The RR Lyrae Star Period - K-band Luminosity Relation of the Globular Cluster M3

That the RR Lyrae star period -- K-band luminosity relation is a promising tool as a distance indicator in the Milky Way and Local Group of Galaxies is apparent on observational and theoretical grounds in the literature. Less clear is the sensitivity of the relation, and consequently the physics of horizontal branch stars, to differences in stellar environment. In this paper, the first measurement of the (fundamental) period -- K-band luminosity relation for the central region of a globular cluster is presented. It is based on a sample of seven RR Lyrae stars imaged with adaptive optics. In addition, the relation for the outer region has been reanalyzed, and is found to be in good agreement with both the previous estimate by Longmore et al. (1990), and with the inner region relation, especially when irregular and double-mode RR Lyrae stars are excluded. Importantly, there is no difference between the slope of the inner and outer region relation within measurement uncertainties, suggesting no difference in evolutionary state (luminosity). Taking the M3 distance modulus as 15.0 +/- 0.07mag, the period -- absolute K-band magnitude relation derived by linear least squares fitting is: M_K = -0.96 (+/- 0.10) - 2.42 (+/- 0.16)Log Po for the inner region. Excluding irregular variable stars, the outer region relation is: M_K = -1.07 (+/- 0.10) - 2.38 (+/- 0.15)Log Po. This good agreement provides further strong support for the near-IR period-luminosity relation as a distance indicator.Comment: Accepted for publication in Astronomy & Astrophysics, 10 pages, 5 figure

Custom and capital: a financial appraisal of alternative arrangements for large-scale oil palm development on customary land in Sarawak, Malaysia

The oil palm boom in Southeast Asia has increased demand for institutional arrangements facilitating large-scale plantation development on customary lands. A financial model of an oil palm plantation in Sarawak, Malaysia, is used to explore six project types, including managed smallholders, three different joint-venture arrangements, renting, and (for comparison) a private plantation on state land. Benefit-cost analysis is used as the basis for project, private (shareholder), and stakeholder analyses. There is a trade-off between the efficiency and equity outcomes of the alternative arrangements as modelled. While joint venture projects provide higher aggregate net benefits, managed smallholder projects provide more benefits to landholders. When the actual performance of the alternative schemes is taken into account, the managed smallholder approach is superior on both efficiency and equity grounds. The joint venture approach could be improved by paying advance dividends or combining a fixed rent with a share of dividends to reduce the income risk faced by landholders. In all cases, improved management is needed for the schemes to achieve their developmental potential