| 1. |
- Goddi, Ciriaco, et al.
(författare)
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Polarimetric Properties of Event Horizon Telescope Targets from ALMA
- 2021
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 910:1
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Tidskriftsartikel (refereegranskat)abstract
- We present the results from a full polarization study carried out with the Atacama Large Millimeter/submillimeter Array (ALMA) during the first Very Long Baseline Interferometry (VLBI) campaign, which was conducted in 2017 April in the lambda 3 mm and lambda 1.3 mm bands, in concert with the Global mm-VLBI Array (GMVA) and the Event Horizon Telescope (EHT), respectively. We determine the polarization and Faraday properties of all VLBI targets, including Sgr A*, M87, and a dozen radio-loud active galactic nuclei (AGNs), in the two bands at several epochs in a time window of 10 days. We detect high linear polarization fractions (2%-15%) and large rotation measures (RM > 10(3.3)-10(5.5) rad m(-2)), confirming the trends of previous AGN studies at millimeter wavelengths. We find that blazars are more strongly polarized than other AGNs in the sample, while exhibiting (on average) order-of-magnitude lower RM values, consistent with the AGN viewing angle unification scheme. For Sgr A* we report a mean RM of (-4.2 0.3) x 10(5) rad m(-2) at 1.3 mm, consistent with measurements over the past decade and, for the first time, an RM of (-2.1 0.1) x 10(5) rad m(-2) at 3 mm, suggesting that about half of the Faraday rotation at 1.3 mm may occur between the 3 mm photosphere and the 1.3 mm source. We also report the first unambiguous measurement of RM toward the M87 nucleus at millimeter wavelengths, which undergoes significant changes in magnitude and sign reversals on a one year timescale, spanning the range from -1.2 to 0.3 x 10(5) rad m(-2) at 3 mm and -4.1 to 1.5 x 10(5) rad m(-2) at 1.3 mm. Given this time variability, we argue that, unlike the case of Sgr A*, the RM in M87 does not provide an accurate estimate of the mass accretion rate onto the black hole. We put forward a two-component model, comprised of a variable compact region and a static extended region, that can simultaneously explain the polarimetric properties observed by both the EHT (on horizon scales) and ALMA (which observes the combined emission from both components). These measurements provide critical constraints for the calibration, analysis, and interpretation of simultaneously obtained VLBI data with the EHT and GMVA.
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| 2. |
- Ingram, Julie, et al.
(författare)
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What are the priority research questions for digital agriculture?
- 2022
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Ingår i: Land use policy. - : Elsevier. - 0264-8377 .- 1873-5754. ; 114
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Tidskriftsartikel (refereegranskat)abstract
- There is a need to identify key existing and emerging issues relevant to digitalisation in agricultural production that would benefit from a stronger evidence base and help steer policy formulation. To address this, a prioritisation exercise was undertaken to identify priority research questions concerning digital agriculture in the UK, but with a view to also informing international contexts. The prioritisation exercise uses an established and effective participatory methodology for capturing and ordering a wide range of views. The method involves identifying a large number of participants and eliciting an initial long list of research questions which is reduced and refined in subsequent voting stages to select the top priorities by theme. Participants were selected using purposive sampling and snowballing to represent a number of sectors, organisations, companies and disciplines across the UK. They were each invited to submit up to 10 questions according to certain criteria, and this resulted in 195 questions from a range of 40 participants (largely from England with some representation from Scotland and Wales). Preliminary analysis and clustering of these questions through iterative analysis identified seven themes as follows: data governance; data management; enabling use of data and technologies; understanding benefits and uptake of data and technologies; optimising data and technologies for performance; impacts of digital agriculture; and new collaborative arrangements. Subsequent stages of voting, using an online ranking exercise and a participant workshop for in-depth discussion, refined the questions to a total of 27 priority research questions categorised into 15 gold, 7 silver and 5 bronze, across the 7 themes. The questions significantly enrich and extend previous clustering and agenda setting using literature sources, and provide a range of new perspectives. The analysis highlights the interconnectedness of themes and questions, and proposes two nexus for future research: the different dimensions of value, and the social and institutional arrangements to support digitalisation in agriculture. These emphasise the importance of interdisciplinarity and transdisciplinarity, and the need to tackle the binary nature of current analytical frames. These new insights are equally relevant to contexts outside the UK. This paper highlights the need for research actions to inform policy, not only instrumentally by strengthening the evidence base, but also conceptually, to prompt new thinking. To our knowledge this methodology has not been previously applied to this topic.
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| 3. |
- Ingram Bogusz, Claire, et al.
(författare)
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AI for the benefit of society : Progress with trust and transparency
- 2023
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Annan publikation (populärvet., debatt m.m.)abstract
- In this policy paper, the authors argue that trust and legitimacy in the state requires not only that it takes advantage of the quality improvements that generative AI offers, but also that state actors maintain the trust of citizens by acknowledging and advancing generative AI policy with the risks in mind.
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| 4. |
- Ingram Bogusz, Claire, et al.
(författare)
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AI i samhällets tjänst : Utveckling med tillit och transparens
- 2023
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Annan publikation (populärvet., debatt m.m.)abstract
- I detta policypapper argumenterar författarna för hur man upprätthåller förtroendet och legitimiteten för det offentliga i användningen av generativ AI. Offentlig sektor kan och bör dra nytta av de kvalitetsförbättringar som generativ AI erbjuder samtidigt som offentliga aktörer utvecklar lagstiftning med dess risker i åtanke. I syfte att upprätthålla den sociala och institutionella tilliten, krävs det att offentlig sektor tar till sig de möjligheter som generativ AI erbjuder - innan utrymmet och utvecklingen av teknologierna helt kontrolleras av privata aktörer.
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| 5. |
- Schenström, Ulrica, et al.
(författare)
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DEBATT: AI-politiken är i desperat behov av nyansering och reformer
- 2023
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Annan publikation (populärvet., debatt m.m.)abstract
- Dagens AI-politik är i desperat behov av reformer. Det saknas översyn av konsekvenserna när generativ AI redan i dag implementeras ”bakvägen” inom offentlig sektor – utan gemensam förståelse för riskerna, skriver forskare och företrädare för tankesmedjan Fores.
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