181 research outputs found

    Radio-Continuum study of the Nearby Sculptor Group Galaxies. Part 1: NGC 300 at lambda = 20 cm

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    A series of new radio-continuum (lambda=20 cm) mosaic images focused on the NGC 300 galactic system were produced using archived observational data from the VLA and/or ATCA. These new images are both very sensitive (rms=60 microJy) and feature high angular resolution (<10"). The most prominent new feature is the galaxy's extended radio-continuum emission, which does not match its optical appearance. Using these newly created images a number of previously unidentified discrete sources have been discovered. Furthermore, we demonstrate that a joint deconvolution approach to imaging this complete data-set is inferior when compared to an immerge approach.Comment: 13 pages, 12 figures, accepted to APSS, new version to correct the missing reference

    Probing ISM Structure in Trumpler 14 & Carina I Using The Stratospheric Terahertz Observatory 2

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    We present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2 (STO2). The Trumpler 14/Carina I region is in the west part of the Carina Nebula Complex, which is one of the most extreme star-forming regions in the Milky Way. We observed Trumpler 14/Carina I in the 158 μ\mum transition of [C\,{\sc ii}] with a spatial resolution of 48′′'' and a velocity resolution of 0.17 km s−1^{-1}. The observations cover a 0.25∘^\circ by 0.28∘^\circ area with central position {\it l} = 297.34∘^\circ, {\it b} = -0.60∘^\circ. The kinematics show that bright [C\,{\sc ii}] structures are spatially and spectrally correlated with the surfaces of CO clouds, tracing the photodissociation region and ionization front of each molecular cloud. Along 7 lines of sight that traverse Tr 14 into the dark ridge to the southwest, we find that the [C\,{\sc ii}] luminosity from the HII region is 3.7 times that from the PDR. In same los we find in the PDRs an average ratio of 1:4.1:5.6 for the mass in atomic gas:dark-CO gas: molecular gas traced by CO. Comparing multiple gas tracers including HI 21cm, [C\,{\sc ii}], CO, and radio recombination lines, we find that the HII regions of the Carina Nebula Complex are well-described as HII regions with one-side freely expanding towards us, consistent with the champagne model of ionized gas evolution. The dispersal of the GMC in this region is dominated by EUV photoevaporation; the dispersal timescale is 20-30 Myr.Comment: ApJ accepte

    The CLEAR (considering leading experts' antithrombotic regimes around peripheral angioplasty) survey: an international perspective on antiplatelet and anticoagulant practice for peripheral arterial endovascular intervention.

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    Background Antiplatelet and anticoagulant therapy are commonly used before, during and after peripheral arterial endovascular intervention. This survey aimed to establish antiplatelet and anticoagulant choice for peripheral arterial endovascular intervention in contemporary clinical practice. Methods Pilot-tested questionnaire distributed via collaborative research networks. Results One hundred and sixty-two complete responses were collected from responders in 22 countries, predominantly the UK (48%) and the rest of the European Union (44%). Antiplatelet monotherapy was the most common choice pre-procedurally (62%). In the UK, there was no difference between dual and single antiplatelet therapy use post procedure (50% vs. 37% p = 0.107). However, a significant majority of EU respondents used dual therapy (68% vs. 20% p < 0.001). There was variation in choice of antiplatelet therapy by the device used and the anatomical location of the intervention artery. The majority (82%) of respondents believed there was insufficient evidence to guide antithrombotic therapy after peripheral endovascular intervention and most (92%) would support a randomised trial. Conclusions There is widespread variation in the use of antiplatelet therapy, especially post peripheral arterial endovascular intervention. Clinicians would support the development of a randomised trial comparing dual antiplatelet therapy with monotherapy

    Radio-Continuum Study of the Nearby Sculptor Group Galaxies. Part 2: NGC 55 at {\lambda}=20, 13, 6 and 3 cm

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    A series of new radio-continuum ({\lambda}=20, 13, 6 and 3 cm) mosaic images focused on the NGC55 galactic system were produced using archived observational data from the Australia Telescope Compact Array. These new images are both very sensitive (down to rms=33 {\mu}Jy) and feature high angular resolution (down to <4"). Using these newly created images, 66 previously unidentified discrete sources are identified. Of these sources, 46 were classified as background sources, 11 as HII regions and 6 as supernova remnant candidates. This relatively low number of SNR candidates detected coupled with the low number of large HII regions is consistent with the estimated low star formation rate of the galaxy at 0.06 solar masses per year. Our spectral index map shows that the core of galaxy appears to have a shallow spectral index between {\alpha} = -0.2 and -0.4. This indicates that the core of the galaxy is a region of high thermal radiation output.Comment: 11 pages, 8 figures. Accepted for publication in Astrophysics and Space Scienc

    The future of evapotranspiration : global requirements for ecosystem functioning, carbon and climate feedbacks, agricultural management, and water resources

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    The fate of the terrestrial biosphere is highly uncertain given recent and projected changes in climate. This is especially acute for impacts associated with changes in drought frequency and intensity on the distribution and timing of water availability. The development of effective adaptation strategies for these emerging threats to food and water security are compromised by limitations in our understanding of how natural and managed ecosystems are responding to changing hydrological and climatological regimes. This information gap is exacerbated by insufficient monitoring capabilities from local to global scales. Here, we describe how evapotranspiration (ET) represents the key variable in linking ecosystem functioning, carbon and climate feedbacks, agricultural management, and water resources, and highlight both the outstanding science and applications questions and the actions, especially from a space-based perspective, necessary to advance them

    The Third International Symposium on Fungal Stress – ISFUS

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    Stress is a normal part of life for fungi, which can survive in environments considered inhospitable or hostile for other organisms. Due to the ability of fungi to respond to, survive in, and transform the environment, even under severe stresses, many researchers are exploring the mechanisms that enable fungi to adapt to stress. The International Symposium on Fungal Stress (ISFUS) brings together leading scientists from around the world who research fungal stress. This article discusses presentations given at the third ISFUS, held in São José dos Campos, São Paulo, Brazil in 2019, thereby summarizing the state-of-the-art knowledge on fungal stress, a field that includes microbiology, agriculture, environmental science, ecology, biotechnology, medicine, and astrobiology
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