Fast Time Structure During Transient Microwave Brightenings: Evidence for Nonthermal Processes

Transient microwave brightenings (TMBs) are small-scale energy releases from the periphery of sunspot umbrae, with a flux density two orders of magnitude smaller than that from a typical flare. Gopalswamy et al (1994) first reported the detection of the TMBs and it was pointed out that the radio emission implied a region of very high magnetic field so that the emission mechanism has to be gyroresonance or nonthermal gyrosynchrotron, but not free-free emission. It was not possible to decide between gyroresonance and gyrosynchrotron processes because of the low time resolution (30 s) used in the data analysis. We have since performed a detailed analysis of the Very Large Array data with full time resolution (3.3 s) at two wavelengths (2 and 3.6 cm) and we can now adequately address the question of the emission mechanism of the TMBs. We find that nonthermal processes indeed take place during the TMBs. We present evidence for nonthermal emission in the form of temporal and spatial structure of the TMBs. The fast time structure cannot be explained by a thermodynamic cooling time and therefore requires a nonthermal process. Using the physical parameters obtained from X-ray and radio observations, we determine the magnetic field parameters of the loop and estimate the energy released during the TMBs. The impulsive components of TMBs imply an energy release rate of 1.3 x 10^22 erg/s so that the thermal energy content of the TMBs could be less than 10^24 erg.Comment: 15 pages (Latex), 4 figures (eps). ApJ Letters in press (1997

Sending Arms or Twisting Arms: The U.S. Role in the Ukraine War

In the wake of Russia's invasion of Ukraine in February 2022, the United States has backed the government in Kyiv with military hardware and economic assistance. The Biden administration has also done its best to constrain Russia's ability to wage war even as it has been careful not to provoke a direct confrontation or spur escalation on Russia's part.There are two primary scenarios for how the war plays out in the future. Either Ukraine will follow the "Croatia scenario" by pushing Russian troops entirely out of the country and potentially setting into motion the political downfall of Vladimir Putin. Or, in the "Korean scenario," the war will settle into a period of stalemate after the first year of surprising reversals.This backgrounder, prepared for the Rosa Luxemburg Foundation, explores the causes of the war in Ukraine and the actions of different actors in the conflict to date. It also lays out different scenarios for how the conflict may proceed depending on events both internationally and in the United States, and makes the case for a robust international diplomatic response whatever the war's outcome

Building Prime Towers to Understand Prime Number​

There has been a fair amount of research over the past several decades on teachers’ understanding of the multiplicative structure of integers. What can easily be discerned from the literature is a lack of understanding on the part of these educational professionals. It would be easy to assume that this lack of understanding is thereby held by the students in these classrooms. Yet, very little research has examined children\u27s understanding of this mathematical idea. In this quasi-experimental study, we focus the effects of the use of a manipulative, the prime towers, in a three-day teaching experiment carried out in a fourth grade classroom. Students “build” towers of blocks that represent each number 2-100 as a product of prime factors. Towers are studied, compared, and contrasted to build understanding of the significance of prime factorization in predicting a number’s multiplicative structure. The experiment measured students’ ability to identify use prime factorization as a tool to find all the factor pairs, multiples, prime, and composite numbers for natural numbers 1-100 (Common Core Standard 4.OA.4). The results demonstrated represent four classes of fourth grade students spanning two schools. The conclusions drawn will help to identify and refine instructional practices that promote the understanding of the Fundamental Theorem of Arithmetic at a fourth grade level. In connection, both qualitative and quantitative data are presented to insure the practices promoted are both instructional and engaging

Men with intellectual disabilities with a history of sexual offending: empathy for victims of sexual and non-sexual crimes

Background: The objectives were (a) to compare the general empathy abilities of men with intellectual disabilities (IDs) who had a history of sexual offending to men with IDs who had no known history of illegal behaviour, and (b) to determine whether men with IDs who had a history of sexual offending had different levels of specific victim empathy towards their own victim, in comparison to an unknown victim of sexual crime, and a victim of non-sexual crime, and make comparison to non-offenders. Methods: Men with mild IDs (N = 35) were asked to complete a measure of general empathy and a measure of specific victim empathy. All participants completed the victim empathy measure in relation to a hypothetical victim of a sexual offence, and a non-sexual crime, while additionally, men with a history of sexual offending were asked to complete this measure in relation to their own most recent victim. Results: Men with a history of sexual offending had significantly lower general empathy, and specific victim empathy towards an unknown sexual offence victim, than men with no known history of illegal behaviour. Men with a history of sexual offending had significantly lower victim empathy for their own victim than for an unknown sexual offence victim. Victim empathy towards an unknown victim of a non-sexual crime did not differ significantly between the two groups. Conclusions: The findings suggest that it is important include interventions within treatment programmes that attempt to improve empathy and perspective-taking

Moral Machine or Tyranny of the Majority?

With Artificial Intelligence systems increasingly applied in consequential domains, researchers have begun to ask how these systems ought to act in ethically charged situations where even humans lack consensus. In the Moral Machine project, researchers crowdsourced answers to "Trolley Problems" concerning autonomous vehicles. Subsequently, Noothigattu et al. (2018) proposed inferring linear functions that approximate each individual's preferences and aggregating these linear models by averaging parameters across the population. In this paper, we examine this averaging mechanism, focusing on fairness concerns in the presence of strategic effects. We investigate a simple setting where the population consists of two groups, with the minority constituting an {\alpha} < 0.5 share of the population. To simplify the analysis, we consider the extreme case in which within-group preferences are homogeneous. Focusing on the fraction of contested cases where the minority group prevails, we make the following observations: (a) even when all parties report their preferences truthfully, the fraction of disputes where the minority prevails is less than proportionate in {\alpha}; (b) the degree of sub-proportionality grows more severe as the level of disagreement between the groups increases; (c) when parties report preferences strategically, pure strategy equilibria do not always exist; and (d) whenever a pure strategy equilibrium exists, the majority group prevails 100% of the time. These findings raise concerns about stability and fairness of preference vector averaging as a mechanism for aggregating diverging voices. Finally, we discuss alternatives, including randomized dictatorship and median-based mechanisms.Comment: To appear in the proceedings of AAAI 202

The AI Incident Database as an Educational Tool to Raise Awareness of AI Harms: A Classroom Exploration of Efficacy, Limitations, & Future Improvements

Prior work has established the importance of integrating AI ethics topics into computer and data sciences curricula. We provide evidence suggesting that one of the critical objectives of AI Ethics education must be to raise awareness of AI harms. While there are various sources to learn about such harms, The AI Incident Database (AIID) is one of the few attempts at offering a relatively comprehensive database indexing prior instances of harms or near harms stemming from the deployment of AI technologies in the real world. This study assesses the effectiveness of AIID as an educational tool to raise awareness regarding the prevalence and severity of AI harms in socially high-stakes domains. We present findings obtained through a classroom study conducted at an R1 institution as part of a course focused on the societal and ethical considerations around AI and ML. Our qualitative findings characterize students' initial perceptions of core topics in AI ethics and their desire to close the educational gap between their technical skills and their ability to think systematically about ethical and societal aspects of their work. We find that interacting with the database helps students better understand the magnitude and severity of AI harms and instills in them a sense of urgency around (a) designing functional and safe AI and (b) strengthening governance and accountability mechanisms. Finally, we compile students' feedback about the tool and our class activity into actionable recommendations for the database development team and the broader community to improve awareness of AI harms in AI ethics education.Comment: 37 pages, 11 figures; To appear in the proceedings of EAAMO 202