A new family of Marx generators based on commutation circuits

This paper presents a novel topology for the generation of high voltage pulses that uses both slow and fast solid-state power switches. This topology includes diode-capacitor units in parallel with commutation circuits connected to a positive buck-boost converter. This enables the generation of a range of high output voltages with a given number of capacitors. The advantages of this topology are the use of slow switches and a reduced number of diodes in comparison with conventional Marx generator. Simulations performed for single and repetitive pulse generation and experimental tests of a prototype hardware verify the proposed topology.

The legal role of medical professionals in decisions to withhold or withdraw life-sustaining treatment : Part 1 (New South Wales)

This is the first article in a series of three that examines the legal role of medical professionals in decisions to withhold or withdraw life-sustaining treatment from adults who lack capacity. This article considers the position in New South Wales. A review of the law in this State reveals that medical professionals play significant legal roles in these decisions. However, the law is problematic in a number of respects and this is likely to impede medical professionals’ legal knowledge in this area. The article examines the level of training medical professionals receive on issues such as advance directives and substitute decision-making, and the available empirical evidence as to the state of medical professionals’ knowledge of the law at the end of life. It concludes that there are gaps in legal knowledge and that law reform is needed in New South Wales.

For the better or the worse? The impact of business idea changes on new venture performance and novelty

Should new ventures stick to their knitting once they start commercialising or should they engage in frequent changes of their business idea? In this paper we argue that new ventures still need to learn their way in the early phases of commercialisation and that changes are good, but subject to two important contingencies. First is that changes should be aimed at enhancing uniqueness, which in turn enhances new venture performance. Second is that our results show that changes have limited affect on uniqueness and performance for entrepreneurs aiming at maximising opportunities, but that changing the business idea has a significant positive impact for entrepreneurs focusing on minimising losses. Our findings indicate that entrepreneurs aiming at minimising losses may offset their initial disadvantages by engaging in a series of adaptations of the business idea to gain higher performance and a more unique product offering.

Exploring the impact of entrepreneur optimism on the new venture process

By integrating two theoretical foundations of entrepreneurship research, behaviour and process, this conceptual paper proposes a new model to examine the behaviour of the entrepreneur across the new venture development process. Existing macro level research on the new venture creation process recognises the entrepreneur as a central agent in the process yet generally avoids, at each stage of the process, an examination of the micro level psychological experiences of the individual entrepreneur. Similarly, behavioural research examining entrepreneur individual differences has failed to systematically explore the emotion and behaviour of the entrepreneur across the cycle of the new venture creation process. We propose a conceptual framework to integrate the new venture creation process of opportunity discovery, evaluation and exploitation, with the psychological capital (efficacy, hope, resilience and optimism) of the individual entrepreneur. Propositions for future research to facilitate deeper insight into the impact of entrepreneur behaviour on the new venture creation process and ultimately the success or failure of the new venture are provided.

Resource constraints in innovation : the role of bricolage in new venture creation and firm development

The emerging theory of ‘bricolage’ as a resource behaviour represents an attempt to address the central entrepreneurship research problem of making systematic sense of entrepreneurs that sometimes manage to create significant new economic activity under what appears to be severe resource constraints (Baker & Nelson 2005). However, despite growing interest in bricolage there is little large scale empirical evidence about the effectiveness and outcomes of using bricolage processes while developing innovative outcomes in nascent and young firms. In this research we test bricolage using different forms of innovation using data from the Comprehensive Australian Study of Entrepreneurial Emergence (CAUSEE) project. Our results indicate overall positive results of bricolage with all forms of innovativeness. A discussion of the results and recommended future research is provided.

The role of immigrant entrepreneurs in international new ventures

Immigrant Entrepreneurs (IE) are often portrayed as being pushed into self-employment due to employment barriers in their adopted countries. But IE have human resources, like international experience, which can help them form international new ventures (INV). We question the role of IE in INV. We use randomly selected data from 561 young firms from the Comprehensive Australian Study of Entrepreneurial Emergence (CAUSEE) project. We find that IE are overrepresented in INV and have many of the characteristics known to facilitate INV success. These findings have relevance to policy makers, IE and NE.

Evolutionary biology of Gondwanan non-biting midges (Diptera: Chironomidae)

The potential restriction to effective dispersal and gene flow caused by habitat fragmentation can apply to multiple levels of evolutionary scale; from the fragmentation of ancient supercontinents driving diversification and speciation on disjunct landmasses, to the isolation of proximate populations as a result of their inability to cross intervening unsuitable habitat. Investigating the role of habitat fragmentation in driving diversity within and among taxa can thus include inferences of phylogenetic relationships among taxa, assessments of intraspecific phylogeographic structure and analyses of gene flow among neighbouring populations. The proposed Gondwanan clade within the chironomid (non-biting midge) subfamily Orthocladiinae (Diptera: Chironomidae) represents a model system for investigating the role that population fragmentation and isolation has played at different evolutionary scales. A pilot study by Krosch et al (2009) indentified several highly divergent lineages restricted to ancient rainforest refugia and limited gene flow among proximate sites within a refuge for one member of this clade, Echinocladius martini Cranston. This study provided a framework for investigating the evolutionary history of this taxon and its relatives more thoroughly. Populations of E. martini were sampled in the Paluma bioregion of northeast Queensland to investigate patterns of fine-scale within- and among-stream dispersal and gene flow within a refuge more rigorously. Data was incorporated from Krosch et al (2009) and additional sites were sampled up- and downstream of the original sites. Analyses of genetic structure revealed strong natal site fidelity and high genetic structure among geographically proximate streams. Little evidence was found for regular headwater exchange among upstream sites, but there was distinct evidence for rare adult flight among sites on separate stream reaches. Overall, however, the distribution of shared haplotypes implied that both larval and adult dispersal was largely limited to the natal stream channel. Patterns of regional phylogeographic structure were examined in two related austral orthoclad taxa – Naonella forsythi Boothroyd from New Zealand and Ferringtonia patagonica Sæther and Andersen from southern South America – to provide a comparison with patterns revealed in their close relative E. martini. Both taxa inhabit tectonically active areas of the southern hemisphere that have also experienced several glaciation events throughout the Plio-Pleistocene that are thought to have affected population structure dramatically in many taxa. Four highly divergent lineages estimated to have diverged since the late Miocene were revealed in each taxon, mirroring patterns in E. martini; however, there was no evidence for local geographical endemism, implying substantial range expansion post-diversification. The differences in pattern evident among the three related taxa were suggested to have been influenced by variation in the responses of closed forest habitat to climatic fluctuations during interglacial periods across the three landmasses. Phylogeographic structure in E. martini was resolved at a continental scale by expanding upon the sampling design of Krosch et al (2009) to encompass populations in southeast Queensland, New South Wales and Victoria. Patterns of phylogeographic structure were consistent with expectations and several previously unrecognised lineages were revealed from central- and southern Australia that were geographically endemic to closed forest refugia. Estimated divergence times were congruent with the timing of Plio-Pleistocene rainforest contractions across the east coast of Australia. This suggested that dispersal and gene flow of E. martini among isolated refugia was highly restricted and that this taxon was susceptible to the impacts of habitat change. Broader phylogenetic relationships among taxa considered to be members of this Gondwanan orthoclad group were resolved in order to test expected patterns of evolutionary affinities across the austral continents. The inferred phylogeny and estimated divergence times did not accord with expected patterns based on the geological sequence of break-up of the Gondwanan supercontinent and implied instead several transoceanic dispersal events post-vicariance. Difficulties in appropriate taxonomic sampling and accurate calibration of molecular phylogenies notwithstanding, the sampling regime implemented in the current study has been the most intensive yet performed for austral members of the Orthocladiinae and unsurprisingly has revealed both novel taxa and phylogenetic relationships within and among described genera. Several novel associations between life stages are made here for both described and previously unknown taxa. Investigating evolutionary relationships within and among members of this clade of proposed Gondwanan orthoclad taxa has demonstrated that a complex interaction between historical population fragmentation and dispersal at several levels of evolutionary scale has been important in driving diversification in this group. While interruptions to migration, colonisation and gene flow driven by population fragmentation have clearly contributed to the development and maintenance of much of the diversity present in this group, long-distance dispersal has also played a role in influencing diversification of continental biotas and facilitating gene flow among disjunct populations.

A new unequal DC link voltage configuration for a single phase multilevel converter to reduce low order harmonics

Multilevel converters are used in high power and high voltage applications due to their attractive benefits in generating high quality output voltage. Increasing the number of voltage levels can lead to a reduction in lower order harmonics. Various modulation and control techniques are introduced for multilevel converters like Space Vector Modulation (SVM), Sinusoidal Pulse Width Modulation (SPWM) and Harmonic Elimination (HE) methods. Multilevel converters may have a DC link with equal or unequal DC voltages. In this paper a new modulation technique based on harmonic elimination method is proposed for those multilevel converters that have unequal DC link voltages. This new technique has better effect on output voltage quality and less Total Harmonic Distortion (THD) than other modulation techniques. In order to verify the proposed modulation technique, MATLAB simulations are carried out for a single-phase diode-clamped inverter.

Reproducing successful rituals in bad times : exploring interactions of a new science teacher

Teaching is emotional work. This is especially the case in the first years of teaching when new teachers are particularly vulnerable. By understanding changes in teacher emotions in the early years of teaching we hope to identify strategies that might ultimately reduce teacher attrition. As part of a larger study of the transition of new teachers to the profession, this ethnographic case study explores how a new science teacher produced and reproduced positive emotional interaction rituals with her students in her first year of teaching. We show how dialogical interactions were positive and satisfying experiences for the teacher, and how they were reproduced successfully in different contexts. We also illustrate how both teacher and students used humor to create a structure for dialogical interactions. During these successful interactions the students used shared resources to satisfy their teacher that they were engaging in the relevant science content. The implications of what we have learned for the professional development of new teachers are discussed in relation to an expanded understanding of teacher emotions.

Media play : new (and old) pedagogies with young children

Modern technologies mean that the principles of quality arts education are the same (as they ever were) and different. Discussion in this paper is based on a small research project that used art as pedagogy, art as research method and, for the young children participants, celebrated art for art's sake. The project was designed with two aims. Firstly, the authors were interested in how young children engage with media as a strand of the arts. This also informed some of their thinking around the debates over Information and Communication Technology (ICT) as a process for the production of a media text. Secondly, they were interested in the extent to which digital media could enable young children to make their learning visible.

Selected new training documents to update user profile

Relevance Feedback (RF) has been proven very effective for improving retrieval accuracy. Adaptive information filtering (AIF) technology has benefited from the improvements achieved in all the tasks involved over the last decades. A difficult problem in AIF has been how to update the system with new feedback efficiently and effectively. In current feedback methods, the updating processes focus on updating system parameters. In this paper, we developed a new approach, the Adaptive Relevance Features Discovery (ARFD). It automatically updates the system's knowledge based on a sliding window over positive and negative feedback to solve a nonmonotonic problem efficiently. Some of the new training documents will be selected using the knowledge that the system currently obtained. Then, specific features will be extracted from selected training documents. Different methods have been used to merge and revise the weights of features in a vector space. The new model is designed for Relevance Features Discovery (RFD), a pattern mining based approach, which uses negative relevance feedback to improve the quality of extracted features from positive feedback. Learning algorithms are also proposed to implement this approach on Reuters Corpus Volume 1 and TREC topics. Experiments show that the proposed approach can work efficiently and achieves the encouragement performance.

Effect of biochar amendment on the soil-atmosphere exchange of greenhouse gases from an intensive subtropical pasture in northern New South Wales, Australia

We assessed the effect of biochar incorporation into the soil on the soil-atmosphere exchange of the greenhouse gases (GHG) from an intensive subtropical pasture. For this, we measured N2O, CH4 and CO2 emissions with high temporal resolution from April to June 2009 in an existing factorial experiment where cattle feedlot biochar had been applied at 10 t ha-1 in November 2006. Over the whole measurement period, significant emissions of N2O and CO2 were observed, whereas a net uptake of CH4 was measured. N2O emissions were found to be highly episodic with one major emission pulse (up to 502 µg N2O-N m-2 h 1) following heavy rainfall. There was no significant difference in the net flux of GHGs from the biochar amended vs. the control plots. Our results demonstrate that intensively managed subtropical pastures on ferrosols in northern New South Wales of Australia can be a significant source of GHG. Our hypothesis that the application of biochar would lead to a reduction in emissions of GHG from soils was not supported in this field assessment. Additional studies with longer observation periods are needed to clarify the long term effect of biochar amendment on soil microbial processes and the emission of GHGs under field conditions.

Eat, pray, loathe : women’s travel memoir as moving metaphysical journey or narcissistic new-age babble?

This paper considers the contentious space between self-affirmation and selfpreoccupation in Elizabeth Gilbert’s popular travel memoir, Eat, Pray, Love. Following the surveillance of the female confessant, the female traveller has recently come under close scrutiny and public suspicion. She is accused of walking a fine line between critical self-insight and obsessive selfimportance and her travel narratives are branded as accounts of navel gazing that are less concerned with what is seen than with who is doing the seeing. In reading these themes against the backdrop of women’s travel, the possibility arises that the culture of narcissism is increasingly read as a female discursive practice, concerned with authorship, privacy and the subjectivity of truth. The novel, which has been praised by some as ‘the ultimate guide to balanced living’ and dismissed by others as ‘self-serving junk’, poses questions about the requisites in Western culture for being a female traveller and for telling a story that focuses primarily on the self.

Queensland requirements (old and new) for the appointment of a real estate agent

In Moneywood Pty Ltd v Salamon Nominees Pty Ltd 1 the High Court of Australia considered an appeal from the Queensland Court of Appeal in relation to the correct interpretation of s76 (1)(c) Auctioneers and Agents Act 1971 (Qld). In paraphrase, s76(1)(c) provides that a real estate agent shall not be entitled to sue for or recover any commission unless “the engagement or appointment to act as …..real estate agent ….. in respect of such transaction is in writing signed by the person to be charged with such…..commission…..or the person’s agent or representative” (“the statutory requirement”).

Teaching new dogs old tricks. How the move to 24/7 interactive, integrated multimedia, multi-platform news and feature delivery is not really changing the skills employers demand of graduates

The journalism revolution is upon us. In a world where we are constantly being told that everyone can be a publisher and challenges are emerging from bloggers, Twitterers and podcasters, journalism educators are inevitably reassessing what skills we now need to teach to keep our graduates ahead of the game. QUT this year tackled that question head-on as a curriculum review and program restructure resulted in a greater emphasis on online journalism. The author spent a week in the online newsrooms of each of two of the major players – ABC online news and thecouriermail.com to watch, listen and interview some of the key players. This, in addition to interviews with industry leaders from Fairfax and news.com, lead to the conclusion that while there are some new skills involved in new media much of what the industry is demanding is in fact good old fashioned journalism. Themes of good spelling, grammar, accuracy and writing skills and a nose for news recurred when industry players were asked what it was that they would like to see in new graduates. While speed was cited as one of the big attributes needed in online journalism, the conclusion of many of the players was that the skills of a good down-table sub or a journalist working for wire service were not unlike those most used in online newsrooms.