Incorporating Uncertainties in Atomic Data Into the Analysis of Solar and Stellar Observations: A Case Study in Fe XIII

Information about the physical properties of astrophysical objects cannot be measured directly but is inferred by interpreting spectroscopic observations in the context of atomic physics calculations. Ratios of emission lines, for example, can be used to infer the electron density of the emitting plasma. Similarly, the relative intensities of emission lines formed over a wide range of temperatures yield information on the temperature structure. A critical component of this analysis is understanding how uncertainties in the underlying atomic physics propagates to the uncertainties in the inferred plasma parameters. At present, however, atomic physics databases do not include uncertainties on the atomic parameters and there is no established methodology for using them even if they did. In this paper we develop simple models for the uncertainties in the collision strengths and decay rates for Fe XIII and apply them to the interpretation of density sensitive lines observed with the EUV Imagining spectrometer (EIS) on Hinode. We incorporate these uncertainties in a Bayesian framework. We consider both a pragmatic Bayesian method where the atomic physics information is unaffected by the observed data, and a fully Bayesian method where the data can be used to probe the physics. The former generally increases the uncertainty in the inferred density by about a factor of 5 compared with models that incorporate only statistical uncertainties. The latter reduces the uncertainties on the inferred densities, but identifies areas of possible systematic problems with either the atomic physics or the observed intensities.Comment: in press at Ap

Culture, self and the emergence of reactance: is there a “universal” freedom?

In this article we suggest that independent vs. interdependent aspects of the self yield different manifestations of psychological reactance and that this is especially relevant in a cross-cultural context. In Studies 1, 2 and 4 we showed that people from collectivistic cultural backgrounds (individuals holding more interdependent attitudes and values) were less sensitive to a threat to their individual freedom than people from individualistic cultural backgrounds (individuals holding more independent attitudes and values), but more sensitive if their collective freedom was threatened. In Study 3 we activated independent vs. interdependent attitudes and values utilizing a cognitive priming method and yielded similar results as the other studies hinting at the important causal role of self-related aspects in understanding reactance in a cross-cultural context

Subliminal priming and persuasion: Striking while the iron is hot.

Abstract Three studies demonstrated that subliminally priming a goal-relevant cognition (thirst in Studies 1 and 2; sadness in Study 3) influenced behavior (in Study 1) and enhanced the persuasiveness of an ad targeting the goal (in Studies 2 and 3) when people were motivated to pursue the goal (when they were thirsty in Studies 1 and 2; when they expected to interact with another person in Study 3). These results suggest that subliminal priming can be used to enhance persuasion, but only when certain conditions are met. Both the priming of goal-relevant cognitions and the motive to pursue the goal were necessary for ads targeting the goal to be more persuasive. The implications of these results for the role of functionality in subliminal priming and for the use and abuse of subliminal priming in persuasion are discussed

What happened to smokers' beliefs about light cigarettes when "light/mild" brand descriptors were banned in the UK? Findings from the International Tobacco Control (ITC) Four Country Survey

Aim: This paper reports findings of an evaluation that examined how beliefs of smokers in the United Kingdom (UK) were affected by the removal of light and mild brand descriptors which came into effect on September 30, 2003 for Member States of the European Union (EU). Participants: The data come from the first 4 waves (2002-2005) of the International Tobacco Control Policy Evaluation (ITC) 4 Country Survey, an annual cohort telephone survey of adult smokers in Canada, United States, United Kingdom, and Australia (15450 individual cases). Design: The UK ban on misleading descriptors occurred around the 2nd wave of data collection in the ITC survey, permitting us to compare beliefs about light cigarettes among adult smokers in the UK both before and after the ban, with beliefs in three other countries unaffected by the ban. Results: The findings reveal that high levels of misperceptions about light cigarettes existed among smokers in all four countries before and after the EU ban took effect. There was a substantial decline in reported beliefs about the benefits of Lights in the UK following the policy change and an associated public information campaign, but by 2006 (i.e., Wave 4), these beliefs rebounded slightly and the change in beliefs was no greater than in the United States, where there was no policy change. Conclusion: We cannot conclude that the policy which required removal of the misleading labels has been effective in changing beliefs about light cigarettes. What seems apparent is that efforts to correct decades of consumer misperceptions about light cigarettes will require more than simply removing brand descriptors

PoGOLite - A High Sensitivity Balloon-Borne Soft Gamma-ray Polarimeter

We describe a new balloon-borne instrument (PoGOLite) capable of detecting 10% polarisation from 200mCrab point-like sources between 25 and 80keV in one 6 hour flight. Polarisation measurements in the soft gamma-ray band are expected to provide a powerful probe into high-energy emission mechanisms as well as the distribution of magnetic fields, radiation fields and interstellar matter. At present, only exploratory polarisation measurements have been carried out in the soft gamma-ray band. Reduction of the large background produced by cosmic-ray particles has been the biggest challenge. PoGOLite uses Compton scattering and photo-absorption in an array of 217 well-type phoswich detector cells made of plastic and BGO scintillators surrounded by a BGO anticoincidence shield and a thick polyethylene neutron shield. The narrow FOV (1.25msr) obtained with well-type phoswich detector technology and the use of thick background shields enhance the detected S/N ratio. Event selections based on recorded phototube waveforms and Compton kinematics reduce the background to that expected for a 40-100mCrab source between 25 and 50keV. A 6 hour observation on the Crab will differentiate between the Polar Cap/Slot Gap, Outer Gap, and Caustic models with greater than 5 sigma; and also cleanly identify the Compton reflection component in the Cygnus X-1 hard state. The first flight is planned for 2010 and long-duration flights from Sweden to Northern Canada are foreseen thereafter.Comment: 11 pages, 11 figures, 2 table

Girls Are Good At STEM: Opening Minds And Providing Evidence Reduce Boys\u27 Stereotyping Of Girls\u27 STEM Ability

Girls and women face persistent negative stereotyping within STEM (science, technology, engineering, mathematics). This field intervention was designed to improve boys\u27 perceptions of girls\u27 STEM ability. Boys (N = 667; mostly White and East Asian) aged 9-15 years in Canadian STEM summer camps (2017-2019) had an intervention or control conversation with trained camp staff. The intervention was a multi-stage persuasive appeal: a values affirmation, an illustration of girls\u27 ability in STEM, a personalized anecdote, and reflection. Control participants discussed general camp experiences. Boys who received the intervention (vs. control) had more positive perceptions of girls\u27 STEM ability, d = 0.23, an effect stronger among younger boys. These findings highlight the importance of engaging elementary-school-aged boys to make STEM climates more inclusive

Social comparison processes in the experience of personal relative deprivation.

Drawing on social comparison and equity theories, we investigated the role that perceived similarity of a comparison target plays in how resentful people feel about their relative financial status. In Study 1, participants tended to choose a comparison target who was better off, and they selected a target they perceived to be more similar than dissimilar along dimensions that surrounded their financial outcomes. In Study 1, perceived relative disadvantage was positively associated with resentment regardless of the perceived similarity of the comparison target. The results of Studies 2 to 5b clarified these findings by showing that being both similar and dissimilar to a target can cause resentment depending on the context. Using hypothetical and real social comparisons, we found that people are more dissatisfied with their financial outcomes when their comparative targets have the same background qualifications (i.e., are similar) but are financially better off (Studies 2, 3b, 4, and 5b). However, we also found that when the comparative financial contexts were similar (i.e., equal affluence), participants were more dissatisfied when their target for comparison had lower qualifications (i.e., was dissimilar; Studies 2, 3a, 4, and 5a). In all cases, perceptions of unfairness mediated the effects of social comparison on financial dissatisfaction. Taken together, these studies address some of the ambiguities around what it means to be similar to a target in the context of social comparisons of affluence, and they underscore the importance of perceived unfairness in the link between social comparison and resentment with one’s financial status.Leverhulme Trust. Grant Number: RPG‐2013‐14

Effect of natalizumab on disease progression in secondary progressive multiple sclerosis (ASCEND). a phase 3, randomised, double-blind, placebo-controlled trial with an open-label extension

Background: Although several disease-modifying treatments are available for relapsing multiple sclerosis, treatment effects have been more modest in progressive multiple sclerosis and have been observed particularly in actively relapsing subgroups or those with lesion activity on imaging. We sought to assess whether natalizumab slows disease progression in secondary progressive multiple sclerosis, independent of relapses. Methods: ASCEND was a phase 3, randomised, double-blind, placebo-controlled trial (part 1) with an optional 2 year open-label extension (part 2). Enrolled patients aged 18–58 years were natalizumab-naive and had secondary progressive multiple sclerosis for 2 years or more, disability progression unrelated to relapses in the previous year, and Expanded Disability Status Scale (EDSS) scores of 3·0–6·5. In part 1, patients from 163 sites in 17 countries were randomly assigned (1:1) to receive 300 mg intravenous natalizumab or placebo every 4 weeks for 2 years. Patients were stratified by site and by EDSS score (3·0–5·5 vs 6·0–6·5). Patients completing part 1 could enrol in part 2, in which all patients received natalizumab every 4 weeks until the end of the study. Throughout both parts, patients and staff were masked to the treatment received in part 1. The primary outcome in part 1 was the proportion of patients with sustained disability progression, assessed by one or more of three measures: the EDSS, Timed 25-Foot Walk (T25FW), and 9-Hole Peg Test (9HPT). The primary outcome in part 2 was the incidence of adverse events and serious adverse events. Efficacy and safety analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01416181. Findings: Between Sept 13, 2011, and July 16, 2015, 889 patients were randomly assigned (n=440 to the natalizumab group, n=449 to the placebo group). In part 1, 195 (44%) of 439 natalizumab-treated patients and 214 (48%) of 448 placebo-treated patients had confirmed disability progression (odds ratio [OR] 0·86; 95% CI 0·66–1·13; p=0·287). No treatment effect was observed on the EDSS (OR 1·06, 95% CI 0·74–1·53; nominal p=0·753) or the T25FW (0·98, 0·74–1·30; nominal p=0·914) components of the primary outcome. However, natalizumab treatment reduced 9HPT progression (OR 0·56, 95% CI 0·40–0·80; nominal p=0·001). In part 1, 100 (22%) placebo-treated and 90 (20%) natalizumab-treated patients had serious adverse events. In part 2, 291 natalizumab-continuing patients and 274 natalizumab-naive patients received natalizumab (median follow-up 160 weeks [range 108–221]). Serious adverse events occurred in 39 (13%) patients continuing natalizumab and in 24 (9%) patients initiating natalizumab. Two deaths occurred in part 1, neither of which was considered related to study treatment. No progressive multifocal leukoencephalopathy occurred. Interpretation: Natalizumab treatment for secondary progressive multiple sclerosis did not reduce progression on the primary multicomponent disability endpoint in part 1, but it did reduce progression on its upper-limb component. Longer-term trials are needed to assess whether treatment of secondary progressive multiple sclerosis might produce benefits on additional disability components. Funding: Biogen