2nd Consultation Report. Bouncing Forward Sustainably: Pathways to a post-COVID World. Governance for Sustainability

COVID-19 has once again brought the role of governments, and their ability to cooperate and coordinate their actions into the spotlight. It has however also highlighted significant gaps in various areas including the science policy interface; the ability of institutional mechanisms to deal with crises; in the preparedness of global and national science communities and government systems; and in access to reliable, verifiable data to inform decision making. The consultative meetings around this topic draw on lessons learned and experiences from the COVID-19 pandemic to identify effective policy tools and mechanisms that would also give due credence to issues of poverty alleviation, justice, inequalities, and the environment. The goal is to suggest pathways for more robustand responsive governance systems for an uncertain future. This report gives a summary over the discussions in the second consultative meeting that took place online, on July 27, 2020

VFTS 243 as predicted by the BPASS fiducial models

The recent discovery of an unambiguous quiescent BH and main sequence O star companion in VFTS 243 opens the door to new constraints on theoretical stellar evolution and population models looking to reproduce the progenitors of black hole - black hole binaries. Here we show that the Binary Population and Spectral Synthesis fiducial models (BPASSv2.2.1) natively predict VFTS 243-like systems: We find that VFTS 243 likely originated from a binary system in a \about 15 day orbit with primary mass ranging from 40 to 50 \msol\, and secondary star with initial mass 24--25\msol. %BPASS systems with initial parameters similar to the ones inferred in the discovery paper result in a final system with an O star 10\msol more massive than indicated by the observations. Additionally we find that the death of the primary star must have resulted in a low energy explosion $E<10^{50}$ ergs. With a uniform prior we find that the kick velocity of the new-born black hole was $<33$ \kms (90 percent credible interval). The very low eccentricity reported for VFTS~243 and the subsequent conclusion by the authors that the SN kick must have been very small is in line with the peak in the posterior distribution between 0 and 5 \kms. Finally, the reduced Hobbs kick distribution commonly used in black hole population synthesis is strongly disfavoured, whereas the Bray kick with the most recent parameter calibration predicts 2 $\pm$ 3.5 \kms, which is very consistent with the posterior velocity distributions obtained for our matching VFTS 243-like models using a uniform kick prior.Comment: 3 figures, 1 table, submitted to MNRA

Training a convolutional neural network for real–bogus classification in the ATLAS survey

We present a convolutional neural network (CNN) for use in the real–bogus classification of transient detections made by the Asteroid Terrestrial-impact Last Alert System (ATLAS) and subsequent efforts to improve performance since initial development. In transient detection surveys, the number of alerts made outstrips the capacity for human scanning, necessitating the use of machine learning aids to reduce the number of false positives presented to annotators. We take a sample of recently annotated data from each of the three operating ATLAS telescope with 340 000 real (known transients) and 1030 000 bogus detections per model. We retrained the CNN architecture with these data specific to each ATLAS unit, achieving a median false positive rate (FPR) of 0.72 per cent for a 1.00 per cent missed detection rate. Further investigations indicate that if we reduce the input image size it results in increased FPR. Finally architecture adjustments and comparisons to contemporary CNNs indicate that our retrained classifier is providing an optimal FPR. We conclude that the periodic retraining and readjustment of classification models on survey data can yield significant improvements as data drift arising from changes in the optical and detector performance can lead to new features in the model and subsequent deteriorations in performance

New constraints on the Bray conservation-of-momentum natal kick model from multiple distinct observations

Natal supernova kicks, the linear momentum compact remnants receive during their formation, are an essential part of binary population synthesis (BPS) models. Although these kicks are well-supported by evidence, their underlying distributions and incorporation into BPS models is uncertain. In this work, we investigate the nature of natal kicks using a previously proposed analytical prescription where the strength of the kick is linearly proportional to the ejecta-remnant mass ratio. We vary the free parameters over large ranges of possible values, comparing these synthetic populations simultaneously against four constraints: the merger rate of compact binary neutron star (BNS) systems, the period-eccentricity distribution of galactic BNSs, the velocity distribution of single-star pulsars, and the likelihood for low-ejecta mass supernovae to produce low-velocity kicks. We find that different samples of the parameter space satisfy each tests, and only 1 per cent of the models satisfy all four constraints simultaneously. Although we cannot identify a single best kick model, we report $\alpha = 80 \pm 30$ km s$^{-1}$, $\beta = 0 \pm 20$ km s$^{-1}$ as the center of the region of the parameter space that fulfils all of our constraints, and expect $\beta \geq 0$ km s$^{-1}$ as a further constraint. We also suggest further observations that will enable future refinement of the kick model. A sensitive test for the kick model will be the redshift evolution of the BNS merger rate since this is effectively a direct measure of the delay-time distribution for mergers. For our best fitting values, we find that the peak of the BNS merger rate is the present-day.Comment: Submitted to MNRA

3rd Consultation Report. Bouncing Forward Sustainably: Pathways to a post-COVID World. Governance for Sustainability

COVID-19 has once again brought the role of governments, and their ability to cooperate and coordinate their actions into the spotlight. It has however also highlighted significant gaps in various areas including the science-policy interface; the ability of institutional mechanisms to deal with crises; in the preparedness of global and national science communities and government systems; and in access to reliable, verifiable data to inform decision making. The consultative meetings around this topic draw on lessons learned and experiences from the COVID-19 pandemic to identify effective policy tools and mechanisms that would also give due credence to issues of poverty alleviation, justice, inequalities, and the environment. The goal is to suggest pathways for more robust and responsive governance systems for an uncertain future. This report gives a summary over the discussions in the third consultative meeting that took place online, on September 1, 2020. Building on overall approach and the 1st and 2nd consultations, the IIASA-ISC team engaged with the experts to identify a set of policy options at global and national systems governance levels. The first consultation focused on drawing lessons from how COVID-19 has been governed at different levels of governance, the second consultation focused on identifying options and opportunities for enhancing governance in support of realizing sustainability objectives. The third consultation further narrowed in on the options and opportunities suggested and harvested policy perspectives with a view to identifying their feasibility and steps needed for successfully translating recommendations and options into to action

Report on First Consultative Science Platform. Bouncing Forward Sustainably: Pathways to a post-COVID World. Governance for Sustainability

COVID-19 has once again brought the role of governments, and their ability to cooperate and coordinate their actions into the spotlight. It has however also highlighted significant gaps in various areas including the science policy interface; the ability of institutional mechanisms to deal with crises; in the preparedness of global and national science communities and government systems; and in access to reliable, verifiable data to inform decision making. The consultative meetings around this topic draw on lessons learned and experiences from the COVID-19 pandemic to identify effective policy tools and mechanisms that would also give due credence to issues of poverty alleviation, justice, inequalities, and the environment. The goal is to suggest pathways for more robustand responsive governance systems for an uncertain future. This report gives a summary over the discussions in the first consultative meeting that took place online, on June 10, 2020

Expert improvisers in Western classical music learning pathways

Despite a growing interest in Western classical improvisation among researchers, educators and musicians in recent decades, research insights on expert improvisers' learning pathways are scarce. In order to further understanding this phenomenon, we formulated the following research question: “What characterizes the learning pathways of Western classical music expert improvisers?” Addressing this question, we designed an exploratory case study, conducting open-ended semi-structured videoconference interviews with a purposeful sampling of N = 8 Western classical music expert improvisers. The participants are international classically trained musicians who are recognized as expert improvisers by their peers and who have improvised on professional albums and in established concert halls. In-depth analysis of our data revealed two distinct learning pathways among the participants: (1) native improvisers, who have improvised since the very beginning of their instrumental learning; and (2) immigrant improvisers, who started to improvise at a later age, during their graduate studies or at the beginning of their professional career. Native improvisers began to improvise spontaneously, without apparent extrinsic incentive, while immigrant improvisers started to improvise in order to attempt to fill a gap in their musical practice. Various factors motivated the immigrant improvisers interviewed to themselves dedicate to this practice, including seeing improvisation as a means to experience (i) a ‘getting back’ to oneself; (ii) an authentic human encounter; (iii) a sense of immediacy characterizing the creative process; and (iv) an equalitarian musical practice. Lastly, a ‘learn-unlearn’ process appears to underlie improvisational expertise development. Implications of these findings for expertise development and skill acquisition will be discussed

The evolution of the 3D shape of the broad-lined Type Ic SN 2014ad

We present optical spectropolarimetry and spectroscopy of the broad-lined Type Ic (Ic-bl) SN 2014ad. Our spectropolarimetric observations cover seven epochs, from −2 to 66 d after V-band maximum, and the spectroscopic data were acquired from −2 to +107 d. The photospheric velocity estimates showed ejecta speeds similar to those of SN 1998bw and other SNe associated with gamma-ray bursts (GRBs). The spectropolarimetric data revealed aspherical outer ejecta and a nearly spherical interior. The polarization associated with O I λ7774 and the Ca II infrared triplet suggests a clumpy and highly asymmetrical distribution of these two species within the ejecta. Furthermore, it was shown that the two line forming regions must have been spatially distinct and oxygen was found to have higher velocities than calcium. Another oxygen line-forming region was also identified much closer to the core of the explosion and distributed in a spherical shell. It is difficult to reconcile the geometry of the deeper ejecta with a jet driven explosion, but the high ejecta velocities of SN 2014ad are typical of those observed in SNe Ic-bl with GRBs and the behaviour of the oxygen and calcium line-forming regions is consistent with fully jet-driven models. The metallicity of the host galaxy of SN 2014ad was also calculated and compared to that of the hosts of other SNe Ic-bl with and without GRBs, but due to the overlap in the two populations no conclusion could be drawn

Bouncing Forward Sustainably: Pathways to a post-COVID World. Governance for Sustainability

The ongoing COVID-19 crisis is generating massive adverse socio-economic impacts for societies around the globe and brings many issues of relevance for ongoing sustainability transformations into the spotlight. One such issue is the role of governance for sustainability, for which COVID-19 provides encouraging as well as challenging lessons. In this background note, we draw first, tentative lessons on how COVID-19 management has been governed across levels of governance, focusing on identifying opportunities for enhancing governance for sustainability including for tackling climate change

Mapping interactions between the sustainable development goals: lessons learned and ways forward

Pursuing integrated research and decision-making to advance action on the sustainable development goals (SDGs) fundamentally depends on understanding interactions between the SDGs, both negative ones (“trade-offs”) and positive ones (“co-benefits”). This quest, triggered by the 2030 Agenda, has however pointed to a gap in current research and policy analysis regarding how to think systematically about interactions across the SDGs. This paper synthesizes experiences and insights from the application of a new conceptual framework for mapping and assessing SDG interactions using a defined typology and characterization approach. Drawing on results from a major international research study applied to the SDGs on health, energy and the ocean, it analyses how interactions depend on key factors such as geographical context, resource endowments, time horizon and governance. The paper discusses the future potential, barriers and opportunities for applying the approach in scientific research, in policy making and in bridging the two through a global SDG Interactions Knowledge Platform as a key mechanism for assembling, systematizing and aggregating knowledge on interactions