33 results on '"Brackin, R."'
Search Results
2. Interrogating RNA and protein spatial subcellular distribution in smFISH data with DypFISH
- Author
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Savulescu, A.F., Brackin, R., Bouilhol, E., Dartigues, B., Warrell, J.H., Gomes, E.R., Nikolski, M., Mhlanga, M.M.K., Savulescu, A.F., Brackin, R., Bouilhol, E., Dartigues, B., Warrell, J.H., Gomes, E.R., Nikolski, M., and Mhlanga, M.M.K.
- Abstract
Contains fulltext : 242550.pdf (Publisher’s version ) (Open Access)
- Published
- 2021
3. Can Nitrogen Source and Nitrification Inhibitors Affect In-Season Nitrogen Supply?
- Author
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Redding, M. R., Phillips, I., Pratt, C., Paungfoo-Lonhienne, C., Levett, I., Hill, J., Mehta, C., Bailey, T., Brackin, R., McAuley, J., Pratt, S., Laycock, B., Mayer, D. G., Redding, M. R., Phillips, I., Pratt, C., Paungfoo-Lonhienne, C., Levett, I., Hill, J., Mehta, C., Bailey, T., Brackin, R., McAuley, J., Pratt, S., Laycock, B., and Mayer, D. G.
- Abstract
This study sought to identify whether piggery effluent-derived nitrogen sources can be formulated with urea and nitrification inhibitors to better synchronize nitrogen (N) supply with crop demand than conventional urea fertilizer alone. A 288 pot pasture growth and leaching growth accelerator trial (5 pasture cuts) was completed with a factorial treatment structure of three N sources (2.63 g N [kg soil]?1 applied as 100% urea-N, 8% struvite-N + 92% urea-N, and 8% piggery pond sludge-N + 92% urea-N), five rates of three nitrification inhibitors (including 3,4-Dimethylpyrazole phosphate, DMPP; limonene+ethanol; and dicyandiamide, DCD), and matrix encapsulated forms of these inhibitors. Applying a combination of piggery sludge with urea increased N uptake during the first 4 weeks of plant growth (by 65%), though total N uptake throughout the trial (22 weeks) did not differ across the N-sources. The microbial community of the soil to which the sludge was added was significantly different from the un-amended soil at the conclusion of the trial. All inhibitor formulations significantly decreased leaching losses of mineral-N relative to the control (by 14 to 61%). The use of DMPP decreased initial nutrient uptake, deferring uptake until later in the experiment. Inhibitor addition resulted in microbial community effects that persisted throughout the trial. The study demonstrated that a piggery-derived N-source and a nitrification inhibitor can be used to manipulate plant N uptake to occur later or earlier in a growing period with equal cumulative uptake, achieving an 11% increase in residual N store, and decreased N leaching losses.
- Published
- 2020
4. Tropical Rainforest Restoration Plantations Are Slow to Restore the Soil Biological and Organic Carbon Characteristics of Old Growth Rainforest
- Author
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Bonner, M. T. L., Allen, D. E., Brackin, R., Smith, T. E., Lewis, Tom, Shoo, L. P., Schmidt, S., Bonner, M. T. L., Allen, D. E., Brackin, R., Smith, T. E., Lewis, Tom, Shoo, L. P., and Schmidt, S.
- Abstract
Widespread and continuing losses of tropical old-growth forests imperil global biodiversity and alter global carbon (C) cycling. Soil organic carbon (SOC) typically declines with land use change from old-growth forest, but the underlying mechanisms are poorly understood. Ecological restoration plantations offer an established means of restoring aboveground biomass, structure and diversity of forests, but their capacity to recover the soil microbial community and SOC is unknown due to limited empirical data and consensus on the mechanisms of SOC formation. Here, we examine soil microbial community response and SOC in tropical rainforest restoration plantings, comparing them with the original old-growth forest and the previous land use (pasture). Two decades post-reforestation, we found a statistically significant but small increase in SOC in the fast-turnover particulate C fraction. Although the delta(13)C signature of the more stable humic organic C (HOC) fraction indicated a significant compositional turnover in reforested soils, from C4 pasture-derived C to C3 forest-derived C, this did not translate to HOC gains compared with the pasture baseline. Matched old-growth rainforest soils had significantly higher concentrations of HOC than pasture and reforested soils, and soil microbial enzyme efficiency and the ratio of gram-positive to gram-negative bacteria followed the same pattern. Restoration plantings had unique soil microbial composition and function, distinct from baseline pasture but not converging on target old growth rainforest within the examined timeframe. Our results suggest that tropical reforestation efforts could benefit from management interventions beyond re-establishing tree cover to realize the ambition of early recovery of soil microbial communities and stable SOC.
- Published
- 2020
5. Can Nitrogen Source and Nitrification Inhibitors Affect In-Season Nitrogen Supply?
- Author
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Redding, M.R., primary, Phillips, I., additional, Pratt, C., additional, Paungfoo-Lonhienne, C., additional, Levett, I., additional, Hill, J., additional, Mehta, C., additional, Bailey, T., additional, Brackin, R., additional, McAuley, J., additional, Pratt, S., additional, Laycock, B., additional, and Mayer, D.G., additional
- Published
- 2020
- Full Text
- View/download PDF
6. Sorbents can tailor nitrogen release from organic wastes to match the uptake capacity of crops
- Author
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Chin, A., primary, Schmidt, S., additional, Buckley, S., additional, Pirie, R., additional, Redding, M., additional, Laycock, B., additional, Luckman, P., additional, Batstone, D.J., additional, Robinson, N., additional, and Brackin, R., additional
- Published
- 2018
- Full Text
- View/download PDF
7. Sorbents can tailor nitrogen release from organic wastes to match the uptake capacity of crops
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Chin, A., Schmidt, S., Buckley, S., Pirie, R., Redding, M., Laycock, B., Luckman, P., Batstone, D. J., Robinson, N., Brackin, R., Chin, A., Schmidt, S., Buckley, S., Pirie, R., Redding, M., Laycock, B., Luckman, P., Batstone, D. J., Robinson, N., and Brackin, R.
- Abstract
Delivering nutrients from mineral or organic fertilizers out of synchrony with crop uptake causes inefficiencies and pollution. We explore methodologies for evaluating sorbents as additives to organic agricultural wastes to retain nitrogen in an exchangeable form and deliver at rates that approximate the uptake capacity of roots. Focussing on ammonium (NH4+) as the main inorganic nitrogen form in the studied wastes (sugarcane mill mud, poultry litter), we tested geo-sorbents and biochar for their ability to retain NH4+. Sorption capacity was ranked palagonite < bentonite, biochar, vermiculite < chabazite, clinoptilolite (5.7 to 24.3 mg NH4+ g−1 sorbent). Sorbent-waste formulations were analysed for sorption capacity, leaching and fluxes of NH4+. Ammonium-sorption capacity broadly translated to sorbent-waste formulations with clinoptilolite conferring the strongest NH4+ attenuation (80%), and palagonite the lowest (7%). A 1:1 ratio of sorbent:waste achieved stronger sorption than a 0.5:1 ratio, and similar sorption as a 1:1.5 ratio. In line with these results, clinoptilolite-amended wastes had the lowest in situ NH4+ fluxes, which exceeded the NH4+ uptake capacity (Imax) of sugarcane and sorghum roots 9 to 84-fold, respectively. Less efficient sorbent-waste formulations and un-amended wastes exceeded Imax of crop roots up to 274-fold. Roots preferentially colonized stronger sorbent-waste formulations and avoided weaker ones, suggesting that lower NH4+ fluxes generate a more favourable growth environment. This study contributes methodologies to identify suitable sorbents to formulate organic wastes as next-generation fertilizers with view of a crop's nutrient physiology. Efficient re-purposing of wastes can improve nutrient use efficiency in agriculture and support the circular nutrient economy.
- Published
- 2018
8. The BEST study - a prospective study to compare business class versus economy class air travel as a cause of thrombosis
- Author
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Jacobson, B. F., Münster, M., Smith, A., Burnand, K. G., Carter, A., Abdool-Carrim, A. T. O., Marcos, E., Becker, P. J., Rogers, T., Le Roux, D., Calvert-Evers, J. L., Nel, M. J., Brackin, R., and Martin Veller
- Abstract
Background. As many as 10% of airline passengers travelling without prophylaxis for long distances may develop a venous thrombosis. There is, however, no evidence that economy class travellers are at increased risk of thrombosis.Objectives. A suitably powered prospective study, based on the incidence of deep-vein thrombosis (DVT) reported in previous studies on long-haul flights, was designed to determine the incidence of positive venous duplex scans and D-dimer elevations in low and intermediate-risk passengers, comparing passengers travelling in business and economy class.Patients/methods. Eight hundred and ninety-nine passengers were recruited (180 travelling business class and 719 travelling economy). D-dimers were measured before and after the flight. A value greater than 500 ng/ml was accepted as abnormal. A thrombophilia screen was conducted which included the factor V Leiden mutation, the prothombin 20210A mutation, protein C and S levels, antithrombin levels, and anticardiolipin antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM). On arrival, lower limb compression ultrasonography of the deep veins was performed. Logistical regression analysis was used to determine the risk factors related to abnormally high D-dimer levels.Results. Only 434 subjects had a full venous duplex scan performed. None had ultrasonic evidence of venous thrombosis. Nine passengers tested at departure had elevated D-dimer levels and these volunteers were excluded from further study. Seventy-four of the 899 passengers had raised D-dimers on arrival. Twenty-two of 180 business class passengers (12%) developed elevated D-dimers compared with 52 of 719 economy class passengers (7%). There was no significant association between elevation of D-dimers and the class flown (odds ratio (OR) 0.61, p = 0.109). The factor V Leiden mutation, factor VIII levels and the use of aspirin were, however, associated with raised D-dimers (OR 3.36, p = 0.024; OR 1.01, p = 0.014; and OR 2.04, p = 0.038, respectively). Five hundred and five passengers were contacted within 6 months and none reported any symptoms of a clinical thrombosis or pulmonary embolus.Conclusion. The incidence of ultrasonically proven DVT is much lower than previously reported. However, more than 10% of all passengers developed raised D-dimers, which were unrelated to the class flown. A rise in D-dimers is associated with an inherent risk of thrombosis and/ or thrombophilia, demonstrates activation of both the coagulation and fibrinolytic systems during long-haul flights, and may indicate the development of small thrombi.
- Published
- 2016
9. Nextgen fertilisers for nutrient stewardship
- Author
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Schmidt, S., Paungfoo-Lonhienne, C., Brackin, R., Laycock, B., Luckman, P., Batstone, D., Yu, C., Redding, M., Schmidt, S., Paungfoo-Lonhienne, C., Brackin, R., Laycock, B., Luckman, P., Batstone, D., Yu, C., and Redding, M.
- Abstract
Fertiliser inefficiencies have enormous environmental costs, globally and locally. Our iconic Great Barrier Reef (GBR) is degrading and nutrient pollution is a main contributor. The GBR lagoon receives 6-times more nitrogen (N) than natural backgrounds, approximately 80,000 tonnes annually, and N-pollution reduction targets remain unmet. This long-standing problem is caused by fertilisers in broad-acre agriculture that rapidly dissolve and are subject to loss from soil. Authorities and stakeholders agree that the nutrient problem demands disruptive and transformative innovation. Enhanced efficiency fertilisers (e.g. plastic-coated urea) can reduce N losses but release patterns remain difficult to control. NextGen fertilisers take a new approach to better synchronise nutrient supply and crop demand. Capitalising on innovation in material science and process engineering, they form part of a future circular nutrient economy without pollution and waste. Our multi-disciplinary consortium of scientists, engineers and industry partners aims to break new ground and address the constraints that are costly for farmers and environment and prevent many tropical crops from reaching their yield potential. With proof-of-concept well established, next-generation fertilisers achieve superior nutrient-release properties by binding nutrients to sorber-matrices (biopolymers, biosorbers, bio-hydrogels, engineered natural clays). Engineered bio-/geo-sorbers form the basis of the NextGen platform that is complemented by re-purposed wastes, biodegradable coatings, crop-beneficial microbes and biostimulants, combined with processing technology. We showcase how agriculture profits from understanding of the crop-soil-microbe interface, and paired with engineering innovation, contributes to a 2nd Green Revolution that does not cost the earth.
- Published
- 2016
10. Addressing the nitrogen problem in sugarcane production to reduce pollution of the Great Barrier Reef
- Author
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Robinson, N., Brackin, R., Paungfoo-Lonhienne, C., Lonhienne, T., Westermann, M., Salazar, M., Yeoh, Y.K., Hugenholtz, P., Ragan, M.A., Redding, M., Robinson, N., Brackin, R., Paungfoo-Lonhienne, C., Lonhienne, T., Westermann, M., Salazar, M., Yeoh, Y.K., Hugenholtz, P., Ragan, M.A., and Redding, M.
- Abstract
The N pollution footprint of sugarcane cropping is large due to inefficiencies caused by mismatched N supply and crop N demand over sugarcane’s long N accumulation phase. The Great Barrier Reef lagoon receives excessive N loads that contribute to the rapidly declining reef health. Exceeding international average nitrous oxide emission rates several fold, sugarcane soils contribute significantly to Australia’s agricultural emissions. Nitrogen pollution reduction schemes over recent decades have mostly targeted reducing N fertiliser rates in line with expected yields and improving soil quality. Overall, these measures have not resulted in the desired N pollution reduction and further innovation is needed to address this problem. We present research that aims to aid agronomic innovation with (i) next-generation fertilisers that are based on repurposed nutrient-rich wastes and sorbent materials to better match N supply and crop demand and to improve soil function and carbon levels, (ii) understanding of soil N cycling and microbial processes, (iii) legume companion cropping as a source of biologically fixed N, and (iv) genetic improvement of sugarcane that more effectively captures and uses N. We conclude that evidence-based innovation has to support crop growers across climate and soil gradients in the 400,000 hectares of catchments of the Great Barrier Reef. This should include investment into new technologies to support ecologically-sound agriculture and a circular economy without waste and pollution.
- Published
- 2016
11. Nitrogen affects cluster root formation and expression of putative peptide transporters
- Author
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Paungfoo-Lonhienne, C., primary, Schenk, P. M., additional, Lonhienne, T. G. A., additional, Brackin, R., additional, Meier, S., additional, Rentsch, D., additional, and Schmidt, S., additional
- Published
- 2009
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12. INTRATHECAL FENTANYL INDUCES A DOSE-DEPENDENT CHANGE IN VENTILATION WHEN GIVEN FOR ANALGESIA DURING LABOR
- Author
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Herman, N. L., primary, Choi, K., additional, Afflick, P., additional, Calicott, R., additional, Brackin, R., additional, Gadalla, F., additional, Hartman, J., additional, Koff, H., additional, Lee, S. H., additional, and Van Decar, T. K., additional
- Published
- 1998
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13. Evidence of differences in nitrogen use efficiency in sugarcane genotypes
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Robinson, N., Gamage, H., Whan, A., Vinall, K., Fletcher, A., Brackin, R., Holst, J., Lakshmanan, P., and susanne schmidt
14. Feedback
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BRACKIN, R. E., primary
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- 1969
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15. ABORTION LIBERALIZATION
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BRACKIN, R. E., primary
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- 1971
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16. COLUMBIUM AND TANTALUM MINERALS
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Brackin, R
- Published
- 1965
17. DeepSpot: A deep neural network for RNA spot enhancement in single-molecule fluorescence in-situ hybridization microscopy images.
- Author
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Bouilhol E, Savulescu AF, Lefevre E, Dartigues B, Brackin R, and Nikolski M
- Abstract
Detection of RNA spots in single-molecule fluorescence in-situ hybridization microscopy images remains a difficult task, especially when applied to large volumes of data. The variable intensity of RNA spots combined with the high noise level of the images often requires manual adjustment of the spot detection thresholds for each image. In this work, we introduce DeepSpot, a Deep Learning-based tool specifically designed for RNA spot enhancement that enables spot detection without the need to resort to image per image parameter tuning. We show how our method can enable downstream accurate spot detection. DeepSpot's architecture is inspired by small object detection approaches. It incorporates dilated convolutions into a module specifically designed for context aggregation for small object and uses Residual Convolutions to propagate this information along the network. This enables DeepSpot to enhance all RNA spots to the same intensity, and thus circumvents the need for parameter tuning. We evaluated how easily spots can be detected in images enhanced with our method by testing DeepSpot on 20 simulated and 3 experimental datasets, and showed that accuracy of more than 97% is achieved. Moreover, comparison with alternative deep learning approaches for mRNA spot detection (deepBlink) indicated that DeepSpot provides more precise mRNA detection. In addition, we generated single-molecule fluorescence in-situ hybridization images of mouse fibroblasts in a wound healing assay to evaluate whether DeepSpot enhancement can enable seamless mRNA spot detection and thus streamline studies of localized mRNA expression in cells., Competing Interests: The authors declare no competing interests exist., (© The Author(s) 2022.)
- Published
- 2022
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18. Effects of Vancomycin on Persistent Pain-Stimulated and Pain-Depressed Behaviors in Female Fischer Rats With or Without Voluntary Access to Running Wheels.
- Author
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Payne E, Harrington K, Richard P, Brackin R, Davis R, Couture S, Liff J, Asmus F, Mutina E, Fisher A, Giuvelis D, Sannajust S, Rostama B, King T, Mattei LM, Lee JJ, Friedman ES, Bittinger K, May M, and Stevenson GW
- Subjects
- Animals, Disease Models, Animal, Female, Inflammation complications, Pain etiology, Rats, Inbred F344, Rats, Amino Acids drug effects, Anti-Bacterial Agents pharmacology, Behavior, Animal drug effects, Gastrointestinal Microbiome drug effects, Inflammation drug therapy, Motor Activity drug effects, Pain drug therapy, Vancomycin pharmacology
- Abstract
The present experiments determined the effects of the narrow-spectrum antibiotic vancomycin on inflammatory pain-stimulated and pain-depressed behaviors in rats. Persistent inflammatory pain was modeled using dilute formalin (0.5%). Two weeks of oral vancomycin administered in drinking water attenuated Phase II formalin pain-stimulated behavior, and prevented formalin pain-depressed wheel running. Fecal microbiota transplantation produced a non-significant trend toward reversal of the vancomycin effect on pain-stimulated behavior. Vancomycin depleted Firmicutes and Bacteroidetes populations in the gut while having a partial sparing effect on Lactobacillus species and Clostridiales. The vancomycin treatment effect was associated with an altered profile in amino acid concentrations in the gut with increases in arginine, glycine, alanine, proline, valine, leucine, and decreases in tyrosine and methionine. These results indicate that vancomycin may have therapeutic effects against persistent inflammatory pain conditions that are distal to the gut. PERSPECTIVE: The narrow-spectrum antibiotic vancomycin reduces pain-related behaviors in the formalin model of inflammatory pain. These data suggest that manipulation of the gut microbiome may be one method to attenuate inflammatory pain amplitude., (Copyright © 2021 United States Association for the Study of Pain, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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19. Interrogating RNA and protein spatial subcellular distribution in smFISH data with DypFISH.
- Author
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Savulescu AF, Brackin R, Bouilhol E, Dartigues B, Warrell JH, Pimentel MR, Beaume N, Fortunato IC, Dallongeville S, Boulle M, Soueidan H, Agou F, Schmoranzer J, Olivo-Marin JC, Franco CA, Gomes ER, Nikolski M, and Mhlanga MM
- Subjects
- In Situ Hybridization, Fluorescence methods, RNA, Messenger genetics, Protein Transport, RNA genetics, Muscle Fibers, Skeletal metabolism
- Abstract
Advances in single-cell RNA sequencing have allowed for the identification of cellular subtypes on the basis of quantification of the number of transcripts in each cell. However, cells might also differ in the spatial distribution of molecules, including RNAs. Here, we present DypFISH, an approach to quantitatively investigate the subcellular localization of RNA and protein. We introduce a range of analytical techniques to interrogate single-molecule RNA fluorescence in situ hybridization (smFISH) data in combination with protein immunolabeling. DypFISH is suited to study patterns of clustering of molecules, the association of mRNA-protein subcellular localization with microtubule organizing center orientation, and interdependence of mRNA-protein spatial distributions. We showcase how our analytical tools can achieve biological insights by utilizing cell micropatterning to constrain cellular architecture, which leads to reduction in subcellular mRNA distribution variation, allowing for the characterization of their localization patterns. Furthermore, we show that our method can be applied to physiological systems such as skeletal muscle fibers., Competing Interests: The authors declare no competing interests., (© 2022 The Authors.)
- Published
- 2021
- Full Text
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20. Tropical Rainforest Restoration Plantations Are Slow to Restore the Soil Biological and Organic Carbon Characteristics of Old Growth Rainforest.
- Author
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Bonner MTL, Allen DE, Brackin R, Smith TE, Lewis T, Shoo LP, and Schmidt S
- Subjects
- Queensland, Tropical Climate, Carbon Cycle, Conservation of Natural Resources, Rainforest, Soil chemistry, Soil Microbiology
- Abstract
Widespread and continuing losses of tropical old-growth forests imperil global biodiversity and alter global carbon (C) cycling. Soil organic carbon (SOC) typically declines with land use change from old-growth forest, but the underlying mechanisms are poorly understood. Ecological restoration plantations offer an established means of restoring aboveground biomass, structure and diversity of forests, but their capacity to recover the soil microbial community and SOC is unknown due to limited empirical data and consensus on the mechanisms of SOC formation. Here, we examine soil microbial community response and SOC in tropical rainforest restoration plantings, comparing them with the original old-growth forest and the previous land use (pasture). Two decades post-reforestation, we found a statistically significant but small increase in SOC in the fast-turnover particulate C fraction. Although the δ
13 C signature of the more stable humic organic C (HOC) fraction indicated a significant compositional turnover in reforested soils, from C4 pasture-derived C to C3 forest-derived C, this did not translate to HOC gains compared with the pasture baseline. Matched old-growth rainforest soils had significantly higher concentrations of HOC than pasture and reforested soils, and soil microbial enzyme efficiency and the ratio of gram-positive to gram-negative bacteria followed the same pattern. Restoration plantings had unique soil microbial composition and function, distinct from baseline pasture but not converging on target old growth rainforest within the examined timeframe. Our results suggest that tropical reforestation efforts could benefit from management interventions beyond re-establishing tree cover to realize the ambition of early recovery of soil microbial communities and stable SOC.- Published
- 2020
- Full Text
- View/download PDF
21. Understanding the Mobilization of a Nitrification Inhibitor from Novel Slow Release Pellets, Fabricated through Extrusion Processing with PHBV Biopolymer.
- Author
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Levett I, Pratt S, Donose BC, Brackin R, Pratt C, Redding M, and Laycock B
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- Agriculture, Biodegradation, Environmental, Capsules, Delayed-Action Preparations, Drug Stability, Fertilizers analysis, Guanidines administration & dosage, Kinetics, Particle Size, Soil chemistry, Agrochemicals chemistry, Guanidines chemistry, Nitrification drug effects, Polyesters chemistry
- Abstract
Dicyandiamide (DCD) has been studied as a stabilizer for nitrogen fertilizers for over 50 years. Its efficacy is limited at elevated temperatures, but this could be addressed by encapsulation to delay exposure. Here, poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) was investigated as a biodegradable matrix for the encapsulation of DCD. Cylindrical ∼3 mm × 3 mm pellets were fabricated through extrusion processing with 23 wt % DCD. Release kinetics were monitored in water, sand, and both active and γ-irradiated agricultural clay loam soils. Raman maps showed a wide particle size distribution of DCD crystals and indicated that Hitachi's classic moving front theory did not hold for this formulation. The inhibitor release kinetics were mediated by four distinct mechanisms: (i) initial rapid dissolution of surface DCD, (ii) channeling of water through voids and pores in the PHBV matrix, (iii) gradual diffusion of water and DCD through layers of PHBV, and (iv) biodegradation of the PHBV matrix. After ∼6 months, 45-100% release occurred, depending on the release media. PHBV is shown to be an effective, biodegradable matrix for the long-term slow release of nitrification inhibitors.
- Published
- 2019
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22. Delta/mu opioid receptor interactions in operant conditioning assays of pain-depressed responding and drug-induced rate suppression: assessment of therapeutic index in male Sprague Dawley rats.
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Cone K, Lanpher J, Kinens A, Richard P, Couture S, Brackin R, Payne E, Harrington K, Rice KC, and Stevenson GW
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- Analgesics, Opioid pharmacology, Analgesics, Opioid therapeutic use, Animals, Benzamides pharmacology, Benzamides therapeutic use, Conditioning, Operant drug effects, Dose-Response Relationship, Drug, Male, Methadone therapeutic use, Piperazines pharmacology, Piperazines therapeutic use, Rats, Rats, Sprague-Dawley, Receptors, Opioid, delta agonists, Receptors, Opioid, mu agonists, Conditioning, Operant physiology, Pain drug therapy, Pain metabolism, Receptors, Opioid, delta metabolism, Receptors, Opioid, mu metabolism, Therapeutic Index
- Abstract
Rationale and Objectives: Although delta/mu receptor interactions vary as a function of behavioral endpoint, there have been no assessments of these interactions using assays of pain-depressed responding. This is the first report of delta/mu interactions using an assay of pain-depressed behavior., Methods: A mult-cycle FR10 operant schedule was utilized in the presence of (nociception) and in the absence of (rate suppression) a lactic acid inflammatory pain-like manipulation. SNC80 and methadone were used as selective/high efficacy delta and mu agonists, respectively. Both SNC80 and methadone alone produced a dose-dependent restoration of pain-depressed responding and dose-dependent response rate suppression. Three fixed ratio mixtures, based on the relative potencies of the drugs in the nociception assay, also produced dose-dependent antinociception and sedation. Isobolographic analysis indicated that all three mixtures produced supra-additive antinociceptive effects and simply additive sedation effects., Conclusions: The therapeutic index (TI) inversely varied as a function of amount of SNC80 in the mixture, such that lower amounts of SNC80 produced a higher TI, and larger amounts produced a lower TI. Compared to literature using standard pain-elicited assays, the orderly relationship between SNC80 and TI reported here may be a unique function of assessing pain-depressed behavior.
- Published
- 2018
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23. Roots-eye view: Using microdialysis and microCT to non-destructively map root nutrient depletion and accumulation zones.
- Author
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Brackin R, Atkinson BS, Sturrock CJ, and Rasmussen A
- Subjects
- Agriculture, Fertilizers analysis, Ammonium Compounds analysis, Microdialysis methods, Nitrates analysis, Plant Roots anatomy & histology, Soil chemistry, X-Ray Microtomography methods
- Abstract
Improvement in fertilizer use efficiency is a key aspect for achieving sustainable agriculture in order to minimize costs, greenhouse gas emissions, and pollution from nutrient run-off. To optimize root architecture for nutrient uptake and efficiency, we need to understand what the roots encounter in their environment. Traditional methods of nutrient sampling, such as salt extractions can only be done at the end of an experiment, are impractical for sampling locations precisely and give total nutrient values that can overestimate the nutrients available to the roots. In contrast, microdialysis provides a non-invasive, continuous method for sampling available nutrients in the soil. Here, for the first time, we have used microCT imaging to position microdialysis probes at known distances from the roots and then measured the available nitrate and ammonium. We found that nitrate accumulated close to roots whereas ammonium was depleted demonstrating that this combination of complementary techniques provides a unique ability to measure root-available nutrients non-destructively and in almost real time., (© 2017 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd.)
- Published
- 2017
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24. Evolutionary conservation of a core root microbiome across plant phyla along a tropical soil chronosequence.
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Yeoh YK, Dennis PG, Paungfoo-Lonhienne C, Weber L, Brackin R, Ragan MA, Schmidt S, and Hugenholtz P
- Subjects
- Biological Evolution, Microbiota, Plant Roots microbiology, RNA, Ribosomal, 16S genetics, Soil Microbiology
- Abstract
Culture-independent molecular surveys of plant root microbiomes indicate that soil type generally has a stronger influence on microbial communities than host phylogeny. However, these studies have mostly focussed on model plants and crops. Here, we examine the root microbiomes of multiple plant phyla including lycopods, ferns, gymnosperms, and angiosperms across a soil chronosequence using 16S rRNA gene amplicon profiling. We confirm that soil type is the primary determinant of root-associated bacterial community composition, but also observe a significant correlation with plant phylogeny. A total of 47 bacterial genera are associated with roots relative to bulk soil microbial communities, including well-recognized plant-associated genera such as Bradyrhizobium, Rhizobium, and Burkholderia, and major uncharacterized lineages such as WPS-2, Ellin329, and FW68. We suggest that these taxa collectively constitute an evolutionarily conserved core root microbiome at this site. This lends support to the inference that a core root microbiome has evolved with terrestrial plants over their 400 million year history.Yeoh et al. study root microbiomes of different plant phyla across a tropical soil chronosequence. They confirm that soil type is the primary determinant of root-associated bacterial communities, but also observe a clear correlation with plant phylogeny and define a core root microbiome at this site.
- Published
- 2017
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25. Nitrogen fluxes at the root-soil interface show a mismatch of nitrogen fertilizer supply and sugarcane root uptake capacity.
- Author
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Brackin R, Näsholm T, Robinson N, Guillou S, Vinall K, Lakshmanan P, Schmidt S, and Inselsbacher E
- Subjects
- Amino Acids metabolism, Ammonium Compounds chemistry, Ammonium Compounds metabolism, Crops, Agricultural, Kinetics, Nitrogen analysis, Nitrogen Isotopes analysis, Plant Roots metabolism, Saccharum growth & development, Nitrogen metabolism, Saccharum metabolism, Soil chemistry
- Abstract
Globally only ≈50% of applied nitrogen (N) fertilizer is captured by crops, and the remainder can cause pollution via runoff and gaseous emissions. Synchronizing soil N supply and crop demand will address this problem, however current soil analysis methods provide little insight into delivery and acquisition of N forms by roots. We used microdialysis, a novel technique for in situ quantification of soil nutrient fluxes, to measure N fluxes in sugarcane cropping soils receiving different fertilizer regimes, and compare these with N uptake capacities of sugarcane roots. We show that in fertilized sugarcane soils, fluxes of inorganic N exceed the uptake capacities of sugarcane roots by several orders of magnitude. Contrary, fluxes of organic N closely matched roots' uptake capacity. These results indicate root uptake capacity constrains plant acquisition of inorganic N. This mismatch between soil N supply and root N uptake capacity is a likely key driver for low N efficiency in the studied crop system. Our results also suggest that (i) the relative contribution of inorganic N for plant nutrition may be overestimated when relying on soil extracts as indicators for root-available N, and (ii) organic N may contribute more to crop N supply than is currently assumed.
- Published
- 2015
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26. Amino acids are a nitrogen source for sugarcane.
- Author
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Vinall K, Schmidt S, Brackin R, Lakshmanan P, and Robinson N
- Abstract
Organic forms of nitrogen (ON) represent potential N sources for crops and an alternative to inorganic N (IN, ammonium nitrate). Sugarcane soils receive organic harvest residues (~40-100kg ON ha-1), but it is unknown whether ON is a direct N source for crops. We investigated whether sugarcane can use organic monomers in the form of amino acids and whether the use of amino acids as a N source results in distinct metabolic or morphological change when compared with use of inorganic N (IN). Plantlets cultivated in sterile culture and young plants grown in non-sterile soil culture were supplied with IN, ON (five amino acids present in sugarcane soils), or combined IN and ON. All treatments resulted in similar biomass and N content indicating that sugarcane has a well developed capacity to use ON and confirms findings in other species. ON-supplied plants in axenic culture had increased total branch root length per unit primary root axis which has not been reported previously. In both experimental systems, ON supplied plants had increased asparagine concentrations suggesting altered N metabolism. Root of ON-supplied soil-grown plants had significantly reduced nitrate concentrations. We interpret the shift from nitrate to asparagine as indicative of N form use other than or in addition to nitrate by sugarcane. N metabolite profiling could advance knowledge of crop N sources and this will aid in development of N efficient cropping systems with a reduced N pollution footprint.
- Published
- 2012
- Full Text
- View/download PDF
27. Arabidopsis and Lobelia anceps access small peptides as a nitrogen source for growth.
- Author
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Soper FM, Paungfoo-Lonhienne C, Brackin R, Rentsch D, Schmidt S, and Robinson N
- Abstract
While importance of amino acids as a nitrogen source for plants is increasingly recognised, other organic N sources including small peptides have received less attention. We assessed the capacity of functionally different species, annual and nonmycorrhizal Arabidopsis thaliana (L.) Heynh. (Brassicaceae) and perennial Lobelia anceps L.f. (Campanulaceae), to acquire, metabolise and use small peptides as a N source independent of symbionts. Plants were grown axenically on media supplemented with small peptides (2-4 amino acids), amino acids or inorganic N. In A. thaliana, peptides of up to four amino acid residues sustained growth and supported up to 74% of the maximum biomass accumulation achieved with inorganic N. Peptides also supported growth of L. anceps, but to a lesser extent. Using metabolite analysis, a proportion of the peptides supplied in the medium were detected intact in root and shoot tissue together with their metabolic products. Nitrogen source preferences, growth responses and shoot-root biomass allocation were species-specific and suggest caution in the use of Arabidopsis as the sole plant model. In particular, glycine peptides of increasing length induced effects ranging from complete inhibition to marked stimulation of root growth. This study contributes to emerging evidence that plants can acquire and metabolise organic N beyond amino acids.
- Published
- 2011
- Full Text
- View/download PDF
28. Nitrate paradigm does not hold up for sugarcane.
- Author
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Robinson N, Brackin R, Vinall K, Soper F, Holst J, Gamage H, Paungfoo-Lonhienne C, Rennenberg H, Lakshmanan P, and Schmidt S
- Subjects
- Crops, Agricultural metabolism, Fertilizers, Nitrogen metabolism, Plant Roots growth & development, Plant Roots metabolism, Quaternary Ammonium Compounds metabolism, Saccharum growth & development, Seasons, Soil, Substrate Specificity, Nitrates metabolism, Saccharum metabolism
- Abstract
Modern agriculture is based on the notion that nitrate is the main source of nitrogen (N) for crops, but nitrate is also the most mobile form of N and easily lost from soil. Efficient acquisition of nitrate by crops is therefore a prerequisite for avoiding off-site N pollution. Sugarcane is considered the most suitable tropical crop for biofuel production, but surprisingly high N fertilizer applications in main producer countries raise doubt about the sustainability of production and are at odds with a carbon-based crop. Examining reasons for the inefficient use of N fertilizer, we hypothesized that sugarcane resembles other giant tropical grasses which inhibit the production of nitrate in soil and differ from related grain crops with a confirmed ability to use nitrate. The results of our study support the hypothesis that N-replete sugarcane and ancestral species in the Andropogoneae supertribe strongly prefer ammonium over nitrate. Sugarcane differs from grain crops, sorghum and maize, which acquired both N sources equally well, while giant grass, Erianthus, displayed an intermediate ability to use nitrate. We conclude that discrimination against nitrate and a low capacity to store nitrate in shoots prevents commercial sugarcane varieties from taking advantage of the high nitrate concentrations in fertilized soils in the first three months of the growing season, leaving nitrate vulnerable to loss. Our study addresses a major caveat of sugarcane production and affords a strong basis for improvement through breeding cultivars with enhanced capacity to use nitrate as well as through agronomic measures that reduce nitrification in soil.
- Published
- 2011
- Full Text
- View/download PDF
29. The BEST study--a prospective study to compare business class versus economy class air travel as a cause of thrombosis.
- Author
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Jacobson BF, Münster M, Smith A, Burnand KG, Carter A, Abdool-Carrim AT, Marcos E, Becker PJ, Rogers T, le Roux D, Calvert-Evers JL, Nel MJ, Brackin R, and Veller M
- Subjects
- Adult, Case-Control Studies, Female, Fibrin Fibrinogen Degradation Products analysis, Humans, Incidence, Leg blood supply, Male, Middle Aged, Phlebotomy, Prospective Studies, Regression Analysis, Specimen Handling, Ultrasonography, Venous Thrombosis diagnosis, Venous Thrombosis diagnostic imaging, Aircraft, Travel, Venous Thrombosis etiology
- Abstract
Background: As many as 10% of airline passengers travelling without prophylaxis for long distances may develop a venous thrombosis. There is, however, no evidence that economy class travellers are at increased risk of thrombosis., Objectives: A suitably powered prospective study, based on the incidence of deep-vein thrombosis (DVT) reported in previous studies on long-haul flights, was designed to determine the incidence of positive venous duplex scans and D-dimer elevations in low and intermediate-risk passengers, comparing passengers travelling in business and economy class., Patients/methods: Eight hundred and ninety-nine passengers were recruited (180 travelling business class and 719 travelling economy). D-dimers were measured before and after the flight. A value greater than 500 ng/ml was accepted as abnormal. A thrombophilia screen was conducted which included the factor V Leiden mutation, the prothombin 20210A mutation, protein C and S levels, antithrombin levels, and anticardiolipin antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM). On arrival, lower limb compression ultrasonography of the deep veins was performed. Logistical regression analysis was used to determine the risk factors related to abnormally high D-dimer levels., Results: Only 434 subjects had a full venous duplex scan performed. None had ultrasonic evidence of venous thrombosis. Nine passengers tested at departure had elevated D-dimer levels and these volunteers were excluded from further study. Seventy-four of the 899 passengers had raised D-dimers on arrival. Twenty-two of 180 business class passengers (12%) developed elevated D-dimers compared with 52 of 719 economy class passengers (7%). There was no significant association between elevation of D-dimers and the class flown (odds ratio (OR) 0.61, p = 0.109). The factor V Leiden mutation, factor VIII levels and the use of aspirin were, however, associated with raised D-dimers (OR 3.36, p = 0.024; OR 1.01, p = 0.014; and OR 2.04, p = 0.038, respectively). Five hundred and five passengers were contacted within 6 months and none reported any symptoms of a clinical thrombosis or pulmonary embolus., Conclusion: The incidence of ultrasonically proven DVT is much lower than previously reported. However, more than 10% of all passengers developed raised D-dimers, which were unrelated to the class flown. A rise in D-dimers is associated with an inherent risk of thrombosis and/or thrombophilia, demonstrates activation of both the coagulation and fibrinolytic systems during long-haul flights, and may indicate the development of small thrombi.
- Published
- 2003
30. Analgesia, pruritus, and ventilation exhibit a dose-response relationship in parturients receiving intrathecal fentanyl during labor.
- Author
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Herman NL, Choi KC, Affleck PJ, Calicott R, Brackin R, Singhal A, Andreasen A, Gadalla F, Fong J, Gomillion MC, Hartman JK, Koff HD, Lee SH, and Van Decar TK
- Subjects
- Adult, Analgesia, Epidural, Analgesics, Opioid adverse effects, Depression, Chemical, Dose-Response Relationship, Drug, Double-Blind Method, Female, Fentanyl adverse effects, Humans, Injections, Spinal, Pain Measurement, Pregnancy, Analgesia, Obstetrical adverse effects, Analgesics, Opioid administration & dosage, Fentanyl administration & dosage, Pruritus chemically induced, Respiration drug effects
- Abstract
Unlabelled: Several studies have characterized the 50% and 95% effective doses (ED50 and ED95, respectively) of intrathecal sufentanil for labor analgesia. Few have investigated these same criteria for the less expensive alternative, fentanyl. In addition, the ventilatory effects of intrathecal fentanyl at clinically relevant doses are unclear. We performed this study to establish the dose-response relationship of intrathecal fentanyl for both analgesia and ventilatory depression. Ninety parturients in active early labor (< or = 5 cm dilation) received intrathecal fentanyl 5, 7.5, 10, 15, 20, or 25 micrograms in a double-blinded, randomized fashion (n = 15 patients in each group). Parturients were monitored for degree of pain (measured using a 100-mm visual analog pain scale), blood pressure, arterial oxygen saturation (SaO2), respiratory rate, ETCO2, and fetal heart rate 0, 1, 5, 10, 15, 20, 25, and 30 min after the administration of intrathecal fentanyl. An absolute visual analog pain scale score < or = 25 mm was defined a priori as analgesic success. The percentage of parturients who achieved analgesic success was used to construct quantal dose-response curves, from which the ED50 and ED95 values were derived for the total population (mixed parity) and the nulliparous and multiparous subpopulations separately. Overall ED50 and ED95 values (95% CI) were 5.5 (3.4-7.2) and 17.4 (13.8-27.1) micrograms, respectively. Nulliparous values were lower (5.3 and 15.9 micrograms, respectively) than multiparous values (6.9 and 26.0 micrograms, respectively) but were within the 95% CIs of the total population. Pruritus incidence in parturients with analgesic success displayed a dose-response relationship identical to that seen for analgesia. ETCO2 displayed a dose-related increase, particularly at doses > or = 15 micrograms, without concomitant changes in respiratory rate or SaO2, which suggests a decrease in tidal volume. Even in the absence of overt signs or symptoms of somnolence, intrathecal fentanyl at doses within the effective analgesic range induced a change in ventilation that may last longer than the 30-min period we studied., Implications: Intrathecal fentanyl induces rapid and satisfying dose-dependent analgesia in early labor; however, it also produces dose-related decreases in ventilation in the absence of overt somnolence.
- Published
- 1999
- Full Text
- View/download PDF
31. Carcinoid tumor of duodenum complicated by cyclic vomiting.
- Author
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BRACKIN RE
- Subjects
- Carcinoid Tumor, Duodenal Neoplasms, Duodenum, Neoplasms, Vomiting etiology
- Published
- 1954
- Full Text
- View/download PDF
32. ANASTOMOSIS OF THE BILE DUCTS TO THE GASTRO-INTESTINAL TRACT BY A METHOD OF TRANSFIXION NECROSING SUTURE.
- Author
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Brackin RE and David VC
- Published
- 1941
- Full Text
- View/download PDF
33. Use of the tomogram after attempted joint fusion.
- Author
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SPEED K and BRACKIN RE
- Subjects
- Humans, Hip surgery, Radiography
- Published
- 1955
- Full Text
- View/download PDF
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