Sugars and circadian regulation make major contributions to the global regulation of diurnal gene expression in Arabidopsis

The diurnal cycle strongly influences many plant metabolic and physiological processes. Arabidopsis thaliana rosettes were harvested six times during 12-h-light/12-h-dark treatments to investigate changes in gene expression using ATH1 arrays. Diagnostic gene sets were identified from published or in-house expression profiles of the response to light, sugar, nitrogen, and water deficit in seedlings and 4 h of darkness or illumination at ambient or compensation point [CO2]. Many sugar-responsive genes showed large diurnal expression changes, whose timing matched that of the diurnal changes of sugars. A set of circadian-regulated genes also showed large diurnal changes in expression. Comparison of published results from a free-running cycle with the diurnal changes in Columbia-0 (Col-0) and the starchless phosphoglucomutase (pgm) mutant indicated that sugars modify the expression of up to half of the clock-regulated genes. Principle component analysis identified genes that make large contributions to diurnal changes and confirmed that sugar and circadian regulation are the major inputs in Col-0 but that sugars dominate the response in pgm. Most of the changes in pgm are triggered by low sugar levels during the night rather than high levels in the light, highlighting the importance of responses to low sugar in diurnal gene regulation. We identified a set of candidate regulatory genes that show robust responses to alterations in sugar levels and change markedly during the diurnal cycle

Hawberry (Crataegus monogyna Jaqc.) extracts inhibit lipid oxidation and improve consumer liking of ready-to-eat (RTE) pork patties

The objective of this work was to study the effectiveness of extracts from hawberry (Crataegus monogyna Jacq.) to inhibit lipid oxidation and odor deterioration during processing of ready-to-eat (RTE) pork patties subjected to roasting (180 °C/16 min), chilling (10 days/+3 °C) and reheating in microwave (600 mW/1 min). Acetone extracts of hawberry were chosen based on their total phenolic content (1281.1 ± 84.8 mg gallic acid equivalent (GAE)/100 g fruit) and in vitro antiradical activity (DPPH) (53.33 ± 15.40 g equivalent Trolox per g of fruits). Pork patties treated with increasing concentrations of hawberry extract, 200 and 800 ppm GAE (T2 and T8, respectively) and a control group (T0) of samples, were analyzed for TBARS, volatile carbonyls and odor liking in a consumer test. Hawberry extracts significantly improved the oxidative stability of cooked pork patties keeping TBARS and hexanal counts at basal levels during the whole process. The addition of hawberry phenolic-rich extracts significantly improved the degree of consumer satisfaction regarding the odor of patties. In conclusion, the hawberry extract displayed potential usage as an ingredient with antioxidant properties for the manufacture of high-quality RTE meat products. © 2017, Association of Food Scientists & Technologists (India)

Relevance of the fluorescence radiation in VHE gamma-ray observations with the Cherenkov technique

Atmospheric fluorescence is usually neglected in the reconstruction of the signals registered by Cherenkov telescopes, both IACTs and wide-angle detector arrays. In this paper we quantify the fluorescence contribution to the total light recorded in typical observational configurations. To this end we have implemented the production and tracking of fluorescence light in the CORSIKA code. Both the Cherenkov and fluorescence light distributions on ground (2200 m a.s.I.) have been simulated for gamma-ray showers in a wide energy range (10(-1) - 10(3) TeV). The relative fluorescence contribution has been evaluated as a function of the shower energy and zenith angle. Our results indicate that at distances from the impact point smaller than 200 m the fluorescence contamination is negligible in both types of telescopes. However, at about 1000 m, the contamination in IACTs is around 5%. At these core distances, the signals recorded by wide-angle detectors contain around 45% of atmospheric fluorescence in the PeV region. (C) 2018 Elsevier B.V. All rights reserved

Gamma-ray observations of MAXI J1820+070 during the 2018 outburst

Artículo firmado por 443 autores. MAGIC acknowledgements: MAGIC would like to thank the Instituto de Astrofisica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF, MPG, and HGF; the Italian INFN and INAF; the Swiss National Fund SNF; the grants PID2019-104114RB-C31, PID2019-104114RB-C32, PID2019-104114RB-C33, PID2019-105510GB-C31, PID2019-107847RB-C41, PID2019-107847RB-C42, PID2019-107847RB-C44, PID2019-107988GB-C22 funded by MCIN/AEI/ 10.13039/501100011033; the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-400/18.12.2020 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also been supported by Centros de Excelencia 'Severo Ochoa' y Unidades 'Maria de Maeztu' program of the MCIN/AEI/ 10.13039/501100011033 (SEV-2016-0588, SEV-2017-0709, CEX2019-000920-S, CEX2019-000918-M, MDM-2015-0509-18-2) and by the CERCA institution of the Generalitat de Catalunya; by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project uniri-prirod-18-48; by the DFG Collaborative Research Centers SFB1491 and SFB876/C3; the Polish Ministry Of Education and Science grant No. 2021/WK/08; and by the Brazilian MCTIC, CNPq and FAPERJ. H.E.S.S. acknowledgements: the support of the Namibian authorities and of the University of Namibia in facilitating the construction and operation of H.E.S.S. is gratefully acknowledged, as is the support by the German Ministry for Education and Research (BMBF), the Max Planck Society, the German Research Foundation (DFG), the Helmholtz Association, the Alexander von Humboldt Foundation, the French Ministry of Higher Education, Research and Innovation, the Centre National de la Recherche Scientifique (CNRS/IN2P3 and CNRS/INSU), the Commissariat a l'energie atomique et aux energies alternatives (CEA), the U.K. Science and Technology Facilities Council (STFC), the Irish Research Council (IRC) and the Science Foundation Ireland (SFI), the Knut and Alice Wallenberg Foundation, the Polish Ministry of Education and Science, agreement no. 2021/WK/06, the South African Department of Science and Technology and National Research Foundation, the University of Namibia, the National Commission on Research, Science & Technology of Namibia (NCRST), the Austrian Federal Ministry of Education, Science and Research and the Austrian Science Fund (FWF), the Australian Research Council (ARC), the Japan Society for the Promotion of Science, the University of Amsterdam and the Science Committee of Armenia grant 21AG-1C085. We appreciate the excellent work of the technical support staff in Berlin, Zeuthen, Heidelberg, Palaiseau, Paris, Saclay, Tubingen and in Namibia in the construction and operation of the equipment. This work benefited from services provided by the H.E.S.S. Virtual Organisation, supported by the national resource providers of the EGI Federation. VERITAS acknowledgements: VERITAS is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation and the Smithsonian Institution, by NSERC in Canada, and by the Helmholtz Association in Germany. This research used resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy's Office of Science, and resources of the National Energy Research Scientific Computing Center (NERSC), a U.S.; Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and at the collaborating institutions in the construction and operation of the instrument. We would also like to thank the referee for his/her constructive and useful comments, which were helpful to improve the manuscript. E. Molina acknowledges support from MCIN through grant BES-2016-076342. V. Bosch-Ramon acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science and Innovation under grant PID2019-105510GB-C31 and through the 'Unit of Excellence Maria de Maeztu 2020-2023 award to the Institute of Cosmos Sciences (CEX2019-000918-M). V. Bosch-Ramon is Correspondent Researcher of CONICET, Argentina, at the IAR. M. Linares has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 101002352). G. Sala acknowledges support from the Spanish MINECO grant PID2020-117252GB-I00. We acknowledge the Fermi-LAT collaboration for making available the data and the analysis tools used in this work. This research has made use of MAXI data provided by RIKEN, JAXA, and the MAXI team. This work also made use of data supplied by the UK Swift Science Data Centre at the University of Leicester. We also used data from the The Joan Oro Telescope (TJO) of the Montsec Astronomical Observatory (OAdM), which is owned by the Catalan Government and operated by the Institute for Space Studies of Catalonia (IEEC). We would also like to thank Sera Markoff, Phil Uttley, and our colleagues from the X-ray, optical/infrared, and radio communities, for the very fruitful exchanges we had on MAXI J1820+070 during the observational campaign.MAXIJ1820+070 is a low-mass X-ray binary with a black hole (BH) as a compact object. This binary underwent an exceptionally bright X-ray outburst from 2018 March to October, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 h of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy (HE) gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to similar to 500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential HE and very-HE gamma-ray emitting region should be located at a distance from the BH ranging between 10(11) and 10(13) cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA.Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEGerman BMBFGerman MPGGerman HGFItalian INFNItalian INAFSwiss National Fund SNFMCIN/AEIIndian Department of Atomic EnergyJapanese ICRRUniversity of TokyoJSPSMEXTBulgarian Ministry of Education and ScienceNational RI Roadmap ProjectAcademy of FinlandCentros de Excelencia 'Severo Ochoa' y Unidades 'María de Maeztu' program of the MCIN/AEICERCA institution of the Generalitat de CatalunyaCroatian Science Foundation (HrZZ)University of RijekaDFGPolish Ministry Of Education and ScienceMCTICCNPqFAPERJGerman Ministry for Education and Research (BMBF)Max Planck SocietyGerman Research Foundation (DFG)Helmholtz AssociationAlexander von Humboldt FoundationFrench Ministry of Higher Education, Research and InnovationCentre National de la Recherche Scientifique (CNRS/IN2P3 and CNRS/INSU)Commissariat a l'energie atomique et aux energies alternatives (CEA)U.K. Science and Technology Facilities Council (STFC)Irish Research Council (IRC)Science Foundation Ireland (SFI)Knut and Alice Wallenberg FoundationSouth African Department of Science and TechnologyNational Research FoundationUniversity of NamibiaNational Commission on Research, Science & Technology of Namibia (NCRST)Austrian Federal Ministry of Education, Science and ResearchAustrian Science Fund (FWF)Australian Research Council (ARC)Japan Society for the Promotion of ScienceUniversity of AmsterdamScience Committee of ArmeniaEGI FederationU.S. Department of Energy Office of ScienceU.S. National Science FoundationSmithsonian InstitutionNSERC in CanadaNational Energy Research Scientific Computing Center (NERSC)U.S. Department of Energy Office of Science User FacilityMCINAgencia Estatal de InvestigaciónUnidad de Excelencia María de Maeztu 2020-2023European Research Council (ERC) under the European UnionMinisterio de Asuntos Económicos y Transformación Digitalpu

Unraveling the Complex Behavior of Mrk 421 with Simultaneous X-Ray and VHE Observations during an Extreme Flaring Activity in 2013 April

We report on a multiband variability and correlation study of the TeV blazar Mrk 421 during an exceptional flaring activity observed from 2013 April 11 to 19. The study uses, among others, data from GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT), Swift, Nuclear Spectroscopic Telescope Array (NuSTAR), Fermi Large Area Telescope, Very Energetic Radiation Imaging Telescope Array System (VERITAS), and Major Atmospheric Gamma Imaging Cherenkov (MAGIC). The large blazar activity and the 43 hr of simultaneous NuSTAR and MAGIC/VERITAS observations permitted variability studies on 15 minute time bins over three X-ray bands (3-7 keV, 7-30 keV, and 30-80 keV) and three very-high-energy (VHE; >0.1 TeV) gamma-ray bands (0.2-0.4 TeV, 0.4-0.8 TeV, and >0.8 TeV). We detected substantial flux variations on multi-hour and sub-hour timescales in all of the X-ray and VHE gamma-ray bands. The characteristics of the sub-hour flux variations are essentially energy independent, while the multi-hour flux variations can have a strong dependence on the energy of the X-rays and the VHE gamma-rays. The three VHE bands and the three X-ray bands are positively correlated with no time lag, but the strength and characteristics of the correlation change substantially over time and across energy bands. Our findings favor multi-zone scenarios for explaining the achromatic/chromatic variability of the fast/slow components of the light curves, as well as the changes in the flux-flux correlation on day-long timescales. We interpret these results within a magnetic reconnection scenario, where the multi-hour flux variations are dominated by the combined emission from various plasmoids of different sizes and velocities, while the sub-hour flux variations are dominated by the emission from a single small plasmoid moving across the magnetic reconnection layer

Study of the GeV to TeV morphology of the gamma Cygni SNR (G 78.2+2.1) with MAGIC and Fermi-LAT: Evidence for cosmic ray escape

Artículo firmado por 183 autores. © ESO 2023. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF and MPG; the Italian INFN and INAF; the Swiss National Fund SNF; the ERDF under the Spanish MINECO (FPA2017-87859-P, FPA2017-85668-P, FPA2017-82729-C6-2-R, FPA2017-82729-C6-6-R, FPA2017-82729-C6-5-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2017-87055-C2-2-P, FPA2017-90566-REDC); the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-268/16.12.2019 and the Academy of Finland grant no. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia "Severo Ochoa" SEV-2016-0588 and SEV-2015-0548, the Unidad de Excelencia "María de Maeztu" MDM-2014-0369 and the "la Caixa" Foundation (fellowship LCF/BQ/PI18/11630012), by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq and FAPERJ. The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat a l'Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucleaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K.A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d'Etudes Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515. This research made use of Astropy (http://www.astropy.org), a community-developed core Python package for Astronomy (Astropy Collaboration 2013, 2018).Context. Diffusive shock acceleration (DSA) is the most promising mechanism that accelerates Galactic cosmic rays (CRs) in the shocks of supernova remnants (SNRs). It is based on particles scattering caused by turbulence ahead and behind the shock. The turbulence upstream is supposedly generated by the CRs, but this process is not well understood. The dominant mechanism may depend on the evolutionary state of the shock and can be studied via the CRs escaping upstream into the interstellar medium (ISM). Aims. Previous observations of the gamma Cygni SNR showed a difference in morphology between GeV and TeV energies. Since this SNR has the right age and is at the evolutionary stage for a significant fraction of CRs to escape, our aim is to understand gamma-ray emission in the vicinity of the gamma Cygni SNR. Methods. We observed the region of the gamma Cygni SNR with the MAGIC Imaging Atmospheric Cherenkov telescopes between 2015 May and 2017 September recording 87 h of good-quality data. Additionally, we analysed Fermi-LAT data to study the energy dependence of the morphology as well as the energy spectrum in the GeV to TeV range. The energy spectra and morphology were compared against theoretical predictions, which include a detailed derivation of the CR escape process and their gamma-ray generation. Results. The MAGIC and Fermi-LAT data allowed us to identify three emission regions that can be associated with the SNR and that dominate at different energies. Our hadronic emission model accounts well for the morphology and energy spectrum of all source components. It constrains the time-dependence of the maximum energy of the CRs at the shock, the time-dependence of the level of turbulence, and the diffusion coefficient immediately outside the SNR shock. While in agreement with the standard picture of DSA, the time-dependence of the maximum energy was found to be steeper than predicted, and the level of turbulence was found to change over the lifetime of the SNR.Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEGerman BMBFGerman MPGItalian INFNItalian INAFSwiss National Fund SNFERDF under the Spanish MINECOIndian Department of Atomic EnergyJapanese ICRRJapanese University of TokyoJapanese JSPSJapanese MEXTBulgarian Ministry of Education and Science, National RI Roadmap ProjectAcademy of FinlandCentro de Excelencia "Severo Ochoa"Unidad de Excelencia "Maria de Maeztu"Fundación "la Caixa"Croatian Science Foundation (HrZZ) ProjectUniversity of Rijeka ProjectDFG Collaborative Research CentersPolish National Research Centre grantBrazilian MCTICBrazilian CNPqBrazilian FAPERJDOEpu

Bounds on Lorentz Invariance Violation from MAGIC Observation of GRB 190114C

On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification

Testing emission models on the extreme blazar 2WHSP J073326.7+515354 detected at very high energies with the MAGIC telescope

Extreme high-energy-peaked BL Lac objects (EHBLs) are an emerging class of blazars. Their typical two-hump-structured spectral energy distribution (SED) peaks at higher energies with respect to conventional blazars. Multiwavelength (MWL) observations constrain their synchrotron peak in the medium to hard X-ray band. Their gamma-ray SED peaks above the GeV band, and in some objects it extends up to several TeV. Up to now, only a few EHBLs have been detected in the TeV gamma-ray range. In this paper, we report the detection of the EHBL 2WHSP J073320,7+515354, observed and detected during 2018 in TeV gamma rays with the MAGIC telescopes. The broad-band SED is studied within an MWL context, including an analysis of the Fermi-LAT data over 10 yr of observation and with simultaneous Swift-XRT, Swift-UVOT, and KVA data. Our analysis results in a set of spectral parameters that confirms the classification of the source as an EIME. In order to investigate the physical nature of this extreme emission, different theoretical frameworks were tested to model the broadband SED. The hard TeV spectrum of 2WHSP J073326.7+515354 sets the SED far from the energy equipartition regime in the standard one-zone leptonic scenario of blazar emission. Conversely, more complex models of the jet, represented by either a two-zone spine-layer model or a hadronic emission model, better represent the broad-hand SED

New Hard-TeV Extreme Blazars Detected with the MAGIC Telescopes*

Extreme high-frequency-peaked BL Lac objects (EHBLs) are blazars that exhibit extremely energetic synchrotron emission. They also feature nonthermal gamma-ray emission whose peak lies in the very high-energy (VHE, E > 100 GeV) range, and in some sources exceeds 1 TeV: this is the case for hard-TeV EHBLs such as 1ES 0229+200. With the aim of increasing the EHBL population, 10 targets were observed with the MAGIC telescopes from 2010 to 2017, for a total of 265 hr of good-quality data. The data were complemented by coordinated Swift observations. The X-ray data analysis confirms that all but two sources are EHBLs. The sources show only a modest variability and a harder-when-brighter behavior, typical for this class of objects. At VHE gamma-rays, three new sources were detected and a hint of a signal was found for another new source. In each case, the intrinsic spectrum is compatible with the hypothesis of a hard-TeV nature of these EHBLs. The broadband spectral energy distributions (SEDs) of all sources are built and modeled in the framework of a single-zone, purely leptonic model. The VHE gamma-ray-detected sources were also interpreted with a spine-layer model and a proton synchrotron model. The three models provide a good description of the SEDs. However, the resulting parameters differ substantially in the three scenarios, in particular the magnetization parameter. This work presents the first mini catalog of VHE gamma-ray and multiwavelength observations of EHBLs