Skateboarding in Place: Creating and Reclaiming Namescapes Through Skatescapes

This exploration paper considers the sport/art/activity of skateboarding as it intertwines with spatial experiences, identities, and our personal and kinetic vernaculars. I try to understand what skateboarders, and Indigenous skateboarders especially, can teach us about alternative ways to understand space, place, and identity. I posit that skateboarding encourages spatial comprehension and landscape-use in particular ways, what I think of as a skatescape: a landscape as seen through skateboarders’ eyes. Through a skateboarding media and art lens, I reflect on some ways in which skateboarding influences narratives of place and belonging. I then consider these personal narratives and attempt to broaden the definition of a skatescape and in so doing speculate on how we create, share, and navigate our unique and personal spatial languages through movement and presence. Finally, I reveal that appreciating Indigenous skatescapes has illuminated a blindspot in my settler psyche: that up until recently I had not acknowledged fully that each and every spot I have ever skated was and is Indigenous land

Doubly Robust Inference when Combining Probability and Non-probability Samples with High-dimensional Data

Non-probability samples become increasingly popular in survey statistics but may suffer from selection biases that limit the generalizability of results to the target population. We consider integrating a non-probability sample with a probability sample which provides high-dimensional representative covariate information of the target population. We propose a two-step approach for variable selection and finite population inference. In the first step, we use penalized estimating equations with folded-concave penalties to select important variables for the sampling score of selection into the non-probability sample and the outcome model. We show that the penalized estimating equation approach enjoys the selection consistency property for general probability samples. The major technical hurdle is due to the possible dependence of the sample under the finite population framework. To overcome this challenge, we construct martingales which enable us to apply Bernstein concentration inequality for martingales. In the second step, we focus on a doubly robust estimator of the finite population mean and re-estimate the nuisance model parameters by minimizing the asymptotic squared bias of the doubly robust estimator. This estimating strategy mitigates the possible first-step selection error and renders the doubly robust estimator root-n consistent if either the sampling probability or the outcome model is correctly specified

Mechanisms of light energy harvesting in dendrimers and hyperbranched polymers

Since their earliest synthesis, much interest has arisen in the use of dendritic and structurally allied forms of polymer for light energy harvesting, especially as organic adjuncts for solar energy devices. With the facility to accommodate a proliferation of antenna chromophores, such materials can capture and channel light energy with a high degree of efficiency, each polymer unit potentially delivering the energy of one photon-or more, when optical nonlinearity is involved. To ensure the highest efficiency of operation, it is essential to understand the processes responsible for photon capture and channelling of the resulting electronic excitation. Highlighting the latest theoretical advances, this paper reviews the principal mechanisms, which prove to involve a complex interplay of structural, spectroscopic and electrodynamic properties. Designing materials with the capacity to capture and control light energy facilitates applications that now extend from solar energy to medical photonics. © 2011 by the authors; licensee MDPI, Basel, Switzerland

Selective detection of guanosine-5 '-triphosphate and iodide by fluorescent benzimidazolium-based cyclophanes

New fluorescent benzimidazolium-based receptors selectively display the effective fluorescence quenching effect for biologically important anions, GTP and I-, in aqueous solution of physiological pH 7.4. These affinities can be attributed to the strong ionic H-bonding along with additional interactions of fluorophore moieties with the nucleic base of GTP and I -close3