Ricci-flat K\"ahler metrics on crepant resolutions of K\"ahler cones

We prove that a crepant resolution of a Ricci-flat K\"ahler cone X admits a complete Ricci-flat K\"ahler metric asymptotic to the cone metric in every K\"ahler class in H^2_c(Y,R). This result contains as a subcase the existence of ALE Ricci-flat K\"ahler metrics on crepant resolutions of X=C^n /G, where G is a finite subgroup of SL(n,C). We consider the case in which X is toric. A result of A. Futaki, H. Ono, and G. Wang guarantees the existence of a Ricci-flat K\"ahler cone metric if X is Gorenstein. We use toric geometry to construct crepant resolutions.Comment: 26 pages. Accepted for publication in Mathematische Annale

Effects of a peer-led Walking In ScHools intervention (the WISH study) on physical activity levels of adolescent girls: a cluster randomised pilot study.

School-based interventions may be effective at increasing levels of physical activity (PA) among adolescents; however, there is a paucity of evidence on whether walking can be successfully promoted to increase PA in this age group. This pilot study aimed to assess the effects of a 12-week school-based peer-led brisk walking programme on levels of school-time PA post intervention

Re-evaluating the impact of urban form on travel patterns in Europe and North America

The work by Newman, Kenworthy and colleagues on the link between land use, transportation systems and travel patterns and energy use has been received enthusiastically but also criticised strongly. In this paper concerns are expressed about the role accorded to individual travellers and the wider space-time context of cities in the empirical-analytical work by Kenworthy and colleagues. To investigate the seriousness of these concerns, the data collected by Kenworthy and colleagues for European, Canadian and US cities in 1990 have been augmented with information on housing, urban development history and the sociodemographic situation. Regression models are described in which the role of urban form is investigated while account is taken of other relevant factors. The empirical analysis suggests that the space-time context of cities should be taken into account in aggregate-level comparisons of the relations between urban form and transport. Policy recommendations based on the original data may be reconsidered and tailored to the space-time context and population characteristics of cities

Aviation as public transport: which regions are underserved?

The White Book on Transport of the European Union deals with Roads, Rail, Inland waterway, Seaways, Pipelines, Energy-networks but only briefly with airports. The emphasis in the White Book is on the modal shift from aviation to high speed rail transport. The Lisbon-strategy, however, advocates an optimal international connectivity for regions. A high speed rail connection is not a viable option for a lot of less densily populated area’s whereas an air connection is. For this reason the Committee of regions also pleads for aviation as an instrument for territorial cohesion. In several countries public transport (bus tram subway train) within regions is a political priority and is (heavily) subsidized. The regulations to connect regions to the international air-traffic network are very limited. For underdeveloped and underserved regions a Public Service Obligation for aviation is eligible. Some EU-countries (for instance Norway, Portugal, France and Ireland) make use of this instrument whereas other countries spend nothing. These differences in terms of the degree states have adopted the PSO mechanism in respect of air transport services poses an number of questions. What kind of regions are served by a Public Service Obligation ? Is it their geographic position (Islands), their demographic or socio-economic position which make them eligible? Which other (comparable) regions are underserved? What are the costs involved ? In order to answer these type of questions we have investigated the international connectivity by air of all regions within the EU for the period 1996-2005. We compare regions with a PSO with regions without PSO which are underserved by air transport. This paper answers some of the questions which are important for future policy initiatives designed to enhance accessibility and economic and social cohesion