120 research outputs found

    New approaches for gamma-hadron separation at the IceCube Neutrino Observatory

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    The IceCube Neutrino Observatory located at the geographic South Pole is composed of two detectors. One is the in-ice optical array, which measures high-energy muons from air showers and charged particles produced by the interaction of high-energy neutrinos in the ice. The other is an array of ice-Cherenkov tanks at the surface, called IceTop, which is used both as veto for the in-ice neutrino measurements and for detecting cosmic-ray air showers. In the next decade, the IceCube-Gen2 extension will increase the surface coverage including surface radio antennas and scintillator panels on the footprint of an extended optical array in the ice. The combination of the current surface and in-ice detectors can be exploited for the study of cosmic rays and the search for PeV gamma rays. The in-ice detector measures the high-energy muonic component of air showers, whereas the signal in IceTop is dominated by the electromagnetic component. The relative size of the muonic and electromagnetic components is different for gamma-and hadron-induced air showers. Thus, the gamma-hadron separation of cosmic rays is attempted using machine learning techniques including deep learning. Here, different approaches are presented. Finally, the prospects for the detection of PeV photons with IceCube-Gen2 will be discussed

    Enhancing PFI Prediction with GDS-MIL: A Graph-based Dual Stream MIL Approach

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    Whole-Slide Images (WSI) are emerging as a promising resource for studying biological tissues, demonstrating a great potential in aiding cancer diagnosis and improving patient treatment. However, the manual pixel-level annotation of WSIs is extremely time-consuming and practically unfeasible in real-world scenarios. Multi-Instance Learning (MIL) have gained attention as a weakly supervised approach able to address lack of annotation tasks. MIL models aggregate patches (e.g., cropping of a WSI) into bag-level representations (e.g., WSI label), but neglect spatial information of the WSIs, crucial for histological analysis. In the High-Grade Serous Ovarian Cancer (HGSOC) context, spatial information is essential to predict a prognosis indicator (the Platinum-Free Interval, PFI) from WSIs. Such a prediction would bring highly valuable insights both for patient treatment and prognosis of chemotherapy resistance. Indeed, NeoAdjuvant ChemoTherapy (NACT) induces changes in tumor tissue morphology and composition, making the prediction of PFI from WSIs extremely challenging. In this paper, we propose GDS-MIL, a method that integrates a state-of-the-art MIL model with a Graph ATtention layer (GAT in short) to inject a local context into each instance before MIL aggregation. Our approach achieves a significant improvement in accuracy on the ``Ome18'' PFI dataset. In summary, this paper presents a novel solution for enhancing PFI prediction in HGSOC, with the potential of significantly improving treatment decisions and patient outcomes

    Isotopic reconstruction of the subsistence strategy for a Central Italian Bronze Age community (Pastena cave, 2nd millennium BCE)

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    The Pastena cave is located in central Italy, and its best-preserved sector is Grotticella W2, which is dated radiometrically to the Early-Middle Bronze Age. The aim of this paper is to explore human diet, animal husbandry, and plant management, analysing the fndings there discovered. Carbon and nitrogen stable isotope analysis was carried out on 40 charred seeds, six faunal remains, and four human individuals, investigating the whole bio-archaeological material available. To the best of our knowledge, this is one of the frst papers presenting stable isotope analysis on carpological remains dated to the Italian Early-Middle Bronze Age. The obtained results are consistent with a diet based on terrestrial protein, mainly on plants, and secondly on animal products. The data suggest that plants, especially broad beans, were partially subjected to human management, while livestock was managed through diferent husbandry strategies. The cooperation between archaeological studies and molecular analysis allows us to contribute to clarifying the economic strategies for a Central Italian community in a scenario that is still poor in published data

    Giosuè Carducci prosatore

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    Questo volume su Giosuè Carducci prosatore raccoglie i contributi presentati al XVII Convegno internazionale di Letteratura italiana "Gennaro Barbarisi", tenutosi a Palazzo Feltrinelli (Gargnano del Garda) dal 29 settembre al 1° ottobre 2016. Si è trattato di una proficua occasione di incontro, di studio e di approfondimento su un tema forse poco frequentato, soprattutto in tempi recenti, ma ricco di sollecitazioni per una più articolata e storicamente fondata definizione della personalità di un autore così significativo nel panorama della cultura italiana fra Otto e primo Novecento; non soltanto sul versante della poesia (un primato sancito dal premio Nobel nel 1906) ma anche, e forse ancora di più, su quello della prosa saggistica, degli scritti di polemica, delle curatele editoriali, delle ricerche erudite, fino alle prove di alta oratoria e all'epistolografia

    Observation of Cosmic Ray Anisotropy with Nine Years of IceCube Data

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    Design of an Efficient, High-Throughput Photomultiplier Tube Testing Facility for the IceCube Upgrade

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    Multi-messenger searches via IceCube’s high-energy neutrinos and gravitational-wave detections of LIGO/Virgo

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    We summarize initial results for high-energy neutrino counterpart searches coinciding with gravitational-wave events in LIGO/Virgo\u27s GWTC-2 catalog using IceCube\u27s neutrino triggers. We did not find any statistically significant high-energy neutrino counterpart and derived upper limits on the time-integrated neutrino emission on Earth as well as the isotropic equivalent energy emitted in high-energy neutrinos for each event

    In-situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

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    The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. A unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. Birefringent light propagation has been examined as a possible explanation for this effect. The predictions of a first-principles birefringence model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties do not only include the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube LED calibration data, the theory and parametrization of the birefringence effect, the fitting procedures of these parameterizations to experimental data as well as the inferred crystal properties.</p

    Searching for time-dependent high-energy neutrino emission from X-ray binaries with IceCube

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