Introduction: Latin American gentrifications

Currently, Latin American cities are seeing simultaneous processes of reinvestment and redevelopment in their historic central areas. These are not just mega-scale interventions like Porto Maravilha in Rio or Puerto Madero in Buenos Aires or the luxury renovations seen in Santa Fé or Nueva Polanco in Mexico City, they also include state-led, piecemeal, high-rise interventions in Santiago, Buenos Aires, Rio de Janeiro, Panamá and Bogotá, all of which are causing the displacement of original populations and thus are forms of gentrification. Until very recently, these processes have been under-conceptualized and little critiqued in Latin America, but they deserve careful scrutiny, along with new forms of neighbourhood organization, activism and resistance. In this introduction, we begin that task, drawing on the work begun in an Urban Studies Foundation-funded workshop on Global Gentrification held in Santiago, Chile in 2012. Our aim is not just to understand these urban changes and conflicts as gentrification, but to empirically test the applicability of a generic understanding of gentrification beyond the usual narratives of/from the global North. From this investigation, we hope to nurture new critical narratives, to engage sensitively with indigenous theoretical narratives and to understand the dialectical interplay between state policies, financial markets, local politics and people. The papers in this special issue deal with the core issues of state power and urban policies (exerted at metropolitan and neighbourhood scales), the enormous influx of financial investment in derelict neighbourhoods that produces exclusion and segregation, the significant loss of urban heritage from rapidly “renewing” neighbourhoods and the institutional arrangements that can enable anti-displacement activism and self-managed social housing production. Full text HTML PD

Low-Mass Eclipsing Binaries in the Initial Kepler Data Release

We identify 231 objects in the newly released Cycle 0 dataset from the Kepler Mission as double-eclipse, detached eclipsing binary systems with Teff < 5500 K and orbital periods shorter than ~32 days. We model each light curve using the JKTEBOP code with a genetic algorithm to obtain precise values for each system. We identify 95 new systems with both components below 1.0 M_sun and eclipses of at least 0.1 magnitudes, suitable for ground-based follow-up. Of these, 14 have periods less than 1.0 day, 52 have periods between 1.0 and 10.0 days, and 29 have periods greater than 10.0 days. This new sample of main-sequence, low-mass, double-eclipse, detached eclipsing binary candidates more than doubles the number of previously known systems, and extends the sample into the completely heretofore unexplored P > 10.0 day period regime. We find preliminary evidence from these systems that the radii of low-mass stars in binary systems decrease with period. This supports the theory that binary spin-up is the primary cause of inflated radii in low-mass binary systems, although a full analysis of each system with radial-velocity and multi-color light curves is needed to fully explore this hypothesis. As well, we present 7 new transiting planet candidates that do not appear among the recently released list of 706 candidates by the Kepler team, nor in the Kepler False Positive Catalog, along with several other new and interesting systems. We also present novel techniques for the identification, period analysis, and modeling of eclipsing binaries.Comment: 22 pages in emulateapj format. 9 figures, 4 tables, 2 appendices. Accepted to AJ. Includes a significant addition of new material since last arXiv submission and an updated method for estimating masses and radi

Brightness variations in totally-eclipsing binary GSC4589-2999

We present multi-colour CCD photometry of GSC4589-2999 obtained in 2008 and 2009. The observations indicate that the system is an active Algol binary. Based on the new data, the mean brightness of the system is decreasing through the years 2007-2009. The light curves obtained in 2008-2009 are modelled using the Wilson-Devinney code. We also discussed the light and colour variations of the system at different orbital phases. Evidence suggests that these brightness and colour variations are due to the rotation of unevenly distributed starspots on two components of the system.Comment: 17 pages, 3 figures, 3 table

Kepler Cycle 1 Observations of Low Mass Stars: New Eclipsing Binaries, Single Star Rotation Rates, and the Nature and Frequency of Starspots

We have analyzed Kepler light curves for 849 stars with T_eff < 5200 K from our Cycle 1 Guest Observer program. We identify six new eclipsing binaries, one of which has an orbital period of 29.91 d, and two of which are probably W UMa variables. In addition, we identify a candidate "warm Jupiter" exoplanet. We further examine a subset of 670 sources for variability. Of these objects, 265 stars clearly show periodic variability that we assign to rotation of the low-mass star. At the photometric precision level provided by Kepler, 251 of our objects showed no evidence for variability. We were unable to determine periods for 154 variable objects. We find that 79% of stars with T_eff < 5200 K are variable. The rotation periods we derive for the periodic variables span the range 0.31 < P_rot < 126.5 d. A considerable number of stars with rotation periods similar to the solar value show activity levels that are 100 times higher than the Sun. This is consistent with results for solar-like field stars. As has been found in previous studies, stars with shorter rotation periods generally exhibit larger modulations. This trend flattens beyond P_rot = 25 d, demonstrating that even long period binaries may still have components with high levels of activity and investigating whether the masses and radii of the stellar components in these systems are consistent with stellar models could remain problematic. Surprisingly, our modeling of the light curves suggests that the active regions on these cool stars are either preferentially located near the rotational poles, or that there are two spot groups located at lower latitudes, but in opposing hemispheres.Comment: 48 pages, 11 figure