Editorial 28(3): Preface to the special issue-Virtual worlds in tertiary education:An Australasian perspective

In recognition of the considerable innovation, experimentation and dialogue that has been taking place in the virtual worlds arena across the tertiary education sector in Australasia (see Dalgarno, Lee, Carlson, Gregory & Tynan, 2011 for a snapshot), this special issue called for contributions from within the Australasian region, as well as from those farther afield able to position their work against the Australasian context. Articles were requested that addressed theory, research and practical issues related to the use of the technology in both higher and vocational education

A new approach to the assessment of lumen visibility of coronary artery stent at various heart rates using 64-slice MDCT

Coronary artery stent lumen visibility was assessed as a function of cardiac movement and temporal resolution with an automated objective method using an anthropomorphic moving heart phantom. Nine different coronary stents filled with contrast fluid and surrounded by fat were scanned using 64-slice multi-detector computed tomography (MDCT) at 50–100 beats/min with the moving heart phantom. Image quality was assessed by measuring in-stent CT attenuation and by a dedicated tool in the longitudinal and axial plane. Images were scored by CT attenuation and lumen visibility and compared with theoretical scoring to analyse the effect of multi-segment reconstruction (MSR). An average increase in CT attenuation of 144 ± 59 HU and average diminished lumen visibility of 29 ± 12% was observed at higher heart rates in both planes. A negative correlation between image quality and heart rate was non-significant for the majority of measurements (P > 0.06). No improvement of image quality was observed in using MSR. In conclusion, in-stent CT attenuation increases and lumen visibility decreases at increasing heart rate. Results obtained with the automated tool show similar behaviour compared with attenuation measurements. Cardiac movement during data acquisition causes approximately twice as much blurring compared with the influence of temporal resolution on image quality

Genes in S and T Subgenomes Are Responsible for Hybrid Lethality in Interspecific Hybrids between Nicotiana tabacum and Nicotiana occidentalis

Many species of Nicotiana section Suaveolentes produce inviable F(1) hybrids after crossing with Nicotiana tabacum (genome constitution SSTT), a phenomenon that is often called hybrid lethality. Through crosses with monosomic lines of N. tabacum lacking a Q chromosome, we previously determined that hybrid lethality is caused by interaction between gene(s) on the Q chromosome belonging to the S subgenome of N. tabacum and gene(s) in Suaveolentes species. Here, we examined if hybrid seedlings from the cross N. occidentalis (section Suaveolentes)×N. tabacum are inviable despite a lack of the Q chromosome.Hybrid lethality in the cross of N. occidentalis×N. tabacum was characterized by shoots with fading color. This symptom differed from what has been previously observed in lethal crosses between many species in section Suaveolentes and N. tabacum. In crosses of monosomic N. tabacum plants lacking the Q chromosome with N. occidentalis, hybrid lethality was observed in hybrid seedlings either lacking or possessing the Q chromosome. N. occidentalis was then crossed with two progenitors of N. tabacum, N. sylvestris (SS) and N. tomentosiformis (TT), to reveal which subgenome of N. tabacum contains gene(s) responsible for hybrid lethality. Hybrid seedlings from the crosses N. occidentalis×N. tomentosiformis and N. occidentalis×N. sylvestris were inviable.Although the specific symptoms of hybrid lethality in the cross N. occidentalis×N. tabacum were similar to those appearing in hybrids from the cross N. occidentalis×N. tomentosiformis, genes in both the S and T subgenomes of N. tabacum appear responsible for hybrid lethality in crosses with N. occidentalis

Australian higher education institutions transforming the future of teaching and learning through 3d virtual worlds

What are educators motivations for using virtual worlds with their students? Are they using them to support the teaching of professions and if this is the case, do they introduce virtual worlds into the curriculum to develop and/or expand students' professional learning networks? Are they using virtual worlds to transform their teaching and learning? In recognition of the exciting opportunities that virtual worlds present for higher education, the DEHub Virtual Worlds Working Group was formed. It is made up of Australian university academics who are investigating the role that virtual worlds will play in the future of education and actively implementing the technology within their own teaching practice and curricula. This paper presents a typology for teaching and learning in 3D virtual worlds and applies the typology to a series of case studies based on the ways in which academics and their institutions are exploiting the power of virtual worlds for diverse purposes ranging from business scenarios and virtual excursions to role-play, experimentation and language development. The case studies offer insight into the ways in which institutions are transforming their teaching for an unknown future through innovative teaching and learning in virtual worlds. The paper demonstrates how virtual worlds enable low cost alternatives to existing pedagogies as well as creating opportunities for rich, immersive and authentic activities that would otherwise not be feasible or maybe not even be possible. Through the use of virtual worlds, teaching and learning can be transformed to cater for an unknown future. © 2010 Sue Gregory, Mark J.W. Lee, Allan Ellis, Brent Gregory, Denise Wood, Mathew Hillier, Matthew Campbell, Jenny Grenfell, Steven Pace, Helen Farley, Angela Thomas, Andrew Cram, Suku Sinnappan, Kerrie Smith, Lyn Hay, Shannon Kennedy-Clark, Ian Warren, Scott Grant, David Craven, Heinz Dreher, Carol Matthews, Deborah Murdoch & Lindy McKeown. © 2010 Sue Gregory, Mark J.W. Lee, Allan Ellis, Brent Gregory, Denise Wood, Mathew Hillier, Matthew Campbell, Jenny Grenfell, Steven Pace, Helen Farley, Angela Thomas, Andrew Cram, Suku Sinnappan, Kerrie Smith, Lyn Hay, Shannon Kennedy-Clark, Ian Warren, Scott Grant, David Craven, Heinz Dreher, Carol Matthews, Deborah Murdoch & Lindy McKeown

Distinct Gene Number-Genome Size Relationships for Eukaryotes and Non-Eukaryotes: Gene Content Estimation for Dinoflagellate Genomes

The ability to predict gene content is highly desirable for characterization of not-yet sequenced genomes like those of dinoflagellates. Using data from completely sequenced and annotated genomes from phylogenetically diverse lineages, we investigated the relationship between gene content and genome size using regression analyses. Distinct relationships between log10-transformed protein-coding gene number (Y′) versus log10-transformed genome size (X′, genome size in kbp) were found for eukaryotes and non-eukaryotes. Eukaryotes best fit a logarithmic model, Y′ = ln(-46.200+22.678X′, whereas non-eukaryotes a linear model, Y′ = 0.045+0.977X′, both with high significance (p<0.001, R2>0.91). Total gene number shows similar trends in both groups to their respective protein coding regressions. The distinct correlations reflect lower and decreasing gene-coding percentages as genome size increases in eukaryotes (82%–1%) compared to higher and relatively stable percentages in prokaryotes and viruses (97%–47%). The eukaryotic regression models project that the smallest dinoflagellate genome (3×106 kbp) contains 38,188 protein-coding (40,086 total) genes and the largest (245×106 kbp) 87,688 protein-coding (92,013 total) genes, corresponding to 1.8% and 0.05% gene-coding percentages. These estimates do not likely represent extraordinarily high functional diversity of the encoded proteome but rather highly redundant genomes as evidenced by high gene copy numbers documented for various dinoflagellate species

Opening Spaces for the Development of Human Agency with Problem Based Learning in Palestinian Higher Education

This paper appraises the impact of Problem Based Learning (PBL) implementations within the (2016-19) Erasmus Plus "Methods" Project (Modernization of Teaching Methodologies in Higher Education: EU experience for Jordan and Palestinian territory) which introduced a range of learning modalities into formal learning contexts in higher education settings in Jordan (4 Universities) and Palestine (4 Universities). The project was jointly led by the Universities of Jordan and Birzeit, Palestine and there were six European partner universities. The paper focuses on the impact of PBL approaches on learners and university teachers through an analysis of semi-structured group interviews with students and individual staff interviews across a range of courses in the arts and sciences within the Palestinian context. The results of this small-scale research study are presented within a thematic framework focusing on participation, collaboration, agency, knowledge creation, problem solving and identity modification. It explores how far the adoption of student-centred PBL designs can open spaces for the development of human agency and capabilities within an existing orthodoxy of practice in Higher Education Settings in Palestine. It locates these student-centred practices within the context of higher education under occupation and examines what contribution they make to developing individuals’ capacity to act effectively for change within the power dynamics and limits of their context

The evolution of the plastid chromosome in land plants: gene content, gene order, gene function

This review bridges functional and evolutionary aspects of plastid chromosome architecture in land plants and their putative ancestors. We provide an overview on the structure and composition of the plastid genome of land plants as well as the functions of its genes in an explicit phylogenetic and evolutionary context. We will discuss the architecture of land plant plastid chromosomes, including gene content and synteny across land plants. Moreover, we will explore the functions and roles of plastid encoded genes in metabolism and their evolutionary importance regarding gene retention and conservation. We suggest that the slow mode at which the plastome typically evolves is likely to be influenced by a combination of different molecular mechanisms. These include the organization of plastid genes in operons, the usually uniparental mode of plastid inheritance, the activity of highly effective repair mechanisms as well as the rarity of plastid fusion. Nevertheless, structurally rearranged plastomes can be found in several unrelated lineages (e.g. ferns, Pinaceae, multiple angiosperm families). Rearrangements and gene losses seem to correlate with an unusual mode of plastid transmission, abundance of repeats, or a heterotrophic lifestyle (parasites or myco-heterotrophs). While only a few functional gene gains and more frequent gene losses have been inferred for land plants, the plastid Ndh complex is one example of multiple independent gene losses and will be discussed in detail. Patterns of ndh-gene loss and functional analyses indicate that these losses are usually found in plant groups with a certain degree of heterotrophy, might rendering plastid encoded Ndh1 subunits dispensable

Virtual worlds in Australian and New Zealand higher education: Remembering the past, Understanding the present and imagining the future

3D virtual reality, including the current generation of multi-user virtual worlds, has had a long history of use in education and training, and it experienced a surge of renewed interest with the advent of Second Life in 2003. What followed shortly after were several years marked by considerable hype around the use of virtual worlds for teaching, learning and research in higher education. For the moment, uptake of the technology seems to have plateaued, with academics either maintaining the status quo and continuing to use virtual worlds as they have previously done or choosing to opt out altogether. This paper presents a brief review of the use of virtual worlds in the Australian and New Zealand higher education sector in the past and reports on its use in the sector at the present time, based on input from members of the Australian and New Zealand Virtual Worlds Working Group. It then adopts a forward-looking perspective amid the current climate of uncertainty, musing on future directions and offering suggestions for potential new applications in light of recent technological developments and innovations in the area

Propagule Pressure: A Null Model for Biological Invasions

null model, propagule pressure Invasion ecology has been criticised for its lack of general principles. To explore this criticism, we con-ducted a meta-analysis that examined characteristics of invasiveness (i.e. the ability of species to establish in, spread to, or become abundant in novel communities) and invasibility (i.e. the susceptibility of habitats to the establishment or proliferation of invaders). There were few consistencies among invasiveness char-acteristics (3 of 13): established and abundant invaders generally occupy similar habitats as native species, while abundant species tend to be less affected by enemies; germination success and reproductive output were significantly positively associated with invasiveness when results from both stages (establishment/ spread and abundance/impact) were combined. Two of six invasibility characteristics were also significant: communities experiencing more disturbance and with higher resource availability sustained greater establishment and proliferation of invaders. We also found that even though ‘propagule pressure ’ was considered in only 29 % of studies, it was a significant predictor of both invasiveness and invasibility (55 of 64 total cases). Given that nonindigenous species are likely introduced non-randomly, we contend that ‘propagule biases ’ may confound current paradigms in invasion ecology. Examples of patterns that could be confounded by propagule biases include characteristics of good invaders and susceptible habitats, release from enemies, evolution of ‘invasiveness’, and invasional meltdown. We conclude that propagule pressure should serve as the basis of a null model for studies of biological invasions when inferring process from patterns of invasion