Regional contingencies in the relationship between aboveground biomass and litter in the world’s grasslands

Based on regional-scale studies, aboveground production and litter decomposition are thought to positively covary, because they are driven by shared biotic and climatic factors. Until now we have been unable to test whether production and decomposition are generally coupled across climatically dissimilar regions, because we lacked replicated data collected within a single vegetation type across multiple regions, obfuscating the drivers and generality of the association between production and decomposition. Furthermore, our understanding of the relationships between production and decomposition rests heavily on separate meta-analyses of each response, because no studies have simultaneously measured production and the accumulation or decomposition of litter using consistent methods at globally relevant scales. Here, we use a multi-country grassland dataset collected using a standardized protocol to show that live plant biomass (an estimate of aboveground net primary production) and litter disappearance (represented by mass loss of aboveground litter) do not strongly covary. Live biomass and litter disappearance varied at different spatial scales. There was substantial variation in live biomass among continents, sites and plots whereas among continent differences accounted for most of the variation in litter disappearance rates. Although there were strong associations among aboveground biomass, litter disappearance and climatic factors in some regions (e.g. U.S. Great Plains), these relationships were inconsistent within and among the regions represented by this study. These results highlight the importance of replication among regions and continents when characterizing the correlations between ecosystem processes and interpreting their global-scale implications for carbon flux. We must exercise caution in parameterizing litter decomposition and aboveground production in future regional and global carbon models as their relationship is complex.

Distinguishing between mean-field, moment dynamics and stochastic descriptions of birth-death-movement processes

Mathematical descriptions of birth–death–movement processes are often calibrated to measurements from cell biology experiments to quantify tissue growth rates. Here we describe and analyze a discrete model of a birth–death-movement process applied to a typical two–dimensional cell biology experiment. We present three different descriptions of the system: (i) a standard mean–field description which neglects correlation effects and clustering; (ii) a moment dynamics description which approximately incorporates correlation and clustering effects, and; (iii) averaged data from repeated discrete simulations which directly incorporates correlation and clustering effects. Comparing these three descriptions indicates that the mean–field and moment dynamics approaches are valid only for certain parameter regimes, and that both these descriptions fail to make accurate predictions of the system for sufficiently fast birth and death rates where the effects of spatial correlations and clustering are sufficiently strong. Without any method to distinguish between the parameter regimes where these three descriptions are valid, it is possible that either the mean–field or moment dynamics model could be calibrated to experimental data under inappropriate conditions, leading to errors in parameter estimation. In this work we demonstrate that a simple measurement of agent clustering and correlation, based on coordination number data, provides an indirect measure of agent correlation and clustering effects, and can therefore be used to make a distinction between the validity of the different descriptions of the birth–death–movement process.

Parent-teacher engagement : a coteaching and cogenerative dialoguing approach

The accumulated evidence from more than four decades of education research strongly suggests that parent involvement in schools carries significant benefits for students as well as for the success of schools (e.g., Henderson & Mapp, 2002). Governments in Australia and overseas have supported parent involvement in schools with a range of initiatives while parent groups have indicated a strong desire for expanded school roles that include participation in formal educational processes namely curriculum, pedagogy, and assessment. Research has also signalled the need for teachers to engage parents rather than adopt traditional parent-school involvement practices so that parents can participate as joint educators in their children's schooling alongside teachers (Pushor, 2001). Actually improving the quality of contact and relationships between parents and teachers to enable engagement however remains problematic. Coteaching and cogenerative dialoguing originally emerged as an innovative approach in the context of teaching secondary school science. Coteaching brings together the collective expertise of several individuals to expand learning opportunities for students while cogenerative dialogues refer to sessions in which participants talk, listen, and learn from one another about the process (Roth & Tobin, 2002a). Coteaching and cogenerative dialoguing reportedly benefits students academically and socially while rewarding educators professionally and emotionally through the support and collaboration they receive from fellow coteachers. These benefits ensue because coteaching theoretically positions teachers at one another's elbows, providing new and different understandings about teaching based on first-hand perspectives and shared goals for assisting students to learn. This thesis proposes that coteaching and cogenerative dialoguing may provide a vehicle for improving quality of contact and relationships between parents and teachers. To investigate coteaching and cogenerative dialoguing as a parent-teacher engagement mechanism, interpretive ethnographic case study research was conducted involving two parents and a secondary school teacher. Sociological ideas, namely Bourdieu's (1977) fields, habitus, and capitals, together with multiple dialectical concepts such as agency|structure (Sewell, 1992) and agency|passivity (Roth, 2007b, 2010) were assembled into a conceptual framework to examine parent-teacher relationships by describing and explaining cultural production and identity construction throughout the case study. Video and audio recordings of cogenerative dialogues and cotaught lessons comprised the chief data sources. Data were analysed using qualitative techniques such as discourse and conversation analysis to identify patterns and contradictions (Roth & Tobin, 2002a). The use of quality criteria detailed by Guba and Lincoln (2005) gives credence to the way in which ethical considerations infused the planning and conduct of this research. From the processes of data collection and analyses, three broad assertions were proffered. The findings highlight the significance of using multiple coordinated dialectical concepts for analysing the affordances and challenges of coteaching and cogenerative dialogues that include parents and teachers. Adopting the principles and purposes of coteaching and cogenerative dialoguing promoted trusting respectful relationships that generated an equitable culture. The simultaneous processes and tensions between logistics and ethics (i.e., the logistics|ethics dialectic) were proposed as a new way to conceptualise how power was redistributed among the participants. Knowledge of positive emotional energy and ongoing capital exchange conceived dialectically as the reciprocal interaction among cultural, social, and symbolic capitals (i.e., the dialectical relationship of cultural|social|symbolic capital) showed how coteaching and cogenerative dialoguing facilitated mutual understandings, joint decision-making, and group solidarity. The notion of passivity as the dialectical partner of agency explained how traditional roles and responsibilities were reconfigured and individual and collective agency expanded. Complexities that surfaced when implementing the coteaching and cogenerative dialoguing approach were outweighed by the multiple benefits that accrued for all involved. These benefits included the development of community-relevant and culturally-significant curricula that increased student agency and learning outcomes, heightened parent self-efficacy for participating in and contributing to formal educational processes, and enhanced teacher professionalism. This case study contributes to existing theory, knowledge and practice, and methodology in the research areas of parent-teacher relationships, specifically in secondary schools, and coteaching and cogenerative dialoguing. The study is particularly relevant given the challenges schools and teachers increasingly face to meaningfully connect with parents to better meet the needs of educational stakeholders in times of continual, complex, and rapid societal change.

Distributed low-power image processing in wireless sensor networks for intelligent video surveillance applications

Distributed Wireless Smart Camera (DWSC) network is a special type of Wireless Sensor Network (WSN) that processes captured images in a distributed manner. While image processing on DWSCs sees a great potential for growth, with its applications possessing a vast practical application domain such as security surveillance and health care, it suffers from tremendous constraints. In addition to the limitations of conventional WSNs, image processing on DWSCs requires more computational power, bandwidth and energy that presents significant challenges for large scale deployments. This dissertation has developed a number of algorithms that are highly scalable, portable, energy efficient and performance efficient, with considerations of practical constraints imposed by the hardware and the nature of WSN. More specifically, these algorithms tackle the problems of multi-object tracking and localisation in distributed wireless smart camera net- works and optimal camera configuration determination. Addressing the first problem of multi-object tracking and localisation requires solving a large array of sub-problems. The sub-problems that are discussed in this dissertation are calibration of internal parameters, multi-camera calibration for localisation and object handover for tracking. These topics have been covered extensively in computer vision literatures, however new algorithms must be invented to accommodate the various constraints introduced and required by the DWSC platform. A technique has been developed for the automatic calibration of low-cost cameras which are assumed to be restricted in their freedom of movement to either pan or tilt movements. Camera internal parameters, including focal length, principal point, lens distortion parameter and the angle and axis of rotation, can be recovered from a minimum set of two images of the camera, provided that the axis of rotation between the two images goes through the camera's optical centre and is parallel to either the vertical (panning) or horizontal (tilting) axis of the image. For object localisation, a novel approach has been developed for the calibration of a network of non-overlapping DWSCs in terms of their ground plane homographies, which can then be used for localising objects. In the proposed approach, a robot travels through the camera network while updating its position in a global coordinate frame, which it broadcasts to the cameras. The cameras use this, along with the image plane location of the robot, to compute a mapping from their image planes to the global coordinate frame. This is combined with an occupancy map generated by the robot during the mapping process to localised objects moving within the network. In addition, to deal with the problem of object handover between DWSCs of non-overlapping fields of view, a highly-scalable, distributed protocol has been designed. Cameras that follow the proposed protocol transmit object descriptions to a selected set of neighbours that are determined using a predictive forwarding strategy. The received descriptions are then matched at the subsequent camera on the object's path using a probability maximisation process with locally generated descriptions. The second problem of camera placement emerges naturally when these pervasive devices are put into real use. The locations, orientations, lens types etc. of the cameras must be chosen in a way that the utility of the network is maximised (e.g. maximum coverage) while user requirements are met. To deal with this, a statistical formulation of the problem of determining optimal camera configurations has been introduced and a Trans-Dimensional Simulated Annealing (TDSA) algorithm has been proposed to effectively solve the problem.

A novel bioreactor for ligament tissue engineering

Bioreactors are defined as devices in which biological and/or biochemical processes develop under closely monitored and tightly controlled environmental and operating conditions (e.g. pH, temperature, mechanical conditions, nutrient supply and waste removal). In functional tissue engineering of musculoskeletal tissues, a bioreactor capable of controlling dynamic loading plays a determinant role. It has been shown that mechanical stretching promotes the expression of type I and III collagens, fibronectin, tenascin-C in cultured ligament fibroblasts (J.C.-H. Goh et al., Tissue Eng. 9 (2003), S31) and that human bone marrow mesenchymal stem cells (hBMMSC) – even in the absence of biochemical regulators – could be induced to differentiate into ligament-like fibroblast by the application of physiologically relevant cyclic strains (G. Vunjak-Novakovic et al., Ann. Rev. Biomed. Eng. 6 (2004), 131; H.A. Awad et al., Tissue Eng. 5 (1999), 267; R.G. Young et al., J. Orthop. Res. 16 (1998), 406). Different bioreactors are commercially available but they are too generic to be used for a given tissue, each tissue showing specific mechanical loading properties. In the case of ligament tissue engineering, the design of a bioreactor is still an open question. Our group proposes a bioreactor allowing cyclic traction–torsion on a scaffold seeded with stem cells.

Vehicle energy throughput analysis as a drivetrain motor design aid

There are many variables to consider in the design of an electric motor. However, meeting the performance requirements for an electric vehicle drive may cause a designer to loose focus on its typical operation and hence fail to optimise the motor in the region where it processes the most power. This paper investigates operating requirements of electric vehicle motor drives using the University concept vehicle as an example. The paper outlines a methodology for determining primary operating region of a vehicle drive. The methodology is applied to standard driving cycles that are commonly used in the design and testing of vehicles.

The life course of Australian researchers : experiences of applying for research funding

The life course of Australian researchers includes regular funding applications, which incur large personal and time costs. We previously estimated that Australian researchers spent 550 years preparing 3,727 proposals for the 2012 NHMRC Project Grant funding round, at an estimated annual salary cost of AU$66 million. Despite the worldwide importance of funding rounds, there is little evidence on what researchers think of the application process. We conducted a web-based survey of Australian researchers (May–July 2013) asking about their experience with NHMRC Project Grants. Almost all researchers (n=224 at 31 May) supported changes to the application (96%) and peer-review (88%) processes; 73% supported the introduction of shorter initial Expressions of Interest; and half (50%) provided extensive comments on the NHMRC processes. Researchers agreed preparing their proposals always took top priority over other work (97%) and personal (87%) commitments. More than half (57%) provided extensive comments on the ongoing personal impact of concurrent grant-writing and holiday seasons on family, children and other relationships. Researchers with experience on Grant Review Panels (34%) or as External Reviewers (78%) reported many sections of the proposals were rarely or never read, which suggests these sections could be cut with no impact on the quality of peer review. Our findings provide evidence on the experience of Australian researchers as applicants. The process of preparing, submitting and reviewing proposals could be streamlined to minimise the burden on applicants and peer reviewers, giving Australian researchers more time to work on actual research and be with their families.

Motivation during videogame play : analysing player experience in terms of cognitive action

This paper describes a method for analysing videogames based on game activities. It examines the impact of these activities on the player experience. The research approach applies heuristic checklists that deconstruct games in terms of cognitive processes that players engage in during gameplay (e.g., addressing goals, interpreting feedback). For this study we examined three puzzle games, Portal 2, I-Fluid and Braid. The Player Experience of Need Satisfaction (PENS) survey is used to measure player experience following gameplay. Cognitive action provided within games is examined in light of reported player experiences to determine the extent to which these activities influence players’ feelings of competence, autonomy, intuitive control and presence. Findings indicate that the positive experiences are directly influenced by game activity design. Our study also demonstrates the value of expert review in deconstructing gameplay activity as a means of providing direction for game design that enhances the player experience.

An examination of the independent certification processes of a construction contract

Construction contracts often provide that the decision of an independent certifier is final and binding. The effect of a contractual term like this has been debated in the courts over time. This paper considers the binding nature of certificates in the context of traditional construction contract arrangements and also considers the implications for more complex contracts like those entered into to facilitate public private partnerships. This article considers the response of the courts and the drafting implications and argues that a different focus would be advantageous.

Social enterprise versus social entrepreneurship : an examination of the ‘why’ and ‘how’ in pursuing social change

This article critically considers distinctions between, social enterprise and social entrepreneurship from a theoretical perspective. Using case study analysis of 10 non-governmental organisations the paper explores these concepts empirically. Findings on social enterprise reveal a focus on the purpose of social businesses, while findings on social entrepreneurship reveal an emphasis on the processes underlying innovative and entrepreneurial activity for social purposes. Discussion of these findings indicates important developments relevant to informing the growing area of social enterprise and social entrepreneurship research. Implications extend to understanding the need for action to achieve social change, and an acceptance of risk when existing actions fail to achieve their intended outcomes.

Measurement as legitimacy versus legitimacy of measures : Performance evaluation of social enterprise

Purpose The purpose of this paper is to review the growing emphasis on quantifiable performance measures such as social return on investment (SROI) in third sector organisations – specifically, social enterprise – through a legitimacy theory lens. It then examines what social enterprises value (i.e. consider important) in terms of performance evaluation, using a case study approach. Design/methodology/approach Case studies involving interviews, documentary analysis, and observation, of three social enterprises at different life-cycle stages with different funding structures, were constructed to consider “what measures matter” from a practitioner's perspective. Findings Findings highlight a priority on quality outcomes and impacts in primarily qualitative terms to evaluate performance. Further, there is a noticeable lack of emphasis on financial measures other than basic access to financial resources to continue pursuing social goals. Social implications The practical challenges faced by social enterprises – many of which are small to medium sized – in evaluating performance and by implication organisational legitimacy are contrasted with measures such as SROI which are resource intensive and have inherent methodological limitations. Hence, findings suggest the limited and valuable resources of social enterprises would be better allocated towards documenting the actual outcomes and impacts as a first step, in order to evaluate social and financial performance in terms appropriate to each objective, in order to demonstrate organisational legitimacy. Originality/value Findings distinguish between processes which may hold symbolic legitimacy for select stakeholder groups, and processes which hold substantive, cognitive legitimacy for stakeholders more broadly, in the under-researched context of social enterprise.

Enhancing teacher education : the School-Community Intergrated Learning (SCIL) pathway

National Australian reviews advocate exploring new models for preservice teacher education. This study investigates the outcomes of the School-Community Integrated Learning (SCIL) pathway as a model for advancing preservice teachers’ understandings of teaching. Thirty-two final-year preservice teachers were surveyed with extended written responses on how the SCIL pathway advanced their understandings of teaching. Results indicated 100% agreement on 6 of the 27 survey items. Indeed, 78% or more preservice teachers agreed that they had a range of experiences across the five categories (i.e., personal-professional skill development, understandings of system requirements, teaching practices, student behaviour and reflective practices). Extended responses suggested they had developed understandings around setting up classrooms, whole school planning processes with professional development, the allocation of teacher responsibilities (e.g., playground duties), parent-teacher interviews, diagnostic testing for literacy and numeracy, commencing running records of students’ assessment results, and the development of relationships (students, teachers and parents). Although a longitudinal study is required to determine long-term effects, the SCIL pathway may be viewed as a positive step towards preparing final-year preservice teachers for their first year as fully-fledged teachers.

High energy states of gold and their importance in electrocatalytic processes at surfaces and interfaces

The ability of metals to store or trap considerable amounts of energy, and thus exist in a non-equilibrium or metastable state, is very well known in metallurgy; however, such behaviour, which is intimately connected with the defect character of metals, has been largely ignored in noble metal surface electrochemistry. Techniques for generating unusually high energy surface states for gold, and the unusual voltammetric responses of such states, are outlined. The surprisingly high (and complex) electrocatalytic activity of gold in aqueous media is attributed to the presence of a range of such non-equilibrium states as the vital entities at active sites on conventional gold surfaces. The possible relevance of these ideas to account for the remarkable catalytic activity of oxide-supported gold microparticles is briefly outlined.

Characterisation of two distinctly different processes associated with the electrocrystallization of microcrystals of phase I CuTCNQ (TCNQ= 7, 7, 8, 8-tetracyanoquinodimethane)

Semi-conducting phase I CuTCNQ (TCNQ = 7,7,8,8-tetracyanoquinodimethane), which is of considerable interest as a switching device for memory storage materials, can be electrocrystallized from CH3CN via two distinctly different pathways when TCNQ is reduced to TCNQ˙− in the presence of [Cu(MeCN)4]+. The first pathway, identified in earlier studies, occurs at potentials where TCNQ is reduced to TCNQ˙− and involves a nucleation–growth mechanism at preferred sites on the electrode to produce arrays of well separated large branched needle-shaped phase I CuTCNQ crystals. The second pathway, now identified at more negative potentials, generates much smaller needle-shaped phase I CuTCNQ crystals. These electrocrystallize on parts of the surface not occupied in the initial process and give rise to film-like characteristics. This process is attributed to the reduction of Cu+[(TCNQ˙−)(TCNQ)] or a stabilised film of TCNQ via a solid–solid conversion process, which also involves ingress of Cu+via a nucleation–growth mechanism. The CuTCNQ surface area coverage is extensive since it occurs at all areas of the electrode and not just at defect sites that dominate the crystal formation sites for the first pathway. Infrared spectra, X-ray diffraction, surface plasmon resonance, quartz crystal microbalance, scanning electron microscopy and optical image data all confirm that two distinctly different pathways are available to produce the kinetically-favoured and more highly conducting phase I CuTCNQ solid, rather than the phase II material.

The role of defects, or active states, in surface electrochemistry with particular reference to gold in neutral solution

Metastable, active, or nonequilibrium states due to the presence of abnormal structures and various types of defects are well known in metallurgy. The role of such states at gold surfaces in neutral aqueous media (an important electrode system in the microsensor area) was explored using cyclic voltammetry. It was demonstrated that, as postulated in earlier work from this laboratory, there is a close relationship between premonolayer oxidation, multilayer hydrous oxide reduction and electrocatalytic behaviour in the case of this and other metal electrode systems. Some of the most active, and therefore most important, entities at surfaces (e.g., metal adatoms) are not readily imageable or detectable by high resolution surface microscopy techniques. Cyclic voltammetry, however, provides significant, though not highly specific, information about such species. The main conclusion is that further practical and theoretical work on active states of metal surfaces is highly desirable as their behaviour is not simple and is of major importance in many electrocatalytic processes.