Distribution, habitat preferences and population sizes of two threatened tree ferns, Cyathea cunninghamii and Cyathea x marcescens, in south-eastern Australia

The distribution, population sizes and habitat preferences of the rare tree ferns Cyathea cunninghamii Hook.f. (Slender Tree Fern) and F1 hybrid Cyathea x marcescens N.A.Wakef. (Skirted Tree Fern) in south-eastern Australia are described, together with the extension of the known distribution range of Cyathea cunninghamii from eastern Victoria into south-eastern New South Wales. Floristic and ecological data, encompassing most of the known habitat types, vegetation associations and population sizes, were collected across 120 locations. Additional information was sought from literature reviews, herbarium collections and field surveys of extant populations. Cyathea cunninghamii is widespread, with the majority of populations occurring in Tasmania and Victoria, one population in south-eastern NSW and a disjunct population in south-eastern Queensland; Cyathea x marcescens is confined to south and eastern Victoria and south and north eastern Tasmania. Both taxa occur on King Island in Bass Strait. Both taxa have a near coastal distribution with most populations occurring in sub-coastal hinterland and escarpment forests with a median altitude of 288 m. Hierarchical cluster analysis of floristic data across the species’ geographic range identified six vegetation communities ranging from rainforest to damp sclerophyll forest. Their micro-habitat preferences were consistently identified as steeply incised gullies of minor headwater streams of coastal and sub-coastal ranges with a plentiful moisture regime and geomorphic protection from extreme stream flow events, flooding and bank scouring. Sporophyte recruitment was associated with exposed soil of stream banks and edges of constructed walking tracks. Population sizes of both taxa are small with the majority of populations consisting of less than five adult individuals, with total populations of Cyathea cunninghamii and Cyathea x marcescens estimated at 919 and 221 mature individuals respectively. Population extinctions in Victoria and Tasmania have primarily been associated with outlier populations in regions subject to agricultural land clearance, habitat modification and changes to fire regimes in crown forests. Nonanthropogenic mortality was associated with land slips, tree falls and stream bank scouring by flood water. Conservation of the hybrid Cyathea x marcescens necessitates the preservation of habitats where both Cyathea cunninghamii and Cyathea australis occur in close proximity to substrates suitable for spore germination. In future, molecular techniques may prove useful for field identification of juvenile stages, facilitating selection of progeny of Cyathea cunninghamii and Cyathea x marcescens for cultivation and re-introduction to sites of previous or possible future extinctions

Case Studies in e-RPL and e-PR

The use of ePortfolios for recognition of prior learning (e-RPL) and for professional recognition (e-PR) is slowly gaining in popularity in the VET sector however their use is sporadic across educational sectors, disciplines, educational institutions and professions. Added to this is an array of purposes and types of e-RPL and e-PR models and practice. The aim of this paper is to build on the conceptual framework developed by Cameron (2012) for e-RPL and e-PR and to provide case studies for each of the four types developed within this framework: e-PR for Professional Accreditation; e-RPL for Workplace Recognition; e-RPL for Access and; e-RPL for Self Recognition. We use the case studies to explore the four types and the two dimensions or continuums central to the framework. The vertical dimension is a continuum between RPL as process and RPL as product and the second horizontal dimension is a continuum between formal learning contexts and low learner control as opposed to informal learning contexts and high levels of learner control. The case studies have aided the further development of the framework and its theoretical and practical applications

Chirality and the angular momentum of light

Chirality is exhibited by objects that cannot be rotated into their mirror images. It is far from obvious that this has anything to do with the angular momentum of light, which owes its existence to rotational symmetries. There is nevertheless a subtle connection between chirality and the angular momentum of light. We demonstrate this connection and, in particular, its significance in the context of chiral light–matter interactions

Optical helicity, optical spin and related quantities in electromagnetic theory

We examine the optical helicity, the optical spin and the ij-infra- zilches in electromagnetic theory and show that these conserved quantities can be combined to form a new description of the angular momentum associated with optical polarization: one that is analogous to the familiar description of optical energy and linear momentum. The symmetries of Maxwell’s equations that underlie the conservation of our quantities are presented and discussed. We explain that a similar but distinct set of quantities, Lipkin’s zilches, describe the ‘angular momentum’ of the curl of the electromagnetic field, rather than the angular momentum of the electromagnetic field itself

Integrated Area Development Projects: Working Towards Innovation

There is growing interest in integrated area development projects as a way of responding to special problem areas, including ameliorating the geographic concentration of social and economic disadvantage. This is expressed through the move towards ‘joined up’ government and development ‘in the round’ at the local level; and new forms of area-based initiatives aimed at neighbourhood renewal and urban economic development. The growing influence of sustainability concepts and developmental approaches to housing and urban development is also leading to multi-faceted projects that incorporate economic, social and environmental dimensions. In the South African context, the interest in integrated area development manifests in the major urban renewal projects that are presently being mounted, and reflects a search for ways of achieving integrated development that are more grounded than the grand scale planning associated with Integrated Development Plans and Spatial Development Frameworks

Age Related Changes in Cerebrovascular Reactivity and Its Relationship to Global Brain Structure

ACKNOWLEDGMENTS This study was funded by Alzheimer’s Research UK (ARUK) and the Aberdeen Biomedical Imaging Centre, University of Aberdeen. GDW, ADM and CS are part of the SINASPE collaboration (Scottish Imaging Network - A Platform for Scientific Excellence www.SINAPSE.ac.uk). The authors thank Gordon Buchan, Baljit Jagpal, Nichola Crouch, Beverly Maclennan and Katrina Klaasen for their help with running the experiment and Dawn Younie and Teresa Morris for their help with recruitment and scheduling. We also thank the residents of Aberdeen and Aberdeenshire, and further afield, for their generous participation.Peer reviewedPublisher PD