15,524 research outputs found

    Characteristics of Hearing and Echolocation in Under-Studied Odontocete Species.

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    Ph.D. Thesis. University of Hawaiʻi at Mānoa 2017

    Consumer preferences for scanning modality to diagnose focal liver lesions

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    Objectives: Differences in the process of using liver imaging technologies might be important to patients. This study aimed to investigate preferences for scanning modalities used in diagnosing focal liver lesions. Methods: A discrete choice experiment was administered to 504 adults aged 25 years. Respondents made repeated choices between two hypothetical scans, described according to waiting time for scan and results, procedure type, the chance of minor side-effects, and whether further scanning procedures were likely to be required. Choice data were analyzed using mixed-logit models with respondent characteristics used to explain preference heterogeneity. Results: Respondents preferred shorter waiting times, the procedure to be undertaken with a handheld scanner on a couch instead of within a body scanner, no side-effects, and no follow–up scans (p .01). The average respondent was willing to wait an additional 2 weeks for the scan if it resulted in avoiding side-effects, 1.5 weeks to avoid further procedures or to be told the results immediately, and 1 week to have the scan performed on a couch with a handheld scanner. However, substantial heterogeneity was observed in the strength of preference for desirable imaging characteristics. Conclusions: An average individual belonging to a general population sub–group most likely to require imaging to characterize focal liver lesions in the United Kingdom would prefer contrast–enhanced ultrasound over magnetic resonance imaging or computed tomography. Insights into the patient perspective around differential characteristics of imaging modalities have the potential to be used to guide recommendations around the use of these technologies

    Anarchy, Groups, and Conflict: An Experiment on the Emergence of Protective Associations

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    In this paper, we investigate the implications of the philosophical considerations presented in Nozick’s Anarchy, State, and Utopia, by examining group formation in a laboratory setting where subjects engage in both cooperative and conflictual interactions. We endow participants with a commodity used to generate earnings, plunder others, or protect against plunder. In our primary treatment, we allow participants to form groups to pool their resources. We conduct a baseline comparison treatment that does not allow group formation. We find that allowing subjects to organize themselves into groups does not lead to more cooperation and may in fact exacerbate tendencies for conflict.Nozickian protective associations, Conflict, Anarchy, Experimental economics

    The Wealth of Nations

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    The Wealth of Nations is a treasured classic of political economy. First published in March of 1776, Adam Smith wrote the book to influence a special audience - the British Parliament - and its arguments in the early spring of that year pressed for peace and cooperation with Britain\u27s colonies rather than war.Smith\u27s message was that economic exploitation, through the monopoly trade of empire, stifled wealth-creation in both home and foreign lands. Moreover, protectionism preserved the status quo, and privileged a few elites at the expense of long run growth.Smith wrote, It is the industry which is carried on for the benefit of the rich and the powerful that is principally encouraged by our mercantile system. That which is carried on for the benefit of the poor and the indigent is too often either neglected or oppressed. This edition, based on the classic Cannan version of the text, includes a foreword by George Osborne MP and an introduction by Jonathan B. Wight, University of Richmond, which aims to place the work in a business context. Wight also provides an invaluable \u27Notable Quotes\u27 section where he extracts and categorises some of the most famous and pertinent sections of Smith\u27s work.This classic work is as essential today as it was when it first written.https://scholarship.richmond.edu/bookshelf/1066/thumbnail.jp

    Fast, Sample-Efficient, Affine-Invariant Private Mean and Covariance Estimation for Subgaussian Distributions

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    We present a fast, differentially private algorithm for high-dimensional covariance-aware mean estimation with nearly optimal sample complexity. Only exponential-time estimators were previously known to achieve this guarantee. Given nn samples from a (sub-)Gaussian distribution with unknown mean μ\mu and covariance Σ\Sigma, our (ε,δ)(\varepsilon,\delta)-differentially private estimator produces μ~\tilde{\mu} such that μμ~Σα\|\mu - \tilde{\mu}\|_{\Sigma} \leq \alpha as long as ndα2+dlog1/δαε+dlog1/δεn \gtrsim \tfrac d {\alpha^2} + \tfrac{d \sqrt{\log 1/\delta}}{\alpha \varepsilon}+\frac{d\log 1/\delta}{\varepsilon}. The Mahalanobis error metric μμ^Σ\|\mu - \hat{\mu}\|_{\Sigma} measures the distance between μ^\hat \mu and μ\mu relative to Σ\Sigma; it characterizes the error of the sample mean. Our algorithm runs in time O~(ndω1+nd/ε)\tilde{O}(nd^{\omega - 1} + nd/\varepsilon), where ω<2.38\omega < 2.38 is the matrix multiplication exponent. We adapt an exponential-time approach of Brown, Gaboardi, Smith, Ullman, and Zakynthinou (2021), giving efficient variants of stable mean and covariance estimation subroutines that also improve the sample complexity to the nearly optimal bound above. Our stable covariance estimator can be turned to private covariance estimation for unrestricted subgaussian distributions. With nd3/2n\gtrsim d^{3/2} samples, our estimate is accurate in spectral norm. This is the first such algorithm using n=o(d2)n= o(d^2) samples, answering an open question posed by Alabi et al. (2022). With nd2n\gtrsim d^2 samples, our estimate is accurate in Frobenius norm. This leads to a fast, nearly optimal algorithm for private learning of unrestricted Gaussian distributions in TV distance. Duchi, Haque, and Kuditipudi (2023) obtained similar results independently and concurrently.Comment: 44 pages. New version fixes typos and includes additional exposition and discussion of related wor

    Exploring the Questionable Academic Practice of Conference Paper Double Dipping

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    We develop a conceptual framework and provide empirical evidence that helps to explain why management scholars submit the same paper to more than one scholarly conference, a practice referred to as double dipping. Drawing from general strain theory,we find that certain features of the social and national institutional context in which these scholars are embedded provides motivation for and facilitates rationalization of engagement in the double-dipping practice. Specifically, our results show that the incidence of conference paper double dipping is greater for junior scholars and for those currently affiliated with research-intensive universities. We also find that authors who received their highest educational degree in countries with higher levels of corruption are more likely to engage in double dipping. The study provides a better theoretical understanding of contextual factors that may lead individuals to engage in questionable academic practices.We hope our findings will raise this issue to fuller scrutiny within the Academy, and motivate some potential remedies to reduce the frequency of this questionable behavior. © Academy of Management Learning & Education,2017

    Anarchy, Groups, and Conflict: An Experiment on the Emergence of Protective Associations

    Get PDF
    In this paper, we investigate the implications of the philosophical considerations presented in Nozick’s Anarchy, State, and Utopia, by examining group formation in a laboratory setting where subjects engage in both cooperative and conflictual interactions. We endow participants with a commodity used to generate earnings, plunder others, or protect against plunder. In our primary treatment, we allow participants to form groups to pool their resources. We conduct a baseline comparison treatment that does not allow group formation. We find that allowing subjects to organize themselves into groups does not lead to more cooperation and may in fact exacerbate tendencies for conflict

    Consumption-Based Conservation Targeting: Linking Biodiversity Loss to Upstream Demand through a Global Wildlife Footprint.

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    Although most conservation efforts address the direct, local causes of biodiversity loss, effective long-term conservation will require complementary efforts to reduce the upstream economic pressures, such as demands for food and forest products, which ultimately drive these downstream losses. Here, we present a wildlife footprint analysis that links global losses of wild birds to consumer purchases across 57 economic sectors in 129 regions. The United States, India, China, and Brazil have the largest regional wildlife footprints, while per-person footprints are highest in Mongolia, Australia, Botswana, and the United Arab Emirates. A US$100 purchase of bovine meat or rice products occupies approximately 0.1 km2 of wild bird ranges, displacing 1-2 individual birds, for 1 year. Globally significant importer regions, including Japan, the United Kingdom, Germany, Italy, and France, have large footprints that drive wildlife losses elsewhere in the world and represent important targets for consumption-focused conservation attention
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