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Asarani NAM, Reynolds AN, Elbalshy M, Burnside M, de Bock M, Lewis DM, Wheeler BJ. Efficacy, safety, and user experience of DIY or open-source artificial pancreas systems: a systematic review. Acta Diabetol 2021; 58:539-547. [PMID: 33128136 DOI: 10.1007/s00592-020-01623-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 08/26/2020] [Accepted: 10/14/2020] [Indexed: 02/07/2023]
Abstract
The do-it-yourself artificial pancreas system (DIYAPS) is a patient-driven initiative with the potential to revolutionise diabetes management, automating insulin delivery with existing pumps and CGM combined with open-source algorithms. Given the considerable interest in this topic within the diabetes community, we have conducted a systematic review of DIYAPS efficacy, safety, and user experience. Following recognised procedures and reporting standards, we identified 10 eligible publications of 730 participants within the peer-reviewed literature. Overall, studies reported improvements in time in range, HbA1c (glycated haemoglobin), reduced hypoglycaemia, and improved quality of life with DIYAPS use. While results were positive, the identified studies were small, and the majority were observational and at high risk of bias. Further research including well-designed randomised trials comparing DIYAPS with appropriate comparators is recommended.
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Affiliation(s)
- N A M Asarani
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - A N Reynolds
- Department of Medicine, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - M Elbalshy
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - M Burnside
- Department of Paediatrics, University of Otago, Christchurch, New Zealand
| | - M de Bock
- Department of Paediatrics, University of Otago, Christchurch, New Zealand
| | | | - B J Wheeler
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.
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Eboibi BE, Lewis DM, Ashman PJ, Chinnasamy S. Influence of process conditions on pretreatment of microalgae for protein extraction and production of biocrude during hydrothermal liquefaction of pretreated Tetraselmis sp. RSC Adv 2015. [DOI: 10.1039/c4ra11662c] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The direct conversion of microalgae to advanced biofuels with hydrothermal liquefaction (HTL) is an attractive option which has drawn attention in recent years.
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Affiliation(s)
- B. E. Eboibi
- Microalgal Engineering Research Group
- School of Chemical Engineering
- The University of Adelaide
- Adelaide
- Australia
| | - D. M. Lewis
- Microalgal Engineering Research Group
- School of Chemical Engineering
- The University of Adelaide
- Adelaide
- Australia
| | - P. J. Ashman
- Microalgal Engineering Research Group
- School of Chemical Engineering
- The University of Adelaide
- Adelaide
- Australia
| | - S. Chinnasamy
- Biotechnology Division
- Aban Infrastructure Pvt Ltd
- Chennai 600 008
- India
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Eboibi BE, Lewis DM, Ashman PJ, Chinnasamy S. Effect of operating conditions on yield and quality of biocrude during hydrothermal liquefaction of halophytic microalga Tetraselmis sp. Bioresour Technol 2014; 170:20-29. [PMID: 25118149 DOI: 10.1016/j.biortech.2014.07.083] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [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: 04/14/2014] [Revised: 07/16/2014] [Accepted: 07/22/2014] [Indexed: 06/03/2023]
Abstract
The biomass of halophytic microalga Tetraselmis sp. with 16%w/w solids was converted into biocrude by a hydrothermal liquefaction (HTL) process in a batch reactor at different temperatures (310, 330, 350 and 370°C) and reaction times (5, 15, 30, 45 and 60min). The biocrude yield, elemental composition, energy density and severity parameter obtained at various reaction conditions were used to predict the optimum condition for maximum recovery of biocrude with improved quality. This study clearly indicated that the operating condition for obtaining maximum biocrude yield and ideal quality biocrude for refining were different. A maximum biocrude yield of ∼65wt% ash free dry weight (AFDW) was obtained at 350°C and 5min, with a severity parameter and energy density of 5.21 and ∼35MJ/kg, respectively. The treatment with 45min reaction time recorded ∼62wt% (AFDW) yield of biocrude with and energy density of ∼39MJ/kg and higher severity parameter of 7.53.
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Affiliation(s)
- B E Eboibi
- Microalgal Engineering Research Group, School of Chemical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia.
| | - D M Lewis
- Microalgal Engineering Research Group, School of Chemical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia; Muradel Pty Ltd, Whyalla, South Australia 5600, Australia
| | - P J Ashman
- Microalgal Engineering Research Group, School of Chemical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - S Chinnasamy
- Biotechnology Division, Aban Infrastructure Pvt. Ltd, Chennai 600 008, Tamil Nadu, India
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Fon Sing S, Isdepsky A, Borowitzka MA, Lewis DM. Pilot-scale continuous recycling of growth medium for the mass culture of a halotolerant Tetraselmis sp. in raceway ponds under increasing salinity: a novel protocol for commercial microalgal biomass production. Bioresour Technol 2014; 161:47-54. [PMID: 24681683 DOI: 10.1016/j.biortech.2014.03.010] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [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: 12/20/2013] [Revised: 02/27/2014] [Accepted: 03/04/2014] [Indexed: 06/03/2023]
Abstract
The opportunity to recycle microalgal culture medium for further cultivation is often hampered by salinity increases from evaporation and fouling by dissolved and particulate matter. In this study, the impact of culture re-use after electro-flocculation of seawater-based medium on growth and biomass productivity of the halotolerant green algal strain Tetraselmis sp., MUR 233, was investigated in pilot-scale open raceway ponds over 5months. Despite a salinity increase from 5.5% to 12% (w/v) NaCl, Tetraselmis MUR 233 grown on naturally DOC-enriched recycled medium produced 48-160% more ash free dry weight (AFDW) biomass daily per unit pond area than when grown on non-recycled medium. A peak productivity of 37.5±3.1gAFDWm(-2)d(-1) was reached in the recycled medium upon transition from ∼14% to ∼7% NaCl. The combination of high biomass-yielding mixotrophic growth under high salinity has been proven to be a successful sustainable cultivation strategy.
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Affiliation(s)
- S Fon Sing
- School of Chemical Engineering, University of Adelaide, South Australia 5005, Australia; Muradel Pty Ltd, 55/239 Magill Rd, Maylands, South Australia 5069, Australia.
| | - A Isdepsky
- Algae R&D Centre, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia; Muradel Pty Ltd, 55/239 Magill Rd, Maylands, South Australia 5069, Australia
| | - M A Borowitzka
- Algae R&D Centre, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - D M Lewis
- School of Chemical Engineering, University of Adelaide, South Australia 5005, Australia; Muradel Pty Ltd, 55/239 Magill Rd, Maylands, South Australia 5069, Australia
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Orandi S, Lewis DM, Moheimani NR. Biofilm establishment and heavy metal removal capacity of an indigenous mining algal-microbial consortium in a photo-rotating biological contactor. ACTA ACUST UNITED AC 2012; 39:1321-31. [DOI: 10.1007/s10295-012-1142-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 04/26/2012] [Indexed: 11/28/2022]
Abstract
Abstract
An indigenous mining algal-microbial consortium was immobilised within a laboratory-scale photo-rotating biological contactor (PRBC) that was used to investigate the potential for heavy metal removal from acid mine drainage (AMD). The microbial consortium, dominated by Ulothrix sp., was collected from the AMD at the Sar Cheshmeh copper mine in Iran. This paper discusses the parameters required to establish an algal-microbial biofilm used for heavy metal removal, including nutrient requirements and rotational speed. The PRBC was tested using synthesised AMD with the multi-ion and acidic composition of wastewater (containing 18 elements, and with a pH of 3.5 ± 0.5), from which the microbial consortium was collected. The biofilm was successfully developed on the PRBC’s disc consortium over 60 days of batch-mode operation. The PRBC was then run continuously with a 24 h hydraulic residence time (HRT) over a ten-week period. Water analysis, performed on a weekly basis, demonstrated the ability of the algal-microbial biofilm to remove 20–50 % of the various metals in the order Cu > Ni > Mn > Zn > Sb > Se > Co > Al. These results clearly indicate the significant potential for indigenous AMD microorganisms to be exploited within a PRBC for AMD treatment.
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Affiliation(s)
- S Orandi
- grid.1010.0 0000000419367304 Microalgae Engineering Research Group, School of Chemical Engineering University of Adelaide North Terrace Campus 5005 Adelaide SA Australia
| | - D M Lewis
- grid.1010.0 0000000419367304 Microalgae Engineering Research Group, School of Chemical Engineering University of Adelaide North Terrace Campus 5005 Adelaide SA Australia
| | - N R Moheimani
- grid.1025.6 0000000404366763 Algae R&D Centre, School of Biological Sciences and Biotechnology Murdoch University 6150 Murdoch WA Australia
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Affiliation(s)
- M Rahman
- Department of Reconstructive Plastic Surgery, James Cook University Hospital, Middlesbrough, UK
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Affiliation(s)
- D. M. Lewis
- International Wool Secretariat, Technical Centre, Valley Drive, Ilkley, Yorkshire
| | - I. Seltzer
- International Wool Secretariat, Technical Centre, Valley Drive, Ilkley, Yorkshire
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Affiliation(s)
- D M Lewis
- International Wool Secretariat Technical Centre Valley Drive llkley West Yorkshire LS29 8PB
| | - M T Pailthorpe
- University of New South Wales School of Textile Technology PO Box 1 Kensington 2033 Sydney Australia
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Croft SN, Lewis DM, Orita R, Sugimoto T. Neutral‐fixing reactive dyes for cotton. Part 1 —synthesis and application of quaternised
S
‐triazinyl reactive dyes. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1992.tb01439.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S N Croft
- Departrnent of Colour Chemistry and Dyeing, University of Leeds, Leeds LS2 9JT, UK
| | - D M Lewis
- Departrnent of Colour Chemistry and Dyeing, University of Leeds, Leeds LS2 9JT, UK
| | - R Orita
- Nippon Kayaku Co. Ltd, Dyestuffs Division, 2‐1 Marunouchi 1‐Chome, Chiyoda‐Ku, Tokyo 100, Japan
| | - T Sugimoto
- Nippon Kayaku Co. Ltd, Dyestuffs Division, 2‐1 Marunouchi 1‐Chome, Chiyoda‐Ku, Tokyo 100, Japan
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Affiliation(s)
- D M Lewis
- International Wool Secretariat Technical Centre Valley Drive llkley West Yorkshire LS29 8PB
| | - M S Otterburn
- Department of Chemical Engineering Queen's University of Belfast 21 Chlorine Gardens Belfast BT9 5DL
| | - D R Savage
- Department of Chemical Engineering Queen's University of Belfast 21 Chlorine Gardens Belfast BT9 5DL
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Burkinshaw SM, Lei XP, Lewis DM. Modification of cotton to improve its dyeability. Part 1 - pretreating cotton with reactive polyamide-epichlorohydrin resin. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1989.tb01189.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Gómez N, Juliá MR, Lewis DM, Erra P. The use of FTIR to investigate modifications to wool treated with sodium sulphite and cationic protein hydrolysate. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1995.tb01742.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lei XP, Lewis DM. Modification of cotton to improve its dyeability. Part 3 - polyamide-epichlorohydrin resins and their ethylenediamine reaction products. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1990.tb01231.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Özcan AS, Clifford AA, Bartle KD, Broadbent PJ, Lewis DM. Dyeing of modified cotton fibres with disperse dyes from supercritical carbon dioxide. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1998.tb01977.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Affiliation(s)
- D. M. Lewis
- IWS Technical Centre Valley Drive, llkley, West Yorkshire LS29 8PB
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Affiliation(s)
- J. D. M. Gibson
- International Wool Secretariat, Valley Drive, Ilkley, Yorkshire
| | - D. M. Lewis
- International Wool Secretariat, Valley Drive, Ilkley, Yorkshire
| | - I. Seltzer
- International Wool Secretariat, Valley Drive, Ilkley, Yorkshire
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Burkinshaw SM, Lei XP, Lewis DM, Easton JR, Parton B, Phillips DAS. Modification of cotton to improve its dyeability. Part 2 - pretreating cotton with a thiourea derivative of polyamide-epichlorohydrin resins. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1990.tb01227.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lei XP, Lewis DM, Wang YN. Level fast dyeing of wool with nucleophilic amino-alkyl dyes and crosslinking agents-Part 2: using bifunctional crosslinking agents. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1995.tb01691.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Affiliation(s)
- D M Lewis
- International Wool Secretariat Technical Centre Valley Drive llkley West Yorkshire LS29 8PB
| | - M T Pailthorpe
- University of New South Wales School of Textile Technology PO Box 1 Kensington 2033 Sydney Australia
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Abstract
Intestinal absorptive cells of the neonatal rat display on their brush border membranes receptors for immunoglobulin G (IgG) which function in selective transfer of maternal IgG. Our Scatchard analysis of [125I]IgG binding to isolated brush borders has corroborated the presence of two classes of specific binding sites (KA1 = 2.4 X 10(7) M-1 and KA2 = 3.7 X 10(5) M-1) and the increase in overall binding with decreased buffer concentration, as shown by Wallace & Rees 1980. However, our Scatchard analysis of binding at different buffer concentrations indicates that the only significant effect of lowered buffer concentration is to increase the number of low-affinity sites. Neither the number nor the affinity of the high-affinity sites is affected. Furthermore, brush borders from rats at 21 days have only the low-affinity sites and at this age the selective transfer of IgG has ceased. Morphological experiments with tracers for both light and electron microscopy suggest that the high-affinity sites correspond to the specific IgG receptors on the apical membrane. The majority of the low-affinity sites are found within the terminal web and are likely not to be involved in selective transport of IgG.
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Affiliation(s)
- M Rahman
- Department of Reconstructive Plastic Surgery, James Cook University Hospital, Middlesbrough, UK.
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Affiliation(s)
- D M Lewis
- Department of Reconstructive Plastic Surgery, James Cook University Hospital, Marton Road, Middlesbrough, United Kingdom.
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Lewis DM, Bala SI. Plankton predation rates in turbulence: A study of the limitations imposed on a predator with a non-spherical field of sensory perception. J Theor Biol 2006; 242:44-61. [PMID: 16542686 DOI: 10.1016/j.jtbi.2006.01.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 01/30/2006] [Accepted: 01/30/2006] [Indexed: 11/15/2022]
Abstract
This paper presents an extension to previously published work which studied encounter rates of planktonic predators with restricted perception fields, to examine the related problems of prey capture and predation rates. Small-scale turbulence influences planktonic predation in two ways: the extra energy of the flow enhances the number of encounter events between individual predator and prey meso/micro-zooplankton, but it lowers the capture probability (because the time spent by the predator and prey in close proximity is reduced). Typically, an 'encounter' has usually been defined as an event when a potential prey swims (or is advected) to within a distance R of the predator in any direction. However, there is a considerable body of experimental evidence showing that predators perception fields are far from spherical; often they are wedge shaped (e.g. fish larvae), or strongly aligned with the directions of sensory antennae (e.g. copepods); and this is certain to influence optimal predation strategies. This paper presents a theoretical model which for the first time examines the combined problems of both encounter and capture for a predator with a restricted perception field swimming in a turbulent flow. If such a predator adopts a cruising strategy (continuous swimming, possibly with direction changes) the model predictions suggest that predation rates actually vary little with swimming speed, in contrast to predictions made for spherical perception fields. Consequently, cruising predators are predicted to swim at relatively low speeds whilst foraging. However, application of the model to examine the net energy gain of a typical pause-travel predator (the Atlantic cod larva), does predict the existence of an optimal ratio of the length of pauses to time spent swimming (specifically one pause phase to every two travel phases), in line with experimental observations. Kinematic simulations are presented which support these findings.
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Affiliation(s)
- D M Lewis
- Department of Applied Mathematics, University of Liverpool, M & O Building, Peach Street, Liverpool L69 7ZL, UK.
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Lewis DM. A simple model of plankton population dynamics coupled with a LES of the surface mixed layer. J Theor Biol 2005; 234:565-91. [PMID: 15808876 DOI: 10.1016/j.jtbi.2004.12.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2004] [Revised: 12/10/2004] [Accepted: 12/10/2004] [Indexed: 11/24/2022]
Abstract
The concentration of phytoplankton in the sea is affected by biological processes, such as growth/mortality rates, predatory zooplankton concentrations and nutrient levels. Phytoplankton concentrations are also influenced by physical processes, in particular the mixing properties of the local fluid environment. On planktonic scales (approximately 10-1000 microm) one can assume the local turbulent flow is isotropic, with no distinction between horizontal and vertical mixing. However, agglomerations of phytoplankton into patches are observed on larger scales of up to hundreds of metres, whose formation will be influenced by the anisotropic advection/mixing properties and large-eddy structures prevalent in the surface mixed layer. This paper presents the results of the coupling of a large-eddy simulation (LES) model of the mixed layer with an advection-diffusion system of coupled equations for nitrate-phytoplankton-zooplankton (NPZ) concentration, incorporating sub-grid parameterizations of the biological processes. Typically these include phytoplankton growth due to light levels and ambient nitrate concentration, offset by grazing losses due to the presence of zooplankton. The primary goal of this work is to investigate how the characteristics of the mixed layer turbulence influence the observed distribution of phytoplankton. One novel feature is the incorporation of a 'vortex-force' term in the LES code in order to generate Langmuir circulations. It has been speculated that the enhanced mixing rates associated with 'Langmuir turbulence' play a significant role in regulating planktonic activity. Results derived from the coupled LES-NPZ model, run with and without the presence of Langmuir circulations, are presented in order to investigate these ideas.
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Affiliation(s)
- D M Lewis
- Department of Applied Mathematics, University of Liverpool, M&O Building, Peach Street, Liverpool L69 7ZL, UK.
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Abstract
UNLABELLED Fungal exposure measurements in indoor environments require accurate and precise monitoring methods. Such techniques may be based on monoclonal antibodies (Mabs) and enzyme-linked immunosorbent assays (ELISA) and here we report the cross-reactivity patterns of Mabs produced against Aspergillus versicolor. Balb/c mice were immunized with the particulate fraction of homogenized spores and 46 Mabs (35 IgM, nine IgG3, two IgG1) were produced and tested for cross-reactivity against 55 fungal species. None of the Mabs was found to be species-specific for A. versicolor. Several Mabs strongly cross-reacted with most Aspergillus, Penicillium and Eurotium species and some Mabs also cross-reacted with Paecilomyces variotii and several Cladosporium and Stachybotrys species. Our results show that antibody responses in mice against spores of A. versicolor are dominated by highly cross-reactive antibodies of the IgM isotype. The widespread cross-reactivity suggests that the specificity of antibodies to be used for the detection of fungi in environmental samples need to be thoroughly characterized in order to avoid ambiguities in the interpretation of monitoring results. Furthermore, accurate estimates of spore concentrations may require the application of species-specific Mabs in order to avoid bias in result interpretation because of the differential reactivity of cross-reactive Mabs with different fungi. PRACTICAL IMPLICATIONS Producers of monoclonal or polyclonal antibodies for the detection of fungi in environmental or clinical samples need to verify antibody reactivity patterns and accurately report that information to potential users. Furthermore, immunoassays based on mouse or human serum or purified immunoglobulin fractions need to consider antibody cross-reactivity as a potential confounding factor during interpretation of results.
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Affiliation(s)
- D Schmechel
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA.
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Nguyen KL, Lewis DM, Jolly M, Robinson J. Determination of soluble aluminium concentration in alkaline humic water using atomic absorption spectrophotometry. Water Res 2004; 38:4039-4044. [PMID: 15491651 DOI: 10.1016/j.watres.2004.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2003] [Revised: 02/23/2004] [Accepted: 07/01/2004] [Indexed: 05/24/2023]
Abstract
The steps of the standard method to determine soluble aluminium concentration are filtering, followed by acidifying, then analysing with the atomic absorption spectrophotometer (AAS). When applied to alkaline humic water, acidification gives rise to the formation of humic acid as a brown particulate matter. Of the total soluble aluminium in the original water, 49-61% forms complexes with the particulate humic acid upon acidification. Although the AAS is capable of detecting the binding aluminium, the particulate nature of humic acid easily induces inaccurate readings as a result of the non-uniform distribution of the particulate matter. A more precise analysis of soluble aluminium concentration of alkaline humic water is shown to be achievable in basicified solutions instead. Basicified solutions keep humic acid in the soluble form; hence maintain the homogeneity of the sample.
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Affiliation(s)
- K L Nguyen
- School of Chemical Engineering, University of Adelaide, SA 5005, Australia
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Schmechel D, Górny RL, Simpson JP, Reponen T, Grinshpun SA, Lewis DM. Limitations of monoclonal antibodies for monitoring of fungal aerosols using Penicillium brevicompactum as a model fungus. J Immunol Methods 2004; 283:235-45. [PMID: 14659915 DOI: 10.1016/j.jim.2003.09.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molds are ubiquitous in every environment and many species have been recently associated with an increase in opportunistic infections in immunocompromised patients or the exacerbation of asthmatic episodes in allergic patients. The degree of environmental contamination with fungi thus needs to be monitored and in this study we report the development of a monoclonal antibody (mAb)-mediated enzyme-linked immunosorbent assay (ELISA) for the detection of spores of Penicillium brevicompactum in experimental model aerosols. In addition, we have investigated the influence of different parameters of air sampling and sample recovery on ELISA performance. MAbs were produced with standard hybridoma techniques and cross-reactivities were determined against spores of 53 fungal species by indirect ELISA. Standardized experimental fungal aerosols were collected with the Button Personal Inhalable Aerosol Sampler onto polycarbonate or polytetrafluoroethylene filters (PTFE) and the effects of different extraction buffers and filter agitation methods during sample processing on spore recovery and ELISA detection were investigated. Five mAbs were produced and all of them cross-reacted with several of 31 related Aspergillus, Penicillium and Eurotium species. However, cross-reactivities with 21 non-related fungi were rare. Spores were recovered in much higher numbers from polycarbonate filters (PFs) than from polytetrafluoroethylene filters. Optical densities (ODs) in ELISA were higher for spores collected into carbonate coating buffer (CCB) than phosphate-buffered saline (PBS). Filter bath sonication following filter vortexing had no positive effects on ELISA sensitivity. The cross-reactivity patterns of mAbs suggest that Aspergillus and Penicillium species share multiple antigens. Quantitative ELISA results for fungal aerosols were found to be influenced by differential sample processing and thus method standardization will be essential to maintain the comparability of immunometric monitoring results.
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Affiliation(s)
- D Schmechel
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 1095 Willowdale Road, M/S H-4218, Morgantown, WV 26505, USA.
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Affiliation(s)
- D. M. Lewis
- Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, UK
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Abstract
It is a well-established fact that encounter rates between different species of planktonic microorganism, either swimming, or passively advected by the flow, are enhanced in the presence of turbulence. However, due to the complexity of the various calculations involved, current encounter rate theories are based on a number of simplifying approximations, which do not reflect reality. In particular, a typical planktonic predator is usually assumed to have perfect 'all round vision', i.e. it can perceive a prey particle at any relative orientation, provided it lies within some given contact radius R. Unfortunately, there is a wide body of experimental evidence that this is not the case. In this study the encounter problem for a predator with a limited field of sensory perception, swimming in a turbulent flow, is examined from first principles and a number of new modelling ideas proposed. A wide range of kinematic simulations are also undertaken to test these predictions. Particular attention is paid to the swimming strategy such a predator might undertake to enhance its encounter rate. It turns out that the predicted optimum swimming strategies differ radically from the results of previous work. Empirical evidence is also presented which appears to support these new findings.
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Affiliation(s)
- D M Lewis
- Department of Meteorology, University of Reading, Earley Gate, P.O. Box 243, Reading, RG6 6BB, UK.
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Zhang XD, Murray DK, Lewis DM, Siegel PD. Dose-response and time course of specific IgE and IgG after single and repeated topical skin exposure to dry trimellitic anhydride powder in a Brown Norway rat model. Allergy 2002; 57:620-6. [PMID: 12100303 DOI: 10.1034/j.1398-9995.2002.03548.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Trimellitic anhydride (TMA)-induced occupational asthma is thought to be associated with its ability to acylate proteins and to induce production of TMA-specific immunoglobulin (Ig)E. Though the respiratory tract is considered to be a major exposure route leading to airway sensitization, the potential role of dermal exposure producing asthmatic sensitization is not known. The present study examines the ability of dry TMA powder to sensitize Brown Norway rats when applied, topically, to the skin. METHODS A patch of hair was carefully clipped with scissors on the rat's back. Dry TMA powder (0.3, 1.25, 5 and 20 mg) was administered on days 0, 7, 14 and 21, and the area occluded with surgical tape overnight after each application. Residual powder recovered from the occluded skin was analyzed by proton nuclear magnetic resonance and was still predominantly TMA. Circulating anti-TMA IgE and IgG were measured by ELISA. RESULTS TMA elicited dose-dependent production of specific IgE and IgG. Specific antibodies were detectable 2 weeks after the first TMA exposure and peaked between 3 and 4 weeks. CONCLUSION The data suggest that topical skin exposure to dry TMA powder can induce allergic/immunological sensitization as demonstrated by the production of specific antibodies.
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Affiliation(s)
- X D Zhang
- Natioanl Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
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