820 research outputs found

    The anatomical properties of selected Populus clones

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    A Uniformly Dissipative Scheme for Stationary Statistical Properties of the Infinite Prandtl Number Model

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    The purpose of this short communication is to announce that a class of numerical schemes, uniformly dissipative approximations, which uniformly preserve the dissipativity of the continuous infinite dimensional dissipative complex (chaotic) systems possess desirable properties in terms of approximating stationary statistics properties. in particular, the stationary statistical properties of these uniformly dissipative schemes converge to those of the continuous system at vanishing mesh size. the idea is illustrated on the infinite Prandtl number model for convection and semi-discretization in time, although the general strategy works for a broad class of dissipative complex systems and fully discretized approximations. as far as we know, this is the first result on rigorous validation of numerical schemes for approximating stationary statistical properties of general infinite dimensional dissipative complex systems. © 2008 Elsevier Ltd. All rights reserved

    The School to Family Pipeline: What Do Religious, Private, and Public Schooling Have to Do with Family Formation?

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    Private religious schools are widely seen as value-laden communities that mold the character of their students. Thus, we expect adults who attended religious schools as children to demonstrate more favorable family outcomes related to stable marriages and childbearing. We further expect Protestant schooling to have a more powerful effect on marital outcomes than Catholic schooling, given the heavier focus of Protestantism on marriage. Finally, we expect stronger positive associations between religious schooling and marital outcomes for adults who grew up in difficult circumstances compared to adults who grew up in advantaged circumstances. We test these hypotheses using survey data from the Understanding America Study. Our three outcome variables are ever marrying and never divorcing, ever divorcing, and conceiving a child out-of-wedlock. Most of the results confirm our hypotheses. Protestant schooling is associated with more positive marital outcomes across all three measures. Catholic schooling is significantly correlated with a lower likelihood of having a child outside of marriage. The associations between religious schooling and desirable marriage outcomes are strongest for adults who grew up poor and for those raised in intact families

    Regional association of pCASL-MRI with FDG-PET and PiB-PET in people at risk for autosomal dominant Alzheimer's disease.

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    Autosomal dominant Alzheimer's disease (ADAD) is a small subset of Alzheimer's disease that is genetically determined with 100% penetrance. It provides a valuable window into studying the course of pathologic processes that leads to dementia. Arterial spin labeling (ASL) MRI is a potential AD imaging marker that non-invasively measures cerebral perfusion. In this study, we investigated the relationship of cerebral blood flow measured by pseudo-continuous ASL (pCASL) MRI with measures of cerebral metabolism (FDG PET) and amyloid deposition (Pittsburgh Compound B (PiB) PET). Thirty-one participants at risk for ADAD (age 39 Â± 13 years, 19 females) were recruited into this study, and 21 of them received both MRI and FDG and PiB PET scans. Considerable variability was observed in regional correlations between ASL-CBF and FDG across subjects. Both regional hypo-perfusion and hypo-metabolism were associated with amyloid deposition. Cross-sectional analyses of each biomarker as a function of the estimated years to expected dementia diagnosis indicated an inverse relationship of both perfusion and glucose metabolism with amyloid deposition during AD development. These findings indicate that neurovascular dysfunction is associated with amyloid pathology, and also indicate that ASL CBF may serve as a sensitive early biomarker for AD. The direct comparison among the three biomarkers provides complementary information for understanding the pathophysiological process of AD

    White, Man, and Highly Followed: Gender and Race Inequalities in Twitter

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    Social media is considered a democratic space in which people connect and interact with each other regardless of their gender, race, or any other demographic factor. Despite numerous efforts that explore demographic factors in social media, it is still unclear whether social media perpetuates old inequalities from the offline world. In this paper, we attempt to identify gender and race of Twitter users located in U.S. using advanced image processing algorithms from Face++. Then, we investigate how different demographic groups (i.e. male/female, Asian/Black/White) connect with other. We quantify to what extent one group follow and interact with each other and the extent to which these connections and interactions reflect in inequalities in Twitter. Our analysis shows that users identified as White and male tend to attain higher positions in Twitter, in terms of the number of followers and number of times in user's lists. We hope our effort can stimulate the development of new theories of demographic information in the online space.Comment: In Proceedings of the IEEE/WIC/ACM International Conference on Web Intelligence (WI'17). Leipzig, Germany. August 201
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