On surface subgroups of doubles of free groups

We give several sufficient conditions for a double of a free group along a cyclic subgroup to contain a surface subgroup.Comment: 21 pages, 1 figur

Rotation periods of exoplanet host stars

The stellar rotation periods of ten exoplanet host stars have been determined using newly analysed Ca II H & K flux records from Mount Wilson Observatory and Stromgren b, y photometric measurements from Tennessee State University's automatic photometric telescopes (APTs) at Fairborn Observatory. Five of the rotation periods have not previously been reported, with that of HD 130322 very strongly detected at Prot = 26.1 \pm 3.5 d. The rotation periods of five other stars have been updated using new data. We use the rotation periods to derive the line-of-sight inclinations of the stellar rotation axes, which may be used to probe theories of planet formation and evolution when combined with the planetary orbital inclination found from other methods. Finally, we estimate the masses of fourteen exoplanets under the assumption that the stellar rotation axis is aligned with the orbital axis. We calculate the mass of HD 92788 b (28 MJ) to be within the low-mass brown dwarf regime and suggest that this object warrants further investigation to confirm its true nature.Comment: Accepted for publication in MNRAS. 15 pages, 11 figure

Qualitative Indicators of Social Resilience in Small-Scale Fishing Communities: An Emphasis on Perceptions and Practice

This paper reports on ethnographic research aimed at understanding what resilience means to those living within fishery-dependent communities. We draw on semi-structured and oral history interviews, focus groups, and household and business interviews in four Maine fishing communities to examine the reflections of fishermen and other community members on the past, present, and future of their communities, including the threats they face and how they are able to respond to them. Based on our analysis, we identify broad qualitative indicators of resilience: survival, social identity, diversification, getting by, and optimism. The indicators of resilience that we identify are difficult to fully understand using secondary data and, therefore, we argue that understanding them also requires an ethnographic research approach that focuses on the practices of fishermen and the context in which those fishermen live