Separating the influences of environment and species interactions on patterns of distribution and abundance : competition between large herbivores

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Much recent research has focused on the use of species distribution models to explore the influence(s) of environment (predominantly climate) on species’ distributions. A weakness of this approach is that it typically does not consider effects of biotic interactions, including competition, on species’ distributions.
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Here we identify and quantify the contribution of environmental factors relative to biotic factors (interspecific competition) to the distribution and abundance of three large, wide-ranging herbivores, the antilopine wallaroo (Macropus antilopinus), common wallaroo (Macropus robustus) and eastern grey kangaroo (Macropus giganteus), across an extensive zone of sympatry in tropical northern Australia.
* 3
To assess the importance of competition relative to habitat features, we constructed models of abundance for each species incorporating habitat only and habitat + the abundance of the other species, and compared their respective likelihoods using Akaike's information criterion. We further assessed the importance of variables predicting abundance across models for each species.
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The best-supported models of antilopine wallaroo and eastern grey kangaroo abundance included both habitat and the abundance of the other species, providing evidence of interspecific competition. Contrastingly, models of common wallaroo abundance were largely influenced by climate and not the abundance of other species. The abundance of antilopine wallaroos was most influenced by water availability, eastern grey kangaroo abundance and the frequency of late season fires. The abundance of eastern grey kangaroos was most influenced by aspects of climate, antilopine wallaroo abundance and a measure of cattle abundance.
* 5
Our study demonstrates that where census and habitat data are available, it is possible to reveal species’ interactions (and measure their relative strength and direction) between large, mobile and/or widely-distributed species for which competition is difficult to demonstrate experimentally. This allows discrimination of the influences of environmental factors and species interactions on species’ distributions, and should therefore improve the predictive power of species distribution models.

The increasing criminalization of economic law : a competition law perspective

Purpose – The purpose of this paper is to examine the trend towards the criminalization of hard core cartel conduct and to consider the appropriateness and effectiveness of extending the criminal law to this conduct. In addition, it will consider some of the legal implications, including the exposure of directors of companies to potential racketeering charges.
Design/methodology/approach – The paper first examines cartel theory and the justification for prohibition. The paper then identifies the emerging trend toward criminalization of hard core cartel conduct, followed by an assessment of potential justifications for criminalization. Implications of criminalization, including the potential impact of organized crime legislation on offenders and regulators, will then be considered.
Findings – There is a clear trend towards the criminalization of hard core cartels. The paper argues that this trend is appropriate, both because of the moral culpability it attracts and because of its potential to enhance general deterrence. The paper also argues that cartel conduct, in jurisdictions in which it is criminalized, will constitute “organized crime” as defined in the Palermo Convention and, as such, expose participants to potential money laundering and asset forfeiture consequences.
Originality/value – This paper is of value to governments and regulators considering adoption or implementation of a criminal cartel regime and to practitioners in advising clients about potential consequences of cartel conduct within a criminal regime.

Optical phase change at the interface between mica and thin silver film

We describe a simple experiment which allows unequivocal determination of optical phase change upon reflection of light at the mica-silver interface. While the physical origin of such a phase change at the dielectric-metal interface is well understood to lie in absorption of electromagnetic energy by the metal, inconsistency and ambiguity has persisted as to what its sign and magnitude should be in the field of thin film optics. Most commonly, it has been assigned to be negative for mathematical convenience or just arbitrarily. Our finding shows that with the convention exp(-iωt) for time dependence of the electromagnetic wave, the phase change at the interface between mica and the thin silver film is necessarily positive and its magnitude falls between π and 3π/2 for silver thicknesses down to nanometres. This gives a physically reasonable correspondence to an increased equivalent thickness of the dielectric material, and it clarifies the assignment of interference orders in the harmonic series in a spectrum.

Software developer policies : economics and s 46 of the Competition and Consumer Act 2010

This article considers the impact of developer policies that hinder or restrict cross platform application development. We suggest that policies that hinder or restrict cross platform development have the potential to erode competition within the market for smartphones. The article also considers the relevance of dominance measures in software markets, arguing that conventional economic approaches may not be applicable. Furthermore, while most monitoring activities tend to focus primarily on protection of consumers, the article points out that modern electronic/information technology markets are multi-sided and there is a need for monitoring of practices designed to attract and retain the favour of developers. While the article is written in the context and application of the applicable Australian legislation, this being s 46 of the Competition and Consumer Act 2010 (Cth), our findings are equally relevant to other jurisdictions.

Kinetic effects of halide ions on the morphological evolution of silver nanoplates

Time-resolved extinction spectroscopy is employed to study the reaction kinetics in the shape-conversion reaction involving halide ions (including Cl-, Br- and I-) etching (sculpturing) silver nanoplates. A series of time-resolved extinction spectra are obtained during the in situ etching process and the evolution of surface plasmon resonance (SPR) of the silver nanoparticles is analyzed. Spectral analysis indicates that the conversion of nanoprisms starts simultaneously with the emergence of nanodisks when the halide ions are added. The etching rate of different halide ions is evaluated through the in-plane dipole resonance peak intensity of silver nanoplates vs. the reaction time (dI/dt). The relationship between the etching rate and the halide ion concentration shows that the halide ion etching reaction can be considered as a pseudo-first-order reaction. The effect of different halide ions on the shape-conversion of silver nanoplates is compared in detail. The activation energy of the etching reaction is calculated, which indicates that the etching ability of different halide ions is on the order of Cl - < I- < Br-.

Photochemical formation of silver nanodecahedra : structural selection by the excitation wavelength

Silver decahedra have been successfully synthesized with high yield via a photochemical reaction using blue light-emitting diodes (LEDs) as the exciting light source. The decahedra display distinct properties with respect to the ability of light scattering. The photochemical growth process of silver decahedra was monitored by both extinction and scattering spectral evolution. A suggested formation mechanism of silver decahedron is discussed.

Photoinduced shape conversion and reconstruction of silver nanoprisms

A series of shapes of silver nanoplates were achieved by adjusting the concentration of citrate in the colloid in the photoinduced process. The local surface plasmon resonance (LSPR) of the silver nanoplates could be tuned gradually in a range from 740 to 440 nm. In contrast, the LSPR band can be photomediated again to the long wavelength region within 620-690 nm only by adding more citrate to the colloidal system. The initial silver nanoprisms converted to the discal shape under the light effect. In this conversion, the coupling effect of the plasmon resonance and the light source speeds up the photothermal reaction. Subsequently, the reconstruction of silver nanoprisms from the nanodisks took place in the presence of more citrate through the photoconversion.

The facet selectivity of inorganic ions on silver nanocrystals in etching reactions

The facet selectivity of the halide ions and chlorauric acid for several shaped silver nanocrystals is presented in this paper. Two inorganic ions show different representations when they are used for etching silver nanocrystals in the self-sacrificial template reaction. The morphological changes of the silver nanocrystals indicate that the halide ions prefer to etch the (110) facets of silver nanocrystals, while in the chlorauric acid etching reaction, gold first modifies the (110) facets and then lets chlorauric acid etch the (111) facets instead. The selective facet etching on individual nanoparticles in the solution phase has crucial significance in the control-synthesis of nanocrystals and the facet asymmetric reaction.

Real-time, in-situ, extinction spectroscopy studies on silver-nanoseed formation

In this paper, real-time extinction spectroscopy was employed to analyze in situ the fast formation process of silver seeds. The influencing factors for silver-seed formation, including the concentration of the reducer (NaBH 4), the amount of stabilizer (citrate), and the addition procedure of NaBH4, were evaluated. The configuration of the surface plasmon resonance (SPR) spectra of silver nanoparticles, which reflected the morphology of the produced silver seeds, was found to be distinctly affected by the NaBH4 concentration. Homogeneous silver nanoparticles were obtained when the added NaBH4 was lower in concentration than 2.00 mM. In contrast, higher concentrations of reducing agent (>3.00 mM NaBH4) resulted in uneven silver nanoparticles. Mie theory was applied to clarify the correlation of the SPR and the size of the silver seeds. Repeated additions of a small amount of the reducing agent could increase the monodispersity and isotropy of silver seeds. Real-time extinction spectroscopy is a convenient technique that achieves the in-situ and nondestructive measurement of intermediates in the formation process of silver nanoseeds.

Competition : the heart and soul of sport management

Understanding competition is central to the task of strategy formulation and implementation and it is the link between competition and strategy that was explored in the 2011 Dr. Earle F. Zeigler Lecture. It was argued that strategy, given its centrality to organizational phenomena, and strategy research in particular, provides rich and diverse competitive contexts with the potential to reveal some of the unique properties of sport management. To ascertain the prevalence of sport-related strategy research, three sport management journals were subject to content analysis to identify published manuscripts related to strategy. Before presenting the results, the Lecture considered competition on and off the field, the origins of competitive behavior in sport management and a brief review of the major research themes in the generic strategic management literature. Results revealed that 20 (2.5%) of the 805 manuscripts published in the three journals were strategy focused. Research themes and contexts were presented as well as a bibliometric analysis of the reference lists of the 20 identified strategy manuscripts. This analysis highlighted the journals that are influencing published sport management strategy-related research. It was concluded that strategy research specific to sport management has been sparse to date, yet the role of strategy formulation is central to the role of management and should also be central to sport management scholarship.

Experiences of Australian professional female tennis players returning to competition from injury

Background: This study examined the experiences of professional female tennis players returning to competition from injury.

Methods: In a study commissioned by Tennis Australia, 55 Australian professional female tennis players responded anonymously to a questionnaire developed for the purposes of this study. The questionnaire consisted of open and closed questions that assessed a player’s attribution style, the occurrence and effect of minor and major injuries, frequency and type of treatment sought, attitudinal chances following injury and preventative injury factors.

Results: The quantitative and qualitative analyses of participants’ responses revealed players generally displayed an internal attribution style with the majority of minor injuries involving lower limb injuries (attributed to playing on hard surfaces). Players reported these injuries were addressed in a variety of ways including self-treatment. The majority of severe injuries were upper limb/shoulder and these were generally treated at tournament sites with some requiring surgery.

Conclusions: Players adopted a range of measures to assist recovery from severe injury including the services of health professionals. In further findings, a player’s attribution style was not a predictive variable, except in terms of the number of tournaments missed for minor injuries. Implications of the study’s results and future research directions for cross-cultural studies are highlighted.