426 research outputs found

    Boundary value problems with Atiyah-Patodi-Singer type conditions and spectral triples

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    We study realizations of pseudodifferential operators acting on sections of vector-bundles on a smooth, compact manifold with boundary, subject to conditions of Atiyah-Patodi-Singer type. Ellipticity and Fredholm property, compositions, adjoints and self-adjointness of such realizations are discussed. We construct regular spectral triples (A,H,D)(\mathcal{A},\mathcal{H},\mathcal{D}) for manifolds with boundary of arbitrary dimension, where H\mathcal{H} is the space of square integrable sections. Starting out from Dirac operators with APS-conditions, these triples are even in case of even dimensional manifolds; we show that the closure of A\mathcal{A} in L(H)\mathscr{L}(\mathcal{H}) coincides with the continuous functions on the manifold being constant on each connected component of the boundary.Comment: 27 pages, to appear in Journal of Noncommutative Geometr

    Sharp Weyl Estimates for Tensor Products of Pseudodifferential Operators

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    We study the asymptotic behavior of the counting function of tensor products of operators, in the cases where the factors are either pseudodifferential operators on closed manifolds, or pseudodifferential operators of Shubin type on Rn\mathbb{R}^n, respectively. We obtain, in particular, the sharpness of the remainder term in the corresponding Weyl formulae, which we prove by means of the analysis of some explicit examples.Comment: 27 pages, 3 figures. Corrected typo

    The global wave front set of tempered oscillatory integrals with inhomogeneous phase functions

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    We study certain families of oscillatory integrals Iφ(a)I_\varphi(a), parametrised by phase functions φ\varphi and amplitude functions aa globally defined on Rd\mathbb{R}^d, which give rise to tempered distributions, avoiding the standard homogeneity requirement on the phase function. The singularities of Iφ(a)I_\varphi(a) are described both from the point of view of the lack of smoothness as well as with respect to the decay at infinity. In particular, the latter will depend on a version of the set of stationary points of φ\varphi, including elements lying at the boundary of the radial compactification of Rd\mathbb{R}^d. As applications, we consider some properties of the two-point function of a free, massive, scalar relativistic field and of classes of global Fourier integral operators on Rd\mathbb{R}^d, with the latter defined in terms of kernels of the form Iφ(a)I_\varphi(a).Comment: 30 pages, 2 figures, mistakes and typos correctio

    Complex responses of global insect pests to climate warming

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    Although it is well known that insects are sensitive to temperature, how they will be affected by ongoing global warming remains uncertain because these responses are multifaceted and ecologically complex. We reviewed the effects of climate warming on 31 globally important phytophagous (plant-eating) insect pests to determine whether general trends in their responses to warming were detectable. We included four response categories (range expansion, life history, population dynamics, and trophic interactions) in this assessment. For the majority of these species, we identified at least one response to warming that affects the severity of the threat they pose as pests. Among these insect species, 41% showed responses expected to lead to increased pest damage, whereas only 4% exhibited responses consistent with reduced effects; notably, most of these species (55%) demonstrated mixed responses. This means that the severity of a given insect pest may both increase and decrease with ongoing climate warming. Overall, our analysis indicated that anticipating the effects of climate warming on phytophagous insect pests is far from straightforward. Rather, efforts to mitigate the undesirable effects of warming on insect pests must include a better understanding of how individual species will respond, and the complex ecological mechanisms underlying their responses

    Delivery status of the ELI-NP gamma beam system

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    International audienceThe ELI-NP GBS is a high intensity and monochromatic gamma source under construction in Magurele (Romania). The design and construction of the Gamma Beam System complex as well as the integration of the technical plants and the commissioning of the overall facility, was awarded to the Eurogammas Consortium in March 2014. The delivery of the facility has been planned in for 4 stages and the first one was fulfilled in October 31st 2015. The engineering aspects related to the delivery stage 1 are presented

    A new medical record proposal to the prognostic risk assessment for mronj in oncologic patients: “Sapienza head and neck unit” proposal

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    Medication-related osteonecrosis of the jaw (MRONJ) is an adverse event associated with antiresorptive and antiangiogenic drugs. The use of these drugs in the treatment of cancer patients with bone metastasis is necessary and standardized in the literature. A multidisciplinary approach for the patient’s management is strongly recommended. Therefore, it should be necessary to integrate the path of these subjects with a dedicated dental screening in order to first assess the individual risk of developing a MRONJ, and then to plan dental treatments and oral hygiene sessions, and finally to schedule a follow-up to intercept and treat early osteonecrosis. The aim of this manuscript is to propose a new simple medical report to evaluate patients affected by metastatic bone cancer in order to reduce the risk of developing MRONJ

    Discovery of a compact gas-rich DLA galaxy at z = 2.2: evidences for a starburst-driven outflow

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    We present the detection of Ly-alpha, [OIII] and H-alpha emission associated with an extremely strong DLA system (N(HI) = 10^22.10 cm^-2) at z=2.207 towards the quasar SDSS J113520-001053. This is the largest HI column density ever measured along a QSO line of sight, though typical of what is seen in GRB-DLAs. This absorption system also classifies as ultrastrong MgII system with W2796_r=3.6 A. The mean metallicity of the gas ([Zn/H]=-1.1) and dust depletion factors ([Zn/Fe]=0.72, [Zn/Cr]=0.49) are consistent with (and only marginally larger than) the mean values found in the general QSO-DLA population. The [OIII]-Ha emitting region has a very small impact parameter with respect to the QSO line of sight, b=0.1", and is unresolved. From the Ha line, we measure SFR=25 Msun/yr. The Ly-a line is double-peaked and is spatially extended. More strikingly, the blue and red Ly-a peaks arise from distinct regions extended over a few kpc on either side of the star-forming region. We propose that this is the consequence of Ly-a transfer in outflowing gas. The presence of starburst-driven outflows is also in agreement with the large SFR together with a small size and low mass of the galaxy (Mvir~10^10 Msun). From the stellar UV continuum luminosity of the galaxy, we estimate an age of at most a few 10^7 yr, again consistent with a recent starburst scenario. We interpret the data as the observation of a young, gas rich, compact starburst galaxy, from which material is expelled through collimated winds powered by the vigorous star formation activity. We substantiate this picture by modelling the radiative transfer of Ly-a photons in the galactic counterpart. Though our model (a spherical galaxy with bipolar outflowing jets) is a simplistic representation of the true gas distribution and velocity field, the agreement between the observed and simulated properties is particularly good. [abridged]Comment: 15 pages, 18 figures, 4 tables, accepted for publication in Astronomy and Astrophysic

    A Chromosomally Encoded Virulence Factor Protects the Lyme Disease Pathogen against Host-Adaptive Immunity

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    Borrelia burgdorferi, the bacterial pathogen of Lyme borreliosis, differentially expresses select genes in vivo, likely contributing to microbial persistence and disease. Expression analysis of spirochete genes encoding potential membrane proteins showed that surface-located membrane protein 1 (lmp1) transcripts were expressed at high levels in the infected murine heart, especially during early stages of infection. Mice and humans with diagnosed Lyme borreliosis also developed antibodies against Lmp1. Deletion of lmp1 severely impaired the pathogen's ability to persist in diverse murine tissues including the heart, and to induce disease, which was restored upon chromosomal complementation of the mutant with the lmp1 gene. Lmp1 performs an immune-related rather than a metabolic function, as its deletion did not affect microbial persistence in immunodeficient mice, but significantly decreased spirochete resistance to the borreliacidal effects of anti-B. burgdorferi sera in a complement-independent manner. These data demonstrate the existence of a virulence factor that helps the pathogen evade host-acquired immune defense and establish persistent infection in mammals

    Herlyn-werner-wunderlich syndrome: MRI findings, radiological guide (two cases and literature review), and differential diagnosis

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    <p>Abstract</p> <p>Background</p> <p>Herlyn-Werner-Wunderlich (HWW) syndrome is a very rare congenital anomaly of the urogenital tract involving MĂĽllerian ducts and Wolffian structures, and it is characterized by the triad of didelphys uterus, obstructed hemivagina and ipsilateral renal agenesis. It generally occurs at puberty and exhibits non-specific and variable symptoms with acute or pelvic pain shortly following menarche, causing a delay in the diagnosis. Moreover, the diagnosis is complicated by the infrequency of this syndrome, because MĂĽllerian duct anomalies (MDA) are infrequently encountered in a routine clinical setting.</p> <p>Cases presentation</p> <p>two cases of HWW syndrome in adolescents and a differential diagnosis for one case of a different MDA, and the impact of magnetic resonance (MR) imaging technology to achieve the correct diagnosis.</p> <p>Conclusions</p> <p>MR imaging is a very suitable diagnostic tool in order to perform the correct diagnosis of HWW syndrome.</p

    The Influence of Information Sources on Inter- and Intra-Firm Diffusion: Evidence from UK Farming

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    We study the effect of different information sources on diffusion between and within companies. Our model of economically optimising farmers replicates results from dual process persuasion theory, and predicts that inter-firm diffusion will be primarily affected by reliable, easily accessible information while intra-firm diffusion will be influenced by technical information. The results are tested on UK farming data. Consistent with our model, information from agents, suppliers, farmers, and agricultural magazines influences inter-firm adoption, from buyers influences intra-firm adoption, and from crop consultants, academics, government, and an industry body influences both
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