132 research outputs found

    Artificial Intelligence and Machine Learning for Systems Analysis of the 21st Century

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    This paper overviews research being done at IIASA with use of machine learning (ML) methods. We elaborate on promising areas of application and advantages and challenges of using ML. These reflections are done as a part of strategic planning process going on at IIASA at the moment, which aims to come up with a new research strategy for 2021-2030, as well as a supporting research plan. It has been recognized that while applications of ML in commercial sector are numerous and become more and more powerful day to day, it is not yet so common to use ML for creating societal impact. To explore the opportunities in this context and to reflect on what IIASA’s role might be, an internal working group was initiated. This paper emerged from the internal workshop held by the working group at IIASA on June 24, 2019; the workshop invited all IIASA scientists to contribute. The workshop program can be found in Appendix A to this paper

    VEGF Promotes Malaria-Associated Acute Lung Injury in Mice

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    The spectrum of the clinical presentation and severity of malaria infections is broad, ranging from uncomplicated febrile illness to severe forms of disease such as cerebral malaria (CM), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), pregnancy-associated malaria (PAM) or severe anemia (SA). Rodent models that mimic human CM, PAM and SA syndromes have been established. Here, we show that DBA/2 mice infected with P. berghei ANKA constitute a new model for malaria-associated ALI. Up to 60% of the mice showed dyspnea, airway obstruction and hypoxemia and died between days 7 and 12 post-infection. The most common pathological findings were pleural effusion, pulmonary hemorrhage and edema, consistent with increased lung vessel permeability, while the blood-brain barrier was intact. Malaria-associated ALI correlated with high levels of circulating VEGF, produced de novo in the spleen, and its blockage led to protection of mice from this syndrome. In addition, either splenectomization or administration of the anti-inflammatory molecule carbon monoxide led to a significant reduction in the levels of sera VEGF and to protection from ALI. The similarities between the physiopathological lesions described here and the ones occurring in humans, as well as the demonstration that VEGF is a critical host factor in the onset of malaria-associated ALI in mice, not only offers important mechanistic insights into the processes underlying the pathology related with malaria but may also pave the way for interventional studies

    Overview of the FTU results

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    Since the 2016 IAEA Fusion Energy Conference, FTU operations have been mainly devoted to experiments on runaway electrons and investigations into a tin liquid limiter; other experiments have involved studies of elongated plasmas and dust. The tearing mode onset in the high density regime has been studied by means of the linear resistive code MARS, and the highly collisional regimes have been investigated. New diagnostics, such as a runaway electron imaging spectroscopy system for in-flight runaway studies and a triple Cherenkov probe for the measurement of escaping electrons, have been successfully installed and tested, and new capabilities of the collective Thomson scattering and the laser induced breakdown spectroscopy diagnostics have been explored

    A Measurement of the CMB Temperature Power Spectrum and Constraints on Cosmology from the SPT-3G 2018 TT/TE/EE Data Set

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    We present a sample-variance-limited measurement of the temperature power spectrum (TTTT) of the cosmic microwave background (CMB) using observations of a  ⁣1500deg2\sim\! 1500 \,\mathrm{deg}^2 field made by SPT-3G in 2018. We report multifrequency power spectrum measurements at 95, 150, and 220GHz covering the angular multipole range 750<3000750 \leq \ell < 3000. We combine this TTTT measurement with the published polarization power spectrum measurements from the 2018 observing season and update their associated covariance matrix to complete the SPT-3G 2018 TT/TE/EETT/TE/EE data set. This is the first analysis to present cosmological constraints from SPT TTTT, TETE, and EEEE power spectrum measurements jointly. We blind the cosmological results and subject the data set to a series of consistency tests at the power spectrum and parameter level. We find excellent agreement between frequencies and spectrum types and our results are robust to the modeling of astrophysical foregrounds. We report results for Λ\LambdaCDM and a series of extensions, drawing on the following parameters: the amplitude of the gravitational lensing effect on primary power spectra ALA_\mathrm{L}, the effective number of neutrino species NeffN_{\mathrm{eff}}, the primordial helium abundance YPY_{\mathrm{P}}, and the baryon clumping factor due to primordial magnetic fields bb. We find that the SPT-3G 2018 T/TE/EET/TE/EE data are well fit by Λ\LambdaCDM with a probability-to-exceed of 15%15\%. For Λ\LambdaCDM, we constrain the expansion rate today to H0=68.3±1.5kms1Mpc1H_0 = 68.3 \pm 1.5\,\mathrm{km\,s^{-1}\,Mpc^{-1}} and the combined structure growth parameter to S8=0.797±0.042S_8 = 0.797 \pm 0.042. The SPT-based results are effectively independent of Planck, and the cosmological parameter constraints from either data set are within <1σ<1\,\sigma of each other. (abridged)Comment: 35 Pages, 17 Figures, 11 Table

    A Measurement of Gravitational Lensing of the Cosmic Microwave Background Using SPT-3G 2018 Data

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    We present a measurement of gravitational lensing over 1500 deg2^2 of the Southern sky using SPT-3G temperature data at 95 and 150 GHz taken in 2018. The lensing amplitude relative to a fiducial Planck 2018 Λ\LambdaCDM cosmology is found to be 1.020±0.0601.020\pm0.060, excluding instrumental and astrophysical systematic uncertainties. We conduct extensive systematic and null tests to check the robustness of the lensing measurements, and report a minimum-variance combined lensing power spectrum over angular multipoles of 50<L<200050<L<2000, which we use to constrain cosmological models. When analyzed alone and jointly with primary cosmic microwave background (CMB) spectra within the Λ\LambdaCDM model, our lensing amplitude measurements are consistent with measurements from SPT-SZ, SPTpol, ACT, and Planck. Incorporating loose priors on the baryon density and other parameters including uncertainties on a foreground bias template, we obtain a 1σ1\sigma constraint on σ8Ωm0.25=0.595±0.026\sigma_8 \Omega_{\rm m}^{0.25}=0.595 \pm 0.026 using the SPT-3G 2018 lensing data alone, where σ8\sigma_8 is a common measure of the amplitude of structure today and Ωm\Omega_{\rm m} is the matter density parameter. Combining SPT-3G 2018 lensing measurements with baryon acoustic oscillation (BAO) data, we derive parameter constraints of σ8=0.810±0.033\sigma_8 = 0.810 \pm 0.033, S8σ8(Ωm/0.3)0.5=0.836±0.039S_8 \equiv \sigma_8(\Omega_{\rm m}/0.3)^{0.5}= 0.836 \pm 0.039, and Hubble constant H0=68.81.6+1.3H_0 =68.8^{+1.3}_{-1.6} km s1^{-1} Mpc1^{-1}. Using CMB anisotropy and lensing measurements from SPT-3G only, we provide independent constraints on the spatial curvature of ΩK=0.0140.026+0.023\Omega_{K} = 0.014^{+0.023}_{-0.026} (95% C.L.) and the dark energy density of ΩΛ=0.7220.026+0.031\Omega_\Lambda = 0.722^{+0.031}_{-0.026} (68% C.L.). When combining SPT-3G lensing data with SPT-3G CMB anisotropy and BAO data, we find an upper limit on the sum of the neutrino masses of mν<0.30\sum m_{\nu}< 0.30 eV (95% C.L.)
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