Convergence groups from subgroups

We give sufficient conditions for a group of homeomorphisms of a Peano continuum X without cut-points to be a convergence group. The condition is that there is a collection of convergence subgroups whose limit sets `cut up' X in the correct fashion. This is closely related to the result in [E Swenson, Axial pairs and convergence groups on S^1, Topology 39 (2000) 229-237].Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol6/paper22.abs.htm

Learning to Question the World: Navigating Critical Discourse around Gender and Racial Inequities and Injustices In a Second and Third Grade Classroom

This qualitative study, situated within a critical theory frame (Friere, 1970; Grant, Brown, & Brown, 2016; hooks, 1994; Kincheloe, 2008), explored the ways elementary students engaged in and constructed meaning from critical classroom discussions exploring inequities and injustices as related to gender and race. The questions guiding the study were: (1) How do my students construct meaning during class discussions regarding issues of equity and injustice around gender and race?, (2) What role do I play in constructing, shaping, and maintaining opportunities for students to create meaning during these discussions?, and (3) What tensions do my students encounter when engaging in discussions about gender and race? The participants for the study were second and third grade students. Data sources included class recordings, photographs, student work, field notes, interviews, lesson plans, and my reflective teaching journal. Constant comparative approach (Glaser, 1965) was used to analyze the data. Findings demonstrate carefully developed opportunities for critical classroom discourse supports students to observe, question, and critique oppressive social practices enacted upon marginalized communities in the United States. The tensions emerging from a diversity of perspectives and relationships within the classroom complicated these discussions while also providing data from which new curriculum could be developed. The broader implications from this study propose a need for classroom teachers to create spaces within their classrooms where students can learn to not only question the world but develop an ability and willingness to engage in critical discourse alongside others in an effort to create an informed citizenry willing to confront issues of oppression (Fifer & Palos, 2011; hooks, 1994; Long, Souto-Manning, & Vazquez, 2015; Macedo, 2006)

Motivation for Heat Adaption: How Perception and Exposure Affect Individual Behaviors During Hot Weather in Knoxville, Tennessee

Heat is the deadliest meteorological hazard; however, those exposed to heat often do not feel they are in danger of heat-health effects and do not take precautions to avoid heat exposure. Socioeconomic factors, such as the high cost of running air conditioning, might prevent people from taking adaption measures. We assessed via a mixed-methods survey how residents of urban Knoxville, Tennessee, (n = 86) describe and interpret their personal vulnerability during hot weather. Thematic analyses reveal that many respondents describe uncomfortably hot weather based on its consequences, such as health effects and the need to change normal behavior, which misaligns with traditional heat-communication measures using specific weather conditions. Only 55% of those who perceived excessive heat as dangerous cited health as a cause for concern. Respondents who have experienced health issues during hot weather were more likely to perceive heat as dangerous and take actions to reduce heat exposure. Social cohesion was not a chief concern for our respondents, even though it has been connected to reducing time-delayed heat-health effects. Results support using thematic analyses, an underutilized tool in climatology research, to improve understanding of public perception of atmospheric hazards. We recommend a multi-faceted approach to addressing heat vulnerability

Simulated rarefied entry of the Galileo probe into the atmosphere of Jupiter

Flow properties and aerodynamics are computed with a direct simulation Monte Carlo (DSMC) method for rarefied entry of the Galileo Probe into the atmosphere of Jupiter. Accurate predictions of vehicle drag coefficients are needed in order to assess atmospheric properties from the onboard Atmosphere Structure Experiment where highly-sensitive accelerometers will measure the drag force to within 10-6 barr during the initial entry phase at high altitudes. The corresponding flow rarefraction extends from the free molecule limit to the near continuum transition regime (Re less than 1000). Simulation results indicate that C(sub D) varies from 2.1 at the free molecule limit down to 1.6 at Re(infinity) = 1,000. Temperatures, densities, and internal energies throughout the flow field were also computed at each altitude ranging from 735 km to 353 km above the 1 barr level in the Jovian atmosphere. Surface heating and temperatures of the probe were computed directly in the DSMC code by assuming radiative equilibrium. Material response was re-asssessed accurately during entry by accounting for conductivity, heat capacity, and pyrolysis which led to surface material mass efflux several times that of the freestream mass influx. The simulation also accounted for the quantum nature of the rotational energy mode of the dominant atmospheric species H2 through partial internal excitation in the freestream gas

Gender, war and militarism: making and questioning the links

The gender dynamics of militarism have traditionally been seen as straightforward, given the cultural mythologies of warfare and the disciplining of ‘masculinity’ that occurs in the training and use of men's capacity for violence in the armed services. However, women's relation to both war and peace has been varied and complex. It is women who have often been most prominent in working for peace, although there are no necessary links between women and opposition to militarism. In addition, more women than ever are serving in many of today's armies, with feminists rather uncertain on how to relate to this phenomenon. In this article, I explore some of the complexities of applying gender analyses to militarism and peace work in sites of conflict today, looking most closely at the Israeli feminist group, New Profile, and their insistence upon the costs of the militarized nature of Israeli society. They expose the very permeable boundaries between the military and civil society, as violence seeps into the fears and practices of everyday life in Israel. I place their work in the context of broader feminist analysis offered by researchers such as Cynthia Enloe and Cynthia Cockburn, who have for decades been writing about the ‘masculinist’ postures and practices of warfare, as well as the situation of women caught up in them. Finally, I suggest that rethinking the gendered nature of warfare must also encompass the costs of war to men, whose fundamental vulnerability to psychological abuse and physical injury is often downplayed, whether in mainstream accounts of warfare or in more specific gender analysis. Feminists need to pay careful attention to masculinity and its fragmentations in addressing the topic of gender, war and militarism

Strategic distortions in analyst forecasts in the presence of short-term institutional investors

We document that analysts cater to short - term investors by issuing optimistic target prices. Catering dominates among analysts at brokers without an investment banking arm as they face lower reputational cost. The market does not see through the analyst catering activity and their forecasts lead to temporary stock overpricing that short - term institutional investors exploit to offload their holdings to retail traders. We also report evidence consistent with catering brokers being rewarded with more future trades channelled through them. Our study identifies a new source of conflicts of interest in analyst research originating from the ownership composition of a stock

Noncyclic covers of knot complements

Hempel has shown that the fundamental groups of knot complements are residually finite. This implies that every nontrivial knot must have a finite-sheeted, noncyclic cover. We give an explicit bound, $\Phi (c)$, such that if $K$ is a nontrivial knot in the three-sphere with a diagram with $c$ crossings and a particularly simple JSJ decomposition then the complement of $K$ has a finite-sheeted, noncyclic cover with at most $\Phi (c)$ sheets.Comment: 29 pages, 8 figures, from Ph.D. thesis at Columbia University; Acknowledgments added; Content correcte

Deep far infrared ISOPHOT survey in "Selected Area 57", I. Observations and source counts

We present here the results of a deep survey in a 0.4 sq.deg. blank field in Selected Area 57 conducted with the ISOPHOT instrument aboard ESAs Infrared Space Observatory (ISO) at both 60 um and 90 um. The resulting sky maps have a spatial resolution of 15 x 23 sq.arcsec. per pixel which is much higher than the 90 x 90 sq.arcsec. pixels of the IRAS All Sky Survey. We describe the main instrumental effects encountered in our data, outline our data reduction and analysis scheme and present astrometry and photometry of the detected point sources. With a formal signal to noise ratio of 6.75 we have source detection limits of 90 mJy at 60 um and 50 mJy at 90 um. To these limits we find cumulated number densities of 5+-3.5 per sq.deg. at 60 um and 14.8+-5.0 per sq.deg.at 90 um. These number densities of sources are found to be lower than previously reported results from ISO but the data do not allow us to discriminate between no-evolution scenarios and various evolutionary models.Comment: 15 pages, 11 figures, accepted by Astronomy & Astrophysic