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Lapp A, Clark I, Macumber A, Patterson T. Hydrology of the North Klondike River: carbon export, water balance and inter-annual climate influences within a sub-alpine permafrost catchment. Isotopes Environ Health Stud 2017; 53:500-517. [PMID: 28745515 DOI: 10.1080/10256016.2017.1355795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 01/11/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
Arctic and sub-arctic watersheds are undergoing significant changes due to recent climate warming and degrading permafrost, engendering enhanced monitoring of arctic rivers. Smaller catchments provide understanding of discharge, solute flux and groundwater recharge at the process level that contributes to an understanding of how larger arctic watersheds are responding to climate change. The North Klondike River, located in west central Yukon, is a sub-alpine permafrost catchment, which maintains an active hydrological monitoring station with a record of >40 years. In addition to being able to monitor intra-annual variability, this data set allows for more complex analysis of streamflow records. Streamflow data, geochemistry and stable isotope data for 2014 show a groundwater-dominated system, predominantly recharged during periods of snowmelt. Radiocarbon is shown to be a valuable tracer of soil zone recharge processes and carbon sources. Winter groundwater baseflow contributes 20 % of total annual discharge, and accounts for up to 50 % of total river discharge during the spring and summer months. Although total stream discharge remains unchanged, mean annual groundwater baseflow has increased over the 40-year monitoring period. Wavelet analysis reveals a catchment that responds to El Niño and longer solar cycles, as well as climatic shifts such as the Pacific Decadal Oscillation. Dedicated to Professor Peter Fritz on the occasion of his 80th birthday.
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Affiliation(s)
- Anthony Lapp
- a André E. Lalonde Accelerator Mass Spectrometry (AMS) Laboratory , University of Ottawa , Ottawa , Ontario , Canada
| | - Ian Clark
- a André E. Lalonde Accelerator Mass Spectrometry (AMS) Laboratory , University of Ottawa , Ottawa , Ontario , Canada
| | - Andrew Macumber
- b Faculty of Science , Carleton University , Ottawa , Ontario , Canada
| | - Tim Patterson
- b Faculty of Science , Carleton University , Ottawa , Ontario , Canada
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Mihok S, Wilk M, Lapp A, St-Amant N, Kwamena NOA, Clark ID. Tritium dynamics in soils and plants grown under three irrigation regimes at a tritium processing facility in Canada. J Environ Radioact 2016; 153:176-187. [PMID: 26773512 DOI: 10.1016/j.jenvrad.2015.12.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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: 10/07/2015] [Revised: 12/27/2015] [Accepted: 12/28/2015] [Indexed: 06/05/2023]
Abstract
The dynamics of tritium released from nuclear facilities as tritiated water (HTO) have been studied extensively with results incorporated into regulatory assessment models. These models typically estimate organically bound tritium (OBT) for calculating public dose as OBT itself is rarely measured. Higher than expected OBT/HTO ratios in plants and soils are an emerging issue that is not well understood. To support the improvement of models, an experimental garden was set up in 2012 at a tritium processing facility in Pembroke, Ontario to characterize the circumstances under which high OBT/HTO ratios may arise. Soils and plants were sampled weekly to coincide with detailed air and stack monitoring. The design included a plot of native grass/soil, contrasted with sod and vegetables grown in barrels with commercial topsoil under natural rain and either low or high tritium irrigation water. Air monitoring indicated that the plume was present infrequently at concentrations of up to about 100 Bq/m(3) (the garden was not in a major wind sector). Mean air concentrations during the day on workdays (HTO 10.3 Bq/m(3), HT 5.8 Bq/m(3)) were higher than at other times (0.7-2.6 Bq/m(3)). Mean Tissue Free Water Tritium (TFWT) in plants and soils and OBT/HTO ratios were only very weakly or not at all correlated with releases on a weekly basis. TFWT was equal in soils and plants and in above and below ground parts of vegetables. OBT/HTO ratios in above ground parts of vegetables were above one when the main source of tritium was from high tritium irrigation water (1.5-1.8). Ratios were below one in below ground parts of vegetables when irrigated with high tritium water (0.4-0.6) and above one in vegetables rain-fed or irrigated with low tritium water (1.3-2.8). In contrast, OBT/HTO ratios were very high (9.0-13.5) when the source of tritium was mainly from the atmosphere. TFWT varied considerably through time as a result of SRBT's operations; OBT/HTO ratios showed no clear temporal pattern in above or below ground plant parts. Native soil after ∼20 years of operations at SRBT had high initial OBT that persisted through the growing season; little OBT formed in garden plot soil during experiments. High OBT in native soil appeared to be a signature of higher past releases at SRBT. This phenomenon was confirmed in soils obtained at another processing facility in Canada with a similar history. The insights into variation in OBT/HTO ratios found here are of regulatory interest and should be incorporated in assessment models to aid in the design of relevant environmental monitoring programs for OBT.
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Affiliation(s)
- S Mihok
- Canadian Nuclear Safety Commission, 280 Slater Street, P.O. Box 1046, Station B, Ottawa, Ontario K1P 5S9, Canada.
| | - M Wilk
- Department of Earth Sciences, 140 Louis-Pasteur, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - A Lapp
- Department of Earth Sciences, 140 Louis-Pasteur, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - N St-Amant
- Canadian Nuclear Safety Commission, 280 Slater Street, P.O. Box 1046, Station B, Ottawa, Ontario K1P 5S9, Canada
| | - N-O A Kwamena
- Canadian Nuclear Safety Commission, 280 Slater Street, P.O. Box 1046, Station B, Ottawa, Ontario K1P 5S9, Canada
| | - I D Clark
- Department of Earth Sciences, 140 Louis-Pasteur, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
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Renard D, Garnier C, Lapp A, Schmitt C, Sanchez C. Corrigendum to “Structure of arabinogalactan-protein from Acacia gum: From porous ellipsoids to supramolecular architectures” [Carbohydr. Polym. 90 (2012) 322–332]. Carbohydr Polym 2013; 97:864-7. [DOI: 10.1016/j.carbpol.2013.05.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Renard D, Garnier C, Lapp A, Schmitt C, Sanchez C. Structure of arabinogalactan-protein from Acacia gum: from porous ellipsoids to supramolecular architectures. Carbohydr Polym 2012; 90:322-32. [PMID: 24751048 DOI: 10.1016/j.carbpol.2012.05.046] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 05/14/2012] [Accepted: 05/16/2012] [Indexed: 11/29/2022]
Abstract
The structure of the arabinogalactan-protein (AGP) fraction of the gum exudate of Acacia senegal (gum Arabic) isolated from hydrophobic interaction chromatography was investigated using HPSEC-MALLS, small angle neutron scattering and TEM observations. Literature reported that the AGP structure of gum Arabic adopts a very compact conformation in solution due to the attachment of short arabinoside side chains and much larger blocks of carbohydrate to the polypeptidic backbone. The present study revealed that AGP in solution had a weight average molecular weight Mw of 1.86×10(6) g mol(-1) and a radius of gyration Rg of 30 nm. In addition, two exponent values were identified in the Rg, [η], Rh and ρ vs. Mw relationships highlighting two types of conformations depending on the molecular weight range considered: a low molar mass population with long-chain branching and a compact conformation and a high molar mass population with short-chain branching and an elongated conformation. AGP would behave in solution as a branched or hyper-branched polymer with conformations ranging from globular to elongated shape depending on the size of the carbohydrate branches. Small angle scattering form factor revealed an elongated average conformation corresponding to a triaxial ellipsoid while inverse Fourier transform of the scattering form factor gave a maximum dimension for AGP of 64 nm. Transmission electron microscopy highlighted the existence of two types of flat objects with thicknesses below 3-5 nm, single particles with a more or less anisotropic spheroidal shape and aggregated structures with a more elongated shape. A remarkable feature of all particle morphologies was the presence of an outer structure combined to an inner more or less porous network of interspersed chains or interacting structural blocks, as previously found for the arabinogalactan (AG) main molecular fraction of Acacia gum. However, clear differences were observed in the density and morphology of the inner porous network, probably highlighting differences in the degree of branching. The existence of assembled AG as part of the AGP family was confirmed using TEM micrographs at high resolution. Fused AGP dimers, trimers, tetramers and multimers were also identified. These molecular assemblies questioned about the nature of interactions involved.
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Affiliation(s)
- D Renard
- INRA, UR1268 Biopolymères Interactions Assemblages, F-44300 Nantes, France
| | - C Garnier
- UMR CNRS 6290 Equipe TAF «Translation and Folding», Université de Rennes 1, Campus Beaulieu, F-35042 Rennes Cedex, France
| | - A Lapp
- Laboratoire Léon Brillouin, CEA Saclay, Bâtiment 563, F-91191 Gif-sur-Yvette, France
| | - C Schmitt
- Department of Food Science and Technology, Nestlé Research Center, Vers-chez-les-Blanc, CH-1000 Lausanne 26, Switzerland
| | - C Sanchez
- UMR1208 Ingénierie des Agropolymères et Technologies Emergentes, INRA-Montpellier SupAgro-CIRAD-Université Montpellier 2, Place Pierre Viala, F-34060 Montpellier, France
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Pépy G, Cotton J, Hardouin F, Keller P, Lambert M, Moussa F, Noirez L, Lapp A, Strazielle C. Liquid crystal polymers: Studies of labelled parts by Neutron scattering. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19880150120] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Wellert S, Altmann HJ, Richardt A, Lapp A, Falus P, Farago B, Hellweg T. Dynamics of the interfacial film in bicontinuous microemulsions based on a partly ionic surfactant mixture: A neutron spin-echo study. Eur Phys J E Soft Matter 2010; 33:243-250. [PMID: 21061040 DOI: 10.1140/epje/i2010-10668-1] [Citation(s) in RCA: 6] [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: 03/05/2010] [Revised: 08/03/2010] [Accepted: 10/12/2010] [Indexed: 05/30/2023]
Abstract
In a microemulsion system based on a mixture of nonionic and ionic surfactants the addition of alcohol instead of changing the temperature was used to tune the curvature of the surfactant interface. The influence of the addition of the short-chain alcohol 2-propanol in the system water-perchloroethylene- Marlowet IHF-2-propanol is studied using neutron spin-echo spectroscopy. In contrast to alcohols with long alkyl chains 2-propanol is no strong co-surfactant, but changes the properties of the solvents. The present contribution focuses on the bicontinuous phase in this system and a quantitative analysis of the obtained neutron spin-echo data is proposed within the theoretical framework given by Zilman and Granek for amphiphilic membranes. It turns out that, in addition to the local movements of the surfactant film, also a collective diffusional mode of the bicontinuous structure has to be taken into account. The presented approach allows to calculate the bending elastic constant κ of the film. The approach is subsequently applied to follow changes of κ as induced by changes of the alcohol concentration.
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Affiliation(s)
- S Wellert
- Helmholtz-Center Berlin for Energy and Materials, Berlin, Germany
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Beaudoin E, Favier A, Galindo C, Lapp A, Petit C, Gigmes D, Marque S, Bertin D. Reduced sample recovery in liquid chromatography at critical adsorption point of high molar mass polystyrene. Eur Polym J 2008. [DOI: 10.1016/j.eurpolymj.2007.11.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Sanchez C, Schmitt C, Kolodziejczyk E, Lapp A, Gaillard C, Renard D. The acacia gum arabinogalactan fraction is a thin oblate ellipsoid: a new model based on small-angle neutron scattering and ab initio calculation. Biophys J 2008; 94:629-39. [PMID: 17526575 PMCID: PMC2157261 DOI: 10.1529/biophysj.107.109124] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [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: 03/19/2007] [Accepted: 05/21/2007] [Indexed: 11/18/2022] Open
Abstract
Acacia gum is a branched complex polysaccharide whose main chain consists of 1,3-linked beta-D-galactopyranosyl units. Acacia gum is defined as a heteropolysaccharide since it contains approximately 2% of a polypeptide. The major molecular fraction (F1) accounting for approximately 88% of the total acacia gum mass is an arabinogalactan peptide with a weight-average molecular weight of 2.86 x 10(5) g/mol. The molecular structure of F1 is actually unknown. From small angle neutron scattering experiments in charge screening conditions, F1 appeared to be a dispersion of two-dimensional structures with a radius of gyration of approximately 6.5 nm and an inner dense branched structure. Inverse Fourier transform of F1 scattering form factor revealed a disk-like morphology with a diameter of approximately 20 nm and a thickness below 2 nm. Ab initio calculations on the pair distance distribution function produced a porous oblate ellipsoid particle with a central intricated "network". Both transmission electron microscopy and atomic force microscopy confirm the thin disk model and structural dimensions. The model proposed is a breakthrough in the field of arabinogalactan-protein-type macromolecules. In particular, concerning the site of biosynthesis of these macromolecules, the structural dimensions found in this study would be in agreement with a phloem-mediated long-distance transport. In addition, the structure of F1 could also explain the low viscosity of acacia gum solutions, and its ability to self-assemble and to interact with proteins.
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Affiliation(s)
- C Sanchez
- Laboratoire de Science et Génie Alimentaires, ENSAIA-INPL, F-54505 Vandoeuvre-lès-Nancy cedex 5, France.
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Korobko AV, Jesse W, Lapp A, Egelhaaf SU, van der Maarel JRC. Structure of strongly interacting polyelectrolyte diblock copolymer micelles. J Chem Phys 2005; 122:024902. [PMID: 15638625 DOI: 10.1063/1.1829039] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The structure of spherical micelles of the diblock poly(styrene-block-acrylic acid) [PS-b-PA] copolymer in water was investigated up to concentrations where the polyelectrolyte coronal layers have to shrink and/or interpenetrate in order to accommodate the micelles in the increasingly crowded volume. We obtained the partial structure factors pertaining to the core and corona density correlations with small angle neutron scattering and contrast matching in the water. The counterion structure factor was obtained with small angle x-ray scattering (SAXS) with a synchrotron radiation source. Furthermore, we have measured the flow curves and dynamic visco-elastic moduli. The functionality of the micelles is fixed with a 9 nm diameter PS core and a corona formed by around 100 PA arms. As shown by the SAXS intensities, the counterions are distributed in the coronal layer with the same density profile as the corona forming segments. Irrespective ionic strength and micelle charge, the corona shrinks with increasing packing fraction. At high charge and minimal screening conditions, the polyelectrolyte chains remain almost fully stretched and they interdigitate once the volume fraction exceeds the critical value 0.53+/-0.02. Interpenetration of the polyelectrolyte brushes also controls the fluid rheology: The viscosity increases by three orders of magnitude and the parallel frequency scaling behavior of the dynamic moduli suggests the formation of a physical gel. In excess salt, the coronal layers are less extended and they do not interpenetrate in the present concentration range.
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Affiliation(s)
- A V Korobko
- Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, the Netherlands
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Korobko AV, Jesse W, Egelhaaf SU, Lapp A, van der Maarel JRC. Do spherical polyelectrolyte brushes interdigitate? Phys Rev Lett 2004; 93:177801. [PMID: 15525127 DOI: 10.1103/physrevlett.93.177801] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Indexed: 05/24/2023]
Abstract
The structure of spherical micelles of the diblock copolymer poly(styrene-block-acrylic acid) in water was investigated with small angle neutron scattering and contrast matching. We have monitored intermicelle correlation and the extension of the polyelectrolyte chains in the coronal layer through the overlap concentration. Irrespective of ionic strength, the corona shrinks with increasing packing fraction. Furthermore, at high charge and minimal screening conditions, the corona layers interpenetrate once the volume fraction exceeds the critical value 0.53+/-0.02.
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Affiliation(s)
- A V Korobko
- Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands
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van der Maarel JRC, Jesse W, Zakharova S, Backendorf C, Egelhaaf S, Lapp A. Dimensions of plectonemically supercoiled DNA. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302091560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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van der Maarel JRC, Groenewegen W, Egelhaaf SU, Lapp A. Polyelectrolyte diblock copolymer micelles studied by SANS. Acta Crystallogr A 2002. [DOI: 10.1107/s010876730208755x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Lee LT, Guiselin O, Farnoux B, Lapp A. Neutron reflectivity studies of polymer concentration profiles at the liquid/air interface. Macromolecules 2002. [DOI: 10.1021/ma00009a059] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [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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Benoit H, Wu W, Benmouna M, Mozer B, Bauer B, Lapp A. Elastic coherent scattering from multicomponent systems. Application to homopolymer mixtures and copolymers. Macromolecules 2002. [DOI: 10.1021/ma00147a030] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Perreur C, Habas JP, Peyrelasse J, François J, Lapp A. Rheological and small-angle neutron scattering studies of aqueous solutions of branched PEO-PPO-PEO copolymers. Phys Rev E Stat Nonlin Soft Matter Phys 2001; 63:031505. [PMID: 11308655 DOI: 10.1103/physreve.63.031505] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2000] [Indexed: 05/23/2023]
Abstract
Tetronic 908 is a four-branched copolymer comprised of polyethylene oxide (PEO) and polypropylene oxide (PPO) blocks fixed on an aliphatic diamine. In aqueous solution, this polymer has an amphiphilic character due to the difference in PEO and PPO solubilities with increase in temperature. This system presents interesting rheological properties depending on the polymer concentration in solution and temperature. At low temperatures and/or concentrations, the solution behaves as a Newtonian fluid. For a weight percentage p comprised between 2% and 22%, the viscosity of the solution goes through a maximum. Small-angle neutron scattering experiments show that the increase in viscosity is due to progressive aggregation of chains. For weight percentages higher than p=22%, the viscosity of the system diverges and the mixture becomes gel-like. In fact, spectromechanical measurements show that the solution behaves as an entangled polymer with a high relaxation time in the flow zone. Small-angle neutron scattering (SANS) studies of the same solution reveal the presence of several peaks indicating that the micelles are organized in a cubic structure. We have developed a model that suitably describes the SANS curves of this system in the region where micelles are formed. Our model considers that micelles are trilayered spherical entities that coexist with unimers by obeying an equilibrium reaction. Moreover, it allows the calculation of several parameters such as the volume fraction of micelles, their size, and composition. The evolution of these parameters with temperature and polymer concentration is detailed. Comparisons with literature models are presented and discussed. This compilation of results has permitted the establishment of precise relations between the structure of this polymer in solution and its rheological properties.
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Affiliation(s)
- C Perreur
- Laboratoire de Physicochimie des Polymères, UMR 5067, Université de Pau et des Pays de l'Adour, Avenue de l'Université, 64000 Pau, France
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Groenewegen W, Lapp A, Egelhaaf SU, van der Maarel JRC. Counterion Distribution in the Coronal Layer of Polyelectrolyte Diblock Copolymer Micelles. Macromolecules 2000. [DOI: 10.1021/ma000096h] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- W. Groenewegen
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Department of Physics and Astronomy, JCMB, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom, and Laboratoire Léon Brillouin, CE de Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - A. Lapp
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Department of Physics and Astronomy, JCMB, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom, and Laboratoire Léon Brillouin, CE de Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - S. U. Egelhaaf
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Department of Physics and Astronomy, JCMB, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom, and Laboratoire Léon Brillouin, CE de Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - J. R. C. van der Maarel
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Department of Physics and Astronomy, JCMB, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom, and Laboratoire Léon Brillouin, CE de Saclay, 91191 Gif-sur-Yvette Cedex, France
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Groenewegen W, Egelhaaf SU, Lapp A, van der Maarel JRC. Neutron Scattering Estimates of the Effect of Charge on the Micelle Structure in Aqueous Polyelectrolyte Diblock Copolymer Solutions. Macromolecules 2000. [DOI: 10.1021/ma992116p] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- W. Groenewegen
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Department of Physics and Astronomy, JCMB, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom, and Laboratoire Léon Brillouin, CE de Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - S. U. Egelhaaf
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Department of Physics and Astronomy, JCMB, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom, and Laboratoire Léon Brillouin, CE de Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - A. Lapp
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Department of Physics and Astronomy, JCMB, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom, and Laboratoire Léon Brillouin, CE de Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - J. R. C. van der Maarel
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Department of Physics and Astronomy, JCMB, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom, and Laboratoire Léon Brillouin, CE de Saclay, 91191 Gif-sur-Yvette Cedex, France
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Kassapidou K, Jesse W, Kuil ME, Lapp A, Egelhaaf S, van der Maarel JRC. Structure and Charge Distribution in DNA and Poly(styrenesulfonate) Aqueous Solutions Volume 30, Number 9, May 5, 1997, p 2679. Macromolecules 1998. [DOI: 10.1021/ma981980z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kassapidou K, Jesse W, Kuil ME, Lapp A, Egelhaaf S, van der Maarel JRC. Structure and Charge Distribution in DNA and Poly(styrenesulfonate) Aqueous Solutions. Macromolecules 1997. [DOI: 10.1021/ma9617126] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [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)
- K. Kassapidou
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Laboratoire Léon Brillouin, CENSaclay, 91191 Gif sur Yvette Cedex, France, and Institute Max von Laue−Paul Langevin, 156 X, 38042 Grenoble Cedex, France
| | - W. Jesse
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Laboratoire Léon Brillouin, CENSaclay, 91191 Gif sur Yvette Cedex, France, and Institute Max von Laue−Paul Langevin, 156 X, 38042 Grenoble Cedex, France
| | - M. E. Kuil
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Laboratoire Léon Brillouin, CENSaclay, 91191 Gif sur Yvette Cedex, France, and Institute Max von Laue−Paul Langevin, 156 X, 38042 Grenoble Cedex, France
| | - A. Lapp
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Laboratoire Léon Brillouin, CENSaclay, 91191 Gif sur Yvette Cedex, France, and Institute Max von Laue−Paul Langevin, 156 X, 38042 Grenoble Cedex, France
| | - S. Egelhaaf
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Laboratoire Léon Brillouin, CENSaclay, 91191 Gif sur Yvette Cedex, France, and Institute Max von Laue−Paul Langevin, 156 X, 38042 Grenoble Cedex, France
| | - J. R. C. van der Maarel
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Laboratoire Léon Brillouin, CENSaclay, 91191 Gif sur Yvette Cedex, France, and Institute Max von Laue−Paul Langevin, 156 X, 38042 Grenoble Cedex, France
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Spiteri MN, Boué F, Lapp A, Cotton JP. Persistence Length for a PSSNa Polyion in Semidilute Solution as a Function of the Ionic Strength. Phys Rev Lett 1996; 77:5218-5220. [PMID: 10062745 DOI: 10.1103/physrevlett.77.5218] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Noirez L, Lapp A. Steady-state shear experiments on a side-chain liquid-crystal polymer: Determination of the polymer conformation and liquid-crystal structure. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1996; 53:6115-6120. [PMID: 9964972 DOI: 10.1103/physreve.53.6115] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Affiliation(s)
- J. R. C. van der Maarel
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Laboratoire Léon Brillouin, Laboratoire Commun CEA-CNRS, C.E. Saclay, 91191 Gif sur Yvette, France
| | - W. Jesse
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Laboratoire Léon Brillouin, Laboratoire Commun CEA-CNRS, C.E. Saclay, 91191 Gif sur Yvette, France
| | - M. E. Kuil
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Laboratoire Léon Brillouin, Laboratoire Commun CEA-CNRS, C.E. Saclay, 91191 Gif sur Yvette, France
| | - A. Lapp
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Laboratoire Léon Brillouin, Laboratoire Commun CEA-CNRS, C.E. Saclay, 91191 Gif sur Yvette, France
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Boué F, Cotton JP, Lapp A, Jannink G. A direct measurement of the polyion conformation in aqueous solutions at different temperatures. Small angle neutron scattering of PSSNa using zero average and full contrast. J Chem Phys 1994. [DOI: 10.1063/1.467629] [Citation(s) in RCA: 48] [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: 11/14/2022] Open
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Lapp A, Mottin M, Strazielle C, Broseta D, Leibler L. Experimental evidence for the strong interpenetration of two polymer chains very different in size. ACTA ACUST UNITED AC 1992. [DOI: 10.1051/jp2:1992197] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Lee LT, Guiselin O, Lapp A, Farnoux B, Penfold J. Direct measurements of polymer depletion layers by neutron reflectivity. Phys Rev Lett 1991; 67:2838-2841. [PMID: 10044568 DOI: 10.1103/physrevlett.67.2838] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Csiba T, Jannink G, Durand D, Papoular R, Lapp A, Auvray L, Boué F, Cotton JP, Borsali R. Diffusion in semi-dilute polymer solutions. A complementary experiment. ACTA ACUST UNITED AC 1991. [DOI: 10.1051/jp2:1991175] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Benoit H, Benmouna M, Strazielle C, Lapp A, Ould-Kaddour L. Polymer and copolymer characterization by light and neutron scattering: Theoretical considerations and experimental examples. J Appl Polym Sci 1991. [DOI: 10.1002/app.1991.070480023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bou� F, Bastide J, Buzier M, Collette C, Lapp A, Herz J. Dynamics of permanent and temporary networks: Small angle neutron scattering measurements and related remarks on the classical models of rubber deformation. ACTA ACUST UNITED AC 1987. [DOI: 10.1007/bf01188369] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nierlich M, Boué F, Lapp A, Oberthur R. Radius of gyration of a polyion in salt free polyelectrolyte solutions measured by S. A. N. S. ACTA ACUST UNITED AC 1985. [DOI: 10.1051/jphys:01985004604064900] [Citation(s) in RCA: 62] [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: 11/14/2022]
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Abstract
Turkey hens were allowed to incubate eggs and to hatch and rear young. Plasma prolactin (Prl) levels increased prior to the start of continuous incubation and rose sharply as incubation progressed to reach a peak of 1178.2 +/- 221.8 ng/ml (mean +/- SEM) just before hatching. Prl levels then fell precipitously before the hens left the nest, and returned to preincubation levels (36.8 +/- 3.4 ng/ml) by the time the poults were 2 weeks old. These results show that the high plasma concentrations of Prl found during incubation are not initiated or maintained only by the stimulus of nesting. We suggest that the decline in Prl levels at the end of incubation could be related to the pipping and hatching of eggs, and the consequent shift to maternal behavior. Plasma growth hormone (GH) levels were significantly increased in hens which were brooding poults, but not in hens incubating eggs. An elevenfold, 1-day increase in plasma GH was observed immediately after the hens left the nests. Mean plasma GH levels rose from 12.0 +/- 4.7 ng/ml on the day that the hens left the nests to 133.0 +/- 32.0 ng/ml on the following day, and then declined to 23.1 +/- 9.6 ng/ml after an additional day. There were no significant changes in plasma thyroxine levels during laying, incubation and brooding. Plasma glucose concentration was significantly depressed during incubation.
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