Ambiguity: A new way of thinking about responses to climate change.

Diversity, interdisciplinarity and transdisciplinarity are now recognized as vital to tackling wicked problems such as those presented by a changing climate (Nature editorial 2015, Ledford 2015; Dick et al., 2016). Including diverse disciplines in science projects enables a range of different views which often facilitate the creation of innovative solutions. Supporting multiple views and options requires a different way of working beyond traditional reductionist approaches to science, communication and decision-making. To embrace diversity in scientific project teams in order to tackle complex, integrated and urgent issues but to expect singular and linear pathways forward is paradoxical. Much has been written about the need for the scientific community to embrace uncertainty (e.g. Popper, Lempert & Bankes 2005; Lempert et al., 2004; Nelson, Howden & Hayman 2013; Bammer & Smithson 2008). We argue that this in itself will not suffice, and that there is also a need to embrace ambiguity in certain situations. Thus, in this article we explore: (1) what ambiguity is, including the benefits it can offer to climate adaptation in particular, using existing approaches to ambiguity in the arts and humanities as examples (2), we discuss practical meanings of ambiguity in relation to climate change, (3) we propose possible next steps for bringing ambiguity into interdisciplinary practice, and (4) we identify some challenges and necessary preconditions to successfully and appropriately embracing ambiguity.

Services for children with developmental co-ordination disorder: the experiences of parents.

BACKGROUND: Parents provide valuable information on their experiences of engaging with therapy services for their children, which can inform the future development of these services. The aim of this study was to explore the views and experiences of parents who had accessed therapy services for their child with developmental co-ordination disorder (DCD). METHODS: Seven focus groups were conducted incorporating 52 parents who had a child diagnosed with, or fitting the diagnostic criteria for DCD. Focus groups were audiotaped, transcribed and analysed thematically. FINDINGS: Parents reported struggling to gain access to therapy services. When they gained access, they found the services beneficial for their child but continued to experience difficulties regarding the quality of service delivery. CONCLUSIONS/IMPLICATIONS: The study suggests that parents thought some health-care professionals lacked knowledge and understanding of DCD, which they believed impacted upon early recognition and access to services. They perceived that therapy at an early age was vital for children's development, and indicated that a clearer path for accessing these services was necessary in addition to improved service quality. They called for an increase in awareness of DCD by all therapy service professionals to aid early recognition and improved treatment.

Integration of functional bacterial artificial chromosomes into human cord blood-derived multipotent stem cells.

Stem cells from a patient with a genetic disease could be used for cell therapy if it were possible to insert a functional copy of the defective gene. In this study, we investigate the transfection and subsequent integration of large genomic fragments into human cord blood-derived multipotent stem cells. We describe for the first time the creation of clonal stem cells carrying a human bacterial artificial chromosome (BAC) containing the Friedreich ataxia locus with an enhanced green fluorescent protein (EGFP) reporter gene fused to exon 5a of the frataxin (FXN) gene. Integration of the BAC into the host cell genome was confirmed by PCR, Southern blot and fluorescent in situ hybridization analysis. Reverse transcription-PCR and flow cytometry confirmed expression of FXN-EGFP. Correct mitochondrial localization of the protein was confirmed using fluorescent microscopy. The transfected stem cells also retained the ability to differentiate into cells from all three germline layers, as demonstrated by the capacity to form neuron-specific beta-tubulin-expressing cells, Alizarin Red S-positive bone-like cells, and epithelial-like cells expressing surfactant protein C. This is the first study to demonstrate that cord blood-derived multipotent stem cells may be useful targets for gene therapy applications using large genomic loci.

Site-specific, Rep-mediated integration of the intact beta-globin locus in the human erythroleukaemic cell line K562.

The stable, regulated and tissue-specific expression of a therapeutic transgene can be best achieved by the transfer of a complete genomic locus, which will include the short- and long-range regulatory elements that are critical for the accurate control of gene expression. However, when techniques that rely on the random integration of exogenous DNA into the human genome are used for gene transfer, the risk of insertional mutagenesis remains a major issue. Using components derived from the adeno-associated virus (AAV), we have successfully targeted the integration of 200 kb bacterial artificial chromosomes containing the entire beta-globin locus into the AAVS1 site on human chromosome 19. We show that transient expression of the AAV Rep proteins in K562 cells facilitated site-specific transgene integration in 17% (6 of 36) of all analysed integration sites. Southern blot analysis revealed the locus had integrated into AAVS1 as an intact, functional unit in five of the six clones generated. Furthermore, each of the site-specific integrants exhibited sustained and appropriately regulated transgene gene expression over a period of 8 months of continuous culture in the absence of selective pressure. We anticipate that the approach developed in this study may be suitable for facilitating targeted integration of intact genomic loci in adult and embryonic stem cells, and therefore provide a powerful tool not just for functional studies but in establishing model systems for the ex vivo correction of genetic disorders.

The transient expression of mRNA coding for Rep protein from AAV facilitates targeted plasmid integration.

BACKGROUND: There is a risk of insertional mutagenesis when techniques that facilitate random integration of exogenous DNA into the human genome are used for gene therapy. Wild-type adeno-associated virus (AAV) integrates preferentially into a specific site on human chromosome 19 (AAVS1). This is mediated by the interaction of the viral Rep68/78 proteins with Rep-binding elements in the AAV genome and AAVS1. This specificity is often lost when AAV is used as a gene therapy vector due to removal of the sequences coding for Rep. METHODS: Messenger RNA coding for the Rep68/78 proteins was prepared in vitro and co-transfected with a 21 kb DNA plasmid containing the P5 integration efficiency element (P5IEE) from AAV. Single cells were seeded in plates to establish clonal cell lines that were subsequently analysed by dual colour fluorescent in situ hybridisation (FISH) to determine whether site-specific plasmid integration had occurred on chromosome 19. RESULTS: The co-transfection of plasmid DNA with Rep68/78 mRNA gave a 2.5-fold increase in DNA integration when compared to transfection of cells with plasmid DNA alone. Rep68/78 mRNA expression facilitated site-specific plasmid integration to chromosome 19 in 30% (14/44) of all analysed integration sites, while no targeted integration events were observed following transfection of cells with plasmid DNA alone. CONCLUSIONS: These results demonstrate that transient expression of Rep protein using transfected mRNA facilitates site-specific integration of plasmid DNA. This approach allows expression of Rep for only a short time, and may circumvent the toxicity and chromosome instability associated with long-term expression of Rep.

Learning from episodes of degradation and recovery in variable Australian rangelands.

Land-change science emphasizes the intimate linkages between the human and environmental components of land management systems. Recent theoretical developments in drylands identify a small set of key principles that can guide the understanding of these linkages. Using these principles, a detailed study of seven major degradation episodes over the past century in Australian grazed rangelands was reanalyzed to show a common set of events: (i) good climatic and economic conditions for a period, leading to local and regional social responses of increasing stocking rates, setting the preconditions for rapid environmental collapse, followed by (ii) a major drought coupled with a fall in the market making destocking financially unattractive, further exacerbating the pressure on the environment; then (iii) permanent or temporary declines in grazing productivity, depending on follow-up seasons coupled again with market and social conditions. The analysis supports recent theoretical developments but shows that the establishment of environmental knowledge that is strictly local may be insufficient on its own for sustainable management. Learning systems based in a wider community are needed that combine local knowledge, formal research, and institutional support. It also illustrates how natural variability in the state of both ecological and social systems can interact to precipitate nonequilibrial change in each other, so that planning cannot be based only on average conditions. Indeed, it is this variability in both environment and social subsystems that hinders the local learning required to prevent collapse.

Crop and pasture response to climate change.

We review recent research of importance to understanding crop and pasture plant species response to climate change. Topics include plant response to elevated CO(2) concentration, interactions with climate change variables and air pollutants, impacts of increased climate variability and frequency of extreme events, the role of weeds and pests, disease and animal health, issues in biodiversity, and vulnerability of soil carbon pools. We critically analyze the links between fundamental knowledge at the plant and plot level and the additional socio-economic variables that determine actual production and trade of food at regional to global scales. We conclude by making recommendations for current and future research needs, with a focus on continued and improved integration of experimental and modeling efforts.

Adapting agriculture to climate change.

The strong trends in climate change already evident, the likelihood of further changes occurring, and the increasing scale of potential climate impacts give urgency to addressing agricultural adaptation more coherently. There are many potential adaptation options available for marginal change of existing agricultural systems, often variations of existing climate risk management. We show that implementation of these options is likely to have substantial benefits under moderate climate change for some cropping systems. However, there are limits to their effectiveness under more severe climate changes. Hence, more systemic changes in resource allocation need to be considered, such as targeted diversification of production systems and livelihoods. We argue that achieving increased adaptation action will necessitate integration of climate change-related issues with other risk factors, such as climate variability and market risk, and with other policy domains, such as sustainable development. Dealing with the many barriers to effective adaptation will require a comprehensive and dynamic policy approach covering a range of scales and issues, for example, from the understanding by farmers of change in risk profiles to the establishment of efficient markets that facilitate response strategies. Science, too, has to adapt. Multidisciplinary problems require multidisciplinary solutions, i.e., a focus on integrated rather than disciplinary science and a strengthening of the interface with decision makers. A crucial component of this approach is the implementation of adaptation assessment frameworks that are relevant, robust, and easily operated by all stakeholders, practitioners, policymakers, and scientists.

The dynamics of grazed woodlands in southwest Queensland, Australia and their effect on greenhouse gas emissions.

This study outlines the development of an approach to evaluate the sources, sinks, and magnitudes of greenhouse gas emissions from a grazed semiarid rangeland dominated by mulga (Acacia aneura) and how these emissions may be altered by changes in management. This paper describes the modification of an existing pasture production model (GRASP) to include a gas emission component and a dynamic tree growth and population model. An exploratory study was completed to investigate the likely impact of changes in burning practices and stock management on emissions. This study indicates that there is a fundamental conflict between maintaining agricultural productivity and reducing greenhouse gas emissions on a given unit of land. Greater agricultural productivity is allied with the system being an emissions source while production declines and the system becomes a net emissions sink as mulga density increases. Effective management for sheep production results in the system acting as a net source (approximately 60-200 kg CO2 equivalents/ha/year). The magnitude of the source depends on the management strategies used to maintain the productivity of the system and is largely determined by starting density and average density of the mulga over the simulation period. Prior to European settlement, it is believed that the mulga lands were burnt almost annually. Simulations indicate that such a management approach results in the system acting as a small net sink with an average net absorption of greenhouse gases of 14 kg CO2 equivalents/ha/year through minimal growth of mulga stands. In contrast, the suppression of fire and the introduction of grazing results in thickening of mulga stands and the system can act as a significant net sink absorbing an average of 1000 kg CO2 equivalents/ha/year. Although dense mulga will render the land largely useless for grazing, land in this region is relatively inexpensive and could possibly be developed as a cost-effective carbon offset for greenhouse gas emissions elsewhere. These results also provide support for the hypothesis that changes in land management, and particularly, suppression of fire is chiefly responsible for the observed increases in mulga density over the past century.

Impacts of climate change and climate variability on the competitiveness of wheat and beef cattle production in Emerald, north-east Australia.

Emerald, north-east Queensland, is at the northern margin of the wheat cropping region of Australia. The Emerald region was previously used predominantly for grazing beef cattle; however, cropping has developed in importance over the past 30 years. We use historical climate records (1890-1998) to simulate and compare wheat yields, grass production and live-weight gain (LWG) over time. The cropping expansion from the 1970s to the early 1990s has occurred in a unique period in the 108-year record with the highest average wheat yields, lowest wheat yield variability and the greatest relative productivity of wheat production against grass production. If this window of opportunity is a result of long-term climate variability, then cropping is likely to decline in the region as conditions return to those experienced earlier in the record. If this increase is related to climate change, then cropping is likely to persist in the region with productivity maintained at current levels particularly through the yield-enhancing effects of increased atmospheric CO2 concentrations. However, this persistence will be influenced by the frequencies of El Niño conditions that may increase with global warming. The high relative productivities experienced over the past few decades have probably biased producers' expectations, and applications for drought support need to take into account the longer-term perspective provided by this analysis. Nevertheless, the last 6 years have the lowest simulated mean LWG production on the record. The identification of poor production periods depended on the production element being addressed and the timescale involved.

Global change and the mulga woodlands of southwest Queensland: greenhouse gas emissions, impacts, and adaptation.

The possibility of trading greenhouse gas emission permits as a result of the Kyoto Protocol has spurred interest in developing land-based sinks for greenhouse gases. Extensive grazing lands that have the potential to develop substantial woody biomass are one obvious candidate for such activities. However, such activities need to consider the possible impacts on existing grazing and the possible impacts of continuing CO2 buildup in the atmosphere and resultant climate change. We used simulation models to investigate these issues in the mulga (Acacia aneura) woodlands of southwest Queensland. The simulation results suggest that this system can be managed to act as either a net source or a net sink of greenhouse gases under current climate and CO2 and under a range of global change scenarios. The key component in determining source or sink status is the management of the woody mulga. The most effective means of permanently increasing carbon stores and hence reducing net emissions is to exclude both burning and grazing. There are combinations of management regimes, such as excluding fire with light grazing, which, on average, allows productive grazing but transient carbon storage. The effects of increased CO2 on ecosystem carbon stores were unexpected. Carbon stores increased (7-17%) with doubling of CO2 only in those simulations where burning did not occur, but decreased when burnt. This occurred because the substantial increases in grass growth with doubling of CO2 (34-56%) enabled more fires, killing off the establishing cohorts needed to ensure continued carbon accumulation. On average, the doubling of atmospheric CO2 concentration increased grass growth by 44%, which is identical with mean literature values, suggesting that this result may be applicable in other ecosystems where fire has a similar function. A sensitivity analysis of the CO2 response of mulga showed only minor impacts. We discuss additional uncertainties and shortcomings.

Global change impacts on wheat production along an environmental gradient in south Australia.

Crop production is likely to change in the future as a result of global changes in CO2 levels in the atmosphere and climate. APSIM, a cropping system model, was used to investigate the potential impact of these changes on the distribution of cropping along an environmental transect in south Australia. The effects of several global change scenarios were studied, including: (1) historical climate and CO2 levels, (2) historic climate with elevated CO2 (700 ppm), (3) warmer climate (+2.4 degrees C) +700 ppm CO2, (4) drier climate (-15% summer, -20% winter rainfall) +2.4 degrees C +700 ppm CO2, (5) wetter climate (+10% summer rainfall) +2.4 degrees C +700 ppm CO2 and (6) most likely climate changes (+1.8 degrees C, -8% annual rainfall) +700 ppm CO2. Based on an analysis of the current cropping boundary, a criterion of 1 t/ha was used to assess potential changes in the boundary under global change. Under most scenarios, the cropping boundary moved northwards with a further 240,000 ha potentially being available for cropping. The exception was the reduced rainfall scenario (4), which resulted in a small retreat of cropping from its current extent. However, the impact of this scenario may only be small (in the order of 10,000-20,000 ha reduction in cropping area). Increases in CO2 levels over the current climate record have resulted in small but significant increases in simulated yields. Model limitations are discussed.

Dormancy and germination characteristics of herbaceous species in the seasonally dry tropics of northern Australia.

This study investigated changes in dormancy and germination over 8 months for 23 common species (annual and perennial grasses, legumes and other dicotyledons) from herbaceous communities in northern Australia. Seeds were exposed to three storage treatments: relatively constant laboratory conditions, an oven with fluctuating temperatures similar to those found on the soil surface (25/60°C), or exposed on the soil surface at Townsville. There were wide ranges of initial levels of dormancy (9-100%), rates of change of dormancy and response to the different storage conditions showing that species with several types of dormancy characteristics are able to coexist in these communities. The general trend in dormancy levels was a decline with time with the rate of decline greatest for seeds exposed on the soil surface and least for those stored in the laboratory. The species were divided into groups based on dormancy levels in seeds on the soil surface during the late dry and mid wet seasons. The dormancy characteristics of the groups were related to the ecology of the species in the groups. There was an approximately linear increase in germination rate (i.e. a decrease in the number of days to 50% of final germination) over time for all storage treatments; rates for seeds on the soil surface increased more rapidly than those of seeds in laboratory and oven samples.