Applying a Dynamic Model of Consumer Choice to Guide Brand Development at Jetstar Airways

This paper describes the use of a marketing science model by Jetstar, a subsidiary of Australia's leading airline, Qantas, to effectively and profitably compete in the low-cost carrier marketplace. We trace the evolution of the Jetstar strategy from a baseline calibration of its initial position, to its efforts to attain price competitiveness and service parity, followed by its highly focused, cost-effective service delivery strategy. We develop a hierarchical model with parameters estimated at the individual level. This allows us to study not only how service design and pricing initiatives shift the perceived performance of Jetstar relative to its competitors but also how the airline can move market preferences toward areas in which it has competitive advantage. The contribution of the research is substantial. The Jetstar market share went from 14.0% to 18.1% during the first five quarterly waves of the research, and profits went from $79 million in 2006-2007, before the study was commissioned, to$124 million in 2008-2009

Designing to see and share structure in number sequences

This paper reports on a design experiment in the domain of number sequences conducted in the course of the WebLabs project. We iteratively designed and tested a set of activities and tools in which 10-14 year old students used the ToonTalk programming environment to construct models of sequences and series, and then shared their models and their observations about them utilising a webbased collaboration system. We report on the evolution of a design pattern (programming method) called ‘Streams’ which enables students to engage in the process of summing and ‘hold the series in their hand’, and consequently make sophisticated arguments regarding the mathematical structures of the sequences without requiring the use of algebra. While the focus of this paper is mainly on the design of activities, and in particular their epistemological foundations, some illustrative examples of one group of students’ work indicate the potential of the activities and tools for expressing and reflecting on deep mathematical ideas

Thinking in progress

Relates the story of 11-14 year-old students using a programming system to represent and discuss some mathematical ideas in Great Britain. Programming with the Toontalk language; Tools developed within the programming system; Use of programmed models as elements of students' discourse

Macronutrients mediate the functional relationship between Drosophila and Wolbachia

Wolbachia are maternally inherited bacterial endosymbionts that naturally infect a diverse array of arthropods. They are primarily known for their manipulation of host reproductive biology, and recently, infections with Wolbachia have been proposed as a new strategy for controlling insect vectors and subsequent human-transmissible diseases. Yet, Wolbachia abundance has been shown to vary greatly between individuals and the magnitude of the effects of infection on host life-history traits and protection against infection is correlated to within-host Wolbachia abundance. It is therefore essential to better understand the factors that modulate Wolbachia abundance and effects on host fitness. Nutrition is known to be one of the most important mediators of host-symbiont interactions. Here, we used nutritional geometry to quantify the role of macronutrients on insect-Wolbachia relationships in Drosophila melanogaster. Our results show fundamental interactions between diet composition, host diet selection, Wolbachia abundance and effects on host lifespan and fecundity. The results and methods described here open a new avenue in the study of insect-Wolbachia relationships and are of general interest to numerous research disciplines, ranging from nutrition and life-history theory to public health

Suicide Among Aboriginal People in Canada

This report looks at the complex issues that surround Aboriginal suicide in Canad

Solving the Bethe-Salpeter equation for bound states of scalar theories in Minkowski space

We apply the perturbation theory integral representation (PTIR) to solve for the bound state Bethe-Salpeter (BS) vertex for an arbitrary scattering kernel, without the need for any Wick rotation. The results derived are applicable to any scalar field theory (without derivative coupling). It is shown that solving directly for the BS vertex, rather than the BS amplitude, has several major advantages, notably its relative simplicity and superior numerical accuracy. In order to illustrate the generality of the approach we obtain numerical solutions using this formalism for a number of scattering kernels, including cases where the Wick rotation is not possible.Comment: 28 pages of LaTeX, uses psfig.sty with 5 figures. Also available via WWW at http://www.physics.adelaide.edu.au/theory/papers/ADP-97-10.T248-abs.html or via anonymous ftp at ftp://bragg.physics.adelaide.edu.au/pub/theory/ADP-97-10.T248.ps A number of (crucial) typographical errors in Appendix C corrected. To be published in Phys. Rev. D, October 199

Invasion by P. falciparum Merozoites Suggests a Hierarchy of Molecular Interactions

Central to the pathology of malaria disease are the repeated cycles of parasite invasion and destruction of human erythrocytes. In Plasmodium falciparum, the most virulent species causing malaria, erythrocyte invasion involves several specific receptor–ligand interactions that direct the pathway used to invade the host cell, with parasites varying in their dependency on these different pathways. Gene disruption of a key invasion ligand in the 3D7 parasite strain, the P. falciparum reticulocyte binding-like homolog 2b (PfRh2b), resulted in the parasite invading via a novel pathway. Here, we show results that suggest the molecular basis for this novel pathway is not due to a molecular switch but is instead mediated by the redeployment of machinery already present in the parent parasite but masked by the dominant role of PfRh2b. This would suggest that interactions directing invasion are organized hierarchically, where silencing of dominant invasion ligands reveal underlying alternative pathways. This provides wild parasites with the ability to adapt to immune-mediated selection or polymorphism in erythrocyte receptors and has implications for the use of invasion-related molecules in candidate vaccines