► Tiller appearance rate and maximum tiller number was higher in barley than in wheat. ► Increases in the N and S levels at soil promoted those effects. ► Final tiller number was closely related to ...maximum tiller number. ► Final tiller number was pre-defined during the early phase of the tillering process. ► Barley showed higher values of tiller initiated per leaf appeared (synchrony) than wheat.
It is traditionally assumed that barley has a higher tillering capacity than wheat whatever the environmental condition; however, this supposition has not been formally tested under experimental conditions nor analyzed its relationship with leaf appearance. In the present work, leaf appearance and tillering dynamics were studied in wheat and barley genotypes grown under contrasting nitrogen and sulfur levels at sowing. There was no difference in phenology (seedling emergence, first visible node and flowering) between wheat and barley or due to different nutrients. Phyllochron in barley tended to be higher than (or at least equal to) that observed in wheat, without effect of the N or S levels on this trait. Differences in final leaf number were negligible. Tillering dynamics was analyzed considering the tillering appearance rate (TAR), the maximum number of tillers appeared (MTN), the tillering mortality rate (TMR), and the final number of tillers per plant (FTN). TAR was significantly greater in barley than in wheat genotypes in all experiments. In both species, TAR was enhanced as N supply was increased while S promoted TAR only under high N conditions. The MTN was positively and significantly associated with TAR. Although cessation of tillering was similar between both species, the maximum number of tillers was superior in barley than in wheat, due to the differences between species in tiller appearance rate. A high MTN was related to a high tiller mortality rate. In spite of that counterbalance, FTN was closely related to MTN; as a consequence, FTN was pre-defined during the early phase of the tillering process. Barley showed higher values of tiller initiated per leaf appeared (synchrony) than wheat, while N and S deficiencies decreased that synchrony.
The First Level Trigger of JEM-EUSO: Concept and tests Bertaina, M.; Caruso, R.; Catalano, O. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Volume:
824
Journal Article
Peer reviewed
Open access
The trigger system of JEM-EUSO is designed to meet specific challenging requirements. These include managing a large number of pixels (~3·105) and using a very fast, low power consuming, and ...radiation hard electronics. It must achieve a high signal-to-noise performance and flexibility and cope with the limited down-link transmission rate from the International Space Station (ISS) to Earth. The general overview of the First Level Trigger for cosmic ray detection is reviewed; tests that validate its performance are discussed.
Mini-EUSO is part of the JEM-EUSO program and operates on board the International Space Station (ISS). It is a UV-telescope with single-photon counting capability looking at nighttime downwards to ...the Earth through a nadir-facing UV-transparent window. As part of the pre-flight tests, the Mini-EUSO engineering model, a telescope with 1/9 of the original focal surface and a lens of 2.5 cm diameter, has been built and tested. Tests of the Mini-EUSO engineering model have been made in laboratory and in open-sky conditions. Laboratory tests have been performed at the TurLab facility, located at the Physics Department of the University of Turin, equipped with a rotating tank containing different types of materials and light sources. In this way, the configuration for the observation of the Earth from space was emulated, including the Mini-EUSO trigger schemes. In addition to the qualification and calibration tests, the Mini-EUSO engineering model has also been used to evaluate the possibility of using a JEM-EUSO-type detector for applications such as observation of space debris. Furthermore, observations in open-sky conditions allowed the studies of natural light sources such as stars, meteors, planets, and artificial light sources such as airplanes, satellites reflecting the sunlight, and city lights. Most of these targets could be detected also with Mini-EUSO. In this paper, the tests in laboratory and in open-sky conditions are reported, as well as the obtained results. In addition, the contribution that such tests provided to foresee and improve the performance of Mini-EUSO on board the ISS is discussed.
The EUSO@TurLab project aims at performing experiments to reproduce Earth UV emissions as seen from a low Earth orbit by the planned missions of the JEM-EUSO program. It makes use of the TurLab ...facility, which is a laboratory, equipped with a 5 m diameter and 1 m depth rotating tank, located at the Physics Department of the University of Turin. All the experiments are designed and performed based on simulations of the expected response of the detectors to be flown in space. In April 2016 the TUS detector and more recently in October 2019 the Mini-EUSO experiment, both part of the JEM-EUSO program, have been placed in orbit to map the UV Earth emissions. It is, therefore, now possible to compare the replicas performed at TurLab with the actual images detected in space to understand the level of fidelity in terms of reproduction of the expected signals. We show that the laboratory tests reproduce at the order of magnitude level the measurements from space in terms of spatial extension and time duration of the emitted UV light, as well as the intensity in terms of expected counts per pixel per unit time when atmospheric transient events, diffuse nightlow background light, and artificial light sources are considered. Therefore, TurLab is found to be a very useful facility for testing the acquisition logic of the detectors of the present and future missions of the JEM-EUSO program and beyond in order to reproduce atmospheric signals in the laboratory.
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.
Micro Pattern Gas Detectors (MPGD) are the new frontier in gas trackers. Among this kind of devices, the Gas Electron Multiplier (GEM) chambers are widely used. The experimental signals acquired with ...the detector must obviously be reconstructed and analysed. In this contribution, a new offline software to perform reconstruction, alignment and analysis on the data collected with APV-25 and TIGER ASICs will be presented. GRAAL (Gem Reconstruction And Analysis Library) is able to measure the performance of a MPGD detector with a strip segmented anode (presently). The code is divided in three parts: reconstruction, where the hits are digitized and clusterized; tracking, where a procedure fits the points from the tracking system and uses that information to align the chamber with rotations and shifts; analysis, where the performance is evaluated (e.g. efficiency, spatial resolution,etc.). The user must set the geometry of the setup and then the program returns automatically the analysis results, taking care of different conditions of gas mixture, electric field, magnetic field, geometries, strip orientation, dead strip, misalignment and many others.
The experiment BESIII, running at the accelerator BEPCII in Beijing (P.R.C.), is going to be updated with the replacement of the Inner Drift Chamber with a Cylindrical triple-GEM Inner Tracker ...(CGEM-IT). In the R&D stage, two standalone C++ codes were implemented: GTS (Garfield-based Triple-GEM Simulator), for digitization and tuning of simulated data to the experimental ones, and GRAAL (GEM Reconstruction And Analysis Library), for the reconstruction and analysis of the experimental events collected in testbeams. GTS simulates the triple-GEM response to the particle passage, treating each stage separately: ionization, GEM properties, gas mixture, magnetic field and finally the induction of the signal on the anode. The necessary information was extracted by GARFIELD++ simulations, parametrized and used as input in GTS. This speeds up the simulation, since GTS performs only samplings instead of the full digitization chain. The simulated events were reconstructed with the same procedure used for experimental data and tuning factors were evaluated to obtain a satisfactory match. GRAAL is used in the analysis of the testbeam experimental data. It provides several levels of reconstruction: from the cluster formation, gathering contiguous firing strips, to the spatial position and the signal time reconstruciton. Two algorithms are used: the charge centroid and the micro-TPC, which exploit the charge deposition on the strips and the time information. Also a merging of the two algorithms is available to efficiently weight the two outcomes and obtain the best estimate of the spatial coordinate. Moreover, GRAAL performs tracking and alignment. Both codes are going to be made available also for other MPGDs simulation and reconstruction.
Triple-GEM detectors are a well known technology in high energy physics. In order to have a complete understanding of their behavior, in parallel with on beam testing, a Monte Carlo code has to be ...developed to simulate their response to the passage of particles. The software must take into account all the physical processes involved from the primary ionization up to the signal formation, e.g. the avalanche multiplication and the effect of the diffusion on the electrons. In the case of gas detectors, existing software such as Garfield already perform a very detailed simulation but are CPU time consuming. A description of a reliable but faster simulation is presented here: it uses a parametric description of the variables of interest obtained by suitable preliminary Garfield simulations and tuned to the test beam data. It can reproduce the real values of the charge measured by the strip, needed to reconstruct the position with the Charge Centroid method. In addition, particular attention was put to the simulation of the timing information, which permits to apply also the micro-Time Projection Chamber position reconstruction, for the first time on a triple-GEM. A comparison between simulation and experimental values of some sentinel variables in different conditions of magnetic field, high voltage settings and incident angle will be shown.
THE AUGURAL CONTEST AT ROME MIGNONE, L. M.
Classical philology,
10/2016, Volume:
111, Issue:
4
Journal Article
Peer reviewed
The contest of the augeries between Romulus and Remus determined what age could not: it was left to the birds to indicate which of the twins would found and name their new city and where. The hill on ...which Remus' auguraculum stood became in some respects a monument to his dashed hopes. Until Claudius' extension in 49 CE, the pomerium, the sacred circuit that delimited Rome's urban auspices, excluded the Aventine--and the Aventine alone of Rome's seven hills. Here, Mignon examines this augural content at Rome.
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