Mutation frequency of non-ESBL phenotype SENTRY (Asia-Pacific) isolates of Klebsiella pneumoniae conversion to an ESBL positive phenotype

Extended spectrum β-lactamases or ESBLs, which are derived from non-ESBL precursors by point mutation of β-lactamase genes (bla), are spreading rapidly all over the world and have caused considerable problems in the treatment of infections caused by bacteria which harbour them. The mechanism of this resistance is not fully understood and a better understanding of these mechanisms might significantly impact on choosing proper diagnostic and treatment strategies. Previous work on SHV β-lactamase gene, blaSHV, has shown that only Klebsiella pneumoniae strains which contain plasmid-borne blaSHV are able to mutate to phenotypically ESBL-positive strains and there was also evidence of an increase in blaSHV copy number. Therefore, it was hypothesised that although specific point mutation is essential for acquisition of ESBL activity, it is not yet enough, and blaSHV copy number amplification is also essential for an ESBL-positive phenotype, with homologous recombination being the likely mechanism of blaSHV copy number expansion. In this study, we investigated the mutation rate of non-ESBL expressing K. pneumoniae isolates to an ESBL-positive status by using the MSS-maximum likelihood method. Our data showed that blaSHV mutation rate of a non-ESBL expressing isolate is lower than the mutation rate of the other single base changes on the chromosome, even with a plasmid-borne blaSHV gene. On the other hand, mutation rate from a low MIC ESBL-positive (≤ 8 µg/mL for cefotaxime) to high MIC ESBL-positive (≥16 µg/mL for cefotaxime) is very high. This is because only gene copy number increase is needed which is probably mediated by homologous recombination that typically takes place at a much higher frequencies than point mutations. Using a subinhibitory concentration of novobiocin, as a homologous recombination inhibitor, revealed that this is the case.

A surface plasmon resonance-based solution affinity assay for heparan sulfate-binding proteins

A surface plasmon resonance-based solution affinity assay is described for measuring the Kd of binding of heparin/heparan sulfate-binding proteins with a variety of ligands. The assay involves the passage of a pre-equilibrated solution of protein and ligand over a sensor chip onto which heparin has been immobilised. Heparin sensor chips prepared by four different methods, including biotin–streptavidin affinity capture and direct covalent attachment to the chip surface, were successfully used in the assay and gave similar Kd values. The assay is applicable to a wide variety of heparin/HS-binding proteins of diverse structure and function (e.g., FGF-1, FGF-2, VEGF, IL-8, MCP-2, ATIII, PF4) and to ligands of varying molecular weight and degree of sulfation (e.g., heparin, PI-88, sucrose octasulfate, naphthalene trisulfonate) and is thus well suited for the rapid screening of ligands in drug discovery applications.

Communicating ecologically positive development

It is difficult to present a paradigm shift from resource efficient to ecologically sustainable design, when many students have not yet thought about what sustainability is, let alone what it implies for the design of the built environment ‘Positive Development’ requires students to think beyond green building to something that does not yet exist. The concept of ecologically positive development suggests a product, building, system or urban area that leaves the ecological base and public estate better off than if no development had occurred. For some years now, I have experimented with communicating this paradigm shift in design to students and professionals ‐ with mixed results. This paper discusses some of the challenges, failures and successes in shifting design studio work from environmentally‐sensitive to eco-positive. The framework underlying this exploration is action research. Conclusions about the success of the strategies used for overcoming perceptual barriers to new typologies of architecture are drawn from recent student feedback. The talk will show examples of student projects that attempt eco-positive development projects.

Impulsivity and positive psychotic symptoms influence hostility in methamphetamine users

Methamphetamine (MA) use is associated with hostility, aggression, and positive psychotic symptoms. However, little is known of the processes or mechanisms that underlie this relationship. The present research was designed to investigate putative mediating and moderating variables between MA dependence and hostility in a sample of injecting MA users (N=237). Both positive symptoms of psychosis and higher levels of impulsivity functioned as mediators and moderators of this relationship. This pattern of findings suggests that MA use leads to greater hostility by increasing positive psychotic symptoms that contribute to a perception of the environment as a hostile and threatening place as well as by increasing impulsivity. Those who were high in positive symptoms and high in impulsivity were the most hostile. Individual differences in impulsivity and positive psychotic symptoms should be taken into account in the assessment and management of MA dependence.

Application of Dynamic Hysteresis Band Height Control to Improve Output Voltage Transient in Boost and Positive Buck-Boost Converters

This paper presents dynamic hysteresis band height control to reduce the overshoot and undershoot issue on output voltage caused by load change. The converters in this study are Boost and Positive Buck-Boost (PBB) converters. PBB has been controlled to work in a step up conversion and avoid overshoot when load is changed. Simulation and experimental results have been presented to verify the proposed method.

Utilizing robustness of positive buck-boost converter against input voltage and load current disturbances

A Positive Buck- Boost (PBB) converter is a known DC-DC converter that can operate in step up and step down modes. Unlike Buck, Boost, and Inverting Buck Boost converters, the inductor current of a PBB can be controlled independently of its voltage conversion ratio. In other words, the inductor of PBB can be utilised as an energy storage unit in addition to its main function of energy transfer. In this paper, the capability of PBB to store energy has been utilised to achieve robustness against input voltage fluctuations and output current changes. The control strategy has been developed to keep accuracy, affordability, and simplicity acceptable. To improve the efficiency of the system a Smart Load Controller (SLC) has been suggested. Applying SLC extra current storage occurs when there is sudden loads change otherwise little extra current is stored.

Eco-retrofitting - from managerialism to design

As all environmental problems are caused by human systems of design, sustainability can be seen as a design problem. Given the massive energy and material flows through the built environment, sustainability simply cannot be achieved without the re-design of our urban areas. ‘Eco-retrofitting’, as used here, means modifying buildings and/or urban areas to create net positive social and environmental impacts – both on site and off site. While this has probably not been achieved anywhere as yet, myriad but untapped eco-solutions are already available which could be up-scaled to the urban level. It is now well established that eco-retrofitting buildings and cities with appropriate design technology can pay for itself through lower health costs, productivity increases and resource savings. Good design would also mean happier human and ecological communities at a much lower cost over time. In fact, good design could increase life quality and the life support services of nature while creating sustainable‘economic’growth. The impediments are largely institutional and intellectual, which can be encapsulated in the term ‘managerial’. There are, however, also systems design solutions to the managerial obstacles that seem to be stalling the transition to sustainable systems designs. Given the sustainability imperative, then, why is the adoption of better management systems so slow? The oral presentation will show examples of ways in which built environment design can create environments that not only reduce the ongoing damage of past design, but could theoretically generate net positive social and ecological outcomes over their life cycle. These illustrations show that eco-retrofitting could cost society less than doing nothing - especially given the ongoing renovations of buildings - but for managerial hurdles. The paper outlines on how traditional managerial approaches stand in the way of ‘design for ecosystem services’, and list some management solutions that have long been identified, but are not yet widely adopted. Given the pervasive nature of these impediments and their alternatives, they are presented by way of examples. A sampling of eco-retrofitting solutions are also listed to show that ecoretrofitting is a win-win-win solution that stands ready to be implemented by people having management skills and/or positions of influence.

Impact of music therapy to promote positive parenting and child development

The effectiveness of a 10-week group music therapy program for marginalized parents and their children aged 0–5 years was examined. Musical activities were used to promote positive parent–child relationships and children’s behavioral, communicative and social development. Participants were 358 parents and children from families facing social disadvantage, young parents or parents of a child with a disability. Significant improvements were found for therapist-observed parent and child behaviors, and parent-reported irritable parenting, educational activities in the home, parent mental health and child communication and social play skills. This study provides evidence of the potential effectiveness of music therapy for early intervention.

A model of teacher professional development based on the principles of lesson study

The researcher’s professional role as an Education Officer was the impetus for this study. Designing and implementing professional development activities is a significant component of the researcher’s position description and as a result of reflection and feedback from participants and colleagues, the creation of a more effective model of professional development became the focus for this study. Few studies have examined all three links between the purposes of professional development that is, increasing teacher knowledge, improving teacher practice, and improving student outcomes. This study is significant in that it investigates the nature of the growth of teachers who participated in a model of professional development which was based upon the principles of Lesson Study. The research provides qualitative and empirical data to establish some links between teacher knowledge, teacher practice, and student learning outcomes. Teacher knowledge in this study refers to mathematics content knowledge as well as pedagogical-content knowledge. The outcomes for students include achievement outcomes, attitudinal outcomes, and behavioural outcomes. As the study was conducted at one school-site, existence proof research was the focus of the methodology and data collection. Developing over the 2007 school year, with five teacher-participants and approximately 160 students from Year Levels 6 to 9, the Lesson Study-principled model of professional development provided the teacher-participants with on-site, on-going, and reflective learning based on their classroom environment. The focus area for the professional development was strategising the engagement with and solution of worded mathematics problems. A design experiment was used to develop the professional development as an intervention of prevailing teacher practice for which data were collected prior to and after the period of intervention. A model of teacher change was developed as an underpinning framework for the development of the study, and was useful in making decisions about data collection and analyses. Data sources consisted of questionnaires, pre-tests and post-tests, interviews, and researcher observations and field notes. The data clearly showed that: content knowledge and pedagogical-content knowledge were increased among the teacher-participants; teacher practice changed in a positive manner; and that a majority of students demonstrated improved learning outcomes. The positive changes to teacher practice are described in this study as the demonstrated use of mixed pedagogical practices rather than a polarisation to either traditional pedagogical practices or contemporary pedagogical practices. The improvement in student learning outcomes was most significant as improved achievement outcomes as indicated by the comparison of pre-test and post-test scores. The effectiveness of the Lesson Study-principled model of professional development used in this study was evaluated using Guskey’s (2005) Five Levels of Professional Development Evaluation.