Are power laws that estimate fractal dimension a good descriptor of soil structure and its link to soil biological properties?

The study of interrelationships between soil structure and its functional properties is complicated by the fact that the quantitative description of soil structure is challenging. Soil scientists have tackled this challenge by taking advantage of approaches such as fractal geometry, which describes soil architectural complexity through a scaling exponent (D) relating mass and numbers of particles/aggregates to particle/aggregate size. Typically, soil biologists use empirical indices such as mean weight diameters (MWD) and percent of water stable aggregates (WSA), or the entire size distribution, and they have successfully related these indices to key soil features such as C and N dynamics and biological promoters of soil structure. Here, we focused on D, WSA and MWD and we tested whether: D estimated by the exponent of the power law of number-size distributions is a good and consistent correlate of MWD and WSA; D carries information that differs from MWD and WSA; the fraction of variation in D that is uncorrelated with MWD and WSA is related to soil chemical and biological properties that are thought to establish interdependence with soil structure (e.g., organic C, N, arbuscular mycorrhizal fungi). We analysed observational data from a broad scale field study and results from a greenhouse experiment where arbuscular mycorrhizal fungi (AMF) and collembola altered soil structure. We were able to develop empirical models that account for a highly significant and large portion of the correlation observed between WSA and MWD but we did not uncover the mechanisms that underlie this correlation. We conclude that most of the covariance between D and soil biotic (AMF, plant roots) and abiotic (C. N) properties can be accounted for by WSA and MWD. This result implies that the ecological effects of the fragmentation properties described by D and generally discussed under the framework of fractal models can be interpreted under the intuitive perspective of simpler indices and we suggest that the biotic components mostly impacted the largest size fractions, which dominate MWD, WSA and the scaling exponent ruling number-size distributions. (C) 2010 Elsevier Ltd. All rights reserved.

“Shall we playe the good girles”: Playing Girls, Performing Girlhood on Early Modern Stages

This essay investigates the extent to which girlhood functions as a queer category in two theatrical representations of schoolgirls in early seventeenth-century England. It focuses on the depictions of schoolgirls in the anonymous The Wit of a Woman (1604), written for the all-male stage of the professional theatre, and in Robert White’s masque, Cupid’s Banishment (1617), performed by the young Ladies of Deptford Hall before Queen Anna of Denmark, to examine the intersections of age, gender, sexuality and education in early modern concepts of girlhood. Situating these plays within wider debates about female education and the history of the contested role of performance in the schooling of early modern girls, it argues that they deploy the category of girlhood to demonstrate the subversive potential of educating girls. Yet, this essay proposes, these plays simultaneously reveal the potential agency of young women who manipulate girlhood to claim their distinct sexual, aged and gendered states as girls. It argues that early modern girlhood is a state that might be performed by young women to disrupt normative expectations of feminine behaviour and desire. Placing dramatic representations of schoolgirls and the experiences of schoolgirls on the early modern stage side by side, this essay demonstrates that the schoolroom and performance are sites in which this transgressive potential is realised.

A Study of Tower Shadow Effect on Fixed-Speed Wind Turbines

This paper studies the impact of tower shadow effect on the power output of a fixed-speed wind farm. A data acquisition unit was placed at a wind farm in Northern Ireland which consists of ten fixed-speed wind turbines. The recording equipment logged the wind farmpsilas electrical data, which was time stamped using the global positioning network. Video footage of the wind farm was recorded and from it the blade angle of each turbine was determined with respect to time. Using the blade angle data and the wind farmpsilas power output, studies where performed to ascertain the extent of tower shadow effect on power fluctuation. This paper presents evidence that suggests that tower shadow effect has a significant impact on power fluctuation and that this effect is increased due to the synchronising of turbine blades around the tower region.

Structure and dynamics of dextran in binary mixtures of a good and a bad solvent

The structure and dynamics of the common polysaccharide dextran have been investigated in mixed solvents at two different temperatures using small-angle X-ray scattering (SAXS) and viscosity measurements. More specifically, binary mixtures of a good solvent (water, formamide, dimethylsulfoxide, ethanolamine) and the bad solvent ethanol as the minority component have been considered. The experimentally observed effects on the polymer conformation (intrinsic viscosity, coil radius, and radius of gyration) of the bad solvent addition are discussed in terms of hydrogen bonding density and are correlated with the Hansen solubility parameters and the surface tension of the solvent mixtures. Hydrogen bonding appears to be an important contributor to the solubility of dextran but is not sufficient to capture the dextran coil contraction in the mixtures of good+bad solvents.

Deconstructing Victim and offender Identities in Discourses on Child Sexual Abuse: Hierarchies, Blame and the Good/Evil Dialectic

Contemporary social and political constructions of victimhood and offending behaviour lie at the heart of regulatory policies on child sexual abuse. Legislation is named after specific child victims of high profile cases, and a burgeoning range of pre-emptive measures are enacted to protect an amorphous class of ‘all potential victims’ from the risk sex offenders are seen as posing. Such policies are also heavily premised on the omnipresent predatory stranger. These constructed identities, however, are at odds with the actual identities of victims and offenders of such crimes. Drawing on a range of literatures, the core task of this article is to confront some of the complexities and tensions surrounding constructions of the victim/offender dyad within the specific context of sexual offending against children. In particular, the article argues that discourses on ‘blame’ – and the polarised notions of ‘innocence’ and ‘guilt’ – inform respective hierarchies of victimhood and offending concerning ‘legitimate’ victim and offender status. Based on these insights, the article argues for the need to move beyond such monochromatic understandings of victims and offenders of sexual crime and to reframe the politics of risk accordingly.