The perturbation of electromagnetic fields at distances that are large compared with the object's size

Abstract We rigorously derive the leading-order terms in asymptotic expansions for the scattered electric and magnetic fields in the presence of a small object at distances that are large compared with its size. Our expansions hold for fixed wavenumber when the scatterer is a (lossy) homogeneous dielectric object with constant material parameters or a perfect conductor. We also derive the corresponding leading-order terms in expansions for the fields for a low-frequency problem when the scatterer is a non-lossy homogeneous dielectric object with constant material parameters or a perfect conductor. In each case, we express our results in terms of polarization tensors.</jats:p

Effect of sparsity and exposure on total variation regularized X-ray tomography from few projections

We address effects of exposure and image gradient sparsity for total variation-regularized reconstruction: is it better to collect many low-quality or few high-quality projections, and can gradient sparsity predict how many projections are necessary? Preliminary results suggest collecting many low-quality projections is favorable, and that a link may exist between gradient sparsity level and successful reconstruction

Measuring the cosmological bulk flow using the peculiar velocities of supernovae

We study large-scale coherent motion in our universe using the existing Type IA supernovae data. If the recently observed bulk flow is real, then some imprint must be left on supernovae motion. We run a series of Monte Carlo Markov Chain runs in various redshift bins and find a sharp contrast between the z 0.05 data. The$z < 0.05 data are consistent with the bulk flow in the direction (l,b)=({290^{+39}_{-31}}^{\circ}, {20^{+32}_{-32}}^{\circ}) with a magnitude of v_bulk = 188^{+119}_{-103} km/s at 68% confidence. The significance of detection (compared to the null hypothesis) is 95%. In contrast, z > 0.05 data (which contains 425 of the 557 supernovae in the Union2 data set) show no evidence for bulk flow. While the direction of the bulk flow agrees very well with previous studies, the magnitude is significantly smaller. For example, the Kashlinsky, et al.'s original bulk flow result of v_bulk > 600 km/s is inconsistent with our analysis at greater than 99.7% confidence level. Furthermore, our best-fit bulk flow velocity is consistent with the expectation for the \Lambda CDM model, which lies inside the 68% confidence limit.Comment: Version published in JCA

Structural, item, and test generalizability of the psychopathology checklist - revised to offenders with intellectual disabilities

The Psychopathy Checklist–Revised (PCL-R) is the most widely used measure of psychopathy in forensic clinical practice, but the generalizability of the measure to offenders with intellectual disabilities (ID) has not been clearly established. This study examined the structural equivalence and scalar equivalence of the PCL-R in a sample of 185 male offenders with ID in forensic mental health settings, as compared with a sample of 1,212 male prisoners without ID. Three models of the PCL-R’s factor structure were evaluated with confirmatory factor analysis. The 3-factor hierarchical model of psychopathy was found to be a good fit to the ID PCL-R data, whereas neither the 4-factor model nor the traditional 2-factor model fitted. There were no cross-group differences in the factor structure, providing evidence of structural equivalence. However, item response theory analyses indicated metric differences in the ratings of psychopathy symptoms between the ID group and the comparison prisoner group. This finding has potential implications for the interpretation of PCL-R scores obtained with people with ID in forensic psychiatric settings

Long-Term Efficacy and Safety of Adalimumab in Pediatric Patients with Crohn's Disease

Background: IMAgINE 1 assessed 52-week efficacy and safety of adalimumab in children with moderate to severe Crohn's disease. Long-Term efficacy and safety of adalimumab for patients who entered the IMAgINE 2 extension are reported. Methods: Patients who completed IMAgINE 1 could enroll in IMAgINE 2. Endpoints assessed from weeks 0 to 240 of IMAgINE 2 were Pediatric Crohn's Disease Activity Index remission (Pediatric Crohn's Disease Activity Index ≤ 10) and response (Pediatric Crohn's Disease Activity Index decrease ≥15 from IMAgINE 1 baseline) using observed analysis and hybrid nonresponder imputation (hNRI). For hNRI, discontinued patients were imputed as failures unless they transitioned to commercial adalimumab (with study site closure) or adult care, where last observation was carried forward. Corticosteroid-free remission in patients receiving corticosteroids at IMAgINE 1 baseline, discontinuation of immunomodulators (IMMs) in patients receiving IMMs at IMAgINE 2 baseline, and linear growth improvement were reported as observed. Adverse events were assessed for patients receiving ≥1 adalimumab dose in IMAgINE 1 and 2 through January 2015. Results: Of 100 patients enrolled in IMAgINE 2, 41% and 48% achieved remission and response (hNRI) at IMAgINE 2 week 240. Remission rates were maintained by 45% (30/67, hNRI) of patients who entered IMAgINE 2 in remission. At IMAgINE 2 week 240, 63% (12/19) of patients receiving corticosteroids at IMAgINE 1 baseline achieved corticosteroid-free remission and 30% (6/20) of patients receiving IMMs at IMAgINE 2 baseline discontinued IMMs. Adalimumab treatment led to growth velocity normalization. No new safety signals were identified. Conclusions: Efficacy and safety profiles of prolonged adalimumab treatment in children with Crohn's disease were consistent with IMAgINE 1 and adult Crohn's disease adalimumab trials

Evolution of Models to Support Community and Policy Action with Science: Balancing Pastoral Livelihoods and Wildlife Conservation in Savannas of East Africa

We developed a “continual engagement” model to better integrate knowledge from policy makers, communities, and researchers with the goal of promoting more effective action to balance poverty alleviation and wildlife conservation in 4 pastoral ecosystems of East Africa. The model involved the creation of a core boundary-spanning team, including community facilitators, a policy facilitator, and transdisciplinary researchers, responsible for linking with a wide range of actors from local to global scales. Collaborative researcher–facilitator community teams integrated local and scientific knowledge to help communities and policy makers improve herd quality and health, expand biodiversity payment schemes, develop land-use plans, and fully engage together in pastoral and wildlife policy development. This model focused on the creation of hybrid scientific–local knowledge highly relevant to community and policy maker needs. The facilitation team learned to be more effective by focusing on noncontroversial livelihood issues before addressing more difficult wildlife issues, using strategic and periodic engagement with most partners instead of continual engagement, and reducing costs by providing new scientific information only when deemed essential. We conclude by examining the role of facilitation in redressing asymmetries in power in researcher–community–policy maker teams, the role of individual values and character in establishing trust, and how to sustain knowledge-action links when project funding ends

Optical Spectra of SNR Candidates in NGC 300

We present moderate-resolution (<5A) long-slit optical spectra of 51 nebular objects in the nearby Sculptor Group galaxy NGC 300 obtained with the 2.3 meter Advanced Technology Telescope at Siding Spring Observatory, Australia. Adopting the criterion of [SII]/Ha>=0.4 to confirm supernova remnants (SNRs) from optical spectra, we find that of 28 objects previously proposed as SNRs from optical observations, 22 meet this criterion with six showing [SII]/Ha of less than 0.4. Of 27 objects suggested as SNRs from radio data, four are associated with the 28 previously proposed SNRs. Of these four, three (included in the 22 above) meet the criterion. In all, 22 of the 51 nebular objects meet the [SII]/Ha criterion as SNRs while the nature of the remaining 29 objects remains undetermined by these observations.Comment: Accepted for publication in Astrophysics & Space Scienc

A hybrid multi-particle approach to range assessment-based treatment verification in particle therapy

Particle therapy (PT) used for cancer treatment can spare healthy tissue and reduce treatment toxicity. However, full exploitation of the dosimetric advantages of PT is not yet possible due to range uncertainties, warranting development of range-monitoring techniques. This study proposes a novel range-monitoring technique introducing the yet unexplored concept of simultaneous detection and imaging of fast neutrons and prompt-gamma rays produced in beam-tissue interactions. A quasimonolithic organic detector array is proposed, and its feasibility for detecting range shifts in the context of proton therapy is explored through Monte Carlo simulations of realistic patient models and detector resolution efects. The results indicate that range shifts of 1 mm can be detected at relatively low proton intensities (22.30(13) × 107 protons/spot) when spatial information obtained through imaging of both particle species are used simultaneously. This study lays the foundation for multiparticle detection and imaging systems in the context of range verifcation in PTpublishedVersio

Multi-scale waves in sound-proof global simulations with EULAG

EULAG is a computational model for simulating flows across a wide range of scales and physical scenarios. A standard option employs an anelastic approximation to capture nonhydrostatic effects and simultaneously filter sound waves from the solution. In this study, we examine a localized gravity wave packet generated by instabilities in Held-Suarez climates. Although still simplified versus the Earth’s atmosphere, a rich set of planetary wave instabilities and ensuing radiated gravity waves can arise. Wave packets are observed that have lifetimes ≤ 2 days, are negligibly impacted by Coriolis force, and do not show the rotational effects of differential jet advection typical of inertia-gravity waves. Linear modal analysis shows that wavelength, period, and phase speed fit the dispersion equation to within a mean difference of ∼ 4%, suggesting an excellent fit. However, the group velocities match poorly even though a propagation of uncertainty analysis indicates that they should be predicted as well as the phase velocities. Theoretical arguments suggest the discrepancy is due to nonlinearity — a strong southerly flow leads to a critical surface forming to the southwest of the wave packet that prevents the expected propagation

LIMITS ON ANISOTROPY AND INHOMOGENEITY FROM THE COSMIC BACKGROUND RADIATION,

We consider directly the equations by which matter imposes anisotropies on freely propagating background radiation, leading to a new way of using anisotropy measurements to limit the deviations of the Universe from a Friedmann-Robertson-Walker (FRW) geometry. This approach is complementary to the usual Sachs-Wolfe approach: the limits obtained are not as detailed, but they are more model-independent. We also give new results about combined matter-radiation perturbations in an almost-FRW universe, and a new exact solution of the linearised equations.Comment: 18 pages Latex