D'Andreta D.,Research Fellow
Journal of health services research & policy | Year: 2013
We contribute to existing knowledge translation (KT) literature by developing the notion of 'enactment' and illustrate this through an interpretative, comparative case-study analysis of three Collaborations for Leadership in Applied Health Research and Care (CLAHRC) initiatives. We argue for a focus on the way in which the CLAHRC model has been 'enacted' as central to the different KT challenges and capabilities encountered. A comparative, mixed method study created a typology of enactments (Classical, Home-grown and Imported) using qualitative analysis and social network analysis. We identify systematic differences in the enactment of the CLAHRC model. The sources of these different enactments are subsequently related to variation in formative interpretations and leadership styles, the implementation of different governance structures, and the relative epistemic differences between the professional groups involved. Enactment concerns the creative agency of individuals and groups in constituting a particular context for their work through their local interpretation of a particular KT model. Our theory of enactment goes beyond highlighting variation between CLAHRCs, to explore the mechanisms that influence the way a particular model is interpreted and acted upon. We thus encourage less focus on conceptual models and more on the formative role played by leaders of KT initiatives. Source
Abstract: Researchers from CIC nanoGUNE, in collaboration with ICFO and Graphenea, have demonstrated how infrared light can be captured by nanostructures made of graphene. This happens when light couples to charge oscillations in the graphene. The resulting mixture of light and charge oscillations - called plasmon - can be squeezed into record-small volumes - millions times smaller than in conventional dielectric optical cavities. This process has been visualized by the researchers now, for the first time, with the help of a state-of the-art near-field microscope and explained by theory. Particularly, the researchers identified two types of plasmons - edge and sheet modes - propagating either along the sheet or along the sheet edges. The edge plasmons are unique for their ability to channel electromagnetic energy in one dimension. The work - funded by the EC Graphene Flagship and reported in Nature Photonics - opens new opportunities for ultra-small and efficient photodetectors, sensors and other photonic and optoelectronic nanodevices. Graphene-based technologies enable extremely small optical nanodevices. The wavelength of light captured by a graphene sheet - a monolayer sheet of carbon atoms can be shortened by a factor of 100 compared to light propagating in free space. As a consequence, this light propagating along the graphene sheet - called graphene plasmon - requires much less space. For that reason, photonic devices can be made much smaller. The plasmonic field concentration can be further enhanced by fabricating graphene nanostructures acting as nanoresonators for the plasmons. The enhanced field have been already applied for enhanced infrared and terahertz photodetection or infrared vibrational sensing of molecules, among others. "The development of efficient devices based on plasmonic graphene nanoresonators will critically depend on precise understanding and control of the plasmonic modes inside them" says Dr. Pablo Alonso-Gonzalez, (now at Oviedo University) who performed the real-space imaging of the graphene nanoresonators (disks and rectangles) with a near-field microscope. "We have been strongly impressed by the diversity of plasmonic contrasts observed in the near-field images" continues Dr. Alexey Nikitin, Ikerbasque Research Fellow at nanoGUNE, who developed the theory to identify the individual plasmon modes. The research team has disentangled the individual plasmonic modes and separated them into two different classes. The first class of plasmons - "sheet plasmons" - can exist "inside" graphene nanostructures, extending over the whole area of graphene. Conversely, the second class of plasmons - "edge plasmons" -can exclusively propagate along the edges of graphene nanostructures, leading to whispering gallery modes in disk-shaped nanoresonators or Fabry-Perot resonances in graphene nanorectangles due to reflection at their corners. The edge plasmons are much better confined than the sheet plasmons and, most importantly, transfer the energy only in one dimension. The real-space images reveal dipolar edge modes with a mode volume that is 100 million times smaller that a cube of the free-space wavelength. The researchers also measured the dispersion (energy as a function of momentum) of the edge plasmons based on their near-field images, highlighting the shortened wavelength of edge plasmons compared to sheet plasmons. Thanks to their unique properties, edge plasmons could be a promising platform for coupling quantum dots or single molecules in future quantum opto-electronic devices. "Our results also provide novel insights into the physics of near-field microscopy of graphene plasmons, which could be very useful for interpreting near-field images of other light-matter interactions in two-dimensional materials", adds Ikerbasque Research Professor Rainer Hillenbrand who led the project. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Changes in environmental conditions may affect epidemics not only by altering the number of free-living pathogens but also by directly increasing pathogen virulence with immediate changes in the physiological status of infecting bacteria. Pathogens' abilities to cause infections is often considered to be consequence of long term selection pressures with their hosts. However, changes in environmental conditions could affect epidemics by altering the number of free-living pathogens but also by directly increasing pathogen virulence with immediate changes in the physiological status of infecting bacteria. Researchers tested if short-term exposure to different outside host resource types and concentrations affect Serratia marcescens –bacterium's virulence in Galleria mellonella –moth. S. marcescens is an environmentally growing opportunistic pathogen that can infect a wide range of host, including immunocompromised humans. As expected, severity of the infection was mostly dictated by the bacterial dose, but researchers also found a clear increase in virulence when the bacterium had inhabited a low (vs. high) resource concentration, or animal based (vs. plant based) resources 48 hours prior to infection. The findings suggest that depending on the exposure to different food sources prior infection, even genetically similar bacteria can differ in their virulence. "Based on these results one could say that depending on if a single genetically similar bacterial cell originates from a piece of meat, instead of a plant, the virulence is higher. Such changes in virulence could stem from commonly observed resource dependent upregulation of genes that are known to regulate important virulence factors," says Academy Research Fellow Tarmo Ketola. Explore further: How an aggressive fungal pathogen causes mold in fruits and vegetables More information: Ketola T., Mikonranta L., Laakso J. & Mappes J.: Different food sources elicit fast changes to bacterial virulence. Biology Letters, 2016. 12: 20150660. dx.doi.org/10.1098/rsbl.2015.0660
Flinders University researchers have developed clean technology to dissolve waste wool and unwanted woollen products to produce a high-value protein called keratin and other byproducts with varied potential applications. Well known on packaging of popular hair products, the scientists have worked out how to distil keratin from wool using a non-toxic, biodegradable chemical process to 'dissolve' the wool fibres with an eye on potential end uses in the cosmetic, pharmaceutical and even animal feed markets. The South Australia Premier's Professorial Research Fellow in Clean Technology at Flinders, Professor Colin Raston, says the discovery is an outstanding example of reducing waste in a safe way to make use of – and create value – from an existing resource. "The future of clean technology is rapidly growing as the cost of producing expensive substances is offset against the benefits of low-cost, efficient, and environmentally sustainable recycling processes such as this," said Raston. "After breakdown using a choline-chloride-urea solvent 'melt', the keratin nano-materials can be further refined and freeze dried to form a protein powder, to be used for a range of products ranging from wound healing in bandages to animal feedstock. The 'green chemistry' process is simple, efficient, and environmentally friendly, said Ramiz Boulos, Ph.D., who worked on the breakthrough technology with Professor Raston and fellow researchers Katherine Moore, Ph.D., Daniel Mangos and Ashley Slattery, Ph.D. "Sheep wool is clearly an abundant biomaterial, with the wool weaving industry worldwide discarding tonnes of low grade non-spin wool fibres every year and much more landfill from wool garments from human waste," Boulos said. "Our system makes use of a waste stream, deemed unsuitable for the clothing industry, to produce an additional revenue source." Boulos, who previously demonstrated a similar process to deconstruct his own hair, says the benign eutectic melt used to break down wool and human hair creates the opportunity to extract the valuable keratin with another straight forward process, such as simple dialysis techniques and then concentrated using freeze drying. "The final product would be highly useful for electro-spinning to form keratin bandages or for implantation into a hydrogel, both of which have demonstrated clear wound healing advantages." The research, funded by the Australian Research Council and Government of South Australia, was supported by Flinders Microscopy and the Australian Proteome Analysis Facility through the Federal Government's National Collaborative Research Infrastructure Strategy. The paper, Wool deconstruction using a benign eutectic melt, has been published by the Royal Society of Chemistry journal RSC Advances.
News Article | August 18, 2016
The United Nations climate change conference held last year in Paris had the aim of tackling future climate change. After the deadlocks and weak measures that arose at previous meetings, such as Copenhagen in 2009, the Paris summit was different. The resulting Paris Agreementcommitted to: The agreement was widely met with cautious optimism. Certainly, some of the media were pleased with the outcome while acknowledging the deal’s limitations. Many climate scientists were pleased to see a more ambitious target being pursued, but what many people fail to realise is that actually staying within a 1.5℃ global warming limit is nigh on impossible. There seems to be a strong disconnect between what the public and climate scientists think is achievable. The problem is not helped by the media’s apparent reluctance to treat it as a true crisis. In 2015, we saw global average temperatures a little over 1℃ above pre-industrial levels, and 2016 will very likely be even hotter. In February and March of this year, temperatures were 1.38℃ above pre-industrial averages. Admittedly, these are individual months and years with a strong El Niñoinfluence (which makes global temperatures more likely to be warmer), but the point is we’re already well on track to reach 1.5℃ pretty soon. So when will we actually reach 1.5℃ of global warming? Timeline showing best current estimates of when global average temperatures will rise beyond 1.5℃ and 2℃ above pre-industrial levels. Boxes represent 90% confidence intervals; whiskers show the full range. Image via Andrew King. On our current emissions trajectory we will likely reach 1.5℃ within the next couple of decades (2024 is our best estimate). The less ambitious 2℃ target would be surpassed not much later. This means we probably have only about a decade before we break through the ambitious 1.5℃ global warming target agreed to by the world’s nations in Paris. A University of Melbourne research group recently published these spiral graphs showing just how close we are getting to 1.5℃ warming. Realistically, we have very little time left to limit warming to 2℃, let alone 1.5℃. This is especially true when you bear in mind that even if we stopped all greenhouse gas emissions right now, we would likely experience about another half-degree of warming as the oceans “catch up” with the atmosphere. The public seriously underestimates the level of consensus among climate scientists that human activities have caused the majority of global warming in recent history. Similarly, there appears to be a lack of public awareness about just how urgent the problem is. Many people think we have plenty of time to act on climate change and that we can avoid the worst impacts by slowly and steadily reducing greenhouse gas emissions over the next few decades. This is simply not the case. Rapid and drastic cuts to emissions are needed as soon as possible. In conjunction, we must also urgently find ways to remove greenhouse gases already in the atmosphere. At present, this is not yet viable on a large scale. The 1.5℃ and 2℃ targets are designed to avoid the worst impacts of climate change. It’s certainly true that the more we warm the planet, the worse the impacts are likely to be. However, we are already experiencing dangerous consequences of climate change, with clear impacts on society and the environment. For example, a recent study found that many of the excess deaths reported during the summer 2003 heatwave in Europe could be attributed to human-induced climate change. Also, research has shown that the warm seas associated with the bleaching of the Great Barrier Reef in March 2016 would have been almost impossible without climate change. Climate change is already increasing the frequency of extreme weather events, from heatwaves in Australia to heavy rainfall in Britain. These events are just a taste of the effects of climate change. Worse is almost certainly set to come as we continue to warm the planet. It’s highly unlikely we will achieve the targets set out in the Paris Agreement, but that doesn’t mean governments should give up. It is vital that we do as much as we can to limit global warming. The more we do now, the less severe the impacts will be, regardless of targets. The simple take-home message is that immediate, drastic climate action will mean far fewer deaths and less environmental damage in the future. By Andrew King, Climate Extremes Research Fellow, University of Melbourne and Benjamin J. Henley, Research Fellow in Climate and Water Resources, University of Melbourne. This article has been cross-posted from The Conversation.