A rep-based hairpin inhibits replication of diverse maize streak virus isolates in a transient assay

Centre for High-Performance Computing, Rosebank, Cape Town, South Africa Maize streak disease, caused by the A strain of the African endemic geminivirus, maize streak mastrevirus (MSV-A), threatens the food security and livelihoods of subsistence farmers throughout sub-Saharan Africa. Using a well-established transient expression assay, this study investigated the potential of a spliceable-intron hairpin RNA (hpRNA) approach to interfere with MSV replication. Two strategies were explored: (i) an inverted repeat of a 662 bp region of the MSV replication-associated protein gene (rep), which is essential for virus replication and is therefore a good target for post-transcriptional gene silencing; and (ii) an inverted repeat of the viral long intergenic region (LIR), considered for its potential to trigger transcriptional silencing of the viral promoter region. After co-bombardment of cultured maize cells with each construct and an infectious partial dimer of the cognate virus genome (MSV-Kom), followed by viral replicativeform-specific PCR, it was clear that, whilst the hairpin rep construct (pHPrepDI662) completely inhibited MSV replication, the LIR hairpin construct was ineffective in this regard. In addition, pHPrepDI662 inhibited or reduced replication of six MSV-A genotypes representing the entire breadth of known MSV-A diversity. Further investigation by real-time PCR revealed that the pHPrepDI662 inverted repeat was 22-fold more effective at reducing virus replication than a construct containing the sense copy, whilst the antisense copy had no effect on replication when compared with the wild type. This is the first indication that an hpRNA strategy targeting MSV rep has the potential to protect transgenic. © 2011 SGM.

Narrative : family trauma or challenge and resilience in the Galapagos Archipelago

The chapter is a "here and now" narration in the first person as witnessed and experienced by the author during field work in the Galapagos Islands in 1976-79. The story begins on the most remote volcanic island of Fernandina where the breeding biology of Flightless cormorants was being studied. A small selection of the many potentially life threatening situations and challenges is described including stories related to the birth of their son.

"More tick-the-box": the challenge of promoting interdisciplinary learning in the middle years through the Australian history curriculum

The Australian Curriculum marks national reforms in social science education, first with the return to the disciplines of history and geography and second, through a new approach to interdisciplinary learning. This paper raises the question of whether the promise of interdisciplinary learning can be realised in the middle years of schooling if teachers have to teach history as a discipline rather than within an over-arching integrated curriculum framework. The paper explores the national blueprints and considers the national history curriculum in light of theories of teachers’ knowledge and middle school education. Evidence from teacher interviews indicates that historical understanding can be achieved through integrated frameworks to meet the goals of middle schooling.

Quantifying the roles of cell motility and cell proliferation in a circular barrier assay

Moving fronts of cells are essential features of embryonic development, wound repair and cancer metastasis. This paper describes a set of experiments to investigate the roles of random motility and proliferation in driving the spread of an initially confined cell population. The experiments include an analysis of cell spreading when proliferation was inhibited. Our data have been analysed using two mathematical models: a lattice-based discrete model and a related continuum partial differential equation model. We obtain independent estimates of the random motility parameter, D, and the intrinsic proliferation rate, λ, and we confirm that these estimates lead to accurate modelling predictions of the position of the leading edge of the moving front as well as the evolution of the cell density profiles. Previous work suggests that systems with a high λ/D ratio will be characterized by steep fronts, whereas systems with a low λ/D ratio will lead to shallow diffuse fronts and this is confirmed in the present study. Our results provide evidence that continuum models, based on the Fisher–Kolmogorov equation, are a reliable platform upon which we can interpret and predict such experimental observations.

The sixth 48 hour game making challenge (2012)

Game jams provide design researchers with extraordinary opportunity to watch creative teams in action and recent years have seen a number of projects which seek to illuminate the design process as seen in these events. For example, Gaydos, Harris and Martinez discuss the opportunity of the jam to expose students to principles of design process and design spaces (2011). Rouse muses on the game jam ‘as radical practice’ and a ‘corrective to game creation as it is normally practiced’. His observations about his own experience in a jam emphasise the same artistic endeavour forefronted earlier, where the experience is about creation that is divorced from the instrumental motivations of commercial game design (Rouse 2011) and where the focus is on process over product. Other participants remark on the social milieu of the event as a critical factor and the collaborative opportunity as a rich site to engage participants in design processes (Shin et al, 2012). Shin et al are particularly interested in the notion of the site of the process and the ramifications of participants being in the same location. They applaud the more localized event where there is an emphasis on local participation and collaboration. For other commentators, it is specifically the social experience in the place of the jam is the most important aspect (See Keogh 2011), not the material site but rather the physical embodied experience of ‘being there’ and being part of the event. Participants talk about game jams they have attended in a similar manner to those observations made by Dourish where the experience is layered on top of the physical space of the event (Dourish 2006). It is as if the event has taken on qualities of place where we find echoes of Tuan’s description of a particular site having an aura of history that makes it a very different place, redolent and evocative (Tuan 1977). Re-presenting the experience in place has become the goal of the data visualisation project that has become the focus of our own curated 48hr game jam. Taking our cue from the work of Tim Ingold on embodied practice, we have now established the 48hr game making challenge as a site for data visualisation research in place.

Preparing citizens for a complex world : the grand challenge of teaching socio-scientific issues in science education

The dawn of the twenty-first century encouraged a number of scientific and technological organisations to identify what they saw as ‘Grand Challenges and Opportunities’. Issues of environment and health featured very prominently in these quite short lists, as can be seen from a sample of these challenges in Table 1. Indeed, the first two lists of challenges in Table 1 were identified as for the environment and for health, respectively.

The challenge of generic competences to science education

Since 2000 there has been pressure on education systems for develop in students a number of competences that are described as generic. This pressure stems from studies of the changing nature of work in the Knowledge Society that is now so dominant. The DeSeCo project identified a number of these competences, and listed them under the headings of communicative, analytical and personal. They include thinking, creativity, communication skills, knowing how to learn, working in teams, adapting to change, and problem solving. These competences pose a substantial challenge to the manner in which education as a whole, and science education in particular, has hitherto been generally conceived. It is now common to find their importance acknowledged in new formulation of the curriculum. The paper reviews a number of these curriculum documents and how they have tried to relate these competences to the teaching and learning of Science, a subject with its own very specific content for learning. It will be suggested that the challenge provides an opportunity for a reconstruction of the teaching and learning of science in schools that will increase its effectiveness for more students.

Who's afraid of China? The challenge of Chinese soft power [Review]

What role does China play in Western imagination and how does it affect Western selfconceptions? The rise of China as an alternative model to Western liberalism has created a fear that developing countries will stray from Western standards of democracy, transparency and human rights. However, such fears often say as much about those who hold them as they do about China itself. In this short and easily readable book Barr holds a mirror to Sino–Western relations in order to better understand how the West’s own past, hopes and fears shape the way it thinks about and engages with China. Focusing on three key areas—models of development, soft power and ethnocentrism—he argues that the rise of China ‘hits a nerve in the Western psyche . . . because its actions reflect the West’s own ambivalence to modernity and uncertainty over the proper role and limits of state power’ (p. 21). To make his point, Barr focuses on China’s soft power and the connections between China’s domestic politics and its attempts to shape its image internationally...

The diversity of interests in environmental governance : a challenge for the rule of law

The function of environmental governance and the principle of the rule of law are both controversial and challenging. To apply the principle of the rule of law to the function of environmental governance is perhaps even more controversial and challenging. A system of environmental governance seeks to bring together the range of competitive and potentially conflicting interests in how the environment and its resources are managed. Increasingly it is the need for economic, social and ecological sustainability that brings these interests – both public and private – together. Then there is the relevance of the principle of the rule of law. Economic, social and ecological sustainability will be achieved – if at all – by a complex series of rules of law that are capable of enforcement so as to ensure compliance with them. To what extent do these rules of law reflect the principle of the rule of law? Is the principle of the rule of law the formally unstated value that is expected to underpin the legal system or is it the normative predicate that directs the legal system both vertically and horizontally? Is sustainability an aspirational value or a normative predicate according to which the environment and its resources are managed? Let us deal sequentially with these issues by reviewing a number of examples that demonstrate the relationship between environmental governance and the rule of law.

Dancing Diseases : an applied theatre response to the challenge of conveying emotionally contradictory messages in HIV education

Health educators face an unusual challenge in relation to HIV: the need to convey two emotionally contradictory messages. On the one hand, there is currently no cure for HIV, which eventually leads to death (emotionally negative message). On the other hand, people with HIV can live long, healthy and productive lives (emotionally positive message). In developing countries where HIV prevalence is high, it is imperative that both messages are conveyed effectively. This article reports on a specific form, Dancing Diseases, implemented as one component of the Life Drama pilot study on Karkar Island, Papua New Guinea. Life Drama is an applied theatre and performance approach to HIV education. The article discusses Dancing Diseases as an example of applied theatre and performance practice, reflects on the participant group’s engagement with the form, and offers some ways in which the form could be refined and used in other health education contexts.

The Rise of the BASIC Group Within the International Climate Regime : The Challenge of Ensuring Equitable Mitigation Obligations

The chapter examines the current emission reduction obligations within the climate regime. It looks at the formation and rise of the BASIC negotiation group within the international climate COP negotiations and examines the role that BASIC nations are now playing shaping international mitigation policy.

An improved method for the assay of platelet pyruvate dehydrogenase

An improved method for the assay of human platelet pyruvate dehydrogenase is described. By generating the substrate [1-14C]pyruvate in situ from [1-14C]lactate plus l-lactate dehydrogenase, the rate of spontaneous decarboxylation is dramatically reduced, allowing far greater sensitivity in the assay of low activities of pyruvate dehydrogenase. In addition, no special precautions are required for the storage and use of [1-14C]lactate, in contrast to those for [1-14C] pyruvate. These factors allow a 5–10-fold increase in sensitivity compared with current methods. The pyruvate dehydrogenase activity of normal subjects as determined by the [1-14C]lactate system was 215 ± 55 pmol · min−1 · mg−1 protein (n = 18). The advantages of this assay system are discussed.

IS-RT-PCR assay detection of MT-MMP in a human breast cancer cell line

The in situ-reverse transcription-polymerase chain reaction (IS-RT-PCR) is a method that allows the direct localisation of gene expression. The method utilises the dual buffer mediated activity of the enzyme rTth DNA polymerase enabling both reverse transcription and DNA amplification. Labelled nucleoside triphosphates allow the site of expression to be labelled, rather than the PCR primers themselves, giving a more accurate localisation of transcript expression and decreased background than standard in situ hybridisation (ISH) assays. The MDA-MB-231 human breast carcinoma (HBC) cell line was assayed via the IS-RT-PCR technique, using primers encoding MT-MMP (membrane-type matrix metalloproteinase) and human β-actin. Our results clearly indicate baseline expression of MT-MMP in the relatively invasive MDA-MB-231 cell line at a signal intensity similar to the housekeeping gene β-actin, and results following induction with Concanavalin A (Con A) are consistent with our previous results obtained via Northern blotting.