The RR Lyrae Distance Scale

We review seven methods of measuring the absolute magnitude M_V of RR Lyrae stars in light of the Hipparcos mission and other recent developments. We focus on identifying possible systematic errors and rank the methods by relative immunity to such errors. For the three most robust methods, statistical parallax, trigonometric parallax, and cluster kinematics, we find M_V (at [Fe/H] = -1.6) of 0.77 +/- 0.13, 0.71 +/- 0.15, 0.67 +/- 0.10. These methods cluster consistently around 0.71 +/- 0.07. We find that Baade-Wesselink and theoretical models both yield a broad range of possible values (0.45-0.70 and 0.45-0.65) due to systematic uncertainties in the temperature scale and input physics. Main-sequence fitting gives a much brighter M_V = 0.45 +/- 0.04 but this may be due to a difference in the metallicity scales of the cluster giants and the calibrating subdwarfs. White-dwarf cooling-sequence fitting gives 0.67 +/- 0.13 and is potentially very robust, but at present is too new to be fully tested for systematics. If the three most robust methods are combined with Walker's mean measurement for 6 LMC clusters, V_{0,LMC} = 18.98 +/- 0.03 at [Fe/H] = -1.9, then mu_{LMC} = 18.33 +/- 0.08.Comment: Invited review article to appear in: `Post-Hipparcos Cosmic Candles', A. Heck & F. Caputo (Eds), Kluwer Academic Publ., Dordrecht, in press. 21 pages including 1 table; uses Kluwer's crckapb.sty LaTeX style file, enclose

Globular Cluster Distance Determinations

The present status of the distance scale to Galactic globular clusters is reviewed. Six distance determination techniques which are deemed to be most reliable are discussed in depth. These different techniques are used to calibrate the absolute magnitude of the RR Lyrae stars. The various calibrations fall into three groups. Main sequence fitting using Hipparcos parallaxes, theoretical HB models and the RR Lyrae in the LMC all favor a bright calibration, implying a `long' globular cluster distance scale. White dwarf fitting and the astrometric distances yield a somewhat fainter RR Lyrae calibration, while the statistical parallax solution yields faint RR Lyrae stars implying a `short' distance scale to globular clusters. Various secondary distance indicators discussed all favor the long distance scale. The `long' and `short' distance scales differ by (0.31+/-0.16) mag. Averaging together all of the different distance determinations yields Mv(RR) = (0.23+/-0.04)([Fe/H] + 1.6) + (0.56+/-0.12) mag.Comment: Invited review article to appear in: `Post-Hipparcos Cosmic Candles', A. Heck & F. Caputo (Eds), Kluwer Academic Publ., Dordrecht, in pres

Relativistic Binaries in Globular Clusters

Galactic globular clusters are old, dense star systems typically containing 10\super{4}--10\super{7} stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of hard binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct {\it N}-body integrations and Fokker--Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.Comment: 88 pages, 13 figures. Submitted update of Living Reviews articl

Co-constructing cultural ecosystem services and wellbeing through a place-based approach

Reductive practices in fisheries management have tended to focus on ecological and economic dimensions that have rendered the social and cultural importance of fishing largely invisible, at least in the context of governance and policy making. This chapter builds on 5 years’ research in the English Channel and Southern North Sea in which the authors adopted a sense of place perspective as a framework for understanding the social and cultural value of small-scale fisheries. Through a number of case studies, the chapter describes how small-scale fisheries result in a series of ‘transformations’ as the marine environment is translated into cultural ecosystem services in coastal settings giving rise to socio-cultural value. This perspective is further developed by considering the value of the social wellbeing ‘lens’ to broaden the sense of place / cultural ecosystem services framework. In pursuing ‘values’ through sense of place, cultural ecosystem services and social wellbeing we discuss how the dualistic treatment of nature and society is problematic. We conclude that a relational co-constructionist approach, although challenging, offers a way of making visible an array of social and cultural values that emerge from the activity of small-scale fisheries

Monoclonal antibodies defined abnormalities of T-lymphocytes in type I (insulin-dependent) diabetes.

Peripheral T-lymphocytes subsets have been investigated in 36 patients with type I (insulin-dependent) diabetes of varying duration, 18 patients with type II (non-insulin-dependent) diabetes, and in 23 healthy subjects, using six different monoclonal antibodies. At the time of diagnosis of type I diabetes, there was evidence of an increase in cytotoxic T-lymphocytes, a decrease in suppressor T-lymphocytes, but a normal proportion of helper/inducer T-lymphocytes. In six of seven newly diagnosed cases studied, there was evidence of an increased number of activated T cells. An increase in activated T-cells was also found in 5 of 10 genetically susceptible islet cell antibody positive unaffected siblings in type I diabetic probands. In type I diabetes of long standing, the total T-cell population was decreased, largely due to a marked decrease in helper/inducer T-lymphocytes. Type II diabetic patients showed no abnormalities in T-lymphocyte subsets, making it unlikely that hyperglycemia was responsible for the changes observed. These results suggest that an imbalance of T-lymphocyte regulation is an important feature of type I diabetes and lend support for an immunologic role in its early pathogenesis