The roles of natural and sexual selection during adaptation to a novel environment

The net effect of sexual selection on nonsexual fitness is controversial. On one side, elaborate display traits and preferences for them can be costly, reducing the nonsexual fitness of individuals possessing them, as well as their offspring, In contrast, sexual selection may reinforce nonsexual fitness if an individual's attractiveness and quality are genetically correlated. According to recent models, such good-genes mate choice should increase both the extent and rate of adaptation. We evolved 12 replicate populations of Drosophila serrata in a powerful two-way factorial experimental design to test the separate and combined contributions of natural and sexual selection to adaptation to a novel larval food resource. Populations evolving in the presence of natural selection had significantly higher mean nonsexual fitness when measured over three generations (13-15) during the course of experimental evolution (16-23% increase). The effect of natural selection was even more substantial when measured in a standardized, monogamous mating environment at the end of the experiment (generation 16; 52% increase). In contrast, and despite strong sexual selection on display traits, there was no evidence from any of the four replicate fitness measures that sexual selection promoted adaptation. In addition, a comparison of fitness measures conducted under different mating environments demonstrated a significant direct cost of sexual selection to females, likely arising from some form of male-induced harm. Indirect benefits of sexual selection in promoting adaptation to this novel resource environment therefore appear to be absent in this species, despite prior evidence suggesting the operation of good-genes mate choice in their ancestral environment. How novel environments affect the operation of good-genes mate choice is a fundamental question for future sexual selection research.

Going up? Women in the public sector

Abstract: Purpose – This paper aims to document women's reflections on their careers over a ten-year period to provide quantitative baseline data on which to frame follow-up in-depth interviews. The participants work in the public service in Queensland (Australia) and had been recommended for, and participated in, women in management (WIM) courses conducted in the early 1990s. Design/methodology/approach – Data were collected by means of a survey (containing closed and open items) which gathered demographic data and data related to employment history, perceptions of success and satisfaction, and the women's future career expectations. Findings – Findings revealed that the percentage of women in middle and senior management had increased over the ten-year period, although not to the extent one might have anticipated, given that the women had been targeted as high flyers by their supervisors. While not content with their classification levels (i.e. seniority), the majority of the cohort viewed their careers as being successful. Practical implications – Questions arise from this study as to why women are still “not getting to the top”. There are also policy implications for the public service concerning women's possible “reinventive contribution” and training implications associated with women only courses. Originality/value – The study is part of an Australian longitudinal study on the careers of women who attended a prestigious women-only management course in the early 1990s in Queensland. This is now becoming a study of older women.

Managing change and time in dynamic workflow processes

Business environments have become exceedingly dynamic and competitive in recent times. This dynamism is manifested in the form of changing process requirements and time constraints. Workflow technology is currently one of the most promising fields of research in business process automation. However, workflow systems to date do not provide the flexibility necessary to support the dynamic nature of business processes. In this paper we primarily discuss the issues and challenges related to managing change and time in workflows representing dynamic business processes. We also present an analysis of workflow modifications and provide feasibility considerations for the automation of this process.

A formal framework for modelling and analysing mobile systems

This paper presents a formal framework for modelling and analysing mobile systems. The framework comprises a collection of models of the dominant design paradigms which are readily extended to incorporate details of particular technologies, i.e., programming languages and their run-time support, and applications. The modelling language is Object-Z, an extension of the well-known Z specification language with explicit support for object-oriented concepts. Its support for object orientation makes Object-Z particularly suited to our task. The system structuring techniques offered by object-orientation are well suited to modelling mobile systems. In addition, inheritance and polymorphism allow us to exploit commonalities in mobile systems by defining more complex models in terms of simpler ones.

Architectural design in object-z

We present a process for introducing an object-oriented architecture into an abstract functional specification written in Object-Z. Since the design is derived from the specification, correctness concerns are addressed as pan of the design process. We base our approach on refactoring rules that apply to class structure, and use the rules to implement design patterns. As a motivating example, we introduce a user-interface design that follows the model-view-controller paradigm into an existing specification.

An experiment in the design of distributed programs

This paper describes an experiment in the design of distributed programs. It is based on the theory of Owicki and Gries extended with rules for reasoning about message passing. The experiment is designed to test the effectiveness of the extended theory for designing distributed programs.

Engaging game characters: Informing design with player perspectives

The behavior of characters in current computer games is generally scripted and predictable. This paper discusses some issues related to creating game characters that enhance player engagement and identifies the need for a more player-centered approach to game character design. This paper reports the results of a focus group that was carried out with experienced game players to determine what game character behaviors would enhance their engagement in a game. The four general areas of concern that came out of this discussion were consistency with context, player expectations, social interactions and consistency with the environment. This paper discusses these issues and their implication for game character design with a view to creating engaging game characters. © Springer

Modelling and using imperfect context information

Most recently developed context-aware software applicationsmake unrealistic assumptions about the quality of the available context information, which can lead to inappropriate actions by the application and frustration on the part of the user. In this paper, we explore the problem of imperfect context information and some of its causes, and propose a novel approach for modelling incomplete and inaccurate information. Additionally, we present a discussion of our experiences in developing a contextaware communication application, highlighting design issues that are pertinent when developing applications that rely on imperfect context information.

National culture, infrastructure, and costs: Factors that lead to the use of wireless technologies

This research-in-progress paper utilizes the Technology Acceptance Model (TAM) to assess the effects of National Culture, Infrastructure, and Access Costs on the adoption of Wireless Technologies in Australia. The cultural dimensions emanating from the GLOBE project were chosen because of their broad coverage and contemporary nature. Australia is unique in that it has one of the lowest population densities in the world. The provision of wireless technologies is challenging in such an environment, and I believe the model developed in this research will have applicability in other similarly populated countries.

How does your model grow? An empirical investigation of the effects of ontological clarity and application domain size on query performance

Semantic data models provide a map of the components of an information system. The characteristics of these models affect their usefulness for various tasks (e.g., information retrieval). The quality of information retrieval has obvious important consequences, both economic and otherwise. Traditionally, data base designers have produced parsimonious logical data models. In spite of their increased size, ontologically clearer conceptual models have been shown to facilitate better performance for both problem solving and information retrieval tasks in experimental settings. The experiments producing evidence of enhanced performance for ontologically clearer models have, however, used application domains of modest size. Data models in organizational settings are likely to be substantially larger than those used in these experiments. This research used an experiment to investigate whether the benefits of improved information retrieval performance associated with ontologically clearer models are robust as the size of the application domains increase. The experiment used an application domain of approximately twice the size as tested in prior experiments. The results indicate that, relative to the users of the parsimonious implementation, end users of the ontologically clearer implementation made significantly more semantic errors, took significantly more time to compose their queries, and were significantly less confident in the accuracy of their queries.