149 research outputs found

    The Use of Ground Penetrating Radar and Microwave Tomography for the Detection of Decay and Cavities in Tree Trunks

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    Acknowledgements This paper is dedicated to the memory of Jonathan West; a friend, a colleague, a forester, a conservationist and an environmentalist, who died following an accident in the woodland that he loved.Peer reviewedPublisher PD

    GPR and microwave tomography for the assessment of hollowed tree trunks

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    The danger related to the structural stability of hollowed trees is a matter of wide discussion among the scientific community. Hollow cores in trees can extend to more than 50% of the total diameter [1] and, while the presence of a hollow tree might appear dramatic in terms of public safety, it is not always a cause of concern. It is known that hollow trees can form in many years or even decades [2] and, although the heartwood is effectively dead, the tree can continue to form sapwood on the exterior of the trunk to create a cylinder. However, robustness and structural support provided by this cylinder to the trunk and canopy above depend on the ratio of healthy to diseased tissue. In this context, Ground Penetrating Radar (GPR) has proven to be an effective non-invasive tool, capable of generating information about the inner structure of tree trunks in terms of existence, location, and geometry of defects [3], [4]. Nevertheless, it had been observed that the currently available and known GPR-related processing and data interpretation methods and tools are able to provide only limited information on the tree inner structure. In this study, we present a microwave tomographic approach for improved GPR data processing with the aim of detecting and characterising the geometry of hollowed trees. Tests were performed at Gunnesbury Park, London, UK. In particular, a number of 15 circular measurements were collected around the tree using the Aladdin 2 GHz hand-held antenna system manufactured by IDS GeoRadar (Part of Hexagon), covering a height of 140 cm. The tree was eventually felled and three sections were cut for validation purposes. Results presented in this abstract are part of a major research project that the authors have undertaken for the last three years

    Biomarkers of Acute Graft-Versus-Host Disease: Surface Antigens and Micro Rnas in Extracellular Vesicles

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    Introduction Biomarkers could be crucial to identify patients at high-risk of acute Graft-vs.-Host Disease (aGVHD). Given their involvement in inflammation, Extracellular Vesicles (EVs) may become attractive biomarkers. Moreover, EVs are non-invasively extracted from body fluids. In a preliminary study, we significantly correlated CD146, CD31 and CD140a expression on EVs membranes with the onset of aGVHD (Lia G. Leukemia 2017). Objectives We designed a prospective study to further characterize EVs by their surface antigens and by their content in MicroRNAs. Methods EVs are extracted from serum samples at given time-points (pre-transplant, on day 0, 3, 7, 14, 21, 28, 35, 45 and then monthly up to 1 year) by a protamine-based precipitation method and analyzed by flow-cytometry (Guava EasyCyte Flow Cytometer) for the expression of 13 membrane proteins (CD44, CD138, CD146, KRT18, CD120a, CD8, CD30, CD106, CD25, CD31, CD144, CD86, and CD140a). MicroRNAs (miR100, miR92b, miR155, miR194) are extracted from EVs at pre- transplant and on day 0, 7, 14, 28, and quantified by real time PCR as relative quantification compared to healthy donors after cDNA Reverse Transcription. Logistic Regression Analysis is performed for each marker. Results Thirty-five transplant patients with hematological diseases have so far been enrolled. Seventeen/35 patients (49%) developed grade II-IV aGVHD. Our preliminary findings show that CD146 (melanoma cell adhesion molecule, MCAM-1) and CD44 (homing-associated cell adhesion molecule, H-CAM) were associated with an increased risk of aGVHD (Odds Ratio (OR) 4.3, p=0.008; OR 2.1, p=0.039), whereas CD31 (platelet endothelial cell adhesion molecule, PECAM-1) level was associated with a decreased risk of aGVHD (OR 0.31, p=0.001). Moreover, increased risk of aGVHD was significantly correlated with levels of miR100 (OR 4.66, p=0.004), miR194 (OR 2.2, p=0.01) and miR155 (OR 3.56, p=0.035). Of note, biomarkers associated with aGVHD showed a constant consensual change in signal levels before aGVHD onset (Figure 1). Conclusions An association of 3 EVs membrane antigens and onset of aGVHD was observed. Of note, CD146, CD44 and CD31 belong to the Cell Adhesion Molecule Family and are critical for endothelium and immune cells interactions. The functional role of miR-194 in GVHD pathogenesis remains to be determined while JAK/STAT and TGFβ pathways were shown to be involved in other studies (Gimondi S Exp Hematol, 2016). MiR-100 has been reported to regulate inflammatory neovascularization during GvHD (Leonhardt F, Blood 2013) while miR-155 drives donor T cell expansion and tissue infiltration (Zitzer N, J Immunol 2018, Ranganathan P Blood 2012)

    Advantages and Requirements in Time Resolving Tracking for Astroparticle Experiments in Space

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    A large-area, solid-state detector with single-hit precision timing measurement will enable several breakthrough experimental advances for the direct measurement of particles in space. Silicon microstrip detectors are the most promising candidate technology to instrument the large areas of the next-generation astroparticle space borne detectors that could meet the limitations on power consumption required by operations in space. We overview the novel experimental opportunities that could be enabled by the introduction of the timing measurement, concurrent with the accurate spatial and charge measurement, in Silicon microstrip tracking detectors, and we discuss the technological solutions and their readiness to enable the operations of large-area Silicon microstrip timing detectors in space

    Risk of SARS-CoV-2 infection in migrants and ethnic minorities compared with the general population in the European WHO region during the first year of the pandemic. A systematic review

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    Background: Migrants and ethnic minorities have suffered a disproportionate impact of the COVID-19 pandemic compared to the general population from different perspectives. Our aim was to assess specifically their risk of infection in the 53 countries belonging to the World Health Organization European Region, during the first year of the pandemic. Methods: We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO CRD42021247326). We searched multiple databases for peer-reviewed literature, published on Medline, Embase, Scisearch, Biosis and Esbiobase in 2020 and preprints from PubMed up to 29/03/2021. We included cross-sectional, case-control, cohort, intervention, case-series, prevalence or ecological studies, reporting the risk of SARS-CoV-2 infection among migrants, refugees, and ethnic minorities. Results: Among the 1905 records screened, 25 met our inclusion criteria and were included in the final analysis. We found that migrants and ethnic minorities during the first wave of the pandemic were at increased exposure and risk of infection and were disproportionately represented among COVID-19 cases. However, the impact of COVID-19 on minorities does not seem homogeneous, since some ethnic groups seem to be more at risk than others. Risk factors include high-risk occupations, overcrowded accommodations, geographic distribution, social deprivation, barriers to access to information concerning preventive measures (due to the language barrier or to their marginality), together with biological and genetic susceptibilities. Conclusions: Although mixed methods studies will be required to fully understand the complex interplay between the various biological, social, and cultural factors underlying these findings, the impact of structural determinants of health is evident. Our findings corroborate the need to collect migration and ethnicity-disaggregated data and contribute to advocacy for inclusive policies and programmatic actions tailored to reach migrants and ethnic minorities

    The On-Site Analysis of the Cherenkov Telescope Array

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    The Cherenkov Telescope Array (CTA) observatory will be one of the largest ground-based very high-energy gamma-ray observatories. The On-Site Analysis will be the first CTA scientific analysis of data acquired from the array of telescopes, in both northern and southern sites. The On-Site Analysis will have two pipelines: the Level-A pipeline (also known as Real-Time Analysis, RTA) and the level-B one. The RTA performs data quality monitoring and must be able to issue automated alerts on variable and transient astrophysical sources within 30 seconds from the last acquired Cherenkov event that contributes to the alert, with a sensitivity not worse than the one achieved by the final pipeline by more than a factor of 3. The Level-B Analysis has a better sensitivity (not be worse than the final one by a factor of 2) and the results should be available within 10 hours from the acquisition of the data: for this reason this analysis could be performed at the end of an observation or next morning. The latency (in particular for the RTA) and the sensitivity requirements are challenging because of the large data rate, a few GByte/s. The remote connection to the CTA candidate site with a rather limited network bandwidth makes the issue of the exported data size extremely critical and prevents any kind of processing in real-time of the data outside the site of the telescopes. For these reasons the analysis will be performed on-site with infrastructures co-located with the telescopes, with limited electrical power availability and with a reduced possibility of human intervention. This means, for example, that the on-site hardware infrastructure should have low-power consumption. A substantial effort towards the optimization of high-throughput computing service is envisioned to provide hardware and software solutions with high-throughput, low-power consumption at a low-cost.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

    Le Soprintendenze bibliografiche dello Stato

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    The intervention sums up the story of the bibliographic Superintendences, ministerial offices funded in 1919 and transferred to the Regions in 1972, and talks about their positioning within the history of the cultural policies from the Italian unification onwards. Sources used have been legislative and regulatory acts, essays on the subject from different periods and written testimonies of sector's operators. The immediate reason for this has been the need to study the development of state and regional policies on this matter when reform interventions deeply modify the balance of the last forty years. The survey has outlined also the persistence of never-solved problems in the planning of public interventions: for example, different functions have been managed by eclectic structures and at the same time the performance of the single functions has been fragmented based on their own institutions

    ASTRI SST-2M: the design evolution from the prototype to the array telescope

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    The Cherenkov Telescope Array (CTA) observatory will represent the new frontier of imaging atmospheric Cherenkov Telescope. The simultaneous use of large, medium and small telescopes (respectively LST, MST and SST) will allow to explore the astronomy related to the very high energy domain, typical of Gamma rays, with a sensitivity, angular resolution and image quality never seen before. Within this project, ASTRI, the Italian 2 mirrors Schwarzshild-Couder configuration Small SST led by Italian National Institute of Astronomy (INAF), has moved quickly developing a 4m class telescope prototype which has been tested with results which demonstrates excellent performance as well as wide margins for further improvements. On the basis of the experiences made on the prototype, this paper focus on the design enhancements carried out for the telescope which will be part of the Cherenkov Telescope Array
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