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- Ade, Peter, et al.
(author)
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The Simons Observatory : science goals and forecasts
- 2019
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In: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :2
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Journal article (peer-reviewed)abstract
- The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial con figuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping approximate to 10% of the sky to a white noise level of 2 mu K-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of sigma(r) = 0.003. The large aperture telescope will map approximate to 40% of the sky at arcminute angular resolution to an expected white noise level of 6 mu K-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.
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| 2. |
- Abazajian, Kevork, et al.
(author)
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CMB-S4 : Forecasting Constraints on Primordial Gravitational Waves
- 2022
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In: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 926:1
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Journal article (peer-reviewed)abstract
- CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the universe. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semianalytic projection tool, targeted explicitly toward optimizing constraints on the tensor-to-scalar ratio, r, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2–3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments, given a desired scientific goal. To form a closed-loop process, we couple this semianalytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for r > 0.003 at greater than 5σ, or in the absence of a detection, of reaching an upper limit of r < 0.001 at 95% CL.
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| 4. |
- Forsberg, Camilla, et al.
(author)
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Students’ views of factors affecting their bystander behaviors in response to school bullying : a cross-collaborative conceptual qualitative analysis
- 2018
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In: Research Papers in Education. - : Taylor & Francis Group. - 0267-1522 .- 1470-1146. ; 33:1, s. 127-142
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Journal article (peer-reviewed)abstract
- The aim of the present study was to focus on how students articulate and discuss what factors influence students’ decisions to defend or not defend victims when witnessing bullying. In this unique qualitative cross-collaborative study, where two research teams collected interviews from two cultural contexts, eighty-nine students with an age-range from 9 to 14 years old participated. Participants included 43 Swedish students and 46 US students (50 girls, 39 boys). The interviews were analysed through a collaborative qualitative analysis aimed at constructing shared concepts of our data as a whole. The results revealed five broad factors among the students when they reasoned about how they act as a bystander in bullying situations: (a) informed awareness, (b) bystander expectations, (c) personal feelings, (d) behavioural seriousness, and (e) sense of responsibility. The results indicated that each of these considerations could make the students more or less likely to defend as well as to defend in a certain way. According to these five broad factors, students seemed to adjust their bystander acts, which suggests that students’ bystander acts vary depending on situational factors that influence bystanders’ interpretations of bullying and decision-making about how to respond to observed bullying.
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| 9. |
- Parris, Leandra, et al.
(author)
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Bullying bystander behaviors : The role of coping effectiveness and the moderating effect of gender
- 2020
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In: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 61:1, s. 38-46
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Journal article (peer-reviewed)abstract
- Researchers have suggested that bystander behaviors and victim coping play an important role in counteracting the negative effects of bullying. The current study investigated the relationship between students’ ratings of coping effectiveness when addressing bullying and their behaviors as bystanders when witnessing bullying. Surveys were administered in a Midwestern, suburban school district. Some associations between perceptions of coping effectiveness and bystander behavior supported our hypotheses (e.g., constructive coping associated with defending bystander behaviors, externalizing associated with pro-bullying behaviors). However, some findings did not support hypothesized relationships. For example, higher ratings of effectiveness for cognitive distancing as a coping strategy were associated with increased defending behaviors as a bystander. Gender moderated some of these relationships. Pro-bullying bystander behavior was associated with increased ratings of cognitive distancing and decreased reports of constructive coping effectiveness for girls. Implications for future research and practice are discussed.
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| 10. |
- Thornberg, Robert, et al.
(author)
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Bystander motivation in bullying incidents : To intervene or not to intervene?
- 2012
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In: Western Journal of Emergency Medicine. - : eScholarship. - 1936-900X .- 1936-9018. ; 13:3, s. 247-252
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Journal article (other academic/artistic)abstract
- IntroductionThis research sought to extend knowledge about bystanders in bullying situations with a focus on the motivations that lead them to different responses. The 2 primary goals of this study were to investigate the reasons for children's decisions to help or not to help a victim when witnessing bullying, and to generate a grounded theory (or conceptual framework) of bystander motivation in bullying situations.MethodsThirty students ranging in age from 9 to 15 years (M = 11.9; SD = 1.7) from an elementary and middle school in the southeastern United States participated in this study. Open- ended, semi-structured interviews were used, and sessions ranged from 30 to 45 minutes. We conducted qualitative methodology and analyses to gain an in-depth understanding of children's perspectives and concerns when witnessing bullying.ResultsA key finding was a conceptual framework of bystander motivation to intervene in bullying situations suggesting that deciding whether to help or not help the victim in a bullying situation depends on how bystanders define and evaluate the situation, the social context, and their own agency. Qualitative analysis revealed 5 themes related to bystander motives and included: interpretation of harm in the bullying situation, emotional reactions, social evaluating, moral evaluating, and intervention self-efficacy.ConclusionGiven the themes that emerged surrounding bystanders' motives to intervene or abstain from intervening, respondents reported 3 key elements that need to be confirmed in future research and that may have implications for future work on bullying prevention. These included: first, the potential importance of clear communication to children that adults expect bystanders to intervene when witnessing bullying; second, the potential of direct education about how bystanders can intervene to increase children's self-efficacy as defenders of those who are victims of bullying; and third, the assumption that it may be effective to encourage children's belief that bullying is morally wrong.
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