made, Modern Women, Modern Work boldly reenvisions the history of modern professionalism in the United States.https://scholarworks.wm.edu/asbookchapters/1128/thumbnail.jp

    Introduction to The Difficult Art of Giving Patronage, Philanthropy, and the American Literary Market

    Get PDF
    The Difficult Art of Giving rethinks standard economic histories of the literary marketplace. Traditionally, American literary histories maintain that the post-Civil War period marked the transition from a system of elite patronage and genteel amateurism to what is described as the free literary market and an era of self-supporting professionalism. These histories assert that the market helped to democratize literary production and consumption, enabling writers to sustain themselves without the need for private sponsorship. By contrast, Francesca Sawaya demonstrates the continuing importance of patronage and the new significance of corporate-based philanthropy for cultural production in the United States in the postbellum and modern periods. Focusing on Henry James, William Dean Howells, Mark Twain, Charles Chesnutt, and Theodore Dreiser, Sawaya explores the notions of a free market in cultural goods and the autonomy of the author. Building on debates in the history of the emotions, the history and sociology of philanthropy, feminist theory, and the new economic criticism, Sawaya examines these major writers\u27 careers as well as their rich and complex representations of the economic world. Their work, she argues, demonstrates that patronage and corporate-based philanthropy helped construct the putatively free market in literature. The book thereby highlights the social and economic interventions that shape markets, challenging old and contemporary forms of free market fundamentalism.https://scholarworks.wm.edu/asbookchapters/1127/thumbnail.jp
    • …
    corecore