150 research outputs found

    Breaking Down the Lockdown: The Causal Effects of Stay-At-Home Mandates on Uncertainty and Sentiments During the COVID-19 Pandemic

    Full text link
    We study the causal effects of lockdown measures on uncertainty and sentiment on Twitter. To this end, we exploit the quasi-experimental framework created by the first COVID-19 lockdown in a high-income economy--the unexpected Italian lockdown in February 2020. We measure changes in public sentiment using deep learning and dictionary-based methods on the text of daily tweets geolocated within and near the locked-down areas, before and after the treatment. We classify tweets into four categories--economics, health, politics, and lockdown policy--to examine how the policy affected emotions heterogeneously. Using a staggered difference-in-differences approach, we show that the lockdown did not have a significantly robust impact on economic uncertainty and sentiment. However, the policy came at the price of higher uncertainty on health and politics and more negative political sentiments. These results, which are robust to a battery of robustness tests, show that lockdowns have relevant non-health related implications

    GIANO-TNG spectroscopy of red supergiants in the young star cluster RSGC3

    Full text link
    The Scutum complex in the inner disk of the Galaxy has a number of young star clusters dominated by red supergiants that are heavily obscured by dust extinction and observable only at infrared wavelengths. These clusters are important tracers of the recent star formation and chemical enrichment history in the inner Galaxy. During the technical commissioning and as a first science verification of the GIANO spectrograph at the Telescopio Nazionale Galileo, we secured high-resolution (R=50,000) near-infrared spectra of five red supergiants in the young Scutum cluster RSGC3. Taking advantage of the full YJHK spectral coverage of GIANO in a single exposure, we were able to measure several tens of atomic and molecular lines that were suitable for determining chemical abundances. By means of spectral synthesis and line equivalent width measurements, we obtained abundances of Fe and iron-peak elements such as Ni, Cr, and Cu, alpha (O, Mg, Si, Ca, Ti), other light elements (C, N, F, Na, Al, and Sc), and some s-process elements (Y, Sr). We found average half-solar iron abundances and solar-scaled [X/Fe] abundance patterns for most of the elements, consistent with a thin-disk chemistry. We found depletion of [C/Fe] and enhancement of [N/Fe], consistent with standard CN burning, and low 12C/13C abundance ratios (between 9 and 11), which require extra-mixing processes in the stellar interiors during the post-main sequence evolution. We also found local standard of rest V(LSR)=106 km/s and heliocentric V(HEL)=90 km/s radial velocities with a dispersion of 2.3 km/s. The inferred radial velocities, abundances, and abundance patterns of RSGC3 are very similar to those previously measured in the other two young clusters of the Scutum complex, RSGC1 and RSGC2, suggesting a common kinematics and chemistry within the Scutum complex

    The TNG Near Infrared Camera Spectrometer

    Get PDF
    NICS (acronym for Near Infrared Camera Spectrometer) is the near-infrared cooled camera-spectrometer that has been developed by the Arcetri Infrared Group at the Arcetri Astrophysical Observatory, in collaboration with the CAISMI-CNR for the TNG (the Italian National Telescope Galileo at La Palma, Canary Islands, Spain). As NICS is in its scientific commissioning phase, we report its observing capabilities in the near-infrared bands at the TNG, along with the measured performance and the limiting magnitudes. We also describe some technical details of the project, such as cryogenics, mechanics, and the system which executes data acquisition and control, along with the related software.Comment: 7 pages, 5 figures, compiled with A&A macros. A&A in pres

    Developing a questionnaire evaluating knowledge, attitudes and behaviors on audit & feedback among general practitioners. A mixed methods study

    Get PDF
    Background: Audit and Feedback (A&F) is one of the most common strategies used to improve quality in healthcare. However, there is still lack of awareness regarding the enabling factors and barriers that could influence its effectiveness. The aim of this study was to develop a questionnaire to measure the knowledge, attitudes and behaviors of general practitioners (GPs) regarding A&F. The study was performed in the context of the EASY-NET program (project code NET-2016-02364191). Methods: The survey was developed according to two steps. Firstly, a scoping review was performed in order to map the literature on the existing similar instruments with the aim of identifying the sub-domains and possible items to include in a preliminary version of the questionnaire. In the second phase, the questionnaire was reviewed by a multidisciplinary group of experts and administrated to a convenience sample in a pilot survey. Results: Ten papers were included in the scoping review. The survey target and development methodology were heterogenous among the studies. The knowledge, attitudes and behaviors domains were assessed in six, nine and seven studies, respectively. In the first step, 126 pertinent items were extracted and categorized as follows: 8 investigated knowledge, 93 investigated attitudes, and 25 investigated behaviors. Then, 2 sub-domains were identified for knowledge, 14 for attitudes and 7 for behavior. Based on these results, a first version of the survey was developed via consensus among two authors and then revised by the multidisciplinary group of experts in the field of A&F. The final version of the survey included 36 items: 8 in the knowledge domain, 19 in the attitudes domain and 9 in the behaviors domain. The results of the pilot study among 15 GPs suggested a good acceptability and item relevance and accuracy, with positive answers totaling 100% and 93.3% in the proposed questions. Conclusions: The methodology used has shown to be a good strategy for the development of the survey. The survey will be administrated before and after the implementation of an A&F intervention to assess both baseline characteristics and changes after the intervention

    Finsler geodesics in the presence of a convex function and their applications

    Full text link
    We obtain a result about the existence of only a finite number of geodesics between two fixed non-conjugate points in a Finsler manifold endowed with a convex function. We apply it to Randers and Zermelo metrics. As a by-product, we also get a result about the finiteness of the number of lightlike and timelike geodesics connecting an event to a line in a standard stationary spacetime.Comment: 16 pages, AMSLaTex. v2 is a minor revision: title changed, references updated, typos fixed; it matches the published version. This preprint and arXiv:math/0702323v3 [math.DG] substitute arXiv:math/0702323v2 [math.DG

    Lines and continuum sky emission in the near infrared: observational constraints from deep high spectral resolution spectra with GIANO-TNG

    Get PDF
    Aims Determining the intensity of lines and continuum airglow emission in the H-band is important for the design of faint-object infrared spectrographs. Existing spectra at low/medium resolution cannot disentangle the true sky-continuum from instrumental effects (e.g. diffuse light in the wings of strong lines). We aim to obtain, for the first time, a high resolution infrared spectrum deep enough to set significant constraints on the continuum emission between the lines in the H-band. Methods During the second commissioning run of the GIANO high-resolution infrared spectrograph at La Palma Observatory, we pointed the instrument directly to the sky and obtained a deep spectrum that extends from 0.97 to 2.4 micron. Results The spectrum shows about 1500 emission lines, a factor of two more than in previous works. Of these, 80% are identified as OH transitions; half of these are from highly excited molecules (hot-OH component) that are not included in the OH airglow emission models normally used for astronomical applications. The other lines are attributable to O2 or unidentified. Several of the faint lines are in spectral regions that were previously believed to be free of line emission. The continuum in the H-band is marginally detected at a level of about 300 photons/m^2/s/arcsec^2/micron, equivalent to 20.1 AB-mag/arcsec^2. The observed spectrum and the list of observed sky-lines are published in electronic format. Conclusions Our measurements indicate that the sky continuum in the H-band could be even darker than previously believed. However, the myriad of airglow emission lines severely limits the spectral ranges where very low background can be effectively achieved with low/medium resolution spectrographs. We identify a few spectral bands that could still remain quite dark at the resolving power foreseen for VLT-MOONS (R ~6,600).Comment: 7 pages, 4 figures, to be published in Astronomy & Astrophysic

    GIANO-TNG spectroscopy of red supergiants in the young star cluster RSGC2

    Full text link
    The inner disk of the Galaxy has a number of young star clusters dominated by red supergiants that are heavily obscured by dust extinction and observable only at infrared wavelengths. These clusters are important tracers of the recent star formation and chemical enrichment history in the inner Galaxy. During the technical commissioning and as a first science verification of the GIANO spectrograph at the Telescopio Nazionale Galileo, we secured high-resolution (R~50,000) near-infrared spectra of three red supergiants in the young Scutum cluster RSGC2. Taking advantage of the full YJHK spectral coverage of GIANO in a single exposure, we were able to identify several tens of atomic and molecular lines suitable for chemical abundance determinations. By means of spectral synthesis and line equivalent width measurements, we obtained abundances of Fe and other iron-peak elements such as V, Cr, Ni, of alpha (O, Mg, Si, Ca and Ti) and other light elements (C, N, Na, Al, K, Sc), and of some s-process elements (Y, Sr). We found iron abundances between half and one third solar and solar-scaled [X/Fe] abundance patterns of iron-peak, alpha and most of the light elements, consistent with a thin-disk chemistry. We found a depletion of [C/Fe] and enhancement of [N/Fe], consistent with CN burning, and low 12C/13C abundance ratios (between 9 and 11), requiring extra-mixing processes in the stellar interiors during the post-main sequence evolution. Finally, we found a slight [Sr/Fe] enhancement and a slight [Y/Fe] depletion (by a factor of <=2), with respect to solar.Comment: Paper accepted on A&

    Low Cohomogeneity and Polar Actions on Exceptional Compact Lie Groups

    Full text link
    We study isometric Lie group actions on the compact exceptional groups E6, E7, E8, F4 and G2 endowed with a biinvariant metric. We classify polar actions on these groups. We determine all isometric actions of cohomogeneity less than three on E6, E7, F4 and all isometric actions of cohomogeneity less than 20 on E8. Moreover we determine the principal isotropy algebras for all isometric actions on G2.Comment: 27 pages; introduction rewritten; references updated; final version; to appear in Transformation Group

    The fiber-fed preslit of GIANO at T.N.G

    Full text link
    Giano is a Cryogenic Spectrograph located in T.N.G. (Spain) and commisioned in 2013. It works in the range 950-2500 nm with a resolving power of 50000. This instrument was designed and built for direct feeding from the telescope [2]. However, due to constraints imposed on the telescope interfacing during the pre-commissioning phase, it had to be positioned on the rotating building, far from the telescope focus. Therefore, a new interface to the telescope, based on IR-transmitting ZBLAN fibers with 85\mu m core, was developed.Originally designed to work directly at the f/11f/11 nasmyth focus of the telescope, in 2011 it has decided to use a fiber to feed it. The beam from the telescope is focused on a double fiber boundle by a Preslit Optical Bench attached to the Nasmith A interface of the telescope. This Optical Bench contains the fiber feeding system and other important features as a guiding system, a fiber viewer, a fiber feed calibration lamp and a nodding facility between the two fibers. The use of two fibers allow us to have in the echellogram two spectrograms side by side in the same acquisition: one of the star and the other of the sky or simultaneously to have the star and a calibration lamp. Before entering the cryostat the light from the fiber is collectd by a second Preslit Optical Bench attached directly to the Giano cryostat: on this bench the correct f-number to illuminate the cold stop is generated and on the same bench is placed an image slicer to increase the efficiency of the system.Comment: 21 pages, 24 figures, 3 tables. Presented at SPIE Astronomical Telescope + Instrumentation 2014 (Ground-based and Airbone Instrumentation for Astronomy 5, 9147-360). To be published in Proceeding of SPIE Volume 914
    • …
    corecore