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Author (down) Medjigbodo, G.; Rozière, E.; Charrier, K.; Izoret, L.; Loukili, A. url  doi
openurl 
  Title Hydration, shrinkage, and durability of ternary binders containing Portland cement, limestone filler and metakaolin Type Journal Article
  Year 2018 Publication Construction and Building Materials Abbreviated Journal  
  Volume 183 Issue Pages 114-126  
  Keywords Durability; Limestone filler; Metakaolin; Shrinkage; Strength; Ternary binders  
  Abstract A partial replacement of the clinker by latent hydraulic or pozzolanic materials is encouraged due to environmental and specific technical requirements. Such substitution remains limited to a relatively low level (less than 30% by mass of cementitious materials). An experimental research work was carried out on mortars made with binary and ternary binders (Portland cement; metakaolin; limestone filler) to reach 45% total replacement. In order to investigate the activating effect of reduced water-to-cement ratio, two series of mixtures were designed with W/C0 of 0.42 and 0.5. Their heat of hydration, portlandite content, shrinkage, porosity, and carbonation were monitored. The tests were performed to understand the evolution of their relative strength (activity index) and durability parameters. The strength development of mortars with ternary binders was found to depend on metakaolin properties, including manufacturing process and particle size distribution. Reducing W/C0 ratio accelerated pozzolanic reaction and allowed improving early-age strength and durability parameters. © 2018 Elsevier Ltd  
  Address Association Technique de l'Industrie des Liants Hydrauliques (ATILH), 7 place de la Défense, Paris La Défense, 92974, France  
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  Notes Export Date: 1 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 814  
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Author (down) McLean, J.P.; Zhang, T.; Bardet, S.; Beauchene, J.; Thibaut, A.; Clair, B.; Thibaut, B. openurl 
  Title The decreasing radial wood stiffness pattern of some tropical trees growing in the primary forest is reversed and increases when they are grown in a plantation Type Journal Article
  Year 2011 Publication Annals of Forest Science Abbreviated Journal Ann. For. Sci.  
  Volume 68 Issue 4 Pages 681-688  
  Keywords Tropical trees; Growth strategy; Wood stiffness; Juvenile wood  
  Abstract Background This study examines the radial trend in wood stiffness of tropical rainforest trees. The objective was to determine if the type of growing environment (exposed plantation or dense primary forest) would have an effect on this radial trend. Methods The axial elastic modulus of wood samples, representing a pith to bark cross-section, of six trees from several French Guianese species (two of Eperua falcata, one of Eperua grandiflora, two of Carapa procera and one of Symphonia gloubulifera) was measured using a dynamic “forced vibration” method. Results Primary forest trees were observed to have a decrease in wood stiffness from pith to bark, whereas plantation trees, from the same genus or species, displayed a corresponding increase in wood stiffness. Juvenile wood stiffness appears to vary depending on the environment in which the tree had grown. Conclusion We suggest that the growth strategy of primary forest trees is to produce wood resistant to self-buckling so that the height of the canopy may be obtained with the maximum of efficiency. In contrast, the growth strategy of the trees growing in an exposed plantation is to produce low-stiffness wood, important to provide flexibility in wind. Further experiments to study the behaviour of more species, with more individuals per species, growing across a range of physical environments, are required.  
  Address [McLean, JP; Bardet, S; Clair, B; Thibaut, B] Univ Montpellier 2, LMGC, CNRS, F-34095 Montpellier, France, Email: p.mclean@auckland.ac.nz  
  Corporate Author Thesis  
  Publisher Springer France Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1286-4560 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000292553400003 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 326  
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Author (down) McLean, J.P.; Arnould, O.; Beauchene, J.; Clair, B. url  openurl
  Title The effect of the G-layer on the viscoelastic properties of tropical hardwoods Type Journal Article
  Year 2012 Publication Annals of Forest Science Abbreviated Journal Ann. Forest Sci.  
  Volume 69 Issue 3 Pages 399-408  
  Keywords Dma; G-layer; Reaction wood; Tropical wood; Viscoelasticity  
  Abstract · Context and aim This study aimed to examine the effect of the tension wood G-layer on the viscoelastic properties of wood. · Methods Tension wood and opposite wood samples were obtained from six French Guianese tropical rainforest species (Sextonia rubra, Ocotea guyanensis, Inga alba, Tachigali melinoni, Iyranthera sagotiana and Virola michelii); the tension wood of the former three of these species had a Glayer, whilst the tension wood from the latter three had no Glayer. Tensile dynamic mechanical analysis (DMA) was performed on green never dried wood samples in the longitudinal direction with samples submerged in a water bath at a temperature (30°C) and frequency (1 Hz) representative of the conditions experienced by wood within a living tree. Then, DMA was repeated with samples conditioned to an air-dried state. Finally, samples were oven-dried to measure longitudinal shrinkage. · Results Tension wood did not always have a higher longitudinal storage (elastic) modulus than opposite wood from the same tree regardless of the presence or absence of a G-layer. For the species containing a G-layer, tension wood had a higher damping coefficient and experienced a greater longitudinal shrinkage upon drying than opposite wood from the same species. No difference was found in damping coefficients between tension wood and opposite wood for the species that had no G-layer. · Conclusion It is proposed that the different molecular composition of the G-layer matrix has an influence on the viscoelasticity of wood, even if a biomechanical gain is not yet clear. This study shows that rheological properties and longitudinal shrinkage can be used to detect the presence of a G-layer in tension wood. © INRA/Springer-Verlag France 2011.  
  Address UMR Ecologie des Forêts de Guyane (ECOFOG), CIRAD, Kourou, French Guiana  
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  ISSN 12864560 (Issn) ISBN Medium  
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  Notes Export Date: 20 June 2012; Source: Scopus; Coden: Afosf; doi: 10.1007/s13595-011-0164-1; Language of Original Document: English; Correspondence Address: McLean, J.P.; Forest Products Research Institute, Edinburgh Napier University, Merchiston Campus, Edinburgh EH10 5DT, United Kingdom; email: p.mclean@napier.ac.uk Approved no  
  Call Number EcoFoG @ webmaster @ Serial 404  
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Author (down) McClure, M.; Chouteau, M.; Dejean, A. openurl 
  Title Territorial aggressiveness on the arboreal ant Azteca alfari by Camponotus blandus in French Guiana due to behavioural constraints Type Journal Article
  Year 2008 Publication Comptes Rendus Biologies Abbreviated Journal C. R. Biol.  
  Volume 331 Issue 9 Pages 663-667  
  Keywords Azteca alfari (Dolichoderinae); Camponotus blandus (Formicinae); foraging; rhythm of activity; territorial aggressiveness  
  Abstract This study reports new information on interactions between two sympatric ant species, the plant-ant Azteca alfari (Dolichoderinae) living in association with the myrmecophyte Cecropia obtusa (Cecropiaceae) and Camponotus blandus (Formicinae), a ground-nesting, arboreal-foraging species. Workers of A. alfari forage only on the foliage and the tipper parts of the trunk of their host Cecropia, while C. blandus nests in the ground but frequently forages and patrols pioneer tree foliage, including Cecropia. The activity pattern of A. alfari and the number of C. blandus on Cecropia obtusa was monitored hourly during a two-day period in a disturbed area in French Guiana. The maximum activity of C. blandus occurred between 8:30 and 12:30, at which time A. alfari had retreated within the domatia and were least present on the trunks. Even though aggressive confrontations were observed, C. blandus workers often initiate confrontations but do not prey on A. alfari nor exploit food bodies produced by Cecropia, the principal food source of A. alfari. Hence hostility appears to be the result of territoriality. Differences in their foraging rhythms are proposed as promoting resource and territory partitioning in this ant assemblage.  
  Address [McClure, Melanie] Concordia Univ, Dept Biol, Montreal, PQ H4B 1R6, Canada, Email: m_mcclur@alcor.concordia.ca  
  Corporate Author Thesis  
  Publisher ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER Place of Publication Editor  
  Language Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 1631-0691 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000259290200004 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 130  
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Author (down) Ménard, L.; McKey, D.; Mühlen, G.S.; Clair, B.; Rowe, N.P. pdf  url
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  Title The Evolutionary Fate of Phenotypic Plasticity and Functional Traits under Domestication in Manioc: Changes in Stem Biomechanics and the Appearance of Stem Brittleness Type Journal Article
  Year 2013 Publication PLoS ONE Abbreviated Journal PLoS ONE  
  Volume 8 Issue 9 Pages e74727  
  Keywords  
  Abstract Domestication can influence many functional traits in plants, from overall life-history and growth form to wood density and cell wall ultrastructure. Such changes can increase fitness of the domesticate in agricultural environments but may negatively affect survival in the wild. We studied effects of domestication on stem biomechanics in manioc by comparing domesticated and ancestral wild taxa from two different regions of greater Amazonia. We compared mechanical properties, tissue organisation and wood characteristics including microfibril angles in both wild and domesticated plants, each growing in two different habitats (forest or savannah) and varying in growth form (shrub or liana). Wild taxa grew as shrubs in open savannah but as lianas in overgrown and forested habitats. Growth form plasticity was retained in domesticated manioc. However, stems of the domesticate showed brittle failure. Wild plants differed in mechanical architecture between shrub and liana phenotypes, a difference that diminished between shrubs and lianas of the domesticate. Stems of wild plants were generally stiffer, failed at higher bending stresses and were less prone to brittle fracture compared with shrub and liana phenotypes of the domesticate. Biomechanical differences between stems of wild and domesticated plants were mainly due to changes in wood density and cellulose microfibril angle rather than changes in secondary growth or tissue geometry. Domestication did not significantly modify “large-scale” trait development or growth form plasticity, since both wild and domesticated manioc can develop as shrubs or lianas. However, “finer-scale” developmental traits crucial to mechanical stability and thus ecological success of the plant were significantly modified. This profoundly influenced the likelihood of brittle failure, particularly in long climbing stems, thereby also influencing the survival of the domesticate in natural situations vulnerable to mechanical perturbation. We discuss the different selective pressures that could explain evolutionary modifications of stem biomechanical properties under domestication in manioc. © 2013 Ménard et al.  
  Address CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, Kourou, French Guiana  
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  ISSN 19326203 (Issn) ISBN Medium  
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  Notes Export Date: 13 September 2013; Source: Scopus; Art. No.: e74727; Coden: Polnc; doi: 10.1371/journal.pone.0074727; Language of Original Document: English; Correspondence Address: Rowe, N. P.; Université Montpellier 2, UMR AMAP, Montpellier, France; email: nrowe@cirad.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 503  
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Author (down) Mayer, V.E.; Lauth, J.; Orivel, J. pdf  url
doi  openurl
  Title Convergent structure and function of mycelial galleries in two unrelated Neotropical plant-ants Type Journal Article
  Year 2017 Publication Insectes Sociaux Abbreviated Journal  
  Volume 64 Issue 3 Pages 365-371  
  Keywords  
  Abstract The construction process and use of galleries by Azteca brevis (Myrmicinae: Dolichoderinae) inhabiting Tetrathylacium macrophyllum (Salicaceae) were compared with Allomerus decemarticulatus (Myrmicinae: Solenopsidini) galleries on Hirtella physophora (Chrysobalanaceae). Though the two ant species are phylogenetically distant, the gallery structure seems to be surprisingly similar and structurally convergent: both are pierced with numerous holes and both ant species use Chaetothyrialean fungi to strengthen the gallery walls. Al. decemarticulatus is known to use the galleries for prey capture and whether this is also the case for Az. brevis was tested in field experiments. We placed Atta workers as potential prey/threat on the galleries and recorded the behaviour of both ant species. We found considerable behavioural differences between them: Al. decemarticulatus was quicker and more efficient at capture than was Az. brevis. While most Atta workers were captured after the first 5 min by Al. decemarticulatus, significantly fewer were captured by Az. brevis even after 20 min. Moreover, the captured Atta were sometimes simply discarded and not taken to the nest by Az. brevis. As a consequence, the major function of the galleries built by Az. brevis may, therefore, be defense against intruders in contrast to Al. decemarticulatus which uses them mainly for prey capture. This may be due to a higher need for protein in Al. decemarticulatus compared to coccid-raising Az. brevis.  
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  ISSN 1420-9098 ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Mayer2017 Serial 784  
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Author (down) Maurice, L.; López, F.; Becerra, S.; Jamhoury, H.; Le Menach, K.; Dévier, M.-H.; Budzinski, H.; Prunier, J.; Juteau-Martineau, G.; Ochoa-Herrera, V.; Quiroga, D.; Schreck, E. doi  openurl
  Title Drinking water quality in areas impacted by oil activities in Ecuador: Associated health risks and social perception of human exposure Type Journal Article
  Year 2019 Publication Science of the Total Environment Abbreviated Journal Sci. Total Environ.  
  Volume 690 Issue Pages 1203-1217  
  Keywords Demineralized waters; Domestic waters; Hydrocarbons; Metal(loid)s; Oil activities; Social risk perception; Benzene refining; Health; Health risks; Hydrocarbons; Petroleum refineries; Petroleum refining; Polycyclic aromatic hydrocarbons; Potable water; Risk assessment; Risk perception; Toluene; Trace elements; Water quality; Water wells; Zinc; Arsenic concentration; Demineralized water; Domestic water; Information sources; Living conditions; Microbiological analysis; Natural backgrounds; Oil activities; Water distribution systems  
  Abstract The unregulated oil exploitation in the Northern Ecuadorian Amazon Region (NEAR), mainly from 1964 to the 90's, led to toxic compounds largely released into the environment. A large majority of people living in the Amazon region have no access to drinking water distribution systems and collects water from rain, wells or small streams. The concentrations of major ions, trace elements, PAHs (polycyclic aromatic hydrocarbons) and BTEX (benzene, toluene, ethylbenzene, xylenes) were analyzed in different water sources to evaluate the impacts of oil extraction and refining. Samples were taken from the NEAR and around the main refinery of the country (Esmeraldas Oil Refinery/State Oil Company of Ecuador) and were compared with domestic waters from the Southern region, not affected by petroleum activities. In most of the samples, microbiological analysis revealed a high level of coliforms representing significant health risks. All measured chemical compounds in waters were in line with national and international guidelines, except for manganese, zinc and aluminum. In several deep-water wells, close to oil camps, toluene concentrations were higher than the natural background while PAHs concentrations never exceeded individually 2 ng·L−1. Water ingestion represented 99% of the total exposure pathways for carcinogenic and non-carcinogenic elements (mainly zinc) in adults and children, while 20% to 49% of the Total Cancer Risk was caused by arsenic concentrations. The health index (HI) indicates acceptable chronic effects for domestic use according the US-EPA thresholds. Nevertheless, these limits do not consider the cocktail effects of metallic and organic compounds. Furthermore, they do not include the social determinants of human exposure, such as socio-economic living conditions or vulnerability. Most (72%) of interviewed families knew sanitary risks but a discrepancy was observed between knowledge and action: religious beliefs, cultural patterns, information sources, experience and emotions play an important role front to exposure. © 2019  
  Address Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel HillNC 2759, United States  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
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  ISSN 00489697 (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 877  
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Author (down) Mathieu, A.; Letort, V.; Cournède, P.H.; Zhang, B.G.; Heuret, P.; De Reffye, P. url  openurl
  Title Oscillations in functional structural plant growth models Type Journal Article
  Year 2012 Publication Mathematical Modelling of Natural Phenomena Abbreviated Journal  
  Volume 7 Issue 6 Pages 47-66  
  Keywords Cecropia trees; Cucumber plant; Dynamic system of plant growth; Functional-structural plant models; GreenLab  
  Abstract The dynamic model of plant growth GreenLab describes plant architecture and functional growth at the level of individual organs. Structural development is controlled by formal grammars and empirical equations compute the amount of biomass produced by the plant, and its partitioning among the growing organs, such as leaves, stems and fruits. The number of organs initiated at each time step depends on the trophic state of the plant, which is evaluated by the ratio of biomass available in plant to the demand of all the organs. The control of the plant organogenesis by this variable induces oscillations in the simulated plant behaviour. The mathematical framework of the GreenLab model allows to compute the conditions for the generation of oscillations and the value of the period according to the set of parameters. Two case-studies are presented, corresponding to emergence of oscillations associated to fructification and branching. Similar alternating patterns are commonly reported by botanists. In this article, two examples were selected: alternate patterns of fruits in cucumber plants and alternate appearances of branches in Cecropia trees. The model was calibrated from experimental data collected on these plants. It shows that a simple feedback hypothesis of trophic control on plant structure allows the emergence of cyclic patterns corresponding to the observed ones. © EDP Sciences, 2012.  
  Address CIRAD, UMR AMAP, Montpellier, France  
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  Notes Export Date: 27 December 2012; Source: Scopus Approved no  
  Call Number EcoFoG @ webmaster @ Serial 452  
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Author (down) Masse, P.S.M.; Kenne, M.; Mony, R.; Dejean, A.; Tindo, M. openurl 
  Title Initial behavior in colony fragments of an introduced population of the invasive ant Wasmannia auropunctata Type Journal Article
  Year 2011 Publication Comptes Rendus Biologies Abbreviated Journal C. R. Biol.  
  Volume 334 Issue 7 Pages 572-576  
  Keywords Aggregation; Death feigning; Thanatosis; Worker transportation; Biological invasion; Little fire ant  
  Abstract We investigated in the laboratory the initial behavior of propagules of the invasive ant Wasmannia auropunctata in Cameroon where it has been introduced. Both workers and queens at first feigned death (thanatosis), and then the workers slowly moved around the experimental arena; the queens did the same about 10 seconds later. Each queen antennated selected workers that then aggregated together by grasping the hind leg of another ant with their mandibles. When encountering the queen again, the lead worker climbed up the queen's hind leg and onto her back, followed by some other individuals. The remaining workers followed the queen to a location in the experimental arena. When brood was present, the workers transferred it to this location. Orphaned workers did not aggregate, but gathered the brood together and took care of it. By permitting propagules to survive, these behaviors likely contribute to the success of W. auropunctata as an invader. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.  
  Address [Kenne, M; Mony, R; Tindo, M] Univ Douala, Fac Sci, Dept Biol Organismes Anim, Douala, Cameroon, Email: tindodouala@yahoo.com  
  Corporate Author Thesis  
  Publisher Elsevier France-Editions Scientifiques Medicales Elsevier Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1631-0691 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000293673300010 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 332  
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Author (down) Martos, F.; Dulormne, M.; Pailler, T.; Bonfante, P.; Faccio, A.; Fournel, J.; Dubois, M.-P.; Selosse, M.-A. doi  openurl
  Title Independent recruitment of saprotrophic fungi as mycorrhizal partners by tropical achlorophyllous orchids Type Journal Article
  Year 2009 Publication New Phytologist Abbreviated Journal New Phytologist  
  Volume 184 Issue 3 Pages 668-681  
  Keywords Mycoheterotrophy; Mycorrhizas; Orchids; Rainforests; Saprotrophic fungi; Stable isotopes  
  Abstract Mycoheterotrophic orchids have adapted to shaded forest understory by shifting to achlorophylly and receiving carbon from their mycorrhizal fungi. In temperate forests, they associate in a highly specific way with fungi forming ectomycorrhizas on nearby trees, and exploiting tree photosynthates. However, many rainforests lack ectomycorrhizal fungi, and there is evidence that some tropical Asiatic species associate with saprotrophic fungi. To investigate this in different geographic and phylogenetic contexts, we identified the mycorrhizal fungi supporting two tropical mycoheterotrophic orchids from Mascarene (Indian Ocean) and Caribbean islands. We tested their possible carbon sources by measuring natural nitrogen (15N) and carbon (13C) abundances. Saprotrophic basidiomycetes were found: Gastrodia similis associates with a wood-decaying Resinicium (Hymenochaetales); Wullschlaegelia aphylla associates with both litter-decaying Gymnopus and Mycena species, whose rhizomorphs link orchid roots to leaf litter. The 15N and 13C abundances make plausible food chains from dead wood to G. similis and from dead leaves to W. aphylla. We propose that temperature and moisture in rainforests, but not in most temperate forests, may favour sufficient saprotrophic activity to support development of mycoheterotrophs. By enlarging the spectrum of mycorrhizal fungi and the level of specificity in mycoheterotrophic orchids, this study provides new insights on orchid and mycorrhizal biology in the tropics. © 2009 New Phytologist.  
  Address Dipartimento di Biologia Vegetale dell'Università, Istituto per la Protezione Delle Piante – CNR, Viale Mattioli 25, I-10125 Torino, Italy  
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  Notes Cited By :65; Export Date: 7 February 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 728  
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