1,034 research outputs found

    On the use of asymmetric PSF on NIR images of crowded stellar fields

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    We present data collected using the camera PISCES coupled with the Firt Light Adaptive Optics (FLAO) mounted at the Large Binocular Telescope (LBT). The images were collected using two natural guide stars with an apparent magnitude of R<13 mag. During these observations the seeing was on average ~0.9". The AO performed very well: the images display a mean FWHM of 0.05 arcsec and of 0.06 arcsec in the J- and in the Ks-band, respectively. The Strehl ratio on the quoted images reaches 13-30% (J) and 50-65% (Ks), in the off and in the central pointings respectively. On the basis of this sample we have reached a J-band limiting magnitude of ~22.5 mag and the deepest Ks-band limiting magnitude ever obtained in a crowded stellar field: Ks~23 mag. J-band images display a complex change in the shape of the PSF when moving at larger radial distances from the natural guide star. In particular, the stellar images become more elongated in approaching the corners of the J-band images whereas the Ks-band images are more uniform. We discuss in detail the strategy used to perform accurate and deep photometry in these very challenging images. In particular we will focus our attention on the use of an updated version of ROMAFOT based on asymmetric and analytical Point Spread Functions. The quality of the photometry allowed us to properly identify a feature that clearly shows up in NIR bands: the main sequence knee (MSK). The MSK is independent of the evolutionary age, therefore the difference in magnitude with the canonical clock to constrain the cluster age, the main sequence turn off (MSTO), provides an estimate of the absolute age of the cluster. The key advantage of this new approach is that the error decreases by a factor of two when compared with the classical one. Combining ground-based Ks with space F606W photometry, we estimate the absolute age of M15 to be 13.70+-0.80 Gyr.Comment: 15 pages, 7 figures, presented at the SPIE conference 201

    Method and apparatus for non-destructive inspection of fruits having an axis of rotational symmetry

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    This invention relates to a method for non-destructive inspection of a fruit (1) having an axis of rotational symmetry (10). The method comprises the step of positioning the fruit (1) in such a way that its axis of rotational symmetry (10) has an orientation that is substantially parallel to a predetermined plane (20) and the step of radiographing the fruit (1), where the direction of emission of X-rays is substantially perpendicular to said predetermined plane (20) and an X-ray image obtained (41) lies on said predetermined plane (20). The X-ray image obtained (41) is processed to calculate, at corresponding points of the X-ray image (41), respective values of attenuation of the X-ray signal through the fruit (1). The X-ray image (41) is divided into a plurality of sections (415) which are perpendicular to the projection (410) of the axis of rotational symmetry (10) on the predetermined plane (20). Each section (415) is the projection of a corresponding slice of the fruit (1) that is substantially perpendicular to the axis of rotational symmetry (10). For each section (415), the deviation between a signal attenuation trend obtained from processing the X-ray image and a reference trend, or the deviation between a trend of a local coefficient of average attenuation obtained from processing the X-ray image and a trend with constant value, is examined in order to identify any anomalies, discontinuities or variations which are indicative of respective nonuniformities in the corresponding slice of fruit. This invention also relates to an apparatus (9) for carrying out a non-destructive inspection of a fruit (1) having an axis of rotational symmetry (10), said apparatus being configured for implementing the method according to the invention

    Urban geomorphology of Genoa old city (Italy)

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    Field survey and geomorphological mapping in urban areas are difficult tasks, particularly those related to the recognition of natural landforms within cities. In this case, it is necessary to apply an integrated scientific approach by combining geomorphology with historical-geography. This paper presents the result of a multi-year survey carried out in the natural morphological amphitheatre where the historic centre of Genoa developed. Our research methods included field surveys in urban areas, interpretation of natural and anthropic landforms from maps and photographs, and analyses of the available borehole logs. As a result, we updated knowledge on urban geomorphology of Genoa old city. An original geomorphological legend has been adopted, including new entries for anthropogenic landforms, targeted at a better visual representation on the changes in the geomorphological landscape during more than one thousand years of urban development of the city. The geomorphological map of Genoa old city is presented as a useful tool for urban planning, as well as for an integrated cultural and landscape enhancement of the territory

    Implementation of Nature-Based Solutions for Hydro-Meteorological Risk Reduction in Small Mediterranean Catchments: The Case of Portofino Natural Regional Park, Italy

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    Nature-based solutions (NBS) are usually defined as complementary or alternative solutions to \u201cgrey infrastructures\u201d (traditionally made with cement) aimed at conserving and regenerating the functionality of natural and semi-natural ecosystems. The research to date shows a considerable potential of NBS to address the current challenges related to climate change and geo-hydrological risks. Despite significant interest in NBS by researchers and practitioners, knowledge concerning their practical implementation, monitoring, and evaluation is still lacking. This is particularly true for large-scale NBS. The present paper discusses how such solutions can be implemented in the context of hydro-meteorological risk reduction in small Mediterranean catchments with a strong tourist vocation. The work presented here is situated within the RECONECT Project (Regenerating ECOsystems with Nature-based solutions for hydro-meteorological risk rEduCTion), which aims to contribute to a European reference framework on NBS by demonstrating, upscaling, and replicating large-scale NBS in rural and natural areas. The Italian case study of RECONECT is the Portofino Natural Regional Park, which represents a unique natural landscape element with high ecologic, social, and economic (touristic) value, which is threatened by a range of geo-hydrological hazards, such as flash floods, hyper-concentrated floods, shallow landslides, rockfalls, and storm surges. This paper also presents details of NBS interventions in two pilot catchments (San Fruttuoso and Paraggi) visited by thousands of tourists throughout the year. It addresses some of the key aspects related to monitoring meteorological and hydrological processes, as well as remote sensing activities (i.e., LiDAR surveys), which are necessary for the identification of critical-instability areas along waterways and the reconstruction of dry stone walls. Lastly, a discussion of relevant mitigation and adaptation strategies that are potentially replicable at national and international levels is also provide

    At the core of cyberaggression: A group-based explanation

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    In this study, prototypicality of the aggressor was tested as a group-level factor predicting social media users' active participation in cyberaggression. Participants were exposed to a fictitious conversation, in which either a prototypical versus non-prototypical user posted an aggressive comment as a reply to a provocative comment. In line with self-categorization theory, we hypothesized that bystander participants would post an aggressive comment and rate the aggression as acceptable to a greater extent in the prototypical than in the non-prototypical condition. Furthermore, we predicted that perceived normativity of aggression would mediate the effect of prototypicality. Results supported these predictions and showed that prototypical members affect the extent to which collective aggressive behaviors in online interactions are approved and enacted. These findings highlight the importance of group-level factors in the study of cyberaggression and provide important information for understanding the psychological underpinnings of collective forms of online aggression

    Detoxification improves multidomain cognitive dysfunction in high-dose benzodiazepine abusers

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    Purpose: High-dose benzodiazepines (BZDs) abuse has been documented to cause multidomain cognitive dysfunction. We explored whether cognitive abnormalities to high-dose BZD abuse might be reversed by detoxification with slow subcutaneous infusion of flumazenil. Methods: We recruited 96 patients consecutively admitted to the Department of Internal Medicine, Addiction Medicine Unit, Verona University Hospital, Italy for detoxification from high-dose BZD dependence. After selection for inclusion and exclusion criteria, 50 patients (23 men, 27 women; age 42.7 \ub1 10.3 years) were included. They underwent a comprehensive neuropsychological battery to explore verbal memory, visuospatial memory, working memory, attention, and executive functions 28-30 days prior to admission for detoxification (T0) and at the end of detoxification, i.e., 7 days after admission (T1). A group of 50 healthy adults (24 men, 26 women; mean age 44.5 \ub1 12.8 years) matched for age, sex, and education served as controls. Results: At T0, patients scored significantly worse than healthy controls in all the neuropsychological tests. Depression and anxiety scores were associated with impaired verbal memory at T0 in patients. T1-T0 comparison showed improved performances in all neuropsychological tests after the end of detoxification in patients. Conclusion: We confirmed that all neuropsychological domains were significantly and profoundly impaired by high-dose BZD abuse and documented that cognitive abnormalities improved after detoxification with slow subcutaneous infusion of flumazenil

    Fiebre recurrente transmitida por garrapatas: ¿otra etiología subdiagnosticada en Latinoamérica tropical?

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    Tick-borne relapsing fever (TBRF) is an infectious zoonotic disease caused by spirochetes of the genus Borrelia, transmitted to humans and animals through the bite of soft ticks (Argasidae) of the genus Ornithodoros (1,2). In nature, borreliae are maintained in an enzootic cycle that involves wild mammals (mainly rodents), where ticks acquire spirochetes after short periods of hematophagy (15-90 minutes), remaining chronically infected with the possibility of transmitting microorganisms to new vertebrate individuals, including man, who acts as an accidental host (2).La fiebre recurrente transmitida por garrapatas (FRTG) es una enfermedad infecciosa de carĂĄcter zoonĂłtico causada por espiroquetas del gĂ©nero Borrelia, transmitidas al hombre y animales a travĂ©s de la picadura de garrapatas “blandas” (familia Argasidae) del gĂ©nero Ornithodoros (1,2). En la naturaleza, las borrelias se mantienen en un ciclo enzoĂłtico que involucra mamĂ­feros silvestres (principalmente roedores), donde las garrapatas adquieren las espiroquetas despuĂ©s de cortos periodos de hematofagia (15-90 minutos), permaneciendo infectadas crĂłnicamente con la posibilidad de transmitir los microorganismos a nuevos individuos vertebrados, incluyendo al hombre, quien actĂșa como un hospedero accidental (2)

    VARIABLE STARS AND STELLAR POPULATIONS IN ANDROMEDA XXV. III. A CENTRAL CLUSTER OR THE GALAXY NUCLEUS?

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    We present B and V time series photometry of Andromeda XXV, the third galaxy in our program on the Andromeda’s satellites, which we have imaged with the Large Binocular Cameras of the Large Binocular Telescope. The field of Andromeda XXV is found to contain 62 variable stars, for which we present light curves and characteristics of the light variation (period, amplitudes, variability type, mean magnitudes, etc.). The sample includes 57 RR Lyrae variables (46 fundamental-mode—RRab, and 11 first-overtone—RRc, pulsators), 3 anomalous Cepheids, 1 eclipsing binary system, and 1 unclassified variable. The average period of the RRab stars ( =0.60 σ = 0.04 days) and the period–amplitude diagram place Andromeda XXV in the class of the Oosterhoff-Intermediate objects. From the average luminosity of the RR Lyrae stars we derive for the galaxy a distance modulus of (m–M)0 = 24.63 ± 0.17 mag. The color–magnitude diagram reveals the presence in Andromeda XXV of a single, metal-poor ([Fe/H] = ‑1.8 dex) stellar population as old as ∌10–12 Gyr, traced by a conspicuous red giant branch and the large population of RR Lyrae stars. We discovered a spherically shaped high density of stars near the galaxy center. This structure appears to be at a distance consistent with Andromeda XXV and we suggest it could either be a star cluster or the nucleus of Andromeda XXV. We provide a summary and compare the number and characteristics of the pulsating stars in the M31 satellites analyzed so far for variability. Based on data collected with the Large Binocular Cameras at the Large Binocular Telescope
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