826 research outputs found

    How Polarized Have We Become? A Multimodal Classification of Trump Followers and Clinton Followers

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    Polarization in American politics has been extensively documented and analyzed for decades, and the phenomenon became all the more apparent during the 2016 presidential election, where Trump and Clinton depicted two radically different pictures of America. Inspired by this gaping polarization and the extensive utilization of Twitter during the 2016 presidential campaign, in this paper we take the first step in measuring polarization in social media and we attempt to predict individuals' Twitter following behavior through analyzing ones' everyday tweets, profile images and posted pictures. As such, we treat polarization as a classification problem and study to what extent Trump followers and Clinton followers on Twitter can be distinguished, which in turn serves as a metric of polarization in general. We apply LSTM to processing tweet features and we extract visual features using the VGG neural network. Integrating these two sets of features boosts the overall performance. We are able to achieve an accuracy of 69%, suggesting that the high degree of polarization recorded in the literature has started to manifest itself in social media as well.Comment: 16 pages, SocInfo 2017, 9th International Conference on Social Informatic

    Evaluating Recruitment Contribution Of A Selectively Bred Aquaculture Line Of The Oyster, Crassostrea Virginica Used In Restoration Efforts

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    Severe over-fishing, habitat degradation, and recent disease impacts have devastated the eastern oyster (Crassostrea virginica) fisherey in the Chesapeake Bay. Several restoration efforts are in progress, including the unconventional approach of seeding reefs with an aquaculture strain selected for disease resistance and fast growth in hopes of mitigating the negative effects of diseases and low census numbers. Supplementation of four sites (The Great Wicomico, Lynnhaven, York and Elizabeth Rivers) examined in this study totaled approximatedly 18,500,000 aquaculture oysters from 2002 to 2006. We collected locally recruited offspring (n = 6517) from 2002 to 2006 at these sites to determine if reproduction by the transplanted oysters produced detectable contributions to recruitment by examining the frequency of a composite mitochondrial haplotype that occurs at high frequencies in this aquaculture strain but is rare in wild Chesapeake Bay oysters. The estimated frequency of this haplotype in locally recruited oysters (average 1.4%, SD = 0.9) was compared with the average frequencies found in the hatchery produced (35%, SD = 12.8) and wild (1.2%, SD = 0.9) oysters, but we were unable to refute the null-hypothesis that population supplementation made no contribution to recruitment. We discuss five nonmutually exclusive explanations for the limited impact of supplementation, including unequal sex-ratio, predation, flushing, relative scale, and aquaculture selection. We argue that predation, relative scale and aquaculture selection are the likely reasons for the limited contribution made by aquaculture oysters used for population supplementation

    Crossing the chasm: a 'tube-map' for agent-based social simulation of policy scenarios in spatially-distributed systems

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    Agent based models (ABMs) simulate actions and interactions of autonomous agents/groups and their effect on systems as a whole, accounting for learning without assuming perfect rationality or complete knowledge. ABMs are an increasingly popular approach to studying complex, spatially distributed socio-environmental systems, but have still to become an established approach in the sense of being one that is expected by those wanting to explore scenarios in such systems. Partly, this is an issue of awareness – ABM is still new enough that many people have not heard of it; partly, it is an issue of confidence – ABM has more to do to prove itself if it is to become a preferred method. This paper will identify advances in the craft and deployment of ABM needed if ABM is to become an accepted part of mainstream science for policy or stakeholders. The conduct of ABM has, over the last decade, seen a transition from using abstracted representations of systems (supporting theory-led thought experiments) to more accessible representations derived empirically (to deliver more applied analysis). This has enhanced the perception of potential users of ABM outputs that the latter are salient and credible. Empirical ABM is not, however, a panacea, as it demands more computing and data resources, limiting applications to domains where data exist along with suitable environmental models where these are required. Further, empirical ABM is still facing serious questions of validation and the ontology used to describe the system in the first place. Using Geoffrey A. Moore’s Crossing the Chasm as a lens, we argue that the way ahead for ABM lies in identifying the niches in which it can best demonstrate its advantages, working with collaborators to demonstrate that it can deliver on its promises. This leads us to identify several areas where work is needed

    The XVth World Congress of Psychiatric Genetics, October 7–11, 2007: Rapporteur summaries of oral presentations

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    The World Congress of Psychiatric Genetics (WCPG) has become an annual event since the early 1990's sponsored by the International Society of Psychiatric Genetics (ISPG). Each year the latest published and unpublished findings are aired for discussion by representatives of the majority of research programs on this topic world-wide. The 2007 congress was held in New York City and attracted over 1000 researchers. The topics emphasized included results from whole genome association studies, the significance of copy number variation and the important contributions of epigenetic events to psychiatric disorders. There were over 20 oral sessions devoted to these and other topics of interest. Young investigator recipients of travel awards served as rapporteurs to summarize sessions and these summaries follow.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58040/1/30711_ftp.pd

    Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

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    We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum pT > 0.5 GeV/c, pseudorapidity |\eta| < 1) produced in association with large transverse momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-pT jet production) in each event to define three regions of \eta-\phi space; toward, away, and transverse, where \phi is the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-pT jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte-Carlo models. The goal of this analysis is to provide data that can be used to test and improve the QCD Monte-Carlo models of the underlying event that are used to simulate hadron-hadron collisions.Comment: Submitted to Phys.Rev.

    Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays

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    We measure the mean lifetime, tau=2/(Gamma_L+Gamma_H), and the width difference, DeltaGamma=Gamma_L-Gamma_H, of the light and heavy mass eigenstates of the B0s meson, B0sL and B0sH, in B0s -> J/psi phi decays using 1.7 fb^-1 of data collected with the CDF II detector at the Fermilab Tevatron ppbar collider. Assuming CP conservation, a good approximation for the B0s system in the Standard Model, we obtain DeltaGamma = 0.076^+0.059_-0.063 (stat.) +- 0.006 (syst.) ps^-1 and tau = 1.52 +- 0.04 (stat.) +- 0.02 (syst.) ps, the most precise measurements to date. Our constraints on the weak phase and DeltaGamma are consistent with CP conservation. Dedicated to the memory of our dear friend and colleague, Michael P. Schmid

    Limits on Anomalous Triple Gauge Couplings in ppbar Collisions at sqrt{s}=1.96 TeV

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    We present a search for anomalous triple gauge couplings (ATGC) in WW and WZ boson production. The boson pairs are produced in ppbar collisions at sqrt{s}=1.96 TeV, and the data sample corresponds to 350 pb-1 of integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. In this search one W decays to leptons, and the other boson (W or Z) decays hadronically. Combining with a previously published CDF measurement of Wgamma boson production yields ATGC limits of -0.18 < lambda < 0.17 and -0.46 < Delta kappa < 0.39 at the 95% confidence level, using a cut-off scale Lambda=1.5 TeV.Comment: 7 pages, 3 figures. Submitted to Phys. Rev.

    Forward-Backward Asymmetry in Top Quark Production in ppbar Collisions at sqrt{s}=1.96 TeV

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    Reconstructable final state kinematics and charge assignment in the reaction ppbar->ttbar allows tests of discrete strong interaction symmetries at high energy. We define frame dependent forward-backward asymmetries for the outgoing top quark in both the ppbar and ttbar rest frames, correct for experimental distortions, and derive values at the parton-level. Using 1.9/fb of ppbar collisions at sqrt{s}=1.96 TeV recorded with the CDF II detector at the Fermilab Tevatron, we measure forward-backward top quark production asymmetries in the ppbar and ttbar rest frames of A_{FB,pp} = 0.17 +- 0.08 and A_{FB,tt} = 0.24 +- 0.14.Comment: 7 pages, 2 figures, submitted to Phys.Rev.Lett, corrected references and change of tex

    Measurement of the W+WW^+W^- Production Cross Section and Search for Anomalous WWγWW\gamma and WWZWWZ Couplings in ppˉp \bar p Collisions at s=1.96\sqrt{s} = 1.96 TeV

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    This Letter describes the current most precise measurement of the WW boson pair production cross section and most sensitive test of anomalous WWγWW\gamma and WWZWWZ couplings in ppˉp \bar p collisions at a center-of-mass energy of 1.96 TeV. The WWWW candidates are reconstructed from decays containing two charged leptons and two neutrinos, where the charged leptons are either electrons or muons. Using data collected by the CDF II detector from 3.6 fb1^{-1} of integrated luminosity, a total of 654 candidate events are observed with an expected background contribution of 320±47320 \pm 47 events. The measured total cross section is σ(ppˉW+W+X)=12.1±0.9(stat)1.4+1.6(syst)\sigma (p \bar p \to W^+ W^- + X) = 12.1 \pm 0.9 \textrm{(stat)} ^{+1.6}_{-1.4} \textrm{(syst)} pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous WWγWW\gamma and WWZWWZ couplings.Comment: submitted to Phys. Rev. Let

    Search for Pair Production of Scalar Top Quarks Decaying to a tau Lepton and a b Quark in ppbar Collisions at sqrt{s}=1.96 TeV

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    We search for pair production of supersymmetric top quarks (~t_1), followed by R-parity violating decay ~t_1 -> tau b with a branching ratio beta, using 322 pb^-1 of ppbar collisions at sqrt{s}=1.96 TeV collected by the CDF II detector at Fermilab. Two candidate events pass our final selection criteria, consistent with the standard model expectation. We set upper limits on the cross section sigma(~t_1 ~tbar_1)*beta^2 as a function of the stop mass m(~t_1). Assuming beta=1, we set a 95% confidence level limit m(~t_1)>153 GeV/c^2. The limits are also applicable to the case of a third generation scalar leptoquark (LQ_3) decaying LQ_3 -> tau b.Comment: 7 pages, 2 eps figure
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