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Stewart K, Spedding PL, Otterburn MS, Lewis DM. Isolating the cuticle layer of wool: a comparison of methods. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1997.tb01844.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Carr CM, Lewis DM. An FTIR spectroscopic study of the photodegradation and thermal degradation of wool. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1993.tb01496.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lewis DM, Broadbent PJ. A universal dye for all fibres - are disperse dyes capable of fulfilling this vision? ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1997.tb01890.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lewis DM, Lei XP. New methods for improving the dyeability of cellulose fibres with reactive dyes*. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1991.tb01312.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Gibson JDM, Lewis DM, Seltzer I. Pad‐Batch Dyeing of Wool Fabric—Development of an Industrial Process*. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1970.tb02956.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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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] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Lewis DM, Pailthorpe MT. The Benzoylation of Wool and its Effect on Dye Affinity and Shrink Resistance. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1478-4408.1983.tb03660.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rodewald R, Lewis DM, Kraehenbuhl JP. Immunoglobulin G receptors of intestinal brush borders from neonatal rats. CIBA FOUNDATION SYMPOSIUM 2008; 95:287-99. [PMID: 6221913 DOI: 10.1002/9780470720769.ch17] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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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Rahman M, Lewis DM, Allison K. A case of paraquat burns following an industrial accident. Emerg Med J 2007; 24:777. [PMID: 17954833 DOI: 10.1136/emj.2006.041962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Lewis DM, Balakrishnan S, Coady MSE, Allison K. Camphor burns to the palm: An unusual self-inflicted burn. Burns 2007; 33:672. [PMID: 17222979 DOI: 10.1016/j.burns.2006.07.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Accepted: 07/28/2006] [Indexed: 11/22/2022]
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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] [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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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] [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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Schmechel D, Simpson JP, Lewis DM. The production and characterization of monoclonal antibodies to the fungus Aspergillus versicolor. INDOOR AIR 2005; 15 Suppl 9:11-9. [PMID: 15910525 DOI: 10.1111/j.1600-0668.2005.00340.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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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Nguyen KL, Lewis DM, Jolly M, Robinson J. Determination of soluble aluminium concentration in alkaline humic water using atomic absorption spectrophotometry. WATER RESEARCH 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] [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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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] [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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Lewis DM. The orientation of gyrotactic spheroidal micro-organisms in a homogeneous isotropic turbulent flow. Proc Math Phys Eng Sci 2003. [DOI: 10.1098/rspa.2002.1046] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Lewis DM. Planktonic encounter rates in homogeneous isotropic turbulence: the case of predators with limited fields of sensory perception. J Theor Biol 2003; 222:73-97. [PMID: 12699736 DOI: 10.1016/s0022-5193(03)00015-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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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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] [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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