13 research outputs found

    Intersexual transfer of a toxic terpenoid during copulation and its paternal allocation to developmental stages - quantification of cantharidin in cantharidin-producing oedemerids (Coleoptera, Oedemeridae) and Canthariphilous pyrochroids (Coleoptera, Pyrochroidae)

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    In whole body extracts of the canthariphilous pyrochroid Schizotus pectinicornis and the cantharidin-producing oedemerid Oedemera femorata cantharidin contents were determined by means of quantitative gas chromatography. Adults and all developmental st

    In vivo cardiac role of migfilin during experimental pressure overload

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    Aims Increased myocardial wall strain triggers the cardiac hypertrophic response by increasing cardiomyocyte size, reprogramming gene expression, and enhancing contractile protein synthesis. The LIM protein, migfilin, is a cytoskeleton-associated protein that was found to translocate in vitro into the nucleus in a Ca2+-dependent manner, where it co-activates the pivotal cardiac transcription factor Csx/Nkx2.5. However, the in vivo role of migfilin in cardiac function and stress response is unclear. Methods and results To define the role of migfilin in cardiac hypertrophy, we induced hypertension by transverse aortic constriction (TAC) and compared cardiac morphology and function of migfilin knockout (KO) with wild-type (WT) hearts. Heart size and myocardial contractility were comparable in untreated migfilin KO and WT hearts, but migfilin-null hearts presented a reduced extent of hypertrophic remodelling in response to chronic hypertensile stress. Migfilin KO mice maintained their cardiac function for a longer time period compared with WT mice, which presented extensive fibrosis and death due to heart failure. Migfilin translocated into the nucleus of TAC-treated cardiomyocytes, and migfilin KO hearts showed reduced Akt activation during the early response to pressure overload. Conclusions Our findings indicate an important role of migfilin in the regulation of cardiac hypertrophy upon experimental TAC

    TeV flaring activity of the AGN PKS 0625-354 in November 2018

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    International audienceMost γ\gamma-ray detected active galactic nuclei are blazars with one of their relativistic jets pointing towards the Earth. Only a few objects belong to the class of radio galaxies or misaligned blazars. Here, we investigate the nature of the object PKS 0625-354, its γ\gamma-ray flux and spectral variability and its broad-band spectral emission with observations from H.E.S.S., Fermi-LAT, Swift-XRT, and UVOT taken in November 2018. The H.E.S.S. light curve above 200 GeV shows an outburst in the first night of observations followed by a declining flux with a halving time scale of 5.9h. The γγ\gamma\gamma-opacity constrains the upper limit of the angle between the jet and the line of sight to 10\sim10^\circ. The broad-band spectral energy distribution shows two humps and can be well fitted with a single-zone synchrotron self Compton emission model. We conclude that PKS 0625-354, as an object showing clear features of both blazars and radio galaxies, can be classified as an intermediate active galactic nuclei. Multi-wavelength studies of such intermediate objects exhibiting features of both blazars and radio galaxies are sparse but crucial for the understanding of the broad-band emission of γ\gamma-ray detected active galactic nuclei in general

    TeV flaring activity of the AGN PKS 0625-354 in November 2018

    No full text
    International audienceMost γ\gamma-ray detected active galactic nuclei are blazars with one of their relativistic jets pointing towards the Earth. Only a few objects belong to the class of radio galaxies or misaligned blazars. Here, we investigate the nature of the object PKS 0625-354, its γ\gamma-ray flux and spectral variability and its broad-band spectral emission with observations from H.E.S.S., Fermi-LAT, Swift-XRT, and UVOT taken in November 2018. The H.E.S.S. light curve above 200 GeV shows an outburst in the first night of observations followed by a declining flux with a halving time scale of 5.9h. The γγ\gamma\gamma-opacity constrains the upper limit of the angle between the jet and the line of sight to 10\sim10^\circ. The broad-band spectral energy distribution shows two humps and can be well fitted with a single-zone synchrotron self Compton emission model. We conclude that PKS 0625-354, as an object showing clear features of both blazars and radio galaxies, can be classified as an intermediate active galactic nuclei. Multi-wavelength studies of such intermediate objects exhibiting features of both blazars and radio galaxies are sparse but crucial for the understanding of the broad-band emission of γ\gamma-ray detected active galactic nuclei in general

    Curvature in the very-high energy gamma-ray spectrum of M87

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    International audienceThe radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray emission is yet to be understood. In this study, we investigate the VHE gamma-ray spectrum of M87 during states of high gamma-ray activity, utilizing 20.2\, hours the H.E.S.S. observations. Our findings indicate a preference for a curved spectrum, characterized by a log-parabola model with extra-galactic background light (EBL) model above 0.3\,TeV at the 4σ\sigma level, compared to a power-law spectrum with EBL. We investigate the degeneracy between the absorption feature and the EBL normalization and derive upper limits on EBL models mainly sensitive in the wavelength range 12.4\,μ\mum - 40\,μ\mum

    TeV flaring activity of the AGN PKS 0625-354 in November 2018

    No full text
    International audienceMost γ\gamma-ray detected active galactic nuclei are blazars with one of their relativistic jets pointing towards the Earth. Only a few objects belong to the class of radio galaxies or misaligned blazars. Here, we investigate the nature of the object PKS 0625-354, its γ\gamma-ray flux and spectral variability and its broad-band spectral emission with observations from H.E.S.S., Fermi-LAT, Swift-XRT, and UVOT taken in November 2018. The H.E.S.S. light curve above 200 GeV shows an outburst in the first night of observations followed by a declining flux with a halving time scale of 5.9h. The γγ\gamma\gamma-opacity constrains the upper limit of the angle between the jet and the line of sight to 10\sim10^\circ. The broad-band spectral energy distribution shows two humps and can be well fitted with a single-zone synchrotron self Compton emission model. We conclude that PKS 0625-354, as an object showing clear features of both blazars and radio galaxies, can be classified as an intermediate active galactic nuclei. Multi-wavelength studies of such intermediate objects exhibiting features of both blazars and radio galaxies are sparse but crucial for the understanding of the broad-band emission of γ\gamma-ray detected active galactic nuclei in general

    Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi-LAT and H.E.S.S. analysis

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    International audienceThe Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy γ\gamma rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's γ\gamma-ray emission between 1 GeV and \sim100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package Gammapy, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing γ\gamma-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties

    Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi-LAT and H.E.S.S. analysis

    No full text
    International audienceThe Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy γ\gamma rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's γ\gamma-ray emission between 1 GeV and \sim100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package Gammapy, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing γ\gamma-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties

    Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi-LAT and H.E.S.S. analysis

    No full text
    International audienceThe Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy γ\gamma rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's γ\gamma-ray emission between 1 GeV and \sim100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package Gammapy, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing γ\gamma-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties
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