Context. Observations of meteors in the Earth's atmosphere offer a unique tool for determining the flux of meteoroids that are too small to be detected by direct telescopic observations. Although these objects are routinely observed from ground-based facilities, such as meteor and fireball networks, space-based instruments come with notable advantages and have the potential to achieve a broad and uniform exposure. Aims. In this paper, we describe the first observations of meteor events with Mini-EUSO, a very wide field-of-view telescope launched in August 2019 from the Baikonur cosmodrome and installed on board the Russian Zvezda module of the International Space Station. Mini-EUSO can map the night-time Earth in the near-UV range (290-130 nm) with a field of view equal to 44 degrees x 44 degrees and a spatial resolution of about 4.7 km at an altitude of 100 km from the ground. The detector saves triggered transient phenomena with a sampling frequency of 2.5 mu s and 320 mu s, as well as a continuous acquisition at 40.96 ms scale that is suitable for meteor observations. Methods. We designed two dedicated and complementary trigger methods, together with an analysis pipeline able to estimate the main physical parameters of the observed population of meteors, such as the duration, horizontal speed, azimuth, and absolute magnitude. To compute the absolute flux of meteors from Mini-EUSO observations, we implemented a simulation framework able to estimate the detection efficiency as a function of the meteor magnitude and the background illumination conditions. Results. The instrument detected 24 thousand meteors within the first 40 data-taking sessions from November 2019 to August 2021, for a total observation time of approximately 6 days with a limiting absolute magnitude of +6. Our estimation of the absolute flux density of meteoroids in the range of mass between 10(-5) kg to 10(-1) kg was found to be comparable to other results available in the literature. Conclusions. The results of this work prove the potential for space-based observations to increase the statistics of meteor observations achievable with instruments operating on the ground. The slope of the mass distribution of meteoroids sampled with Mini-EUSO suggests a mass index of either s = 2.09 +/- 0.02 or s = 2.31 +/- 0.03, according to two different methodologies for the computation of the pre-atmospheric mass starting from the luminosity of each event.

We report an estimation of the injected mass composition of ultrahigh energy cosmic rays (UHECRs) at energies higher than 10 EeV. The composition is inferred from an energy-dependent sky distribution of UHECR events observed by the Telescope Array surface detector by comparing it to the Large Scale Structure of the local Universe. In the case of negligible extragalactic magnetic fields (EGMFs), the results are consistent with a relatively heavy injected composition at E similar to 10 EeV that becomes lighter up to E similar to 100 EeV, while the composition at E > 100 EeV is very heavy. The latter is true even in the presence of highest experimentally allowed extragalactic magnetic fields, while the composition at lower energies can be light if a strong EGMF is present. The effect of the uncertainty in the galactic magnetic field on these results is subdominant.

We report an estimation of the injected mass composition of ultrahigh energy cosmic rays (UHECRs) at energies higher than 10 EeV. The composition is inferred from an energy-dependent sky distribution of UHECR events observed by the Telescope Array surface detector by comparing it to the Large Scale Structure of the local Universe. In the case of negligible extragalactic magnetic fields (EGMFs), the results are consistent with a relatively heavy injected composition at E∼10  EeV that becomes lighter up to E∼100  EeV, while the composition at E>100  EeV is very heavy. The latter is true even in the presence of highest experimentally allowed extragalactic magnetic fields, while the composition at lower energies can be light if a strong EGMF is present. The effect of the uncertainty in the galactic magnetic field on these results is subdominant.

We use a new method to estimate the injected mass composition of ultrahigh cosmic rays (UHECRs) at energies higher than 10 EeV. The method is based on comparison of the energy-dependent distribution of cosmic ray arrival directions as measured by the Telescope Array (TA) experiment with that calculated in a given putative model of UHECR under the assumption that sources trace the large-scale structure (LSS) of the Universe. As we report in the companion Letter, the TA data show large deflections with respect to the LSS which can be explained, assuming small extragalactic magnetic fields (EGMF), by an intermediate composition changing to a heavy one (iron) in the highest energy bin. Here we show that these results are robust to uncertainties in UHECR injection spectra, the energy scale of the experiment and galactic magnetic fields. The assumption of weak EGMF, however, strongly affects this interpretation at all but the highest energies E > 100 EeV, where the remarkable isotropy of the data implies a heavy injected composition even in the case of strong EGMF. This result also holds if UHECR sources are as rare as 2 x 10(-5) Mpc(-3), that is the conservative lower limit for the source number density.

On 11 September 2021, two small thunderstorms developed over the Telescope Array Surface Detector (TASD) that produced an unprecedented number of six downward terrestrial gamma ray flashes (TGFs) within one-hour timeframe. The TGFs occurred during the initial stage of negative cloud-to-ground flashes whose return strokes had increasingly large peak currents up to -223 kA, 147 GeV energy deposit in up to 25 1.2 km-spaced surface detectors, and intermittent bursts of gamma-rays with total durations up to 717 mu s. The analyses are based on observations recorded by the TASD network, complemented by data from a 3D lightning mapping array, broadband VHF interferometer, fast electric field change sensor, high-speed video camera, and the National Lightning Detection Network. The TGFs of the final two flashes had gamma fluences of similar or equal to 2 x 10(14) and 8x10(14), logarithmically bridging the gap between previous TASD and satellite-based detections. The observations further emphasize the similarity between upward and downward TGF varieties, suggesting a common mechanism for their production. Plain Language Summary Terrestrial Gamma-Ray Flashes (TGFs) are high-energy lightning-produced radiation events that have primarily been detected by satellites, but are increasingly detected by ground-based instrumentation. While the upward satellite-detected events exhibit extremely high numbers of gamma photons, the downward ground-based versions observed by the Telescope Array Surface Detector have, until now, displayed much weaker numbers by orders of magnitude. In this paper, we report observations of downward TGFs obtained at the large-area cosmic ray detector Telescope Array facility in west-central Utah, showing strengths midway between previously detected downward TGFs and upward satellite-detected events. The results indicate that TGFs span a wide range of fluences, a finding further supported by recent airborne observations over storm tops.

Background: The situation of Helicobacter pylori eradication therapy has been changing over time, owing to increases in antimicrobial-resistant strains, lifestyle improvements, and changes in indications for eradication. In Japan, eradication therapy is now available to all H. pylori-positive patients under the medical insurance system, and the potassium-competitive acid blocker vonoprazan has been used for eradication from 2015. Recently, with the aging of society, opportunities to provide eradication to elderly patients are increasing, but the current status and effectiveness of eradication in elderly patients remains unclear. Therefore, we aimed to investigate the trends of H. pylori eradication in a metropolitan area to determine the factors associated with successful H. pylori eradication in elderly patients older than 80 years. Methods: Trends in the eradication rates of patients who received first- or second-line eradication at 20 hospitals in the Tokyo metropolitan area from 2013 to 2023 were investigated. Results: The eradication rates in the per-protocol analysis were 82.3% (95% confidence interval [CI]: 81.2%-83.2%) for the first-line treatment (n = 6481), and 87.9% (86.9%-88.9%) for the second-line treatment (n = 4899). Multivariate analysis showed that independent factors for successful eradication in the first-line treatment were an age of older than 80 years (OR: 0.606; 95% CI: 0.448-0.822), peptic ulcers (vs. atrophic gastritis: 3.817; 3.286-4.433), and vonoprazan (vs. proton pump inhibiters (PPIs), 3.817; 3.286-4.433), and an age of older than 80 years (0.503; 0.362-0.699) and vonoprazan (1.386; 1.153-1.667) in the second-line treatment. Conclusion: After 2015, the eradication rate of both first- and second-line therapies were maintained at a higher level than before 2015, owing to the use of vonoprazan. As the H. pylori eradication rate in patients older than 80 years was low, an effective strategy for these patients needs to be developed in the future.

More than three dozen submillisecond events of ELVES type (“elves”), which are the result of the interaction of the front of an electromagnetic pulse from a lightning discharge and the lower layer of the ionosphere, have been identified in the data of a UV Atmosphere orbital multichannel detector (Mini-EUSO). Each event has a characteristic annular glow pattern and occupies a significant part of the detector’s field of view, and the signal in a separate channel has an asymmetric profile with a pronounced peak. The distribution of peak times contains information about both the localization of the discharge and the altitude of the glow. In this paper, we propose a Bayesian (probabilistic) model for reconstructing ELVES events, implemented using probabilistic programming methods in PyMC-5. The capabilities of the model for determining the position of the discharge are shown using the example of several events. Methods for modifying the model to restore the discharge orientation and refine the glow height are outlined.

Optical emissions associated with Terrestrial Gamma-ray Flashes (TGFs) have recently become important subjects in space-based and ground-based observations since these emissions play crucial roles in understanding the generation of TGFs during thunderstorms. In this paper, we present the first time-resolved leader spectra of the optical component associated with a downward TGF. The TGF was observed at the Telescope Array Surface Detector (TASD) simultaneously with other lightning detectors, including a Lightning Mapping Array (LMA), an INTerFerometer (INTF), a Fast Antenna (FA), and a spectroscopic system. The spectroscopic system recorded leader spectra at 29,900 frames per second (33.44 $\mu$s time resolution), covering a spectral range from 400 nm to 900 nm, with 2.1 nm per pixel. The recordings of the leader spectra began 11.7 ms before the $-18$ kA return stroke and at a height of 2.37 km above the ground. These spectra reveal that optical emissions of singly-ionized nitrogen and oxygen occur between 167 $\mu$s before and 267 $\mu$s after the TGF detection, while optical emissions of neutrals (H I, 656 nm; N I, 744 nm, and O I, 777 nm) occur right at the moment of the detection. The time-dependent spectra reveal differences in the optical emissions of lightning leaders with and without downward TGFs.

The complexity of modern cosmic ray observatories and the rich data sets they capture often require a sophisticated software framework to support the simulation of physical processes, detector response, as well as reconstruction and analysis of real and simulated data. Here we present the EUSO-(Off) over bar(line) under bar framework. The code base was originally developed by the Pierre Auger Collaboration, and portions of it have been adopted by other collaborations to suit their needs. We have extended this software to fulfill the requirements of Ultra-High Energy Cosmic Ray detectors and very high energy neutrino detectors developed for the Joint Exploratory Missions for an Extreme Universe Observatory (JEM-EUSO). These path-finder instruments constitute a program to chart the path to a future space-based mission like POEMMA. For completeness, we describe the overall structure of the framework developed by the Auger collaboration and continue with a description of the JEM-EUSO simulation and reconstruction capabilities. The framework is written predominantly in modern C++ (compliled against C++17) and incorporates third-party libraries chosen based on functionality and our best judgment regarding support and longevity. Modularity is a central notion in the framework design, a requirement for large collaborations in which many individuals contribute to a common code base and often want to compare different approaches to a given problem. For the same reason, the framework is designed to be highly configurable, which allows us to contend with a variety of JEM-EUSO missions and observation scenarios. We also discuss how we incorporate broad, industry-standard testing coverage which is necessary to ensure quality and maintainability of a relatively large code base, and the tools we employ to support a multitude of computing platforms and enable fast, reliable installation of external packages. Finally, we provide a few examples of simulation and reconstruction applications using EUSO-(Off) over bar(line) under bar.

The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33~km). After 12~days and 4~hours aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of approximately 3 EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search.

EUSO-TA is a ground-based fluorescence telescope built to validate the design of ultra-high energy cosmic ray fluorescence detectors to be operated in space with the technology developed within the Joint Exploratory Missions for Extreme Universe Space Observatory (JEM-EUSO) program. It operates at the Telescope Array (TA) site in Utah, USA. With an external trigger provided by the Black Rock Mesa fluorescence detectors of the Telescope Array experiment, with EUSO-TA we observed air-showers from ultra-high energy cosmic rays, as well as laser events from the Central Laser Facility at the TA site and from portable lasers like the JEM-EUSO Global Light System prototype. Since the Black Rock Mesa fluorescence detectors have a ∼30 times larger field of view than EUSO-TA, they allow a primary energy reconstruction based on the observation of a large part of the shower evolution, including the shower maximum, while EUSO-TA observes only a part of it, usually far away from the maximum. To estimate the detection limits of EUSO-TA in energy and distance, a method was developed to re-scale their energy, taking into account that EUSO-TA observes only a portion of the air-showers. The method was applied on simulation sets with showers with different primaries, energy, direction, and impact point on the ground, as well as taking into account the experimental environment. EUSO-TA was simulated with an internal trigger and different elevation angles and electronics. The same method was then applied also to real measurements and compared to the simulations. In addition, the method can also be used to estimate the detection limits for experiments that are operated at high altitudes and in most cases can see the maximum of the showers. This was done for EUSO-SPB1, an instrument installed on a super-pressure balloon. Finally, the expected detection rates for EUSO-TA were also assessed using the prepared simulated event sets. The rates correspond to a few detections per recording session of 30 h of observation, depending on the background level and the configuration of the detector.

We report on an observation of the difference between northern and southern skies of the ultrahigh energy cosmic ray energy spectrum with a significance of ∼8σ. We use measurements from the two largest experimentsx2014the Telescope Array observing the northern hemisphere and the Pierre Auger Observatory viewing the southern hemisphere. Since the comparison of two measurements from different observatories introduces the issue of possible systematic differences between detectors and analyses, we validate the methodology of the comparison by examining the region of the sky where the apertures of the two observatories overlap. Although the spectra differ in this region, we find that there is only a 1.8σ difference between the spectrum measurements when anisotropic regions are removed and a fiducial cut in the aperture is applied.

The data have been acquired with the Mini-EUSO detector, an UV telescope operating in the range 290-430 nm and located inside the International Space Station. The detector was launched in August 2019, and it has started operations from the nadir-facing UV-transparent window in the Russian Zvezda module in October 2019. The data presented here refer to 32 sessions acquired between 2019-11-19 and 2021-05-06. The instrument consists of a Fresnel-lens optical system and a focal surface composed of 36 multi-anode photomultiplier tubes, each with 64 channels, for a total of 2304 channels with single photon counting sensitivity. The telescope, with a square field-of-view of 44 degrees, has a spatial resolution on the Earth surface of 6.3 km and saves triggered transient phenomena with a temporal resolution of 2.5 mu s and 320 mu s. The telescope also operates in continuous acquisition at a 40.96 ms scale. In this article, large-area night-time UV maps obtained processing the 40.96 ms data, taking averages over regions of some specific geographical areas (e.g., Europe, North America) and over the entire globe, are presented. Data are binned into 0.1 degrees x 0.1 degrees or 0.05 degrees x 0.05 degrees cells (depending on the scale of the map) over the Earth's surface. Raw data are made available in the form of tables (latitude, longitude, counts) and.kmz files (containing the.png images). These are - to the best of our knowledge - the highest sensitivity data in this wavelength range and can be of use to various disciplines. (C) 2023 The Author(s). Published by Elsevier Inc.

This is a collection of papers presented by the JEM-EUSO Collaboration at the 38th International Cosmic Ray Conference (Nagoya, Japan, July 26-August 3, 2023)

JEM-EUSO is an international program for the development of space-based Ultra-High Energy Cosmic Ray observatories. The program consists of a series of missions which are either under development or in the data analysis phase. All instruments are based on a wide-field-of-view telescope, which operates in the near-UV range, designed to detect the fluorescence light emitted by extensive air showers in the atmosphere. We describe the simulation software ESAF in the framework of the JEM-EUSO program and explain the physical assumptions used. We present here the implementation of the JEM-EUSO, POEMMA, K-EUSO, TUS, Mini-EUSO, EUSO-SPB1 and EUSO-TA configurations in ESAF. For the first time ESAF simulation outputs are compared with experimental data.

The Telescope Array (TA) Cosmic Ray Observatory is the largest cosmic ray detector in the northern hemisphere. TA was built to study ultra-high-energy cosmic rays (UHECRs), cosmic rays with energies above 1018 eV. TA is a hybrid detector, employing two distinct detection methods: a surface detector array and a set of fluorescence telescopes. We will present a measurement of the cosmic ray energy spectrum for energies above 1017.5 eV using only the fluorescence telescopes. A novel weather classification scheme using machine learning was used to select data parts with good weather to ensure the quality of the fluorescence data. The data from the Black Rock Mesa (BRM) and Long Ridge (LR) fluorescence telescope sites were analyzed separately in monocular mode, with the calculated fluxes combined into a single spectrum. The 10-year monocular combined cosmic ray energy spectrum is observed to be in excellent agreement with previous measurements from the northern hemisphere. We present fits of the combined spectrum to a series of broken power law models. The thrice-broken power law was observed to be the best fit considering the Poisson deviance per degrees of freedom. The three breaks suggest an additional feature of the spectrum between the previously observed Ankle feature at 1018.7 eV and the GZK suppression at 1019.8 eV.

In this paper, we present the first high-speed video observation of a cloud-to-ground lightning flash and its associated downward-directed Terrestrial Gamma-ray Flash (TGF). The optical emission of the event was observed by a high-speed video camera running at 40,000 frames per second in conjunction with the Telescope Array Surface Detector, Lightning Mapping Array, interferometer, electric-field fast antenna, and the National Lightning Detection Network. The cloud-to-ground flash associated with the observed TGF was formed by a fast downward leader followed by a very intense return stroke peak current of -154 kA. The TGF occurred while the downward leader was below cloud base, and even when it was halfway in its propagation to ground. The suite of gamma-ray and lightning instruments, timing resolution, and source proximity offer us detailed information and therefore a unique look at the TGF phenomena.

The Trigger Logic (TL) of the Tracking Ultraviolet Setup (TUS) and Multiwavelength Imaging New Instrument for the Extreme Universe Space Observatory (Mini-EUSO) space-based projects of the Joint Experiment Missions-EUSO (JEM-EUSO) program is summarized. The performance results on the search for Ultra-High Energy Cosmic Rays (UHECRs) are presented.

Mini-EUSO is a high-sensitivity imaging telescope that observes the Earth from the ISS in the near ultraviolet band (290 ÷ 430 nm), through the nadir-facing, UV-transparent window in the Russian Zvezda module. The instrument, launched in 2019, has a field of view of 44 ^∘ , a spatial resolution on the Earth’s surface of 6.3 km and a temporal sampling rate of 2.5 microseconds. Thanks to its triggering and on-board processing, the telescope is capable of detecting UV emissions of cosmic, atmospheric, and terrestrial origin on different time scales, from a few microseconds up to tens of milliseconds. The optics is composed of two Fresnel lenses focusing light onto an array of 36 Hamamatsu Multi-Anode PhotoMultiplier Tubes, for a total of 2304 pixels. The telescope also contains two cameras in the near-infrared and visible, an 8-by-8 array of Silicon-PhotoMultipliers and a series of UV sensors to manage night-day transitions. The scientific objectives range from the observation of atmospheric phenomena [lightning, Transient Luminous Events (TLEs), ELVES], the study of meteoroids, the search of interstellar meteoroids and strange quark matter, mapping of the Earth’s nocturnal emissions in the ultraviolet range, and the search of cosmic rays with energy above 10 ^21 eV. The instrument has been integrated and qualified in 2019, with the final tests in Baikonur prior to its launch. Operations involve periodic installation in the Zvezda module of the station with observations during the crew night time, with periodic downlink of data samples, with the full data being sent to the ground via pouches containing the data disks. Mission planning involves the selection of the optimal orbits to maximize the scientific return of the instrument. In this work, we will describe the various phases of construction, testing, and qualification prior to the launch and the in-flight operations of the instrument on board the ISS.