94 research outputs found

    New Seismic Attenuation System (SAS) for the Advanced LIGO Configurations (LIGO2)

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    A new passive seismic attenuation system is being developed to replace the current passive attenuation stacks in LIGO 2, it is expected to drive the seismic contribution to the interferometer noise below any other noise source. The SAS will be effective completely starting at about 5 Hz, well inside the (uncompensated) gravity gradient noise wall

    UAV BLOCK GEOREFERENCING AND CONTROL BY ON-BOARD GNSS DATA

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    Abstract. Unmanned Aerial Vehicles (UAV) are established platforms for photogrammetric surveys in remote areas. They are lightweight, easy to operate and can allow access to remote sites otherwise difficult (or impossible) to be surveyed with other techniques. Very good accuracy can be obtained also with low-cost UAV platforms as far as a reliable ground control is provided. However, placing ground control points (GCP) in these contexts is time consuming and requires accessibility that, in some cases, can be troublesome. RTK-capable UAV platforms are now available at reasonable costs and can overcome most of these problems, requiring just few (or none at all) GCP and still obtaining accurate results. The paper will present a set of experiments performed in cooperation with ARPA VdA (the Environmental Protection Agency of Valle d'Aosta region, Italy) on a test site in the Italian Alps using a Dji Phantom 4 RTK platform. Its goals are: a) compare accuracies obtainable with different calibration procedures (pre- or on-the-job/self-calibration); b) evaluate the accuracy improvements using different number of GCP when the site allows for it; and c) compare alternative positioning modes for camera projection centres determination, (Network RTK, RTK, Post Processing Kinematic and Single Point Positioning)

    Detecting non-Gaussian gravitational wave backgrounds: a unified framework

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    We describe a novel approach to the detection and parameter estimation of a non\textendash Gaussian stochastic background of gravitational waves. The method is based on the determination of relevant statistical parameters using importance sampling. We show that it is possible to improve the Gaussian detection statistics, by simulating realizations of the expected signal for a given model. While computationally expensive, our method improves the detection performance, leveraging the prior knowledge on the expected signal, and can be used in a natural way to extract physical information about the background. We present the basic principles of our approach, characterize the detection statistic performances in a simplified context and discuss possible applications to the detection of some astrophysical foregrounds. We argue that the proposed approach, complementarily to the ones available in literature might be used to detect suitable astrophysical foregrounds by currently operating and future gravitational wave detectors.Comment: 12 Pages, 4 Figures, Supplemental material (published on 24 March 2023

    Improved detection statistics for non Gaussian gravitational wave stochastic backgrounds

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    In a recent paper we described a novel approach to the detection and parameter estimation of a non-Gaussian stochastic background of gravitational waves. In this work we propose an improved version of the detection procedure, preserving robustness against imperfect noise knowledge at no cost of detection performance: in the previous approach, the solution proposed to ensure robustness reduced the performances of the detection statistics, which in some cases (namely, mild non-Gaussianity) could be outperformed by Gaussian ones established in literature. We show, through a simple toy model, that the new detection statistic performs better than the previous one (and than the Gaussian statistic) everywhere in the parameter space. It approaches the optimal Neyman-Pearson statistics monotonically with increasing non-Gaussianity and/or number of detectors. In this study we discuss in detail its efficiency. This is a second, important step towards the implementation of a nearly--optimal detection procedure for a realistic non-Gaussian stochastic background. We discuss the relevance of results obtained in the context of the toy model used, and their importance for understanding a more realistic scenario.Comment: 12 pages, 5 figures (published on 23 June 2023

    Apprenticeship in Early Modern Venice

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    The desire of the Republican state to regulate the production and sale of food led to the establishment, during the twelfth century, of the Giustizia Vecchia, a magistracy which later developed an authority over the majority of the city’s guilds. The further decision to set a public register of contracts of apprenticeship reflects the ambition of Venetian authorities to regulate and control both vocational training and access to the urban job market, acting as a guarantor between masters and young apprentices. This chapter presents an historical overview of apprenticeship in early modern Venice, examining the development of the city’s legislation on the matter, and analysing a new sample of contracts recorded in the city’s apprenticeship registers during the sixteenth and seventeenth centuries. In particular, we discuss the complex relationship between the general legal framework established by Venetian public authorities and the particular set of norms detailed in guilds statutes. Our analysis reveals that apprenticeship contracts were used to accommodate a variety of situations, including paying for intense training to masked working contracts, while following the general framework provided by state and guild regulations. We then present an in-depth study of apprenticeship contracts from three crafts (goldsmiths, carpenters and printers), chosen for their economic importance, and because they possibly represented different realities in terms of technological specialization, capital (or labour) intensiveness and typology of market. This highlights yet another aspect of apprenticeship in Venice: the influence of guilds. Some guilds such as the Goldsmiths, were more closed to foreigners, favouring Venetians instead. Apprenticeship in early modern Venice is an institution which, despite appearing as highly regulated and formalized, accommodated a variety of realities with remarkable flexibility

    Testing accuracy and repeatability of UAV blocks oriented with gnss-supported aerial triangulation

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    UAV Photogrammetry today already enjoys a largely automated and efficient data processing pipeline. However, the goal of dispensing with Ground Control Points looks closer, as dual-frequency GNSS receivers are put on board. This paper reports on the accuracy in object space obtained by GNSS-supported orientation of four photogrammetric blocks, acquired by a senseFly eBee RTK and all flown according to the same flight plan at 80 m above ground over a test field. Differential corrections were sent to the eBee from a nearby ground station. Block orientation has been performed with three software packages: PhotoScan, Pix4D and MicMac. The influence on the checkpoint errors of the precision given to the projection centers has been studied: in most cases, values in Z are critical. Without GCP, the RTK solution consistently achieves a RMSE of about 2-3 cm on the horizontal coordinates of checkpoints. In elevation, the RMSE varies from flight to flight, from 2 to 10 cm. Using at least one GCP, with all packages and all test flights, the geocoding accuracy of GNSS-supported orientation is almost as good as that of a traditional GCP orientation in XY and only slightly worse in Z

    Cabozantinib in neuroendocrine tumours: tackling drug activity and resistance mechanisms

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    Neuroendocrine tumors (NETs) are highly vascularized malignancies in which angiogenesis may entail cell proliferation and survival. Among the emerging compounds with antivascular properties, cabozantinib (CAB) appeared promising. We analyzed the antitumor activity of CAB against NETs utilizing in vitro and in vivo models. For cell cultures, we used BON-1, NCI-H727 and NCI-H720 cell lines. Cell viability was assessed by manual count coupled with quantification of cell death, performed through fluorescence-activated cell sorting analysis as propidium iodide exclusion assay. In addition, we investigated the modulation of the antiapoptotic myeloid cell leukemia 1 protein under CAB exposure, as a putative adaptive pro-survival mechanism, and compared the responses with sunitinib. The activity of CAB was also tested in mouse and zebrafish xenograft tumor models. Cabozantinib showed a dose-dependent and time-dependent effect on cell viability and proliferation in human NET cultures, besides a halting of cell cycle progression for endoduplication, never reported for other tyrosine kinase inhibitors. In a transplantable zebrafish model, CAB drastically inhibited NET-induced angiogenesis and migration of implanted cells through the embryo body. CAB showed encouraging activity in NETs, both in vitro and in vivo models. On this basis, we envisage future research to further investigate along these promising lines

    From Documents to Structured Data: First Milestones of the Garzoni Project

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    Led by an interdisciplinary consortium, the Garzoni project undertakes the study of apprenticeship, work and society in early modern Venice by focusing on a specific archival source, namely the Accordi dei Garzoni from the Venetian State Archives. The project revolves around two main phases with, in the first instance, the design and the development of tools to extract and render information contained in the documents (according to Semantic Web standards) and, as a second step, the examination of such information. This paper outlines the main progress and achievements during the first year of the project

    Characterization of spotted fever group Rickettsiae in ticks from a city park of Rome, Italy

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     Background: Ticks are vectors and important reservoirs for microbial agents that cause disease in humans and animals. Among these pathogens, the members of Rickettsia species play an important role in public health.Aim and Methods: One hundred twenty-nine ticks belonging to four tick species (Ixodes ricinus, Rhipicephalus turanicus, Dermacentor marginatus, and Haemaphysalis punctata) were collected at different sites of the Insugherata Natural Reserve, localized in the urban area of Rome, Italy. Questing ticks were tested by PCR for Rickettsia spp., amplifying partial gene of ompA.Results: Forty-six ticks were found to be infected with Rickettsia species. Five SFG rickettsiae were identified: three human pathogens Rickettsia conorii, Rickettsia massiliae and Rickettsia aeschlimannii, and two putative new strains Rickettsia sp. strain RM1 and Rickettsia sp. strain RM2. The phylogenetic analysis of partial gene sequences of ompA, gltA, and 17-kd antigen showed that they clustered with several rickettsiae with unidentified pathogenicity. However, Rickettsia sp. strain RM1 and Rickettsia sp. strain RM2 clustered in a statistically supported clade with R. massiliae, and R. monacensis, respectively.Conclusion: Our findings suggest that Rickettsia species other than R. conorii are implicated in human disease in Italy

    Virgo gravitational wave detector: Results and perspectives

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    The Virgo detector reached during the past science run a sensitivity very close to the design one. During the last year the detector has been improved by suspending the main interferometer mirrors with monolithic fibers, with the goal of reducing the thermal noise contribution and testing the new technology. At the same time the design of the next detector improvements are on-going and they will be implemented during the construction of Advanced Virgo
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