Learning in the nectar foraging behaviour of Helicoverpa armigera

Abstract. 1. Learning may enable insects to obtain nectar from flowers more efficiently. Learning in nectar foraging has been shown primarily in studies of bees and butterflies. Here, learning is demonstrated in the nectar foraging behaviour of a noctuid moth, Helicoverpa armigera. 2. The present studies show that: (1) previous experience with a flowering host species increases the probability of that species being selected for nectar foraging, and (2) previous experience of a particular flower type (food source at bottom or top of the corolla tube) increases the likelihood of the food source being found when that flower type is being searched. 3. The implications of these findings for understanding the pattern of oviposition observed in wild populations of this important pest species are discussed.

Structure character in small-carbon-cluster deposition on diamond surface

Experimentally, hydrogen-free diamond-like carbon (DLC) films were assembled by means of pulsed laser deposition (PLD), where energetic small-carbon-clusters were deposited on the substrate. In this paper, the chemisorption of energetic C2 and C10 clusters on diamond (001)-( 2×1) surface was investigated by molecular dynamics simulation. The influence of cluster size and the impact energy on the structure character of the deposited clusters is mainly addressed. The impact energy was varied from a few tens eV to 100 eV. The chemisorption of C10 was found to occur only when its incident energy is above a threshold value ( E th). While, the C2 cluster was easily to adsorb on the surface even at much lower incident energy. With increasing the impact energy, the structures of the deposited C2 and C10 are different from the free clusters. Finally, the growth of films synthesized by energetic C2 and C10 clusters were simulated. The statistics indicate the C2 cluster has high probability of adsorption and films assembled of C2 present slightly higher SP3 fraction than that of C10-films, especially at higher impact energy and lower substrate temperature. Our result supports the experimental findings. Moreover, the simulation underlines the deposition mechanism at atomic scale.

Phantom Scatter and the A-SI EPID

Introduction: The use of amorphous-silicon electronic portal imaging devices (a-Si EPIDs) for dosimetry is complicated by the effects of scattered radiation. In photon radiotherapy, primary signal at the detector can be accompanied by photons scattered from linear accelerator components, detector materials, intervening air, treatment room surfaces (floor, walls, etc) and from the patient/phantom being irradiated. Consequently, EPID measurements which presume to take scatter into account are highly sensitive to the identification of these contributions. One example of this susceptibility is the process of calibrating an EPID for use as a gauge of (radiological) thickness, where specific allowance must be made for the effect of phantom-scatter on the intensity of radiation measured through different thicknesses of phantom. This is usually done via a theoretical calculation which assumes that phantom scatter is linearly related to thickness and field-size. We have, however, undertaken a more detailed study of the scattering effects of fields of different dimensions when applied to phantoms of various thicknesses in order to derive scattered-primary ratios (SPRs) directly from simulation results. This allows us to make a more-accurate calibration of the EPID, and to qualify the appositeness of the theoretical SPR calculations. Methods: This study uses a full MC model of the entire linac-phantom-detector system simulated using EGSnrc/BEAMnrc codes. The Elekta linac and EPID are modelled according to specifications from the manufacturer and the intervening phantoms are modelled as rectilinear blocks of water or plastic, with their densities set to a range of physically realistic and unrealistic values. Transmissions through these various phantoms are calculated using the dose detected in the model EPID and used in an evaluation of the field-size-dependence of SPR, in different media, applying a method suggested for experimental systems by Swindell and Evans [1]. These results are compared firstly with SPRs calculated using the theoretical, linear relationship between SPR and irradiated volume, and secondly with SPRs evaluated from our own experimental data. An alternate evaluation of the SPR in each simulated system is also made by modifying the BEAMnrc user code READPHSP, to identify and count those particles in a given plane of the system that have undergone a scattering event. In addition to these simulations, which are designed to closely replicate the experimental setup, we also used MC models to examine the effects of varying the setup in experimentally challenging ways (changing the size of the air gap between the phantom and the EPID, changing the longitudinal position of the EPID itself). Experimental measurements used in this study were made using an Elekta Precise linear accelerator, operating at 6MV, with an Elekta iView GT a-Si EPID. Results and Discussion: 1. Comparison with theory: With the Elekta iView EPID fixed at 160 cm from the photon source, the phantoms, when positioned isocentrically, are located 41 to 55 cm from the surface of the panel. At this geometry, a close but imperfect agreement (differing by up to 5%) can be identified between the results of the simulations and the theoretical calculations. However, this agreement can be totally disrupted by shifting the phantom out of the isocentric position. Evidently, the allowance made for source-phantom-detector geometry by the theoretical expression for SPR is inadequate to describe the effect that phantom proximity can have on measurements made using an (infamously low-energy sensitive) a-Si EPID. 2. Comparison with experiment: For various square field sizes and across the range of phantom thicknesses, there is good agreement between simulation data and experimental measurements of the transmissions and the derived values of the primary intensities. However, the values of SPR obtained through these simulations and measurements seem to be much more sensitive to slight differences between the simulated and real systems, leading to difficulties in producing a simulated system which adequately replicates the experimental data. (For instance, small changes to simulated phantom density make large differences to resulting SPR.) 3. Comparison with direct calculation: By developing a method for directly counting the number scattered particles reaching the detector after passing through the various isocentric phantom thicknesses, we show that the experimental method discussed above is providing a good measure of the actual degree of scattering produced by the phantom. This calculation also permits the analysis of the scattering sources/sinks within the linac and EPID, as well as the phantom and intervening air. Conclusions: This work challenges the assumption that scatter to and within an EPID can be accounted for using a simple, linear model. Simulations discussed here are intended to contribute to a fuller understanding of the contribution of scattered radiation to the EPID images that are used in dosimetry calculations. Acknowledgements: This work is funded by the NHMRC, through a project grant, and supported by the Queensland University of Technology (QUT) and the Royal Brisbane and Women's Hospital, Brisbane, Australia. The authors are also grateful to Elekta for the provision of manufacturing specifications which permitted the detailed simulation of their linear accelerators and amorphous-silicon electronic portal imaging devices. Computational resources and services used in this work were provided by the HPC and Research Support Group, QUT, Brisbane, Australia.

Cultivating creative ecologies : creative teaching and teaching for creativity

Australian universities now commonly list creativity amongst the generic attributes that graduates are expected to have achieved or demonstrated upon graduation. While this reflects emerging local and global trends to encourage creativity at every educational level, creativity as a generic capability has special difficulties. These include problems of definition, its perceived value, the gap between espoused beliefs and practice, and tensions between standards and accreditation agendas and the desire to embed creative outcomes in the curriculum. Contextual and disciplinary differences also shape the expression of creative teaching and teaching for creativity. This paper explores these issues, acknowledging the role of information and communications technologies in shaping the technology-enhanced learning spaces where creativity may emerge. Csikszentmihalyi’s model of creativity as a system of interactions is presented as a useful foundation for furthering the discourse in this domain, along with the notion of creative ecologies as spaces for effecting change.

The voices of the exegesis : Composing the speech genres of the practitioner-researcher into a connective thesis

Postgraduate candidates in the creative arts encounter unique challenges when writing an exegesis (the written document that accompanies creative work as a thesis). As a practitioner-researcher, they must adopt a dual perspective–looking out towards an established field of research, exemplars and theories, as well as inwards towards their experiential creative processes and practice. This dual orientation provides clear benefits, for it enables them to situate the research within its field and make objective claims for the research methodologies and outcomes while maintaining an intimate, voiced relationship with the practice. However, a dual orientation introduces considerable complexities in the writing. It requires a reconciliation of multi-perspectival subject positions: the disinterested academic posture of the observer/ethnographer/analyst/theorist at times; and the invested, subjective stance the practitioner/producer at others. It requires the author to negotiate a range of writing styles and speech genres–from the formal, polemical style of the theorist to the personal, questioning and emotive voice of reflexivity. Moreover, these multi-variant orientations, subject positions, styles and voices must be integrated into a unified and coherent text. In this chapter I offer a conceptual framework and strategies for approaching this relatively new genre of thesis. I begin by summarizing the characteristics of what has begun to emerge as the predominant model of exegesis (the dual-oriented ‘Connective’ exegesis). Framing it against theoretical and philosophical understandings of polyvocality and matrixicality, I go on to point to recent textual models that provide precedents for connecting differently oriented perspectives, subjectivities and voices. I then turn to emergent archives of practice-led research to explain how the challenge of writing a ‘Connective’ exegesis has so far been resolved by higher degree research (HDR) candidates. Exemplars illustrate a range of strategies they have used to compose a multi-perspectival text, reconcile the divergent subject positions of the practitioner researcher, and harmonize the speech genres of a ployvocal text.

Randomized phase II study of cetuximab plus cisplatin/vinorelbine compared with cisplatin/vinorelbine alone as first-line therapy in EGFR-expressing advanced non-small-cell lung cancer

Background: The Lung Cancer Cetuximab Study is an open-label, randomized phase II pilot study of cisplatin and vinorelbine combined with the epidermal growth factor receptor (EGFR)-targeted monoclonal antibody cetuximab versus cisplatin and vinorelbine alone, in patients with advanced EGFR-expressing, non-small-cell lung cancer (NSCLC). End points of the study are activity, safety and pharmacokinetics. Patients and methods: Following randomization, for a maximum of eight cycles, patients received three-weekly cycles of cisplatin (80 mg/m2, day 1) and vinorelbine (25 mg/m2 on days 1 and 8) alone or following cetuximab treatment (initial dose 400 mg/m, followed by 250 mg/m2 weekly thereafter). Results: Eighty-six patients were randomly allocated to the study (43 per arm). Confirmed response rates were 28% in the cisplatin/vinorelbine arm (A) and 35% in the cetuximab plus cisplatin/vinorelbine arm (B). Median progression-free survival (PFS) was 4.6 months in arm A and 5.0 months in arm B, with PFS rates at 12 months of 0% and 15%, respectively. Median survival was 7.3 months in arm A and 8.3 months in arm B. The 24-month survival rates were 0% and 16%, respectively. The cetuximab combination was well tolerated. Conclusion: In the first-line treatment of advanced NSCLC, the combination of cetuximab plus cisplatin/vinorelbine demonstrated an acceptable safety profile and the potential to improve activity over cisplatin/vinorelbine alone. © 2007 European Society for Medical Oncology.

Block models for improved earthwork allocation planning in linear infrastructure construction

Earthwork planning has been considered in this article and a generic block partitioning and modelling approach has been devised to provide strategic plans of various levels of detail. Conceptually this approach is more accurate and comprehensive than others, for instance those that are section based. In response to environmental concerns the metric for decision making was fuel consumption and emissions. Haulage distance and gradient are also included as they are important components of these metrics. Advantageously the fuel consumption metric is generic and captures the physical difficulties of travelling over inclines of different gradients, that is consistent across all hauling vehicles. For validation, the proposed models and techniques have been applied to a real world road project. The numerical investigations have demonstrated that the models can be solved with relatively little CPU time. The proposed block models also result in solutions of superior quality, i.e. they have reduced fuel consumption and cost. Furthermore the plans differ considerably from those based solely upon a distance based metric thus demonstrating a need for industry to reflect upon their current practices.

Cost and environmental efficiency of rice farms in South Korea

We examine cost and nutrient use efficiency of farms and determine the cost to move farms to nutrient-efficient operation using Data Envelopment Analysis (DEA) with a dataset of 96 rice farms in Gangwon province of South Korea from 2003 to 2007. Our findings show that improvements in technical efficiency would result in both lower production costs and better environmental performance. It is, however, not costless for farms to move from their current operation to the environmentally efficient operation. On average, this movement would increase production costs by 119% but benefit the water system through an approximately 69% reduction in eutrofying power (EP). The average estimated cost of each EP kg of aggregate nutrient reduction is approximately one thousand two hundred won. For technically efficient farms, there is a trade-off between cost and environmental efficiency. We also find that the environmental performance of farms varies across farms and regions. We suggest that agri-environmental policies should be (re)designed to improve both cost and environmental performance of rice farms.

Variations in acculturation and Australian physical education teacher education students' receptiveness to an alternative pedagogical approach to games teaching

Background The development of intelligent, thinking performers as a central theme in Physical Education curriculum documents worldwide has highlighted the need for an evolution of teaching styles from the dominant reproductive approach. This has prompted an Australian university to change the content and delivery of a games unit within their Physical Education Teacher Education (PETE) course and adopt a productive student centred approach that is compatible with current curriculum directives. The significance of prospective physical educators’ biographies on their receptiveness to this pedagogical innovation was studied to help recognise and understand potential differences and subsequently guide programme development to help improve the impact of teacher education. Purpose To investigate whether past school and sporting experiences are powerful influences on Australian PETE recruits’ initial perspectives about effective physical education teaching practice and their receptiveness to an alternative pedagogical approach. Participants and Setting 49 first year pre-service PETE students (53% male; 47% female; mean age 18.88 ± 1.57 years) undertaking a compulsory unit on games teaching at an Australian university volunteered to take part in the study and were grouped according to their highest level of representation in games, either school/club (n=13), regional (n=20), or state/national (n=16). Students experienced the constraints-led approach as learners and teachers during an 8-week games unit informed by nonlinear pedagogy and underpinned by motor learning theory. Data collection and Analysis Prior to the commencement of the unit participants completed part A of a two part mixed response questionnaire aimed at gathering data about their physical education and sporting background. The data were summarised using descriptive statistics. Pre and post intervention, participants completed part B responding, via Likert Scale with their opinion of the importance of each sub-component of the traditional reproductive style for an effective games teaching session. This resulted in a traditional reproductive games teaching belief score. For each sub-component, participants were invited to respond in more detail to justify their opinions. A one-way between groups analysis of variance (ANOVA), Tukey’s HSD Post Hoc Test and a two - tailed, paired samples t test were used to analyse the quantitative data. Content analysis was used to analyse the qualitative data. Findings The traditional, reproductive approach was the most frequently reported teaching approach used by the physical education teachers and sports coaches of participants in all groups. Prior to the commencement of the alternate games unit, participants in each representative level group held very strong custodial traditional reproductive games teaching beliefs. After experiencing the alternative games unit there were statistically significant differences in the traditional reproductive games teaching belief mean scores for each group, This combined with participants’ qualitative responses indicated a receptiveness to the alternative pedagogy. Conclusions The results of this present study show that, contrary to previous research undertaken in North America, in Australia, it is possible for PETE educators to change beliefs in order to overcome the constraint of acculturation and provide PETE students with the knowledge, understanding and belief in an alternate approach to teaching games in physical education compatible with curriculum documents.

Carbon nanotube composite sensor for structural health monitoring of bridge structures

Bridges are important infrastructures of all nations and are required for transportation of goods as well as human. A catastrophic failure can result in loss of lives and enormous financial hardship to the nation. Although various kinds of sensors are now available to monitor the health of the structures due to corrosion, they do not provide permanent and long term measurements. This paper investigates the fabrication of Carbon Nanotube (CNT) based composite sensors for corrosion detection of structures. Multi-wall CNT (MWCNT)/Nafion composite sensors were fabricated to evaluate their electrical properties for corrosion detection. The test specimens were subjected to real life corrosion experimental tests and the results confirm that the electrical resistance of the sensor electrode was dramatically changed due to corrosion.

Imagining social justice

This paper examines how creativity and the arts can assist teachers who teach from a social justice perspective, and how knowledge built through meaningful experiences of difference can make a difference. Just as imagining is central to visual arts practice, so too the capacity to imagine is a necessity for social justice. The authors ask what art can do, and how art can work, to bring about greater understandings and practices around social justice and the early years. A ‘recognitive justice’ (Fraser, 1997, 2000; Cazden, 2012) requires the capacity to be sensitive to the multiple voices that need to be heard, and the ability to imagine how lives might be lived differently. The arts can provide powerful means for thinking social justice, and the experiences described in this paper can have application in addressing social justice in the professional preparation of prospective teachers. Three teacher educators who teach from a social justice perspective apply a collective biography methodology to their stories of art activity. Data were collected from three sites: transcripts, notes and digital images from a salon evening; ethnographic observations, field notes and artefacts from a school classroom; and a/r/tographic data generated in a university art classroom. Data were analysed using Foucault and the conceptual work of other post-structuralist philosophies, to explore how aesthetic and creative artistic activity could excite imaginations and open up multiple possibilities for richer forms of educational outcomes – for teacher educators, their students, and ultimately for young children.

Using the quantum probability ranking principle to rank interdependent documents

A known limitation of the Probability Ranking Principle (PRP) is that it does not cater for dependence between documents. Recently, the Quantum Probability Ranking Principle (QPRP) has been proposed, which implicitly captures dependencies between documents through “quantum interference”. This paper explores whether this new ranking principle leads to improved performance for subtopic retrieval, where novelty and diversity is required. In a thorough empirical investigation, models based on the PRP, as well as other recently proposed ranking strategies for subtopic retrieval (i.e. Maximal Marginal Relevance (MMR) and Portfolio Theory(PT)), are compared against the QPRP. On the given task, it is shown that the QPRP outperforms these other ranking strategies. And unlike MMR and PT, one of the main advantages of the QPRP is that no parameter estimation/tuning is required; making the QPRP both simple and effective. This research demonstrates that the application of quantum theory to problems within information retrieval can lead to significant improvements.