Arbuscular mycorrhizal fungi reduce nitrous oxide emissions from N2O hotspots.

Nitrous oxide (N 2O) is a potent, globally important, greenhouse gas, predominantly released from agricultural soils during nitrogen (N) cycling. Arbuscular mycorrhizal fungi (AMF) form a mutualistic symbiosis with two-thirds of land plants, providing phosphorus and/or N in exchange for carbon. As AMF acquire N, it was hypothesized that AMF hyphae may reduce N 2O production. AMF hyphae were either allowed (AMF) or prevented (nonAMF) access to a compartment containing an organic matter and soil patch in two independent microcosm experiments. Compartment and patch N 2O production was measured both before and after addition of ammonium and nitrate. In both experiments, N 2O production decreased when AMF hyphae were present before inorganic N addition. In the presence of AMF hyphae, N 2O production remained low following ammonium application, but increased in the nonAMF controls. By contrast, negligible N 2O was produced following nitrate application to either AMF treatment. Thus, the main N 2O source in this system appeared to be via nitrification, and the production of N 2O was reduced in the presence of AMF hyphae. It is hypothesized that AMF hyphae may be outcompeting slow-growing nitrifiers for ammonium. This has significant global implications for our understanding of soil N cycling pathways and N 2O production

Thresholds and prediction models to support the sustainable management of herbivorous insects in wheat. A review

AbstractWheat is one of the most important arable crops grown worldwide, providing a significant proportion of the daily calorific intake for countries across the globe. Wheat crops are attacked by a diverse range of herbivorous invertebrates, pests, that cause significant yield loss. It is anticipated that yield loss caused by pests will increase in response to a changing climate. Currently, these pests are primarily controlled using pesticides; however, there is an increased need for more sustainable pest management solutions. Economic thresholds represent one avenue that can support the sustainable management of pests. Briefly, thresholds are the number of pests above which there is sufficient risk of yield loss. Here, we review the economic thresholds and prediction methods available for sustainable pest management in wheat. We focus on five economically damaging pests affecting wheat crops in the UK and Europe. For each, we highlight the key period of crop risk to pest attack, identify economic thresholds, and provide an overview of current decision support models that can help estimate crop risk and advise sustainable pest management; we end by proposing areas for future improvement for each pest. Furthermore, we take a novel approach by discussing economic thresholds and their applications to sustainable pest management within the context of crop physiology and the capacity for crops to tolerate pest damage, a consideration that is often overlooked when developing pest management strategies. We use the stem-boring pest, the gout fly, as a case study and use the economic injury level equation to conduct a theoretical assessment of the appropriateness of the current gout fly threshold. This theoretical assessment indicates that wheat crops can tolerate greater gout fly damage than currently considered, and shows that by incorporating crop physiology into sustainable pest tolerance schemes we can work towards developing more appropriate physiological-based pest thresholds.</jats:p

Interactions between arbuscular mycorrhizal fungi and soil greenhouse gas fluxes

Arbuscular mycorrhizal fungi (AMF) can form a mutualistic symbiosis with over two-thirds of all land plants, providing phosphorus and/or nitrogen in exchange for carbon. They can have a significant effect on the surrounding soil, altering pH, water content, structure, and drainage. Important greenhouse gases (GHG) including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) can be influenced by these factors, yet to date the interactions between AMF and soil GHG fluxes are surprisingly understudied. A microcosm system was developed to study GHG fluxes in the presence and absence of AMF hyphae. A central compartment contained an AMF host plant (Zea mays L.), with two outer compartments, that either allowed (AMA) or prevented (NAMA) AMF hyphal access. Organic matter patches of dried, milled, Z. mays leaves mixed with soil were added to the outer compartments to encourage proliferation of AMF hyphae and GHG production. Soil-atmosphere fluxes of N2O, CO2 and CH4 from the outer compartments were quantified, and gas probes were developed to measure N2O concentrations within the organic matter patches. Data from a series of microcosm experiments provide evidence for AMF interactions with soil fluxes of N2O and CO2, but not CH4. Soil CO2 fluxes were found to be a useful non-invasive method for determining the presence of AMF in hyphal compartments. The N2O concentrations in organic patches decreased in AMA treatments, and a subsequent experiment demonstrated that N2O production by nitrifiers may be limited in the presence of AMF hyphae. In contrast, following harvesting, N2O fluxes from organic matter patches were higher in the AMA treatment; possibly because carbon release from severed AMF hyphae fuelled denitrification. These interactions have important implications for N cycling and sustainable agriculture. The evidence presented in this thesis suggests that AMF may play a previously unappreciated role in reducing soil-atmosphere losses of N2O

Development of laboratory tests for assessing vitamin status

Aim To develop assays for the determination of functional vitamin status and to determine the functional vitamin status of an elderly population. Specifically the focus has been to develop assays to measure the biological concentrations of N,N dimethylglycine and glycine betaine as possible markers of functional folate status. Background Functional vitamin deficiencies arise when the tissue concentration of a vitamin derived coenzyme is inadequate this can occur despite normal concentrations of the vitamin in the blood or urine, and leads to lower activity of the vitamin dependent enzyme. The lowered enzyme activity causes changes in the concentrations of metabolites associated with the biochemical pathway catalysed by the enzyme. The amount of vitamin at a tissue level can be determined by measuring these changes. Functional vitamin deficiencies have been associated with many chronic diseases. Further investigations of the relationships between nutrients create a need for appropriate assays. Methods and results Two new trifluromethanesulfonate reagents (2-phenanthrenacyl and 6-methoxynapthacyl) have been synthesised. These reagents form highly fluorescent derivatives with N,N dimethylglycine, and betaines including glycine betaine and propionylcarnitine. Using 2 phenanthrenacyl triflate as the derivatising reagent the detection limit for glycine betaine is improved from 0.2 μM to 0.04 μM. Optimisation is achieved by changing the solvent, base and water content of the reaction mixture. Polar aprotic solvents are used, with the presence of some water or alcohol tolerated. Suitable bases include the inorganic bases, magnesium hydroxide, silver oxide and lithium phosphate. The cationic derivatives of N,N-dimethylglycine and glycine betaine in plasma are separated by HPLC on an alumina column within 50 minutes (Between batch CV < 20%). Cation exchange HPLC is carried out using a polar organic solvent containing an aqueous buffer with an organic cation and a hydrophilic anion. Selectivity is affected by the choice of organic solvent and buffer. Increasing the water content and the buffer concentration reduces the retention of the derivatives. Propionylcarnitine can be quantified after separation by HPLC on a non endcapped strong cation exchange column however the use of this assay to detect functional biotin deficiency has not been investigated. 1H NMR can be used to measure N,N-dimethylglycine and glycine betaine in urine. The inter and intra-assay CV’s were < 10% and recoveries were ≥ 97% over a linear range from 50 μM to 1000 μM. Limits of detection using 1H NMR spectroscopy (15 – 25 μM) are higher than HPLC assays, though adequate for the detection of raised concentrations in urine. Elderly hip fracture patients (aged 65-90) were investigated, as they are known to have poor nutrition compared to health elderly, and would be expected to have associated vitamin deficiencies. A greater percentage of hip fracture patients had insufficient vitamin B12 and folate concentrations compared to age matched healthy elderly controls (Folate 55% and 32% <120 pM, Vitamin B12 7% and 5% <8.5 nM). The results for other analytes are difficult to interpret because of the affects of recent trauma in the hip fracture population. In the control population glycine betaine predicts total homocysteine concentrations (multiple linear regression –0.055 P = 0.099) and is a stronger predictor of folate than total homocysteine. The ratio of the concentrations of N,N dimethylglycine/glycine betaine was not significantly associated with folate status. Conclusions The concentrations of N,N-dimethylglycine and glycine betaine in plasma can be measured by HPLC, and in urine by 1H NMR. In healthy elderly there is a high prevalence of vitamin (vitamin B12 and folate) deficiency. The ratio of N,N-dimethylglycine/glycine betaine is not an appropriate marker of functional folate status, however the associations between glycine betaine and homocysteine metabolism require further investigation

Development of laboratory tests for assessing vitamin status

Aim To develop assays for the determination of functional vitamin status and to determine the functional vitamin status of an elderly population. Specifically the focus has been to develop assays to measure the biological concentrations of N,N dimethylglycine and glycine betaine as possible markers of functional folate status. Background Functional vitamin deficiencies arise when the tissue concentration of a vitamin derived coenzyme is inadequate this can occur despite normal concentrations of the vitamin in the blood or urine, and leads to lower activity of the vitamin dependent enzyme. The lowered enzyme activity causes changes in the concentrations of metabolites associated with the biochemical pathway catalysed by the enzyme. The amount of vitamin at a tissue level can be determined by measuring these changes. Functional vitamin deficiencies have been associated with many chronic diseases. Further investigations of the relationships between nutrients create a need for appropriate assays. Methods and results Two new trifluromethanesulfonate reagents (2-phenanthrenacyl and 6-methoxynapthacyl) have been synthesised. These reagents form highly fluorescent derivatives with N,N dimethylglycine, and betaines including glycine betaine and propionylcarnitine. Using 2 phenanthrenacyl triflate as the derivatising reagent the detection limit for glycine betaine is improved from 0.2 μM to 0.04 μM. Optimisation is achieved by changing the solvent, base and water content of the reaction mixture. Polar aprotic solvents are used, with the presence of some water or alcohol tolerated. Suitable bases include the inorganic bases, magnesium hydroxide, silver oxide and lithium phosphate. The cationic derivatives of N,N-dimethylglycine and glycine betaine in plasma are separated by HPLC on an alumina column within 50 minutes (Between batch CV < 20%). Cation exchange HPLC is carried out using a polar organic solvent containing an aqueous buffer with an organic cation and a hydrophilic anion. Selectivity is affected by the choice of organic solvent and buffer. Increasing the water content and the buffer concentration reduces the retention of the derivatives. Propionylcarnitine can be quantified after separation by HPLC on a non endcapped strong cation exchange column however the use of this assay to detect functional biotin deficiency has not been investigated. 1H NMR can be used to measure N,N-dimethylglycine and glycine betaine in urine. The inter and intra-assay CV’s were < 10% and recoveries were ≥ 97% over a linear range from 50 μM to 1000 μM. Limits of detection using 1H NMR spectroscopy (15 – 25 μM) are higher than HPLC assays, though adequate for the detection of raised concentrations in urine. Elderly hip fracture patients (aged 65-90) were investigated, as they are known to have poor nutrition compared to health elderly, and would be expected to have associated vitamin deficiencies. A greater percentage of hip fracture patients had insufficient vitamin B12 and folate concentrations compared to age matched healthy elderly controls (Folate 55% and 32% <120 pM, Vitamin B12 7% and 5% <8.5 nM). The results for other analytes are difficult to interpret because of the affects of recent trauma in the hip fracture population. In the control population glycine betaine predicts total homocysteine concentrations (multiple linear regression –0.055 P = 0.099) and is a stronger predictor of folate than total homocysteine. The ratio of the concentrations of N,N dimethylglycine/glycine betaine was not significantly associated with folate status. Conclusions The concentrations of N,N-dimethylglycine and glycine betaine in plasma can be measured by HPLC, and in urine by 1H NMR. In healthy elderly there is a high prevalence of vitamin (vitamin B12 and folate) deficiency. The ratio of N,N-dimethylglycine/glycine betaine is not an appropriate marker of functional folate status, however the associations between glycine betaine and homocysteine metabolism require further investigation

How does small business impact on utilization of industry-led supply chain innovation capacity?

This research uses conjirmat01y factor analysis and structural equation modelling to examine how organizational size - made up of four dimensions - control, resources, trust and complexity - impacts on utilization of indust1y-led supply chain innovation capacity in a traditional agribusiness industry, the Australian beef industry. It confirms small business rather than larger business accords greater importance to exploiting supply chain dynamic capabilities, particularly in relation to utilizing industry -led supply chain innovation capacity. For small business in Australian beef supply chains, being agile and able to adapt and align their business practices with supply chain partners is integral to ensuring these businesses remain relevant and competitive in this market. In theoretical terms this is supported by authors in the dynamic capabilities literature as they argue these types of capabilities enable organizations to innovate faster (or better), often leading to the creation of newer sources of competitive advantage.15 page(s

Oral dyspraxia in inherited speech and language impairment and acquired dysphasia.

Half of the members of the KE family suffer from an inherited verbal dyspraxia. The affected members of the family have a lasting impairment in phonology and syntax. They were given various tests of oral praxis to investigate whether their deficit extends to nonverbal movements. Performance was compared to adult patients with acquired nonfluent dysphasia, those with comparable right-hemisphere lesions, and age-matched controls. Affected family members and patients with nonfluent dysphasia were impaired overall at performing oral movements, particularly combinations of movements. It is concluded that affected members of the KE family resemble patients with acquired dysphasia in having difficulties with oral praxis and that speech and language problems of affected family members arise from a lower level disorder. Copyright 2000 Academic Pres

Exercise oncology from diagnosis to treatment: An overview of outcomes and considerations

Cancer patients and survivors experience wide-ranging acute and persistent toxicities that have implications to reduced physical function, cardiovascular and metabolic complications, musculoskeletal health and quality of life. Over the past several years, the field of exercise oncology has demonstrated a number of opportunities for the use of exercise as a medicine to preserve function and ameliorate and reverse a range of treatment-related adverse effects in patients with cancer receiving treatment. Numerous randomized controlled trials have evolved from early study reports on symptom controls to more contemporary trials investigating clinical and disease-specific endpoints. In this chapter, we provide a brief overview of common cancer treatments and adverse effects and examples of early to contemporary exercise oncology studies including those from pretreatment to during treatment phases examining a range of outcomes and provide considerations and future opportunities in this well-established and yet continuing area of research growth in exercise oncology. As the field continues to evolve in its breath, scope and rigour, future large definitive trials will provide more conclusive information on the role of exercise and its impact on disease progression and cancer-specific and overall survival