11,989 research outputs found

    Basic features of the predictive tools of early warning systems for water-related natural hazards: examples for shallow landslides

    Get PDF
    Abstract. To manage natural risks, an increasing effort is being put in the development of early warning systems (EWS), namely, approaches facing catastrophic phenomena by timely forecasting and alarm spreading throughout exposed population. Research efforts aimed at the development and implementation of effective EWS should especially concern the definition and calibration of the interpretative model. This paper analyses the main features characterizing predictive models working in EWS by discussing their aims and their features in terms of model accuracy, evolutionary stage of the phenomenon at which the prediction is carried out and model architecture. Original classification criteria based on these features are developed throughout the paper and shown in their practical implementation through examples of flow-like landslides and earth flows, both of which are characterized by rapid evolution and quite representative of many applications of EWS

    POLOCALC: a Novel Method to Measure the Absolute Polarization Orientation of the Cosmic Microwave Background

    Full text link
    We describe a novel method to measure the absolute orientation of the polarization plane of the CMB with arcsecond accuracy, enabling unprecedented measurements for cosmology and fundamental physics. Existing and planned CMB polarization instruments looking for primordial B-mode signals need an independent, experimental method for systematics control on the absolute polarization orientation. The lack of such a method limits the accuracy of the detection of inflationary gravitational waves, the constraining power on the neutrino sector through measurements of gravitational lensing of the CMB, the possibility of detecting Cosmic Birefringence, and the ability to measure primordial magnetic fields. Sky signals used for calibration and direct measurements of the detector orientation cannot provide an accuracy better than 1 deg. Self-calibration methods provide better accuracy, but may be affected by foreground signals and rely heavily on model assumptions. The POLarization Orientation CALibrator for Cosmology, POLOCALC, will dramatically improve instrumental accuracy by means of an artificial calibration source flying on balloons and aerial drones. A balloon-borne calibrator will provide far-field source for larger telescopes, while a drone will be used for tests and smaller polarimeters. POLOCALC will also allow a unique method to measure the telescopes' polarized beam. It will use microwave emitters between 40 and 150 GHz coupled to precise polarizing filters. The orientation of the source polarization plane will be registered to sky coordinates by star cameras and gyroscopes with arcsecond accuracy. This project can become a rung in the calibration ladder for the field: any existing or future CMB polarization experiment observing our polarization calibrator will enable measurements of the polarization angle for each detector with respect to absolute sky coordinates.Comment: 15 pages, 5 figures, Accepted by Journal of Astronomical Instrumentatio

    Markov Chain Beam Randomization: a study of the impact of PLANCK beam measurement errors on cosmological parameter estimation

    Get PDF
    We introduce a new method to propagate uncertainties in the beam shapes used to measure the cosmic microwave background to cosmological parameters determined from those measurements. The method, which we call Markov Chain Beam Randomization, MCBR, randomly samples from a set of templates or functions that describe the beam uncertainties. The method is much faster than direct numerical integration over systematic `nuisance' parameters, and is not restricted to simple, idealized cases as is analytic marginalization. It does not assume the data are normally distributed, and does not require Gaussian priors on the specific systematic uncertainties. We show that MCBR properly accounts for and provides the marginalized errors of the parameters. The method can be generalized and used to propagate any systematic uncertainties for which a set of templates is available. We apply the method to the Planck satellite, and consider future experiments. Beam measurement errors should have a small effect on cosmological parameters as long as the beam fitting is performed after removal of 1/f noise.Comment: 17 pages, 23 figures, revised version with improved explanation of the MCBR and overall wording. Accepted for publication in Astronomy and Astrophysics (to appear in the Planck pre-launch special issue

    α2 High molecular mass cysteine proteinase inhibitor: HMrα2-CPI An inhibitor of human liver cathepsin H as probed by kinetic study

    Get PDF
    AbstractHMrα2CPI was found to be an inhibitor of human liver cathepsin H by the measurement of the dissociation constant (Ki), the association rate constant (k1) and the dissociation rate constant (k−1) between the enzyme and the inhibitor. These data suggest that this protein-proteinase inhibitor can play a physiological role in the regulation of free cathepsin H

    Strategies for Agile Leadership in a Challenging Environment

    Get PDF
    The post pandemic environment has provided many significant challenges for all forms of organisations. The requirement for good leadership in this context is vital. This research considers the features of such leadership and how their application can affect organisations and their required outputs. The need for agility in this sphere is proposed, in order to accommodate the environmental challenges, globally and within the different sectors. There should be an emphasis on creativity in order to provide solutions to the many issues for organisations in the prevailing environment. Recruitment and retention are viewed as critical activities for sustaining these entities by ensuring the supply of the requisite standard of personnel at all levels. The latter should have suitable qualifications or the aptitude to acquire them. These staff should be given appropriate training then empowered, including being given the scope to utilise their own leadership style, as appropriate. The form of the post pandemic environment and its effects on leadership are noted. The principal factors identified here include the economic challenges, hybrid working patterns and the use of agency staff to supplement the permanent resource. The proactive development of leaders is emphasised as a critical activity for organisations, enabling them to address the issues prevalent in their environment. Research into this area occurred, using qualitative techniques. A literature review and interview with a current practitioner were performed, in order to glean the data for an inductive analysis. A template to assist organisations in creating a strategy for ‘Agile Leadership’ was then formulated.How to cite this article: Blair, G., Barratt, S., & Pagano, R., (2023). Strategies for Agile Leadership in a Challenging Environment. GS Spark: Journal of Applied Academic Discourse. 1(1), 55-66. https://doi.org/10.5281/zenodo.837211

    Constraining Modified Gravity with Euclid

    Get PDF
    Future proposed satellite missions as Euclid can offer the opportunity to test general relativity on cosmic scales through mapping of the galaxy weak lensing signal. In this paper we forecast the ability of these experiments to constrain modified gravity scenarios as those predicted by scalar-tensor and f(R)f(R) theories. We found that Euclid will improve constraints expected from the PLANCK satellite on these modified gravity models by two orders of magnitude. We discuss parameter degeneracies and the possible biases introduced by modified gravity

    The role of religiousness on substance-use disorder treatment outcomes: a comparison of black and white adolescents

    Full text link
    This study compares 41 Black and 124 White adolescents at intake and discharge from a residential treatment program for substance-use disorders. Study data were obtained as part of a larger study (N = 195) that sought to assess the relationship of helping behavior and addiction recovery. This post-hoc analysis aims to identify cultural strengths that may be associated with recovery from substance-use disorders among Black adolescents. Using regression analyses and controlling for the severity of substance use and background variables that distinguish racial groups, religious practices and behaviors at intake were examined. Specifically, Black youth and White youth were compared on treatment outcomes, including alcohol or drug use during treatment, drug craving, 12-Step work, and 12-Step helping. The burden of health and socioeconomic disparities at intake did not disproportionately disfavor Black adolescents. Outcomes related to 12-Step measures were similar between Black and White youth. White adolescents reported higher craving scores at discharge, and Black adolescents were more likely to use drugs during treatment. High levels of religiousness at treatment intake were linked to greater 12-Step work and greater 12-Step helping at discharge. High levels of religiousness at intake were not related to drug use during treatment or to craving scores at discharge. The relationship between intake levels of religiousness and treatment-related outcomes did not differ by race.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3437261/Accepted manuscrip

    HAZMAT VI: The Evolution of Extreme Ultraviolet Radiation Emitted from Early M Star

    Full text link
    Quantifying the evolution of stellar extreme ultraviolet (EUV, 100 -- 1000 A\overset{\circ}{A}) emission is critical for assessing the evolution of planetary atmospheres and the habitability of M dwarf systems. Previous studies from the HAbitable Zones and M dwarf Activity across Time (HAZMAT) program showed the far- and near-UV (FUV, NUV) emission from M stars at various stages of a stellar lifetime through photometric measurements from the Galaxy Evolution Explorer (GALEX). The results revealed increased levels of short-wavelength emission that remain elevated for hundreds of millions of years. The trend for EUV flux as a function of age could not be determined empirically because absorption by the interstellar medium prevents access to the EUV wavelengths for the vast majority of stars. In this paper, we model the evolution of EUV flux from early M stars to address this observational gap. We present synthetic spectra spanning EUV to infrared wavelengths of 0.4 ±\pm 0.05 M_{\odot} stars at five distinct ages between 10 and 5000 Myr, computed with the PHOENIX atmosphere code and guided by the GALEX photometry. We model a range of EUV fluxes spanning two orders of magnitude, consistent with the observed spread in X-ray, FUV, and NUV flux at each epoch. Our results show that the stellar EUV emission from young M stars is 100 times stronger than field age M stars, and decreases as t1^{-1} after remaining constant for a few hundred million years. This decline stems from changes in the chromospheric temperature structure, which steadily shifts outward with time. Our models reconstruct the full spectrally and temporally resolved history of an M star's UV radiation, including the unobservable EUV radiation, which drives planetary atmospheric escape, directly impacting a planet's potential for habitability.Comment: 23 pages, 15 figures, accepted to Ap
    corecore