36 research outputs found

    Human dispersal of Trichinella spiralis in domesticated pigs

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    To investigate the human impact on the evolutionary ecology of animal pathogens, we compared genetic diversity of severe foodborne parasites contracted by eating infected pork or wild game. In particular, we characterized Trichinella spp. from twenty-eight countries and four continents by genotyping nine microsatellite loci and sequencing one-fifth of the mitochondrial genome. All specimens of Trichinella spiralis, a swine parasite that can infect many species of wildlife, were remarkably uniform across Europe, North Africa, and the Americas. Far greater diversity characterized a comparable sample of Trichinella britovi, which parasitizes various sylvatic mammals endemic to Eurasia and North-Western Africa. A limited sample of T. spiralis in Asia, where swine were first domesticated, encompassed greater genetic variability than those in the West, as did small samples of Trichinella nativa and Trichinella murrelli, which parasitize wildlife hosts. We conclude that European lineages of T. spiralis originated several thousand years ago, approximately when pigs were first domesticated there. These data also imply that Europeans inadvertently introduced T. spiralis to the Americas via infected pigs and/or rats. Despite evidence that early hominid hunters ingested foodborne parasites by hunting wild game millions of years earlier, swine husbandry has governed the subsequent transmission, dissemination, and evolutionary diversification of T. spiralis. Where viable parasites have been eliminated from their diet, the residual risk posed to swine by exposure to wildlife or rats should be more precisely defined because breaking the cycle of transmission would confer enduring economic and health benefits

    First Report of Trichinella nativa in Red Foxes(Vulpes vulpes schrencki) from Otaru City,Hokkaido,Japan

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    北海道小樽市で捕獲された43頭のキタキツネと9頭のタヌキについて、筋肉中のトリヒナ線虫の寄生状況を調べた。そのうち5頭のキツネからトリヒナ線虫の一種Trichinella nativaの幼虫が検出された。この発見は、北海道でキタキツネが、トリヒナ線虫の野外型の生活環維持の重要な宿主であることを示唆している。北海道におけるキタキツネからT.nativaの寄生報告は、最初のものである

    Design and Status of the ELIMED Beam Line for Laser-Driven Ion Beams

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    Charged particle acceleration using ultra-intense and ultra-short laser pulses has gathered a strong interest in the scientific community and it is now one of the most attractive topics in the relativistic laser-plasma interaction research. Indeed, it could represent the future of particle acceleration and open new scenarios in multidisciplinary fields, in particular, medical applications. One of the biggest challenges consists of using, in a future perspective, high intensity laser-target interaction to generate high-energy ions for therapeutic purposes, eventually replacing the old paradigm of acceleration, characterized by huge and complex machines. The peculiarities of laser-driven beams led to develop new strategies and advanced techniques for transport, diagnostics and dosimetry of the accelerated particles, due to the wide energy spread, the angular divergence and the extremely intense pulses. In this framework, the realization of the ELIMED (ELI-Beamlines MEDical applications) beamline, developed by INFN-LNS (Catania, Italy) and installed in 2017 as a part of the ELIMAIA beamline at the ELI-Beamlines (Extreme Light Infrastructure Beamlines) facility in Prague, has the aim to investigate the feasibility of using laser-driven ion beams in multidisciplinary applications. ELIMED will represent the first user's open transport beam line where a controlled laser-driven ion beam will be used for multidisciplinary and medical studies. In this paper, an overview of the beamline, with a detailed description of the main transport elements, will be presented. Moreover, a description of the detectors dedicated to diagnostics and dosimetry will be reported, with some preliminary results obtained both with accelerator-driven and laser-driven beams

    Clinical and Research Activities at the CATANA Facility of INFN-LNS: From the Conventional Hadrontherapy to the Laser-Driven Approach

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    The CATANA proton therapy center was the first Italian clinical facility making use of energetic (62 MeV) proton beams for the radioactive treatment of solid tumors. Since the date of the first patient treatment in 2002, 294 patients have been successful treated whose majority was affected by choroidal and iris melanomas. In this paper, we report on the current clinical and physical status of the CATANA facility describing the last dosimetric studies and reporting on the last patient follow-up results. The last part of the paper is dedicated to the description of the INFN-LNS ongoing activities on the realization of a beamline for the transport of laser-accelerated ion beams for future applications. The ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) project is introduced and the main scientific aspects will be described

    Event reconstruction for KM3NeT/ORCA using convolutional neural networks

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    The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino detector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower- or track-like, and the main background processes associated with the detection of atmospheric neutrinos are recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance improvements with respect to classical approaches

    Event reconstruction for KM3NeT/ORCA using convolutional neural networks

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    The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino de tector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower-or track-like, and the main background processes associated with the detection of atmospheric neutrinos are recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance improvements with respect to classical approaches

    Human dispersal of Trichinella spiralis in domesticated pigs

    Get PDF
    To investigate the human impact on the evolutionary ecology of animal pathogens, we compared genetic diversity of severe foodborne parasites contracted by eating infected pork or wild game. In particular, we characterized Trichinella spp. from twenty-eight countries and four continents by genotyping nine microsatellite loci and sequencing one-fifth of the mitochondrial genome. All specimens of Trichinella spiralis, a swine parasite that can infect many species of wildlife, were remarkably uniform across Europe, North Africa, and the Americas. Far greater diversity characterized a comparable sample of Trichinella britovi, which parasitizes various sylvatic mammals endemic to Eurasia and North-Western Africa. A limited sample of T. spiralis in Asia, where swine were first domesticated, encompassed greater genetic variability than those in the West, as did small samples of Trichinella nativa and Trichinella murrelli, which parasitize wildlife hosts. We conclude that European lineages of T. spiralis originated several thousand years ago, approximately when pigs were first domesticated there. These data also imply that Europeans inadvertently introduced T. spiralis to the Americas via infected pigs and/or rats. Despite evidence that early hominid hunters ingested foodborne parasites by hunting wild game millions of years earlier, swine husbandry has governed the subsequent transmission, dissemination, and evolutionary diversification of T. spiralis. Where viable parasites have been eliminated from their diet, the residual risk posed to swine by exposure to wildlife or rats should be more precisely defined because breaking the cycle of transmission would confer enduring economic and health benefits

    Evaluation of the stiffness characteristics of rapid palatal expander screws

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    Background: The aim of this study is to evaluate the mechanical properties of the screws used for rapid expansion of the upper jaw. Methods: Ten types of expansion screw were assessed, seven with four arms: Lancer Philosophy 1, Dentaurum Hyrax Click Medium, Forestadent Anatomic Expander type "S", Forestadent Anatomic Expander type "S" for narrow palates, Forestadent Memory, Leone A 2620-10 with telescopic guide, and Leone A 0630-10 with orthogonal arms; and three with two arms: Dentaurum Variety S.P., Target Baby REP Veltri, and Leone A 362113. A test expander with the mean dimensions taken from measurements on a sample of 100 expanders was constructed for each screw. The test expanders were connected to the supports of an Instron 4467 (Instron Corp., USA) mechanical testing machine equipped with a 500 N load cell, and the compression force exerted after each activation was measured. The mean forces expressed by the two-and four-arm expanders were then compared. Results: After five activations, the forces expressed by the two-arm devices were double than those expressed by the four-arm devices on average (224 +/- 59.9 N vs. 103 +/- 32.9 N), and such values remained high after subsequent activations. Conclusions: The expanders tested demonstrated stiffness characteristics compatible with opening of the palatine sutures in pre-adolescent patients. The stiffness of such devices can be further increased during the construction phase

    Diagnostics and dosimetry solutions for multidisciplinary applications at the ELIMAIA Beamline

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    ELI (Extreme Light Infrastructure) multidisciplinary applications of laser-ion acceleration (ELIMAIA) is one the user facilities beamlines of the ELI-Beamlines facility in Prague. It will be dedicated to the transport of laser-driven ion beams and equipped with detectors for diagnostics and dosimetry, in order to carry out experiments for a broad range of multidisciplinary applications. One of the aims of the beamline is also to demonstrate the feasibility of these peculiar beams for possible medical applications, which means delivering controllable and stable beams, properly monitoring their transport parameters and accurately measuring the dose per shot. To fulfil this task, innovative systems of charged particle beam diagnostics have been realized and alternative approaches for relative and absolute dosimetry have been proposed. Concerning the first one, real-time diagnostic solutions have been adopted, involving the use of time-of-flight techniques and Thomson parabola spectrometry for an on-line characterization of the ion beam parameters, as well as radiochromic films, nuclear track detectors (typically CR39), and image plates for single shot measurements. For beam dosimetry, real-time beam/dose monitoring detectors have been realized, like the secondary emission monitor and a double-gap ionization chamber, which can be cross calibrated against a Faraday cup, used for absolute dosimetry. The main features of these detectors are reported in this work together with a description of their working principle and some preliminary tests
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