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George TS, Ashburn NP, Snavely AC, Beaver BP, Chado MA, Cannon H, Costa CG, Winslow JE, Nelson RD, Stopyra JP, Mahler SA. Does Single Dose Epinephrine Improve Outcomes for Patients with Out-of-Hospital Cardiac Arrest and Bystander CPR or a Shockable Rhythm? PREHOSP EMERG CARE 2024:1-14. [PMID: 38713769 DOI: 10.1080/10903127.2024.2348663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 04/11/2024] [Indexed: 05/09/2024]
Abstract
Background: A single dose epinephrine protocol (SDEP) for out-of-hospital cardiac arrest (OHCA) achieves similar survival to hospital discharge (SHD) rates as a multidose epinephrine protocol (MDEP). However, it is unknown if a SDEP improves SHD rates among patients with a shockable rhythm or those receiving bystander cardiopulmonary resuscitation (CPR).Methods: This pre-post study, spanning 11/01/2016-10/29/2019 at 5 North Carolina EMS systems, compared pre-implementation MDEP and post-implementation SDEP in patients ≥18 years old with non-traumatic OHCA. Data on initial rhythm type, performance of bystander CPR, and the primary outcome of SHD were sourced from the Cardiac Arrest Registry to Enhance Survival. We compared SDEP vs MDEP performance in each rhythm (shockable and non-shockable) and CPR (bystander CPR or no bystander CPR) subgroup using Generalized Estimating Equations to account for clustering among EMS systems and to adjust for age, sex, race, witnessed arrest, arrest location, AED availability, EMS response interval, and presence of a shockable rhythm or receiving bystander CPR. The interaction of SDEP implementation with rhythm type and bystander CPR was evaluated.Results: Of 1690 patients accrued (899 MDEP, 791 SDEP), 19.2% (324/1690) had shockable rhythms and 38.9% (658/1690) received bystander CPR. After adjusting for confounders, SHD was increased after SDEP implementation among patients with bystander CPR (aOR 1.61, 95%CI 1.03-2.53). However, SHD was similar in the SDEP cohort vs MDEP cohort among patients without bystander CPR (aOR 0.81, 95%CI 0.60-1.09), with a shockable rhythm (aOR 0.96, 95%CI 0.48-1.91), and with a non-shockable rhythm (aOR 1.26, 95%CI 0.89-1.77). In the adjusted model, the interaction between SDEP implementation and bystander CPR was significant for SHD (p = 0.002).Conclusion: Adjusting for confounders, the SDEP increased SHD in patients who received bystander CPR and there was a significant interaction between SDEP and bystander CPR. Single dose epinephrine protocol and MDEP had similar SHD rates regardless of rhythm type.
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Affiliation(s)
- Tyler S George
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Nicklaus P Ashburn
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Anna C Snavely
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
- Department of Biostatistics and Data Science, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Bryan P Beaver
- Department of Emergency Medicine, University of Kansas School of Medicine, Kansas City, KS, USA
| | - Michael A Chado
- Department of Emergency Medicine, The Ohio State University, Columbus, OH, USA
| | - Harris Cannon
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Casey G Costa
- Department of Emergency Medicine, Virginia Commonwealth University, Richmond VA, USA
| | - James E Winslow
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - R Darrell Nelson
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Jason P Stopyra
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Simon A Mahler
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
- Department of Epidemiology and Prevention, Wake Forest University School of Medicine, Winston-Salem, NC, USA
- Department of Implementation Science, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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Jones MA, George TS, Bullock GS, Sikora RR, Vesely BD, Sinacore DR. Biomarkers of chronic kidney disease-mineral bone disorder (CKD-MBD) in the diabetic foot: A medical record review. Diabetes Res Clin Pract 2022; 194:110160. [PMID: 36410557 DOI: 10.1016/j.diabres.2022.110160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 10/30/2022] [Accepted: 11/13/2022] [Indexed: 11/19/2022]
Abstract
AIMS Determine the prevalence and relative risk of having single and combinations of biomarkers of chronic kidney disease-mineral bone disorder (CKD-MBD) syndrome in the diabetic foot from an electronic medical record (EMR) review. METHODS Review of 152 patients with one foot radiograph and diagnoses of both diabetes mellitus (DM) and chronic kidney disease (CKD) stages 1-5. Presence/absence of peripheral neuropathy (PN), targeted serum markers, and both pedal vessel calcification (PVC) and buckling ratio (BR) of 2nd and 5th metatarsals from radiographs were recorded. Prevalence of single and combinations of foot biomarkers are reported as count and percentage. Risk ratios (RR) with 95% confidence intervals (95% CI) were calculated to assess risk of foot biomarkers in each stage of CKD-MBD. RESULTS Prevalence and RR of PVC, PN, and BR ≥ 3.5 biomarkers, both single and in combination, all increase with progression of CKD. The RR increases to 9.6 (95 % CI: 3, 26; p < 0.001) when all 3 biomarkers present in stage 5. CONCLUSIONS PVC, PN, and BR ≥ 3.5 are prognostic biomarkers of CKD-MBD syndrome in the diabetic foot. Recognition of these foot biomarkers may allow earlier interventions to help reduce nontraumatic lower extremity amputation in individuals with diabetic CKD-MBD.
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Affiliation(s)
- Michael A Jones
- Atrium Health Wake Forest Baptist Department of Orthopaedic Surgery & Rehabilitation, Winston-Salem, NC 27157, United States.
| | - Tyler S George
- Atrium Health Wake Forest Baptist Department of Orthopaedic Surgery & Rehabilitation, Winston-Salem, NC 27157, United States.
| | - Garrett S Bullock
- Atrium Health Wake Forest Baptist Department of Orthopaedic Surgery & Rehabilitation, Winston-Salem, NC 27157, United States.
| | - Rebecca R Sikora
- Atrium Health Wake Forest Baptist Department of Orthopaedic Surgery & Rehabilitation, Winston-Salem, NC 27157, United States.
| | - Bryanna D Vesely
- Atrium Health Wake Forest Baptist Department of Orthopaedic Surgery & Rehabilitation, Winston-Salem, NC 27157, United States.
| | - David R Sinacore
- Department of Physical Therapy, Congdon School of Health Sciences, High Point University, High Point, NC 27268, United States.
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Engelhardt IC, Patko D, Liu Y, Mimault M, de Las Heras Martinez G, George TS, MacDonald M, Ptashnyk M, Sukhodub T, Stanley-Wall NR, Holden N, Daniell TJ, Dupuy LX. Novel form of collective movement by soil bacteria. ISME J 2022; 16:2337-2347. [PMID: 35798939 PMCID: PMC9478162 DOI: 10.1038/s41396-022-01277-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 06/07/2022] [Accepted: 06/17/2022] [Indexed: 04/16/2023]
Abstract
Although migrations are essential for soil microorganisms to exploit scarce and heterogeneously distributed resources, bacterial mobility in soil remains poorly studied due to experimental limitations. In this study, time-lapse images collected using live microscopy techniques captured collective and coordinated groups of B. subtilis cells exhibiting "crowd movement". Groups of B. subtilis cells moved through transparent soil (nafion polymer with particle size resembling sand) toward plant roots and re-arranged dynamically around root tips in the form of elongating and retracting "flocks" resembling collective behaviour usually associated with higher organisms (e.g., bird flocks or fish schools). Genetic analysis reveals B. subtilis flocks are likely driven by the diffusion of extracellular signalling molecules (e.g., chemotaxis, quorum sensing) and may be impacted by the physical obstacles and hydrodynamics encountered in the soil like environment. Our findings advance understanding of bacterial migration through soil matrices and expand known behaviours for coordinated bacterial movement.
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Affiliation(s)
- I C Engelhardt
- Ecological Sciences, The James Hutton Institute, Dundee, UK
- Department of Conservation of Natural Resources, Neiker, Bilbao, Spain
| | - D Patko
- Ecological Sciences, The James Hutton Institute, Dundee, UK
- Department of Conservation of Natural Resources, Neiker, Bilbao, Spain
| | - Y Liu
- Ecological Sciences, The James Hutton Institute, Dundee, UK
- ICS, The James Hutton Institute, Dundee, UK
| | - M Mimault
- ICS, The James Hutton Institute, Dundee, UK
| | | | - T S George
- Ecological Sciences, The James Hutton Institute, Dundee, UK
| | - M MacDonald
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - M Ptashnyk
- School of Mathematical & Computer Sciences, Heriot-Watt University, Edinburgh, UK
| | - T Sukhodub
- School of Life Sciences, University of Dundee, Dundee, UK
| | | | - N Holden
- Ecological Sciences, The James Hutton Institute, Dundee, UK
- North Faculty, Scotland's Rural College, Aberdeen, UK
| | - T J Daniell
- Plants, Photosynthesis and Soil, School of Biosciences, The University of Sheffield, Sheffield, UK
| | - L X Dupuy
- Ecological Sciences, The James Hutton Institute, Dundee, UK.
- Department of Conservation of Natural Resources, Neiker, Bilbao, Spain.
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
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Marin M, Feeney DS, Brown LK, Naveed M, Ruiz S, Koebernick N, Bengough AG, Hallett PD, Roose T, Puértolas J, Dodd IC, George TS. Significance of root hairs for plant performance under contrasting field conditions and water deficit. Ann Bot 2021; 128:1-16. [PMID: 33038211 PMCID: PMC8318266 DOI: 10.1093/aob/mcaa181] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS Previous laboratory studies have suggested selection for root hair traits in future crop breeding to improve resource use efficiency and stress tolerance. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. As such, this study aims to experimentally elucidate some of the impacts that root hairs have on plant performance on a field scale. METHODS A field experiment was set up in Scotland for two consecutive years, under contrasting climate conditions and different soil textures (i.e. clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Root hair length, density and rhizosheath weight were measured at several growth stages, as well as shoot biomass, plant water status, shoot phosphorus (P) accumulation and grain yield. KEY RESULTS Measurements of root hair density, length and its correlation with rhizosheath weight highlighted trait robustness in the field under variable environmental conditions, although significant variations were found between soil textures as the growing season progressed. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance resulting in a less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot P accumulation. Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought. CONCLUSIONS Selecting for beneficial root hair traits can enhance yield stability without diminishing yield potential, overcoming the breeder's dilemma of trying to simultaneously enhance both productivity and resilience. Therefore, the maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.
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Affiliation(s)
- M Marin
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- The James Hutton Institute, Invergowrie, Dundee, UK
| | - D S Feeney
- The James Hutton Institute, Invergowrie, Dundee, UK
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - L K Brown
- The James Hutton Institute, Invergowrie, Dundee, UK
| | - M Naveed
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- School of Computing and Engineering, University of West London, London, UK
| | - S Ruiz
- School of Engineering, University of Southampton, Southampton, UK
| | - N Koebernick
- School of Engineering, University of Southampton, Southampton, UK
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - A G Bengough
- The James Hutton Institute, Invergowrie, Dundee, UK
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - P D Hallett
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - T Roose
- School of Engineering, University of Southampton, Southampton, UK
| | - J Puértolas
- The Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - I C Dodd
- The Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - T S George
- The James Hutton Institute, Invergowrie, Dundee, UK
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Ruiz S, Koebernick N, Duncan S, Fletcher DM, Scotson C, Boghi A, Marin M, Bengough AG, George TS, Brown LK, Hallett PD, Roose T. Significance of root hairs at the field scale - modelling root water and phosphorus uptake under different field conditions. Plant Soil 2019; 447:281-304. [PMID: 32214504 PMCID: PMC7062663 DOI: 10.1007/s11104-019-04308-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/13/2019] [Indexed: 05/22/2023]
Abstract
ABSTRACT BACKGROUND AND AIMS Root hairs play a significant role in phosphorus (P) extraction at the pore scale. However, their importance at the field scale remains poorly understood. METHODS This study uses a continuum model to explore the impact of root hairs on the large-scale uptake of P, comparing root hair influence under different agricultural scenarios. High vs low and constant vs decaying P concentrations down the soil profile are considered, along with early vs late precipitation scenarios. RESULTS Simulation results suggest root hairs accounted for 50% of total P uptake by plants. Furthermore, a delayed initiation time of precipitation potentially limits the P uptake rate by over 50% depending on the growth period. Despite the large differences in the uptake rate, changes in the soil P concentration in the domain due to root solute uptake remains marginal when considering a single growth season. However, over the duration of 6 years, simulation results showed that noticeable differences arise over time. CONCLUSION Root hairs are critical to P capture, with uptake efficiency potentially enhanced by coordinating irrigation with P application during earlier growth stages of crops.
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Affiliation(s)
- S Ruiz
- 1Bioengineering Science Research Group, Department of Mechanical Engineering, School of Engineering, Faculty of Engineering and Physical Science, University of Southampton, Southampton, SO17 1BJ UK
| | - N Koebernick
- 1Bioengineering Science Research Group, Department of Mechanical Engineering, School of Engineering, Faculty of Engineering and Physical Science, University of Southampton, Southampton, SO17 1BJ UK
- 5Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Universitaetplatz 10, 06108 Halle (Saale), Germany
| | - S Duncan
- 1Bioengineering Science Research Group, Department of Mechanical Engineering, School of Engineering, Faculty of Engineering and Physical Science, University of Southampton, Southampton, SO17 1BJ UK
| | - D McKay Fletcher
- 1Bioengineering Science Research Group, Department of Mechanical Engineering, School of Engineering, Faculty of Engineering and Physical Science, University of Southampton, Southampton, SO17 1BJ UK
| | - C Scotson
- 1Bioengineering Science Research Group, Department of Mechanical Engineering, School of Engineering, Faculty of Engineering and Physical Science, University of Southampton, Southampton, SO17 1BJ UK
| | - A Boghi
- 1Bioengineering Science Research Group, Department of Mechanical Engineering, School of Engineering, Faculty of Engineering and Physical Science, University of Southampton, Southampton, SO17 1BJ UK
| | - M Marin
- 2School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU UK
| | - A G Bengough
- 3Ecological Sciences Group, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA UK
- 4School of Science and Engineering, University of Dundee, Dundee, DD1 4HN UK
| | - T S George
- 3Ecological Sciences Group, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA UK
| | - L K Brown
- 3Ecological Sciences Group, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA UK
| | - P D Hallett
- 2School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU UK
| | - T Roose
- 1Bioengineering Science Research Group, Department of Mechanical Engineering, School of Engineering, Faculty of Engineering and Physical Science, University of Southampton, Southampton, SO17 1BJ UK
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Canto CDLF, Kalogiros DI, Ptashnyk M, George TS, Waugh R, Bengough AG, Russell J, Dupuy LX. Morphological and genetic characterisation of the root system architecture of selected barley recombinant chromosome substitution lines using an integrated phenotyping approach. J Theor Biol 2018; 447:84-97. [PMID: 29559229 DOI: 10.1016/j.jtbi.2018.03.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/12/2018] [Accepted: 03/13/2018] [Indexed: 11/27/2022]
Abstract
Discoveries on the genetics of resource acquisition efficiency are limited by the ability to measure plant roots in sufficient number and with adequate genotypic variability. This paper presents a root phenotyping study that explores ways to combine live imaging and computer algorithms for model-based extraction of root growth parameters. The study is based on a subset of barley Recombinant Chromosome Substitution Lines (RCSLs) and a combinatorial approach was designed for fast identification of the regions of the genome that contribute the most to variations in root system architecture (RSA). Results showed there was a strong genotypic variation in root growth parameters within the set of genotypes studied. The chromosomal regions associated with primary root growth differed from the regions of the genome associated with changes in lateral root growth. The concepts presented here are discussed in the context of identifying root QTL and its potential to assist breeding for novel crops with improved root systems.
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Affiliation(s)
- C De La Fuente Canto
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom ; School of Life Sciences, University of Dundee, Dundee DD2 1PP, United Kingdom
| | - D I Kalogiros
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom ; School of Science and Engineering, University of Dundee, Dundee DD2 1PP, United Kingdom
| | - M Ptashnyk
- School of Science and Engineering, University of Dundee, Dundee DD2 1PP, United Kingdom
| | - T S George
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom
| | - R Waugh
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom
| | - A G Bengough
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom ; School of Science and Engineering, University of Dundee, Dundee DD2 1PP, United Kingdom
| | - J Russell
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom
| | - L X Dupuy
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom .
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Holland JE, Bennett AE, Newton AC, White PJ, McKenzie BM, George TS, Pakeman RJ, Bailey JS, Fornara DA, Hayes RC. Liming impacts on soils, crops and biodiversity in the UK: A review. Sci Total Environ 2018; 610-611:316-332. [PMID: 28806549 DOI: 10.1016/j.scitotenv.2017.08.020] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/14/2017] [Accepted: 08/02/2017] [Indexed: 05/22/2023]
Abstract
Fertile soil is fundamental to our ability to achieve food security, but problems with soil degradation (such as acidification) are exacerbated by poor management. Consequently, there is a need to better understand management approaches that deliver multiple ecosystem services from agricultural land. There is global interest in sustainable soil management including the re-evaluation of existing management practices. Liming is a long established practice to ameliorate acidic soils and many liming-induced changes are well understood. For instance, short-term liming impacts are detected on soil biota and in soil biological processes (such as in N cycling where liming can increase N availability for plant uptake). The impacts of liming on soil carbon storage are variable and strongly relate to soil type, land use, climate and multiple management factors. Liming influences all elements in soils and as such there are numerous simultaneous changes to soil processes which in turn affect the plant nutrient uptake; two examples of positive impact for crops are increased P availability and decreased uptake of toxic heavy metals. Soil physical conditions are at least maintained or improved by liming, but the time taken to detect change varies significantly. Arable crops differ in their sensitivity to soil pH and for most crops there is a positive yield response. Liming also introduces implications for the development of different crop diseases and liming management is adjusted according to crop type within a given rotation. Repeated lime applications tend to improve grassland biomass production, although grassland response is variable and indirect as it relates to changes in nutrient availability. Other indicators of liming response in grassland are detected in mineral content and herbage quality which have implications for livestock-based production systems. Ecological studies have shown positive impacts of liming on biodiversity; such as increased earthworm abundance that provides habitat for wading birds in upland grasslands. Finally, understanding of liming impacts on soil and crop processes are explored together with functional aspects (in terms of ecosystems services) in a new qualitative framework that includes consideration of how liming impacts change with time. This holistic approach provides insights into the far-reaching impacts that liming has on ecosystems and the potential for liming to enhance the multiple benefits from agriculturally managed land. Recommendations are given for future research on the impact of liming and the implications for ecosystem services.
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Affiliation(s)
- J E Holland
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK.
| | - A E Bennett
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - A C Newton
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - P J White
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - B M McKenzie
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - T S George
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - R J Pakeman
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - J S Bailey
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK
| | - D A Fornara
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK
| | - R C Hayes
- New South Wales Department of Primary Industries, Wagga Wagga Agricultural Institute, Pine Gully Road, Wagga Wagga, NSW 2650, Australia
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Cooper LJ, Daly KR, Hallett PD, Naveed M, Koebernick N, Bengough AG, George TS, Roose T. Fluid flow in porous media using image-based modelling to parametrize Richards' equation. Proc Math Phys Eng Sci 2017; 473:20170178. [PMID: 29225490 PMCID: PMC5719621 DOI: 10.1098/rspa.2017.0178] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 10/20/2017] [Indexed: 11/12/2022] Open
Abstract
The parameters in Richards' equation are usually calculated from experimentally measured values of the soil-water characteristic curve and saturated hydraulic conductivity. The complex pore structures that often occur in porous media complicate such parametrization due to hysteresis between wetting and drying and the effects of tortuosity. Rather than estimate the parameters in Richards' equation from these indirect measurements, image-based modelling is used to investigate the relationship between the pore structure and the parameters. A three-dimensional, X-ray computed tomography image stack of a soil sample with voxel resolution of 6 μm has been used to create a computational mesh. The Cahn-Hilliard-Stokes equations for two-fluid flow, in this case water and air, were applied to this mesh and solved using the finite-element method in COMSOL Multiphysics. The upscaled parameters in Richards' equation are then obtained via homogenization. The effect on the soil-water retention curve due to three different contact angles, 0°, 20° and 60°, was also investigated. The results show that the pore structure affects the properties of the flow on the large scale, and different contact angles can change the parameters for Richards' equation.
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Affiliation(s)
- L J Cooper
- Bioengineering Sciences Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - K R Daly
- Bioengineering Sciences Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - P D Hallett
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - M Naveed
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - N Koebernick
- Bioengineering Sciences Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - A G Bengough
- The James Hutton Institute, Invergowrie, Dundee, UK.,School of Science and Engineering, University of Dundee, Dundee, UK
| | - T S George
- The James Hutton Institute, Invergowrie, Dundee, UK
| | - T Roose
- Bioengineering Sciences Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
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