A high-precision interpolation method for pulsed radio signals from cosmic-ray air showers

Analysis of radio signals from cosmic-ray induced air showers has been shown to be a reliable method to extract shower parameters such as primary energy and depth of shower maximum. The required detailed air shower simulations take 1 to 3 days of CPU time per shower for a few hundred antennas. With nearly $60,000$ antennas envisioned to be used for air shower studies at the Square Kilometre Array (SKA), simulating all of these would come at unreasonable costs. We present an interpolation algorithm to reconstruct the full pulse time series at any position in the radio footprint, from a set of antennas simulated on a polar grid. Relying on Fourier series representations and cubic splines, it significantly improves on existing linear methods. We show that simulating about 200 antennas is sufficient for high-precision analysis in the SKA era, including e.g. interferometry which relies on accurate pulse shapes and timings. We therefore propose the interpolation algorithm and its implementation as a useful extension of radio simulation codes, to limit computational effort while retaining accuracy.Comment: 19 pages, 12 figures. Submitted for publication in JINST (Journal of Instrumentation

A high-precision interpolation method for pulsed radio signals from cosmic-ray air showers

Analysis of radio signals from cosmic-ray induced air showers has been shown to be a reliable method to extract shower parameters such as primary energy and depth of shower maximum. The required detailed air shower simulations take 1 to 3 days of CPU time per shower for a few hundred antennas. With nearly 60,000 antennas envisioned to be used for air shower studies at the Square Kilometre Array (SKA), simulating all of these would come at unreasonable costs. We present an interpolation algorithm to reconstruct the full pulse time series at any position in the radio footprint, from a set of antennas simulated on a polar grid. Relying on Fourier series representations and cubic splines, it significantly improves on existing linear methods. We show that simulating about 200 antennas is sufficient for high-precision analysis in the SKA era, including e.g. interferometry which relies on accurate pulse shapes and timings. We therefore propose the interpolation algorithm and its implementation as a useful extension of radio simulation codes, to limit computational effort while retaining accuracy

Using pulse-shape information for reconstructing cosmic-ray air showers and validating antenna responses with LOFAR and SKA

The Low Frequency Array (LOFAR) is capable of measuring extensive air showers through their radio emission in the frequency range of 30–80 MHz, while the Square Kilometer Array (SKA) will be able to expand this range to 50–350 MHz. A very important characteristic of cosmic rays is the mass of the primary particle, which is associated with the atmospheric depth of the shower maximum (max). The standard max reconstruction procedure with LOFAR involves the use of a library of CORSIKA/CoREAS simulations for a specific measured event and uses the energy deposited to the ground in terms of radio fluence. In this study, to extract information about shower development, not only the energy fluence is considered but the possibility of using information from the pulse shape is investigated in both frequency ranges (30–80 MHz and 50–350 MHz). The study of the pulse shape through the pulse agreement of measured data and simulations also provides a way to diagnose the proper functioning of individual LOFAR dipoles

A standardised model for stool banking for faecal microbiota transplantation : a consensus report from a multidisciplinary UEG working group

Background Faecal microbiota transplantation is an emerging therapeutic option, particularly for the treatment of recurrent Clostridioides difficile infection. Stool banks that organise recruitment and screening of faeces donors are being embedded within the regulatory frameworks described in the European Union Tissue and Cells Directive and the technical guide to the quality and safety of tissue and cells for human application, published by the European Council. Objective Several European and international consensus statements concerning faecal microbiota transplantation have been issued. While these documents provide overall guidance, we aim to provide a detailed description of all processes that relate to the collection, handling and clinical application of human donor stool in this document. Methods Collaborative subgroups of experts on stool banking drafted concepts for all domains pertaining to stool banking. During a working group meeting in the United European Gastroenterology Week 2019 in Barcelona, these concepts were discussed and finalised to be included in our overall guidance document about faecal microbiota transplantation. Results A guidance document for all domains pertaining to stool banking was created. This document includes standard operating manuals for several processes involved with stool banking, such as handling of donor material, storage and donor screening. Conclusion The implementation of faecal microbiota transplantation by stool banks in concordance with our guidance document will enable quality assurance and guarantee the availability of donor faeces preparations for patients.Peer reviewe

Precision measurement of the index of refraction of deep glacial ice at radio frequencies at Summit Station, Greenland

Glacial ice is used as a target material for the detection of ultra-high energy neutrinos, by measuring the radio signals that are emitted when those neutrinos interact in the ice. Thanks to the large attenuation length at radio frequencies, these signals can be detected over distances of several kilometers. One experiment taking advantage of this is the Radio Neutrino Observatory Greenland (RNO-G), currently under construction at Summit Station, near the apex of the Greenland ice sheet. These experiments require a thorough understanding of the dielectric properties of ice at radio frequencies. Towards this goal, calibration campaigns have been undertaken at Summit, during which we recorded radio reflections off internal layers in the ice sheet. Using data from the nearby GISP2 and GRIP ice cores, we show that these reflectors can be associated with features in the ice conductivity profiles; we use this connection to determine the index of refraction of the bulk ice as n=1.778 +/- 0.006

A high-precision interpolation method for pulsed radio signals from cosmic-ray air showers

Analysis of radio signals from cosmic-ray induced air showers has been shown to be a reliable method to extract shower parameters such as primary energy and depth of shower maximum.The required detailed air shower simulations take 1 to 3 days of CPU time per shower for a few hundred antennas.With nearly 60,000 antennas envisioned to be used for air shower studies at the Square Kilometre Array (SKA), simulating all of these would come at unreasonable costs.We present an interpolation algorithm to reconstruct the full pulse time series at any position in the radio footprint, from a set of antennas simulated on a polar grid.Relying on Fourier series representations and cubic splines, it significantly improves on existing linear methods.We show that simulating about 200 antennas is sufficient for high-precision analysis in the SKA era, including e.g. interferometry which relies on accurate pulse shapes and timings.We therefore propose the interpolation algorithm and its implementation as a useful extension of radio simulation codes, to limit computational effort while retaining accuracy

The use of Faecal Microbiota Transplantation (FMT) in Europe : A Europe-wide survey

Publisher Copyright: © 2021 The AuthorsBackground: Faecal microbiota transplantation (FMT) is an emerging treatment modality, but its current clinical use and organisation are unknown. We aimed to describe the clinical use, conduct, and potential for FMT in Europe. Methods: We invited all hospital-based FMT centres within the European Council member states to answer a web-based questionnaire covering their clinical activities, organisation, and regulation of FMT in 2019. Responders were identified from trials registered at clinicaltrials.gov and from the United European Gastroenterology (UEG) working group for stool banking and FMT. Findings: In 2019, 31 FMT centres from 17 countries reported a total of 1,874 (median 25, quartile 10–64) FMT procedures; 1,077 (57%) with Clostridioides difficile infection (CDI) as indication, 791 (42%) with experimental indications, and 6 (0•3%) unaccounted for. Adjusted to population size, 0•257 per 100,000 population received FMT for CDI and 0•189 per 100,000 population for experimental indications. With estimated 12,400 (6,100–28,500) annual cases of multiple, recurrent CDI and indication for FMT in Europe, the current European FMT activity covers approximately 10% of the patients with indication. The participating centres demonstrated high safety standards and adherence to international consensus guidelines. Formal or informal regulation from health authorities was present at 21 (68%) centres. Interpretation: FMT is a widespread routine treatment for multiple, recurrent CDI and an experimental treatment. Embedded within hospital settings, FMT centres operate with high standards across Europe to provide safe FMT. A significant gap in FMT coverage suggests the need to raise clinical awareness and increase the FMT activity in Europe by at least 10-fold to meet the true, indicated need. Funding: NordForsk under the Nordic Council and Innovation Fund Denmark (j.no. 8056–00006B).Peer reviewe