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Direct outcrop observation and field data collection are key techniques in research, teaching and outreach activities in volcanic areas. However, very often outcrops are of difficult or impossible access, such as in areas with active volcanoes or steep cliffs. Classical remote-sensing surveys by satellites or airplanes are expensive, rarely reach sufficient resolution to allow high-quality 3D visualisation of volcanic features and do not facilitate mapping of vertical cliffs. We describe a novel approach that uses immersive Virtual Reality (VR) based on real-world 3D Digital Outcrop Models (DOMs) from images surveyed by "unoccupied aerial system" (UAS). 3D DOMs are built up using the Structure-from-Motion (SfM) photogrammetry technique, and a VR scene is created using game engine technologies. Immersive real-time exploration of the environment is possible through a head-mounted display, e.g. Oculus Rift. Tools embedded in the VR environment allow the user to map polygons, lines and point features. Tools also allow to measure orientation, dip, inclination, azimuth, area and thickness and even take virtual photographs. Using three examples of volcanic areas with different geological features, we demonstrate the potential of our approach to allow users to be able to virtually map and measure remotely, and to collect data for research and teaching. Our approach is of paramount importance also for outreach, as it allows non-specialist audiences (e.g. common citizens) to experience and appreciate highly complex volcanic features through customised, hands-on immersive VR tools. [ABSTRACT FROM AUTHOR]

We present the results of the photometric analysis of a large part of the main body of the Small Magellanic Cloud. Using the 6.5m Magellan Telescope at the Las Campanas Observatory in Chile, we have acquired deep B and I images in four fields (0.44 deg each in diameter), yielding accurate photometry for 1068 893 stars down to 24th magnitude, with a spatial resolution of 0.20 arcsec per pixel. Colour–magnitude diagrams and (completeness-corrected) luminosity functions have been constructed, yielding significant new results that indicate at least two discrete star formation events over a period from 2.7 to 4 Gyr ago. Also, we have derived star formation rates as a function of look-back time and have found enhancements of SF between 4 and 6 Gyr and at younger ages. [ABSTRACT FROM AUTHOR]

Together with coronal mass ejection, flares are the most energetic stellar magnetic events, ignited by a sudden release of magnetic energy, which triggers a cascade of interconnected phenomena, each resulting in emission in different bands. For this reason, flares are intrinsic multiwavelength phenomena. In particular, optical and soft X‐ray emission probes two different events occurring during flares: the heating of plasma in the upper photosphere at the footpoints of the magnetic loops and the heating and cooling of the plasma confined in the loops in the corona, respectively. To characterize powerful flares observed in optical and X‐rays, constrain the energy released in both bands, the geometry of the loops, and to study flares time evolution, we studied the brightest flares occurred in the 125‐Myr‐old stars in the Pleiades observed simultaneously with x‐ray multi‐mirror mission/Newton and Kepler/K2. [ABSTRACT FROM AUTHOR]

This paper examines the feasibility of using data from OpenStreetMap (OSM), Facebook and Foursquare as a source of information on the function of buildings. Such information is rarely openly available and if available, would vary between cities by nomenclature, making comparisons between places difficult. Volunteered Geographic Information (VGI) including data from social media represents new potential sources of building function data that have not yet been exploited for this purpose. Using a part of the city of Milan as the study area, building data from OSM and points of interest (POIs) from OSM, Facebook and Foursquare were extracted to derive the building function. This resulted in the classification of building function for more than 80 % of the buildings and demonstrated that both Facebook and Foursquare can complement the building function derived from OSM, helping to fill in missing gaps. This preliminary study has demonstrated the potential of this approach for deriving building function information from open data in a simple way yet still requires independent validation with alternative sources as well as extension to other areas that have different amounts of OSM and social media coverage. [ABSTRACT FROM AUTHOR]

The Small Magellanic Cloud (SMC) presents us with a unique opportunity to study in detail the effect of environmental processes (interaction with the LMC and the Milky Way) on its star formation history. With the 6.5m Magellan Telescope at the Las Campanas Observatory in Chile we have acquired deep B and I images in four 0.44 degree fields covering a large part of the main body of the SMC, yielding accurate photometry for 1,068,893 stars down to ~24th magnitude, with a spatial resolution of 0.201 arcsec/pixel. Colour-magnitude diagrams and luminosity functions (corrected for completeness) have been constructed, yielding significant new results that indicate at least two discrete star formation events around 2.7 and 4-5 Gyr ago. [ABSTRACT FROM AUTHOR]

We report on the X-ray spectral and temporal properties of the Be/X-ray binary system XMMUJ004855.5-734946 located in the Small Magellanic Cloud. The system was monitored by Swift/XRT during a moderate outburst in 2016 July, while an unanticipated Chandra target of opportunity observation was triggered when the luminosity of the system was greater than 1036 erg s-1 allowing a detailed study of X-ray properties of the systems. Specifically, its X-ray spectrum, as observed during the outburst, is well modelled by an absorbed power law (T = 0.58). Timing analysis of the collected photon events revealed coherent X-ray pulsations with a period of ~15.64 s, thus confirming XMMU J004855.5-734946 as a high-mass X-ray binary pulsar. By analysing archival XMM-Newton observations, we determined the longterm spin period evolution of the neutron star, showing that the compact star has spun-up by Ṗ ~ -0.0028 s yr-1. By modelling the X-ray pulsed emission as detected by Chandra, we set constraints on the inclination of the magnetic and rotation axis of the neutron star, as well to its compactness (i.e. (M/M☉)/(R/km) = 0.095 ± 0.007). [ABSTRACT FROM AUTHOR]

Background: The knowledge of the exact location of the mental foramen (MF) in dentate and edentulous mandibles is clinically important when constructing complete dentures, performing anaesthetic block of the lower-anterior teeth area and intervening in the MF nearby area. In edentulous mandibles, the bone resorption after teeth loss makes the mental nerve (MN) prone to damage due to the extreme location of the MF very close to the alveolar crest (AC). Chronic compression on the MN may result in pain in the area of MN distribution (ipsilateral face and cheek area) and numbness at the lower lip. The purpose of the current study is to evaluate the exact position of the MF, calculating the distances MF-superior border of the AC and MF-inferior border of the mandible (IBM) in dentate and edentulous mandibles.Materials and Methods: One hundred and two (36 edentulous and 66 dentate) adult dry Greek mandibles were studied.Results: In 9 out of 36 edentulous mandibles (25%), the MF was found nearby the AC, while in 27 edentulous mandibles (75%), the MF was located at an average distance 6.4 mm from the AC and 12.6 mm from the IBM. In 38 out of 66 dentate mandibles (57.6%), the MF was located at an average distance 13.6 mm from the AC and 15.2 mm from the IBM. The dental status significantly affected (p = 0.001) the distances MF-AC and MF-IBM. Side symmetry was observed for both dentate and edentulous mandibles (p = 0.39 and p = 0.45).Conclusions: The MF is an important landmark and its location needs to be considered prior to dental implants placement in order to avoid the MN injury and related complications. The position of MF is altered in edentulous mandibles compared with the dentate ones. The MF is a symmetric structure in Greeks. [ABSTRACT FROM AUTHOR]

Using hundreds of XMM-Newton and Chandra archival observations and nearly a thousand RXTE observations, we have generated a comprehensive library of the known pulsars in the Small and Large Magellanic Clouds (SMC and LMC). The pulsars are detected multiple times across the full parameter spaces of X-ray luminosity (LX =1031-38 erg s-1) and spin period (P<1 s to P>1,000 s), and the library enables time-domain studies at a range of energy scales. The high time resolution and sensitivity of the European Photon Imaging cameras are complemented by the angular resolution of Chandra and the regular monitoring of RXTE. Our processing pipeline uses the latest calibration files and software to generate a suite of useful products for each pulsar detection: event lists, high-time-resolution light curves, periodograms, spectra, and complete histories of Ṗ , the pulsed fraction, and so on, in the broad (0.2-12 keV), soft (0.2-2 keV), and hard (2-12 keV) energy bands. After combining the observations from these telescopes, we found that 27 pulsars show long-term spin up and 24 long-term spin down.We also used the faintest and brightest sources to map out the lower and upper boundaries of accretion-powered X-ray emission: the propeller line and the Eddington line, respectively. We are in the process of comparing the observed pulse profiles to geometric models of X-ray emission in order to constrain the physical parameters of the pulsars. Finally, we are preparing a public release of the library so that it can be used by others in the astronomical community. [ABSTRACT FROM AUTHOR]

In this work we investigate the link between high-mass X-ray binaries (HMXBs) and star formation in the Large Magellanic Cloud (LMC), our nearest star-forming galaxy. Using optical photometric data, we identify the most likely counterpart of 44 X-ray sources. Among the 40 HMXBs classified in this work, we find 33 Be/X-ray binaries (Be-XRBs), and 4 supergiant XRBs. Using this census and the published spatially resolved star formation history map of the LMC, we find that the HMXBs (and as expected the X-ray pulsars) are present in regions with star formation bursts ~6-25 Myr ago, in contrast to the Small Magellanic Cloud (SMC), for which this population peaks at later ages (~25-60 Myr ago). We also estimate the HMXB production rate to be equal to one system per ~23.0+4.4-4.1 ? 10-3 M๏ yr-1 or one system per ~143M๏ of stars formed during the associated star formation episode. Therefore, the formation efficiency of HMXBs in the LMC is ~17 times lower than that in the SMC. We attribute this difference primarily in the different ages and metallicity of the HMXB populations in the two galaxies. We also set limits on the kicks imparted on the neutron star during the supernova explosion. We find that the time elapsed since the supernova kick is ~3 times shorter in the LMC than the SMC. This in combination with the average offsets of the HMXBs from their nearest star clusters results in ~4 times faster transverse velocities for HMXBs in the LMC than in the SMC. [ABSTRACT FROM AUTHOR]

The Magellanic Clouds are uniquely placed to study the stellar contribution to dust emission. Individual stars can be resolved in these systems even in the mid-infrared, and they are close enough to allow detection of infrared excess caused by dust. We have searched the Spitzer Space Telescope data archive for all Infrared Spectrograph (IRS) staring-mode observations of the Small Magellanic Cloud (SMC) and found that 209 Infrared Array Camera (IRAC) point sources within the footprint of the Surveying the Agents of Galaxy Evolution in the Small Magellanic Cloud (SAGE-SMC) Spitzer Legacy programme were targeted, within a total of 311 staring-mode observations. We classify these point sources using a decision tree method of object classification, based on infrared spectral features, continuum and spectral energy distribution shape, bolometric luminosity, cluster membership and variability information. We find 58 asymptotic giant branch (AGB) stars, 51 young stellar objects, 4 post-AGB objects, 22 red supergiants, 27 stars (of which 23 are dusty OB stars), 24 planetary nebulae (PNe), 10 Wolf-Rayet stars, 3 H II regions, 3 R Coronae Borealis stars, 1 Blue Supergiant and 6 other objects, including 2 foreground AGB stars. We use these classifications to evaluate the success of photometric classification methods reported in the literature. [ABSTRACT FROM AUTHOR]

The evaluation of VGI quality has been a very interesting and popular issue amongst academics and researchers. Various metrics and indicators have been proposed for evaluating VGI quality elements. Various efforts have focused on the use of well-established methodologies for the evaluation of VGI quality elements against authoritative data. In this paper, a number of research papers have been reviewed and summarized in a detailed report on measures for each spatial data quality element. Emphasis is given on the methodology followed and the data used in order to assess and evaluate the quality of the VGI datasets. However, as the use of authoritative data is not always possible many researchers have turned their focus on the analysis of new quality indicators that can function as proxies for the understanding of VGI quality. In this paper, the difficulties in using authoritative datasets are briefly presented and new proposed quality indicators are discussed, as recorded through the literature review. We classify theses new indicators in four main categories that relate with: i) data, ii) demographics, iii) socio-economic situation and iv) contributors. This paper presents a dense, yet comprehensive overview of the research on this field and provides the basis for the ongoing academic effort to create a practical quality evaluation method through the use of appropriate quality indicators. [ABSTRACT FROM AUTHOR]

The Small Magellanic Cloud (SMC) hosts a large number of high-mass X-ray binaries, and in particular of Be/X-ray Binaries (BeXRBs; neutron stars orbiting OBe-type stars), offering a unique laboratory to address the effect of metalicity. One key property of their optical companion is Hα in emission, which makes them bright sources when observed through a narrow-band Hα filter. We performed a survey of the SMC Bar and Wing regions using wide-field cameras (WFI@MPG/ESO and MOSAIC@CTIO/Blanco) in order to identify the counterparts of the sources detected in our XMM-Newton survey of the same area. We obtained broad-band R and narrow-band Hα photometry, and identified ~10000 Hα emission sources down to a sensitivity limit of 18.7 mag (equivalent to ~B8 type Main Sequence stars). We find the fraction of OBe/OB stars to be 13% down to this limit, and by investigating this fraction as a function of the brightness of the stars we deduce that Hα excess peaks at the O9-B2 spectral range. Using the most up-to-date numbers of SMC BeXRBs we find their fraction over their parent population to be ~0.002 − 0.025 BeXRBs/OBe, a direct measurement of their formation rate. [ABSTRACT FROM AUTHOR]

We present B, V, R and I photometry for NGC 6779 (M56), a metal-poor globular cluster in the galactic halo. The observations were performed using the 1.3-m telescope at Skinakas Observatory, in Crete. The reddening of the cluster was found to be , significantly higher than previous estimates. The metal abundance of the cluster was derived from various parametrizations of red giant branch characteristics and it was found to be dex on the Zinn–West metallicity scale, or dex on the Carretta–Gratton scale. The distance modulus of the cluster is estimated to be (or 14.62, if we correct for the reddening to the cluster). The horizontal branch of NGC 6779 shows a clear gap at . Finally, the revised value for the metallicity of NGC 6779 led to a revision of its age to 13 Gyr, using the age-index calibrations of Salaris & Weiss. [ABSTRACT FROM AUTHOR]

The present study deals with the analysis of lead in pasture plants and tissues of goats(liver, kidney) from two areas (Arnea, Stratoni) of Central Macedonia, Greece. Analysis was carried out by Atomic Absorption Spectrometry on 42 plants and 66 specimens of goat tissues. The mean lead concentration in plants of Stratoni area was found 88 mg/kg dry weight (d/w) and of Arnea area 46 mg/kg d/w (P< 0,001). Mean lead concentration in plant specimens from both areas were higher than 20 mg/kg d/w which is the most usual concentration referred by several investigators. Mean lead concentration in tissue specimens from Stratoni area was found 0.60 mg/kg wet weight (w/w) for liver and 0.65 mg/kg w/w for kidney, while from Arnea area 0.46 mg/kg w/w and 0.27 mg/kg w/w respectively( P < 0.10 for liver, P < 0.001 for kidney). Lead levels found In tissues of goats were similar to those referred to international bibliography. [ABSTRACT FROM PUBLISHER]