The influence of nitrogen source on the nutrition of arbuscular mycorrhizal plants

Arbuscular mycorrhizal fungi (AMF) form a symbiosis with 70% of land plants and may contribute significantly to plant phosphorus (P) and nitrogen (N) acquisition in exchange for photosynthetic carbon. AMF mainly acquire N as simple, inorganic molecules such as ammonium and nitrate, but whether AMF display a preference for either source, or can increase plant N content is uncertain. Furthermore, soil nutrient availability, especially that of N, may determine the extent to which a fungus engages in nutrient-for-C trade with plants; further experimental validation of this suggestion is warranted. Experiments ranging from Petri plate microcosms to field trials were carried out to address these questions. Plant N uptake via AMF was traced using stable isotope 15N, having been added to hyphal-only compartments which allow access to AMF, while excluding plant roots. AMF species Glomus aggregatum and Rhizophagus irregularis were used individually to inoculate plants allowing comparisons between AMF isolates, while N uptake preferences were tested by providing 15N as ammonium, nitrate or ammonium nitrate. R. irregularis contribution to plant nutrient uptake was sufficient to increase host biomass in chapter 2, but limited evidence of AMF preference for nitrate or ammonium-N was seen in any experiment. N acquisition by AMF was highest in a Petri microcosm experiment when supplied as ammonium nitrate. Functional diversity among AMF species was observed in terms of plant growth and nutrient uptake, and carbon acquisition from the plant: G. aggregatum was less beneficial to plant partners than R. irregularis. Experimental field-trial data suggests that soil nutrient levels influence both the community structure of AMF and the extent to which they engage in N-for-C trade with plant partners. These findings highlight the complexities and potential significance of the AM route for N uptake both in simplified experimental systems and full-scale commercial crop field trial plants

No evidence for a signal in mammalian basal metabolic rate associated with a fossorial lifestyle

A vast array of challenging environments are inhabited by mammals, such as living in confined spaces where oxygen levels are likely to be low. Species can exhibit adaptations in basal metabolic rate (BMR) to exploit such unique niches. In this study we use 801 species to determine the relationship between BMR and burrow use in mammals. We included pre-existing data for mammalian BMR and 16 life history traits. Overall, mammalian BMR is dictated primarily by environmental ambient temperature. There were no significant differences in BMR of terrestrial, semi-fossorial and fossorial mammals, suggesting that species occupying a subterranean niche do not exhibit baseline metabolic costs on account of their burrowing lifestyle. Fossorial mammals likely show instantaneous metabolic responses to low oxygen in tunnels, rather than exhibit adaptive long-term responses in their BMR

Lean towards learning: connecting Lean Thinking and human resource management in UK higher education

From its origins in the automotive industry, Lean Thinking is increasingly being seen as a solution to problems of efficiency and quality in other industries and sectors. In recent years attempts have been made to transfer Lean principles and practice to the higher education sector with indications of mixed consequences and debate over its suitability. This paper contributes to the debate by drawing evidence from thirty-four interviews conducted across two UK universities that have implemented Lean in some of their activities and we pay particular attention to the role of the HR function in facilitating its introduction. The findings suggest there are problems in understanding, communicating and transferring Lean Thinking in the higher education context; that, despite HR systems being vital facets of Lean, HR professionals are excluded from participation; and that as a consequence the depth and breadth of Lean application in the two institutions is very limited

The emerging threat of human-use antifungals in sustainable and circular agriculture schemes

Rapidly growing global populations mandate greater crop productivity despite increasingly scarce natural resources, including freshwater. The adoption of sustainable agricultural practices seek to address such issues, but an unintended consequence is the exposure of agricultural soils and associated biota to emerging contaminants including azole pharmaceutical antifungals. We show that environmentally relevant exposure to three commonly prescribed azole antifungals can reduce mycorrhizal 33P transfer from the soil into the host plant. This suggests that exposure to azoles may have a significant impact on mycorrhizal-mediated transfer of nutrients in soil-plant systems. Understanding the unintended consequences of sustainable agricultural practices is needed to ensure the security and safety of future food production systems. Summary: Sustainable farming practices are increasingly necessary to meet the demands of a growing population under constraints imposed by climate change. These practices, in particular the reuse of wastewater and amending soil with wastewater derived biosolids, provide a pathway for man-made chemicals to enter the agricultural environment. Among the chemicals commonly detected in wastewater and biosolids are pharmaceutical azole antifungals. Fungi, in particular mycorrhiza-forming fungal symbionts of plant roots, are key drivers of nutrient cycling in the soil–plant system. As such, greater understanding of the impacts of azole antifungal exposure in agricultural systems is urgently needed. We exposed wheat (Triticum aestivum L. cv. ‘Skyfall’) and arbuscular mycorrhizal fungi to environmentally relevant concentrations of three azole antifungals (clotrimazole, miconazole nitrate and fluconazole). We traced the mycorrhizal-acquired 33P from the soil into the host plant in contaminated versus non-contaminated soils and found 33P transfer from mycorrhizal fungi to host plants was reduced in soils containing antifungals. This represents a potentially major disruption to soil nutrient flows as a result of soil contamination. Our work raises the major issue of exposure of soil biota to pharmaceuticals such as azole antifungals, introduced via sustainable agricultural practices, as a potentially globally important disruptive influence on soil nutrient cycles. The impacts of these compounds on non-target organisms, beneficial mycorrhizal fungi in particular, could have major implications on security and sustainability of future food systems

Cultivar‐dependent increases in mycorrhizal nutrient acquisition by barley in response to elevated CO2

Societal Impact Statement Modern agriculture is under pressure to meet yield targets while reducing reliance on finite resources to improve sustainability. Climate change represents an additional challenge—elevated atmospheric CO2 concentrations may increase plant growth and boost yield, but the nutritional value of crops grown at elevated CO2 is often reduced. Arbuscular mycorrhizal fungi (AMF) can improve plant nutrition, although how this symbiosis will be affected by climate change is unclear. Here, we demonstrate mycorrhizal contribution to nitrogen and phosphorus nutrition in barley under current and future CO2 concentrations. In one cultivar, AMF substantially increased phosphorus uptake at elevated CO2 and prevented phosphorus dilution, suggesting the symbiosis may become more important for crop nutrient uptake in the future. Summary Globally important cereals such as barley (Hordeum vulgare L.) often engage in symbiosis with arbuscular mycorrhizal fungi (AMF). The impact of elevated atmospheric CO2 on nutrient exchange between these symbionts remains unknown. In controlled environment experiments, we used isotope tracers (15N, 33P, 14C) to quantify nutrient fluxes between two barley cultivars (Moonshine and Riviera) and their associated AMF at ambient (440 ppm) and elevated (800 ppm) CO2. Elevated CO2 reduced shoot N concentration in Moonshine, and shoot N and P concentration in Riviera. Elevated CO2 substantially increased mycorrhizal 33P acquisition in Moonshine. Mycorrhizal contribution to P uptake in Moonshine may have prevented dilution of tissue P concentration at elevated CO2. In Riviera, AMF did not improve 33P acquisition. Both cultivars received 15N from their AMF symbionts, and this acquisition was not influenced by CO2 concentration, although Moonshine received more 15N than Riviera. Our results suggest that AMF may provide substantial contributions to barley nutrition at current and projected future CO2 concentrations. This is especially noteworthy for barley, which is generally considered to have low mycorrhizal receptivity. AMF may help alleviate or avoid nutrient dilution normally observed at elevated CO2. Variation between cultivars indicates that mycorrhizal contribution to cereal nutrition could be improved through selective breeding practices

Variation in mycorrhizal growth response among a spring wheat mapping population shows potential to breed for symbiotic benefit.

Funder: N8 Agrifood SchemeAll cereal crops engage in arbuscular mycorrhizal symbioses which can have profound, but sometimes deleterious, effects on plant nutrient acquisition and growth. The mechanisms underlying variable mycorrhizal responsiveness in cereals are not well characterised or understood. Adapting crops to realise mycorrhizal benefits could reduce fertiliser requirements and improve crop nutrition where fertiliser is unavailable. We conducted a phenotype screen in wheat (Triticum aestivum L.), using 99 lines of an Avalon × Cadenza doubled-haploid mapping population. Plants were grown with or without a mixed inoculum containing 5 species of arbuscular mycorrhizal fungi. Plant growth, nutrition and mycorrhizal colonisation were quantified. Plant growth response to inoculation was remarkably varied among lines, ranging from more than 30% decrease to 80% increase in shoot biomass. Mycorrhizal plants did not suffer decreasing shoot phosphorus concentration with increasing biomass as observed in their non-mycorrhizal counterparts. The extent to which mycorrhizal inoculation was beneficial for individual lines was negatively correlated with shoot biomass in the non-mycorrhizal state but was not correlated with the extent of mycorrhizal colonisation of roots. Highly variable mycorrhizal responsiveness among closely related wheat lines and the identification of several QTL for these traits suggests the potential to breed for improved crop-mycorrhizal symbiosis

New technologies for 3D realization in Art and Design practice

As digital design technologies become ever more widespread, CAD-CAM, virtual and rapid prototyping techniques are increasingly being exploited by creative practitioners working in areas outside the industrial design and engineering contexts in which these technologies are currently predominantly employed. This review paper aims to critically examine work by artists, craft practitioners, and designer-makers who creatively engage with these new and rapidly emerging technologies and, by doing so, extend their own practice and push at the boundaries of art and design disciplines. Historic precedents for new 3D technologies in the fine and applied arts are identified, and writing by Heidegger, Baudrillard, and Virilio informs the critical review of work by art and design practitioners in sculpture, metalwork, jewellery, and ceramics. The discussion reflects on relationships between art and technology and physical and virtual making, and concludes by pointing to the possibility of new “hybrid” forms of practice which bridge the gap between physical and virtual design worlds. The paper closes by suggesting that the notion of “truth to materials” in the arts and crafts might now be extended to one of “truth to virtual materials”, as practitioners creatively negotiate relationships between digital cause and physical effect

Building the New Europe: Western and Eastern Roads to Social Partnership

[Excerpt] While the ways in which neoliberalism and economic integration undermine social partnership and the welfare state have been extensively studied, less attention has been given to the ways in which such economic forces may push actors together, in reinvigorated bargaining relationships, to find workable solutions to difficult problems. In his article, we examine the contemporary status of social partnership in four case study countries—Germany, the United Kingdom, Bulgaria and Poland—as well as for Europe as a whole. In the west, while Germany presents a case of established social partnership under pressure, the United Kingdom has stood over the past two decades on the opposite neoliberal side. In the east, Bulgaria is one of the more developed cases of post-communist tripartism, while Poland exemplifies a weaker tripartism that emerged at a later stage of the transformation process. In selecting more and less developed social partnership cases in both west and east, we test the argument that the rise of Thatcher/Reagan/ Friedman ‘free market economics’ is paradoxically driving a resurgence and consolidation of social partnership relations across the new (both western and eastern) Europe

Development Discourse and Practice: Alternatives and New Directions from Postcolonial Perspectives

Development and aid programs, such as those aimed at promoting economic growth and prosperity in ‘Third World’ nations and transition economies, often arise out of Western and neo-liberal policy ideologies and practices. These programs may, in some cases, provide useful guidelines for restructuring institutional structures and governance mechanisms in nations that have long struggled with poverty, economic instability, health crises, and social and political turmoil. However, a growing number of critical voices are raising concerns over the guiding assumptions and inclusiveness of these policies and programs in their aims to promote economic development and social well-being in non-Western nations. We join these critical perspectives by way of postcolonial frameworks to highlight some of the problematic assumptions and oversights of development programs, while offering new alternatives and directions. By doing so, we contribute to organizational theorizing in a global context, as postcolonial insights provide much needed engagement with international aid policies and programs, as well as development organizations and institutions. To accomplish this, we offer a historical perspective on development, present a critique of the policies and practices guiding many aid programs, and conclude with suggestions emanating from postcoloniality