Hearts of Darkness: the inside out probing of black holes

Classical black holes shield us from the singularities that inevitably appear in general relativity. Singularity regularization being one of the main landmarks for a successful theory of quantum gravity, quantum black holes are not obliged to hide their inner core from the outside world. Notwithstanding the aforesaid, it is often implicitly assumed that quantum gravity effects must remain confined to black hole interiors. In this essay, we argue in the opposite direction, discussing theoretical evidence for the existence of strong correlations between the physics inside and outside nonsingular black holes. We conclude that astronomical tests of the surroundings of black holes can provide invaluable information about their so-far unexplored interiors

Transformation-tolerant object recognition in rats revealed by visual priming

Successful use of rodents as models for studying object vision crucially depends on the ability of their visual system to construct representations of visual objects that tolerate (i.e., remain relatively unchanged with respect to) the tremendous changes in object appearance produced, for instance, by size and viewpoint variation. Whether this is the case is still controversial, despite some recent demonstration of transformation-tolerant object recognition in rats. In fact, it remains unknown to what extent such a tolerant recognition has a spontaneous, perceptual basis, or, alternatively, mainly reflects learning of arbitrary associative relations among trained object appearances. In this study, we addressed this question by training rats to categorize a continuum of morph objects resulting from blending two object prototypes. The resulting psychometric curve (reporting the proportion of responses to one prototype along the morph line) served as a reference when, in a second phase of the experiment, either prototype was briefly presented as a prime, immediately before a test morph object. The resulting shift of the psychometric curve showed that recognition became biased toward the identity of the prime. Critically, this bias was observed also when the primes were transformed along a variety of dimensions (i.e., size, position, viewpoint, and their combination) that the animals had never experienced before. These results indicate that rats spontaneously perceive different views/appearances of an object as similar (i.e., as instances of the same object) and argue for the existence of neuronal substrates underlying formation of transformation-tolerant object representations in rats

Healthcare Associated Infections. educational intervention by "Adult Learning" in an Italian teaching hospital

An educational intervention for HAI prevention based on a combination of training, motivation and subsequent application in the current clinical practice in an Italian teaching hospital

INTEGRATION OF ACTIVE SENSORS FOR GEOMETRIC ANALYSIS OF THE CHAPEL OF THE HOLY SHROUD

Abstract. The digital acquisition of Cultural Heritage is a complex process, highly depending on the nature of the object as well as the purpose of its detection. Even if there are different survey techniques and sensors that allow the generation of realistic 3D models, defined by a good metric quality and a detail consistent with the geometric characteristics of the object, an interesting goal could be to develop a unified treatment of the methodologies. The Chapel of the Holy Shroud, with its intricate articulation, becomes the benchmark to test an integrated protocol between a terrestrial laser scanner (TLS) and a wearable mobile laser system (WMLS) based on a SLAM approach. In order to quantify the accuracy and precision of the latter solution, several forms of comparison are proposed. For the case study the ZEB-REVO, produced and marketed by GeoSLAM, is tested. Computations of cloud-to-cloud (C2C) absolute distances, comparisons of slices and extractions of planar features are performed, using stationary laser scanner (Faro FocusS S350) as a reference. Finally, the obtained results are reported, allowing us to assert that the quality of the WMLS measurements is compatible with the data provided by the manufacturer, thus making the instrumentation suitable for certain specific applications.</p

A dendrochronological analysis of Pinus pinea L. on the Italian mid-Tyrrhenian coast

In order to assess the response of the radial growth of Pinus pinea L. to climatic variability in Central Italy, dendrochronological and dendroclimatological analyses were carried out on five different populations scattered along the Tyrrhenian coasts of the peninsula. The aim of this study is to contribute to the understanding of the ecological demands of this species, particularly in the study area. For each site total ring, early-, and late-wood width chronologies were developed. Multidimensional analyses were performed for the three tree-ring datasets in order to analyze the relations between sites chronologies. Both Principal Component Analyses and hierarchical classifications highlighted an important difference of one site in respect to the other, probably due to site characteristics. Correlation functions were performed to infer the main climatic factors controlling the radial growth of the species. For a comparative study, we limited our attention to the common interval 1926-2003 (78 years) in which the response of the tree-ring chronologies to climate at both local and regional scale was investigated. Positive moisture balance in the late spring-summer period of the year of growth is the climatic driver of P. pinea radial growth in the study area. Moreover, this study shows how low summer temperatures strongly favor the radial growth of the species.Fil: Piraino, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto Argentino de Investigaciones de Zonas Aridas; ArgentinaFil: Camiz, Sergio. Universita degli studi di Roma "Sapienza". Dipartimento di Matematica; ItaliaFil: Di Filippo, Alfredo. Universita Degli Studi Della Tuscia. DendrologyLab; ItaliaFil: Piovesan, Gianluca. Universita Degli Studi Della Tuscia. DendrologyLab; ItaliaFil: Spada, Francesco. Universita degli studi di Roma "Sapienza". Dipartimento de biología ambientale; Itali

Opening the Pandora's box at the core of black holes

We present a geometric classification of all spherically symmetric spacetimes that could result from singularity regularization, using a kinematic construction that is both exhaustive and oblivious to the dynamics of the fields involved. Due to the minimal geometric assumptions underlying it, this classification encompasses virtually all modified gravity theories, and any theory of quantum gravity in which an effective description in terms of an effective metric is available. The first noteworthy conclusion of our analysis is that the number of independent classes of geometries that can be constructed is remarkably limited, with no more than a handful of qualitatively different possibilities. But our most remarkable result is that this catalogue of possibilities clearly demonstrates that the degree of internal consistency and the strength of deviations with respect to general relativity are strongly, and positively, correlated. Hence, either quantum fluctuations of spacetime come to the rescue and solve these internal consistency issues, or singularity regularization will percolate to macroscopic (near-horizon) scales, radically changing our understanding of black holes and opening new opportunities to test quantum gravity

Seismic vulnerability of above-ground storage tanks with unanchored support conditions for Na-tech risks based on Gaussian process regression

AbstractThis paper aims to investigate the seismic vulnerability of an existing unanchored steel storage tank ideally installed in a refinery in Sicily (Italy), along the lines of performance-based earthquake engineering. Tank performance is estimated by means of component-level fragility curves for specific limit states. The assessment is based on a framework that relies on a three-dimensional finite element (3D FE) model and a low-fidelity demand model based on Gaussian process regression, which allows for cheaper simulations. Moreover, to approximate the system response corresponding to the random variation of both peak ground acceleration and liquid filling level, a second-order design of experiments method is adopted. Hence, a parametric investigation is conducted on a specific existing unanchored steel storage tank. The relevant 3D FE model is validated with an experimental campaign carried out on a shaking table test. Special attention is paid to the base uplift due to significant inelastic deformations that occur at the baseplate close to the welded baseplate-to-wall connection, offering extensive information on both capacity and demand. As a result, the tank performance is estimated by means of component-level fragility curves for the aforementioned limit state which are derived through Monte Carlo simulations. The flexibility of the proposed framework allows fragility curves to be derived considering both deterministic and random filling levels. The comparison of the seismic vulnerability of the tank obtained with probabilistic and deterministic mechanical models demonstrates the conservatism of the latter. The same trend is also exhibited in terms of risk assessment

Switching from an EFV-Based STR to a RPV-Based STR is Effective, Safe and Improves HIV Patients Health Status

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On the Inner Horizon Instability of Non-Singular Black Holes

Regular black holes represent a conservative model in which the classical singularity is replaced by a non-singular core without necessarily modifying the spacetime outside the trapping horizon. Given the possible lack of phenomenological signatures, it is crucial to study the consistency of the model. In this short work, we review the physical mechanism leading to the instability of the central core, arguing that that non-perturbative backreation is non-negligible and must be taken into account to provide a meaningful description of physical black holes

Seismic Vulnerability Analysis of a Coupled Tank-Piping System by Means of Hybrid Simulation and Acoustic Emission

AbstractIn order to shed light on the seismic response of complex industrial plants, advanced finite element models should take into account both multicomponents and relevant coupling effects. These models are usually computationally expensive and rely on significant computational resources. Moreover, the relationships between seismic action, system response and relevant damage levels are often characterized by a high level of nonlinearity, which requires a solid background of experimental data. Vulnerability and reliability analyses both depend on the adoption of a significant number of seismic waveforms that are generally not available when seismic risk evaluation is strictly site-specific. In addition, detection of most vulnerable components, i.e., pipe bends and welding points, is an important step to prevent leakage events. In order to handle these issues, a methodology based on a stochastic seismic ground motion model, hybrid simulation and acoustic emission is presented in this paper. The seismic model is able to generate synthetic ground motions coherent with site-specific analysis. In greater detail, the system is composed of a steel slender tank, i.e., the numerical substructure, and a piping network connected through a bolted flange joint, i.e., the physical substructure. Moreover, to monitor the seismic performance of the pipeline and harness the use of sensor technology, acoustic emission sensors are placed through the pipeline. Thus, real-time acoustic emission signals of the system under study are acquired using acoustic emission sensors. Moreover, in addition to seismic events, also a severe monotonic loading is exerted on the physical substructure. As a result, deformation levels of each critical component were investigated; and the processing of acoustic emission signals provided a more in-depth view of the damage of the analysed components