2,314 research outputs found

    Strange and singlet form factors of the nucleon: Predictions for G0, A4, and HAPPEX-II experiments

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    We investigate the strange and flavor-singlet electric and magnetic form factors of the nucleon within the framework of the SU(3) chiral quark-soliton model. Isospin symmetry is assumed and the symmetry-conserving SU(3) quantization is employed, rotational and strange quark mass corrections being included. For the experiments G0, A4, and HAPPEX-II we predict the quantities GE0+βGM0G^{0}_E + \beta G^{0}_M and GEs+βGMsG^{\rm s}_E + \beta G^{\rm s}_M. The dependence of the results on the parameters of the model and the treatment of the Yukawa asymptotic behavior of the soliton are investigated.Comment: 16 pages, 3 figures, Final version for publication in Eur. Phys. J.

    Spheroidal geometry approach to fullerene molecules

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    Graphite is an example of a layered material that can be bent to form fullerenes which promise important applications in electronic nanodevices. The spheroidal geometry of a slightly elliptically deformed sphere was used as a possible approach to fullerenes. We assumed that for a small deformation the eccentricity of the spheroid is smaller than one. We are interested here in the big elliptically deformed fullerenes.The low-lying electronic levels are described by the Dirac equation in (2+1) dimensions. We show how a small deformation of spherical geometry evokes a shift of the electronic spectra compared to the sphere. The flux of a monopole field was included inside the surface to describe the fullerenes. Both the electronic spectrum of spherical and the shift of spheroidal fullerenes were derived.Comment: 12 pages, 2 figure

    Automated Crowdturfing Attacks and Defenses in Online Review Systems

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    Malicious crowdsourcing forums are gaining traction as sources of spreading misinformation online, but are limited by the costs of hiring and managing human workers. In this paper, we identify a new class of attacks that leverage deep learning language models (Recurrent Neural Networks or RNNs) to automate the generation of fake online reviews for products and services. Not only are these attacks cheap and therefore more scalable, but they can control rate of content output to eliminate the signature burstiness that makes crowdsourced campaigns easy to detect. Using Yelp reviews as an example platform, we show how a two phased review generation and customization attack can produce reviews that are indistinguishable by state-of-the-art statistical detectors. We conduct a survey-based user study to show these reviews not only evade human detection, but also score high on "usefulness" metrics by users. Finally, we develop novel automated defenses against these attacks, by leveraging the lossy transformation introduced by the RNN training and generation cycle. We consider countermeasures against our mechanisms, show that they produce unattractive cost-benefit tradeoffs for attackers, and that they can be further curtailed by simple constraints imposed by online service providers

    Utilization of a multimodal preoperative pain regimen prior to gynecologic oncology exploratory laparotomies

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    Objective: The aim of this study was to evaluate the use of a combination of non-opioid preoperative pain medications including Tylenol, Lyrica, and Celecoxib (TLC) in patients undergoing gynecologic oncologic exploratory laparotomies. We evaluated postoperative narcotic use in morphine equvalents (ME) as well as pain scores, anti-emetic use, and length of stay.https://jdc.jefferson.edu/patientsafetyposters/1055/thumbnail.jp

    Multivariate Analysis of the Phase 0 Experiment Data with TMVA

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    Object-Based Integration of Photogrammetric and LiDAR Data for Automated Generation of Complex Polyhedral Building Models

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    This research is concerned with a methodology for automated generation of polyhedral building models for complex structures, whose rooftops are bounded by straight lines. The process starts by utilizing LiDAR data for building hypothesis generation and derivation of individual planar patches constituting building rooftops. Initial boundaries of these patches are then refined through the integration of LiDAR and photogrammetric data and hierarchical processing of the planar patches. Building models for complex structures are finally produced using the refined boundaries. The performance of the developed methodology is evaluated through qualitative and quantitative analysis of the generated building models from real data

    The muon anomalous magnetic moment and a new light gauge boson

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    It is shown that the 2.6 σ\sigma discrepancy between the predicted and recently measured value of the anomalous magnetic moment of positive muons could be explained by the existence of a new light gauge boson X with a mass MXO(5)GeVM_X \leq O(5) GeV. Phenomenological bounds on the X coupling are discussed.Comment: 7 pages, version to appear in PL

    The impact of body mass index on disease progression in ankylosing spondylitis

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    Publisher Copyright: © 2018 De Gruyter Open Ltd. All rights reserved.Obesity can be a factor that affects the course of chronic systemic inflammatory arthritis. The objective of this study was to characterise patients with ankylosing spondylitis (AS) according to an evaluation of their body mass index (BMI) and by exploring the link between the overweightness and obesity with routinely measured disease-specific variables, including disease activity (Bath Ankylosing Spondylitis Disease Activity Index BASDAI; Ankylosing Spondylitis Disease Activity Score, using CRP, ASDAScrp), spinal mobility (Bath Ankylosing Spondylitis Metrology Index, BASMI), functional capacity (BASFI), extraspinal manifestations like fatigue, uveitis, and peripheral arthritis present during the course of the disease. A total of 107 patients were included in the cross-sectional study fulfilling the modified New York criteria for AS. Patients were divided into three groups: with the evaluation of BMI 30.0 (obesity). The mean BMI was 25.13 (SD 4.07). 33% of patients were overweight and 15% were obese. The mean values of age, duration of AS, ASDAScrp, BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI), BASMI, pain in spine, and fatigue in the group with BMI < 24.9 were lower than in the other groups (p < 0.05). There was no difference between groups in age of AS onset, uveitis and peripheral arthritis. AS patients who were overweight or obese had a higher level of the disease activity, pain, fatigue, functional disability and spinal mobility impairment with worse values in the case of obesity.publishersversionPeer reviewe

    Viewing Nature Scenes Positively Affects Recovery of Autonomic Function Following Acute-Mental Stress

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    A randomized crossover study explored whether viewing different scenes prior to a stressor altered autonomic function during the recovery from the stressor. The two scenes were (a) nature (composed of trees, grass, fields) or (b) built (composed of man-made, urban scenes lacking natural characteristics) environments. Autonomic function was assessed using noninvasive techniques of heart rate variability; in particular, time domain analyses evaluated parasympathetic activity, using root-mean-square of successive differences (RMSSD). During stress, secondary cardiovascular markers (heart rate, systolic and diastolic blood pressure) showed significant increases from baseline which did not differ between the two viewing conditions. Parasympathetic activity, however, was significantly higher in recovery following the stressor in the viewing scenes of nature condition compared to viewing scenes depicting built environments (RMSSD; 50.0 ± 31.3 vs 34.8 ± 14.8 ms). Thus, viewing nature scenes prior to a stressor alters autonomic activity in the recovery period. The secondary aim was to examine autonomic function during viewing of the two scenes. Standard deviation of R-R intervals (SDRR), as change from baseline, during the first 5 min of viewing nature scenes was greater than during built scenes. Overall, this suggests that nature can elicit improvements in the recovery process following a stressor. © 2013 American Chemical Society

    Differences in Anatomy and Kinematics in Asian and Caucasian TKA Patients: Influence on Implant Positioning and Subsequent Loading Conditions in Mobile Bearing Knees

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    The objective of our study was to determine the mechanical stress conditions under tibiofemoral loading with an overlay of knee kinematics in deep flexion on two different mobile bearing designs in comparison to in vivo failure modes. This study investigates the seldom but severe complication of fatigue failure of polyethylene components at mobile bearing total knee arthroplasty designs. Assuming a combination of a floor-based lifestyle and tibial malrotation as a possible reason for a higher failure rate in Asian countries we developed a simplified finite element model considering a tibiofemoral roll-back angle of 22 degrees and the range of rotational motion of a clinically established floating platform design (e. motion FP) at a knee flexion angle of 120 degrees in order to compare our results to failure modes found in retrieved implants. Compared to the failure mode observed in the clinical retrievals the locations of the occurring stress maxima as well as the tensile stress distribution show analogies. From our observations, we conclude that the newly introduced finite element model with an overlay of deep knee flexion (lateral roll-back) and considerable internally rotated tibia implant positioning is an appropriate analysis for knee design optimizations and a suitable method to predict clinical failure modes
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