3,679 research outputs found

    CMB Lensing Power Spectrum Biases from Galaxies and Clusters using High-angular Resolution Temperature Maps

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    The lensing power spectrum from cosmic microwave background (CMB) temperature maps will be measured with unprecedented precision with upcoming experiments, including upgrades to ACT and SPT. Achieving significant improvements in cosmological parameter constraints, such as percent level errors on sigma_8 and an uncertainty on the total neutrino mass of approximately 50 meV, requires percent level measurements of the CMB lensing power. This necessitates tight control of systematic biases. We study several types of biases to the temperature-based lensing reconstruction signal from foreground sources such as radio and infrared galaxies and the thermal Sunyaev-Zel'dovich effect from galaxy clusters. These foregrounds bias the CMB lensing signal due to their non-Gaussian nature. Using simulations as well as some analytical models we find that these sources can substantially impact the measured signal if left untreated. However, these biases can be brought to the percent level if one masks galaxies with fluxes at 150 GHz above 1 mJy and galaxy clusters with masses above M_vir = 10^14 M_sun. To achieve such percent level bias, we find that only modes up to a maximum multipole of l_max ~ 2500 should be included in the lensing reconstruction. We also discuss ways to minimize additional bias induced by such aggressive foreground masking by, for example, exploring a two-step masking and in-painting algorithm.Comment: 14 pages, 14 figures, to be submitted to Ap

    Selective Vagus Nerve Stimulation as a Therapeutic Approach for the Treatment of ARDS: A Rationale for Neuro-Immunomodulation in COVID-19 Disease

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    Acute respiratory distress syndrome (ARDS) is the most severe form of acute lung injury. It is induced by sepsis, aspiration, and pneumonia, including that caused by SARS coronavirus and human influenza viruses. The main pathophysiological mechanism of ARDS is a systemic inflammatory response. Vagus nerve stimulation (VNS) can limit cytokine production in the spleen and thereby dampen any systemic inflammation and inflammation-induced tissue damage in the lungs and other organs. However, the effects of increased parasympathetic outflow to the lungs when non-selective VNS is applied may result in bronchoconstriction, increased mucus secretion and enhance local pulmonary inflammatory activity; this may outweigh the beneficial systemic anti-inflammatory action of VNS. Organ/function-specific therapy can be achieved by imaging of localized fascicle activity within the vagus nerve and selective stimulation of identified organ-specific fascicles. This may be able to provide selective neuromodulation of different pathways within the vagus nerve and offer a novel means to improve outcome in ARDS. This has motivated this review in which we discuss the mechanisms of anti-inflammatory effects of VNS, progress in selective VNS techniques, and a possible application for ARDS.</jats:p

    Mechanistic analysis of an asymmetric palladium-catalyzed conjugate addition of arylboronic acids to β-substituted cyclic enones.

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    An asymmetric palladium-catalyzed conjugate addition reaction of arylboronic acids to enone substrates was investigated mechanistically. Desorption electrospray ionization coupled to mass spectrometry was used to identify intermediates of the catalytic cycle and delineate differences in substrate reactivity. Our findings provide evidence for the catalytic cycle proceeding through formation of an arylpalladium(II) cation, subsequent formation of an arylpalladium-enone complex, and, ultimately, formation of the new C-C bond. Reaction monitoring in both positive and negative ion modes revealed that 4-iodophenylboronic acid formed a relatively stable trimeric species under the reaction conditions

    Optimization of the electrode drive pattern for imaging fascicular compound action potentials in peripheral nerve with fast neural electrical impedance tomography (EIT)

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    OBJECTIVE: The main objective of this study was to investigate which injection pattern led to the best imaging of fascicular compound activity in fast neural EIT of peripheral nerve using an external cylindrical 2x14-electrodes cuff. Specifically, the study addressed the identification of the optimal injection pattern and of the optimal region of the reconstructed volume to image fascicles. APPROACH: The effect of three different measurement protocol features (transversal/longitudinal injection, drive electrode spacing, referencing configuration) over imaging was investigated in simulation with the use of realistic impedance changes and noise levels. Image-based metrics were employed to evaluate the quality of the reconstructions over the reconstruction domain. The optimal electrode addressing protocol suggested by the simulations was validated in vivo on the tibial and peroneal fascicles of rat sciatic peripheral nerves (N=3) against MicroCT reference images. MAIN RESULTS: Injecting current transversally, with spacing of ≥4 electrodes apart (≥100°) and single-ring referencing of measurements, led to the best overall localization when reconstructing on the edge of the electrode array closest to the reference. Longitudinal injection protocols led to a higher SNR of the reconstructed image but poorer localization. All in vivo EIT recordings had statistically significant impedance variations (p<0.05). Overall, fascicle center-of-mass (CoM) localization error was estimated at 141±56µm (-26±94µm and 5±29° in radial coordinates). Significant difference was found (p<0.05) between mean angular location of the tibial and peroneal CoMs. SIGNIFICANCE: This study gives the reader recommendations for performing fast neural EIT of fascicular compound activity using the most effective protocol features

    Promoting the achievement of looked after children and young people across Cardiff

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    As of March 2017, there were 5,955 children and young people in care in Wales. Across the Central South Consortium (Bridgend, Cardiff, Merthyr Tydfil, Rhondda Cynonn Taf and Vale of Glamorgan) there were 2,170 children and young people looked after. The majority of these children are in care as a result of birth families being unable to provide a level of care that meets their emotional and well-being needs. Children and young people who are in or have experienced care remain one of the lowest performing groups in terms of educational outcomes. In 2016, eleven per cent of young people in Wales achieved A* to C grade at GCSE. Care leavers can experience poorer employment and health outcomes after leaving school compared to their peers; for example, 45% of young people who were looked after were not engaged in education, training or employment (NEET) or not in touch with their local authority on their 19th birthday in 2015. This compares with around 4.9% of all other children who leave school at the end of Year 13. However, the education and achievement of children and young people in care is currently the focus of renewed policy, research and practice attention across Wales. The Social Services and Wellbeing (Wales) Act 2014 provides the legal framework for improving the well-being of people who need care and support. A national strategic approach to improving outcomes for children looked after is underway with a focus on promoting and improving collaborative working across agencies, identifying and sharing good practice and making improvements where they are needed. The purpose of this report is to share practice in selected in Cardiff schools that is contributing to improved outcomes and school experiences for children and young people in care
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