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Author Revel, M.; Dejean, A.; Cereghino, R.; Roux, O. pdf  openurl
  Title An Assassin among Predators: The Relationship between Plant-Ants, Their Host Myrmecophytes and the Reduviidae Zelus annulosus Type Journal Article
  Year 2010 Publication PLoS One Abbreviated Journal PLoS One  
  Volume 5 Issue (down) 10 Pages e13110  
  Keywords  
  Abstract Tropical plants frequently live in association with ants that protect their foliage from defoliators. Among them, myrmecophytes have evolved mutualisms with a limited number of plant-ants that they shelter and feed, and, in return, benefit from some protection. Hirtella physophora (Chrysobalanaceae), for example, houses Allomerus decemarticulatus (Myrmicinae) that build gallery-shaped traps to catch large prey. In French Guiana, we frequently observed the assassin bug Zelus annulosus (Reduviidae, Harpactorinae) on the leaves of H. physophora. Here, we studied the distribution of Zelus annulosus among understory plants in the Guianese rainforest and found it only on pubescent plants, including H. Physophora, whether or not it was sheltering an A. decemarticulatus colony, but only rarely on other myrmecophytes. The relationship between Z. annulosus and its host plants is, then, also mutualistic, as the plant trichomes act as an enemy-free space protecting the nymphs from large predatory ants, while the nymphs protect their host-plants from herbivorous insects. Through their relationship with A. decemarticulatus colonies, Z. annulosus individuals are protected from army ants, while furnishing nothing in return. In those cases where H. physophora sheltered both an A. decemarticulatus colony and Z. annulosus nymphs, certain plant individuals repeatedly sheltered nymphs, indicating that female bugs may select not only pubescent plants but also particular H. physophora treelets having characteristics more favourable to the development of their progeny.  
  Address [Revel, Messika; Dejean, Alain; Roux, Olivier] Ecofog Ecol Forets Guyane, CNRS, UMR 8172, Kourou, France, Email: olivier.roux@ecofog.gf  
  Corporate Author Thesis  
  Publisher PUBLIC LIBRARY SCIENCE Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000282359300014 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 29  
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Author Delph, L.F.; Arntz, A.M.; Scotti-Saintagne, C.; Scotti, I. openurl 
  Title The Genomic Architecture of Sexual Dimorphism in the Dioecious Plant Silene Latifolia Type Journal Article
  Year 2010 Publication Evolution Abbreviated Journal Evolution  
  Volume 64 Issue (down) 10 Pages 2873-2886  
  Keywords Artificial selection; genetic correlations; linkage map; sex-specific expression; sexual conflict  
  Abstract Evaluating the genetic architecture of sexual dimorphism can aid our understanding of the extent to which shared genetic control of trait variation versus sex-specific control impacts the evolutionary dynamics of phenotypic change within each sex. We performed a QTL analysis on Silene latifolia to evaluate the contribution of sex-specific QTL to phenotypic variation in 46 traits, whether traits involved in trade-offs had colocalized QTL, and whether the distribution of sex-specific loci can explain differences between the sexes in their variance/covariance matrices. We used a backcross generation derived from two artificial-selection lines. We found that sex-specific QTL explained a significantly greater percent of the variation in sexually dimorphic traits than loci expressed in both sexes. Genetically correlated traits often had colocalized QTL, whose signs were in the expected direction. Lastly, traits with different genetic correlations within the sexes displayed a disproportionately high number of sex-specific QTL, and more QTL co-occurred in males than females, suggesting greater trait integration. These results show that sex differences in QTL patterns are congruent with theory on the resolution of sexual conflict and differences based on G-matrix results. They also suggest that trade-offs and trait integration are likely to affect males more than females.  
  Address [Delph, Lynda F.; Arntz, A. Michele; Scotti, Ivan] Indiana Univ, Dept Biol, Bloomington, IN 47405 USA, Email: ldelph@indiana.edu  
  Corporate Author Thesis  
  Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0014-3820 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000282573800006 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 31  
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Author Lebrini, M.; Robert, F.; Vezin, H.; Roos, C. openurl 
  Title Electrochemical and quantum chemical studies of some indole derivatives as corrosion inhibitors for C38 steel in molar hydrochloric acid Type Journal Article
  Year 2010 Publication Corrosion Science Abbreviated Journal Corrosion Sci.  
  Volume 52 Issue (down) 10 Pages 3367-3376  
  Keywords Steel; EIS; Raman spectroscopy; Polarization; Acid inhibition  
  Abstract A comparative study of 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane) as inhibitors for C38 steel corrosion in 1 M HCl solution at 25 degrees C was carried out. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of different concentrations of these inhibitors. The OCP as a function of time were also established. Cathodic and anodic polarization curves show that norharmane and harmane are a mixed-type inhibitors. Adsorption of indole derivatives on the C38 steel surface, in 1 M HCl solution, follows the Langmuir adsorption isotherm model. The Delta G degrees(ads) values were calculated and discussed. The potential of zero charge (PZC) of the C38 steel in inhibited solution was studied by the EIS method, and a mechanism for the adsorption process was proposed. Raman spectroscopy confirmed that indole molecules strongly adsorbed onto the steel surface. The electronic properties of indole derivates, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR). (C) 2010 Elsevier Ltd. All rights reserved.  
  Address [Robert, F.; Roos, C.] UAG UMR ECOFOG, Lab Mat & Mol Milieu Amazonien, Cayenne 97337, French Guiana, Email: christophe.roos@guyane.univ-ag.fr  
  Corporate Author Thesis  
  Publisher PERGAMON-ELSEVIER SCIENCE LTD Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0010-938X ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000281315500026 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 44  
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Author Dejean, A.; Leroy, C.; Corbara, B.; Cereghino, R.; Roux, O.; Herault, B.; Rossi, V.; Guerrero, R.J.; Delabie, J.H.C.; Orivel, J.; Boulay, R. openurl 
  Title A temporary social parasite of tropical plant-ants improves the fitness of a myrmecophyte Type Journal Article
  Year 2010 Publication Naturwissenschaften Abbreviated Journal Naturwissenschaften  
  Volume 97 Issue (down) 10 Pages 925-934  
  Keywords Ant-plant relationships; Biotic defense; Parasites of mutualisms; Temporary social parasites; Azteca; Cecropia  
  Abstract Myrmecophytes offer plant-ants a nesting place in exchange for protection from their enemies, particularly defoliators. These obligate ant-plant mutualisms are common model systems for studying factors that allow horizontally transmitted mutualisms to persist since parasites of ant-myrmecophyte mutualisms exploit the rewards provided by host plants whilst providing no protection in return. In pioneer formations in French Guiana, Azteca alfari and Azteca ovaticeps are known to be mutualists of myrmecophytic Cecropia (Cecropia ants). Here, we show that Azteca andreae, whose colonies build carton nests on myrmecophytic Cecropia, is not a parasite of Azteca-Cecropia mutualisms nor is it a temporary social parasite of A. alfari; it is, however, a temporary social parasite of A. ovaticeps. Contrarily to the two mutualistic Azteca species that are only occasional predators feeding mostly on hemipteran honeydew and food bodies provided by the host trees, A. andreae workers, which also attend hemipterans, do not exploit the food bodies. Rather, they employ an effective hunting technique where the leaf margins are fringed with ambushing workers, waiting for insects to alight. As a result, the host trees' fitness is not affected as A. andreae colonies protect their foliage better than do mutualistic Azteca species resulting in greater fruit production. Yet, contrarily to mutualistic Azteca, when host tree development does not keep pace with colony growth, A. andreae workers forage on surrounding plants; the colonies can even move to a non-Cecropia tree.  
  Address [Dejean, Alain; Leroy, Celine; Roux, Olivier; Orivel, Jerome] CNRS, F-97379 Kourou, France, Email: alain.dejean@wanadoo.fr  
  Corporate Author Thesis  
  Publisher SPRINGER Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-1042 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000282094100006 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 77  
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Author Bourguignon, T.; Sobotnik, J.; Lepoint, G.; Martin, J.M.; Roisin, Y. openurl 
  Title Niche differentiation among neotropical soldierless soil-feeding termites revealed by stable isotope ratios Type Journal Article
  Year 2009 Publication Soil Biology & Biochemistry Abbreviated Journal Soil Biol. Biochem.  
  Volume 41 Issue (down) 10 Pages 2038-2043  
  Keywords Anoplotermes; Termitidae; Isoptera; Resource partitioning; Food web; Decomposition gradient  
  Abstract Termites represent one of the most abundant belowground animal taxa in tropical rainforests, where their species richness is much higher than in any other ecosystem. This high diversity in soil ecosystems is however difficult to explain by classical Hutchinsonian niche theory, as there is little evidence for spatial or temporal separation between species. Using delta C-13 and delta N-15 isotopic ratios, we tested if resource partitioning along the humification gradient occurs; in neotropical soldierless termites of the Anoplotermes-group. Two distinct sites were investigated to check if interspecific differences are transposable between sites. Significant differences in delta N-15 were found between species of the Anoplotermes-group. Although some species displayed higher intersite delta N-15 variation than others, species-average delta N-15 values for both sites were highly correlated, showing that sympatric soldierless soil-feeding termites feed on distinct components of the soil. Our data also suggest that some species are more likely to shift along this gradient than others, in response to overall habitat conditions or to the presence of competitors. Feeding niche differentiation can therefore account for the high species richness and diversity of soldierless soil-feeding termites in neotropical rainforests. (C) 2009 Elsevier Ltd. All rights reserved.  
  Address [Bourguignon, Thomas; Roisin, Yves] Univ Libre Bruxelles, B-1050 Brussels, Belgium, Email: yroisin@ulb.ac.be  
  Corporate Author Thesis  
  Publisher PERGAMON-ELSEVIER SCIENCE LTD Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0038-0717 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000271047800003 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 98  
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Author Cachet, N.; Hoakwie, F.; Bertani, S.; Bourdy, G.; Deharo, E.; Stien, D.; Houel, E.; Gornitzka, H.; Fillaux, J.; Chevalley, S.; Valentin, A.; Jullian, V. openurl 
  Title Antimalarial Activity of Simalikalactone E, a New Quassinoid from Quassia amara L. (Simaroubaceae) Type Journal Article
  Year 2009 Publication Antimicrobial Agents and Chemotherapy Abbreviated Journal Antimicrob. Agents Chemother.  
  Volume 53 Issue (down) 10 Pages 4393-4398  
  Keywords  
  Abstract We report the isolation and identification of a new quassinoid named simalikalactone E (SkE), extracted from a widely used Amazonian antimalarial remedy made out of Quassia amara L. (Simaroubaceae) leaves. This new molecule inhibited the growth of Plasmodium falciparum cultured in vitro by 50%, in the concentration range from 24 to 68 nM, independently of the strain sensitivity to chloroquine. We also showed that this compound was able to decrease gametocytemia with a 50% inhibitory concentration sevenfold lower than that of primaquine. SkE was found to be less toxic than simalikalactone D (SkD), another antimalarial quassinoid from Q. amara, and its cytotoxicity on mammalian cells was dependent on the cell line, displaying a good selectivity index when tested on nontumorogenic cells. In vivo, SkE inhibited murine malaria growth of Plasmodium vinckei petteri by 50% at 1 and 0.5 mg/kg of body weight/day, by the oral or intraperitoneal routes, respectively. The contribution of quassinoids as a source of antimalarial molecules needs therefore to be reconsidered.  
  Address [Cachet, N.; Hoakwie, F.; Bourdy, G.; Deharo, E.; Chevalley, S.; Valentin, A.; Jullian, V.] Univ Toulouse, UPS, Lab Pharmacochim Subst Nat & Pharmacophores Redox, UMR 152, F-31062 Toulouse 9, France, Email: jullian@cict.fr  
  Corporate Author Thesis  
  Publisher AMER SOC MICROBIOLOGY Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0066-4804 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000270020600047 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 103  
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Author Almeras, T. openurl 
  Title Mechanical analysis of the strains generated by water tension in plant stems. Part II: strains in wood and bark and apparent compliance Type Journal Article
  Year 2008 Publication Tree Physiology Abbreviated Journal Tree Physiol.  
  Volume 28 Issue (down) 10 Pages 1513-1523  
  Keywords biomechanics; calibration; diurnal strains; mechanical model; multilayer cylinder; water potential  
  Abstract Tree steins shrink in diameter during the day and swell during the night in response to changes in water tension in the xylem. Stein shrinkage can easily be measured in a nondestructive way, to derive continuous information about tree water status. The relationship between the strain and the change in water tension can be evaluated by empirical calibrations, or can be related to the structure of the plant. A mechanical analysis was performed to make this relationship explicit. The stem is modeled as a cylinder made of multiple layers of tissues, including heartwood, sapwood, and inner and outer bark. The effect of changes in water tension on the apparent strain at the surface of a tissue is quantified as a function of parameters defining stem anatomy and the mechanical properties of the tissues. Various possible applications in the context of tree physiology are suggested.  
  Address INRA UMR Ecofog, Kourou 97379, French Guiana, Email: t_almeras@hotmail.com  
  Corporate Author Thesis  
  Publisher HERON PUBLISHING Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0829-318X ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000260027200009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 129  
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Author Grangier, J.; Dejean, A.; Male, P.J.G.; Orivel, J. openurl 
  Title Indirect defense in a highly specific ant-plant mutualism Type Journal Article
  Year 2008 Publication Naturwissenschaften Abbreviated Journal Naturwissenschaften  
  Volume 95 Issue (down) 10 Pages 909-916  
  Keywords Allomerus decemarticulatus; Hirtella physophora; indirect defense; myrmecophytes; optimal defense theory  
  Abstract Although associations between myrmecophytes and their plant ants are recognized as a particularly effective form of protective mutualism, their functioning remains incompletely understood. This field study examined the ant-plant Hirtella physophora and its obligate ant associate Allomerus decemarticulatus. We formulated two hypotheses on the highly specific nature of this association: (1) Ant presence should be correlated with a marked reduction in the amount of herbivory on the plant foliage; (2) ant activity should be consistent with the “optimal defense” theory predicting that the most vulnerable and valuable parts of the plant are the best defended. We validated the first hypothesis by demonstrating that for ant-excluded plants, expanding leaves, but also newly matured ones in the long term, suffered significantly more herbivore damage than ant-inhabited plants. We showed that A. decemarticulatus workers represent both constitutive and inducible defenses for their host, by patrolling its foliage and rapidly recruiting nestmates to foliar wounds. On examining how these activities change according to the leaves' developmental stage, we found that the number of patrolling ants dramatically decreased as the leaves matured, while leaf wounds induced ant recruitment regardless of the leaf's age. The resulting level of these indirect defenses was roughly proportional to leaf vulnerability and value during its development, thus validating our second hypothesis predicting optimal protection. This led us to discuss the factors influencing ant activity on the plant's surface. Our study emphasizes the importance of studying both the constitutive and inducible components of indirect defense when evaluating its efficacy and optimality.  
  Address [Grangier, Julien; Dejean, Alain; Male, Pierre-Jean G.; Orivel, Jerome] Univ Toulouse 3, Lab Evolut & Diversite Biol, CNRS, UMR 5174, F-31062 Toulouse 9, France, Email: grangier@cict.fr  
  Corporate Author Thesis  
  Publisher SPRINGER Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-1042 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000259737600002 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 207  
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Author Jaouen, G.; Almeras, T.; Coutand, C.; Fournier, M. openurl 
  Title How to determine sapling buckling risk with only a few measurements Type Journal Article
  Year 2007 Publication American Journal of Botany Abbreviated Journal Am. J. Bot.  
  Volume 94 Issue (down) 10 Pages 1583-1593  
  Keywords biomechanics; critical buckling height; French Guiana; risk factor; sapling; stem form; tropical rain forest; trunk volume  
  Abstract Tree buckling risk (actual height/critical buckling height) is an important biomechanical trait of plant growth strategies, and one that contributes to species coexistence. To estimate the diversity of this trait among wide samples, a method that minimizes damage to the plants is necessary. On the basis of the rarely used, complete version of Greenhill's model (1881, Proceedings of the Cambridge Philosophical Society 4(2): 65-73), we precisely measured all the necessary parameters on a sample of 236 saplings of 16 species. Then, using sensitivity (variance) analysis, regressions between successive models for risk factors and species ranks and the use of these models on samples of self- and nonself-supporting saplings, we tested different degrees of simplification up to the most simple and widely used formula that assumes that the tree is a cylindrical homogeneous pole. The size factor had the greatest effect on buckling risk, followed by the form factor and the modulus of elasticity of the wood. Therefore, estimates of buckling risk must consider not only the wood properties but especially the form factor. Finally, we proposed a simple but accurate method of assessing tree buckling risk that is applicable to a wide range of samples and that requires mostly nondestructive measurements.  
  Address INRA, UMR Ecol Forets Guyane, Kourou 97379, French Guiana, Email: jaouen-g@kourou.cirad.fr  
  Corporate Author Thesis  
  Publisher BOTANICAL SOC AMER INC Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-9122 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000251466600001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 148  
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Author Gonzalez, M.A.; Baraloto, C.; Engel, J.; Mori, S.A.; Petronelli, P.; Riera, B.; Roger, A.; Thebaud, C.; Chave, J. pdf  openurl
  Title Identification of Amazonian Trees with DNA Barcodes Type Journal Article
  Year 2009 Publication PLoS One Abbreviated Journal PLoS One  
  Volume 4 Issue (down) 10 Pages e7483  
  Keywords  
  Abstract Background: Large-scale plant diversity inventories are critical to develop informed conservation strategies. However, the workload required for classic taxonomic surveys remains high and is particularly problematic for megadiverse tropical forests. Methodology/Principal Findings: Based on a comprehensive census of all trees in two hectares of a tropical forest in French Guiana, we examined whether plant DNA barcoding could contribute to increasing the quality and the pace of tropical plant biodiversity surveys. Of the eight plant DNA markers we tested (rbcLa, rpoC1, rpoB, matK, ycf5, trnL, psbA-trnH, ITS), matK and ITS had a low rate of sequencing success. More critically, none of the plastid markers achieved a rate of correct plant identification greater than 70%, either alone or combined. The performance of all barcoding markers was noticeably low in few species-rich clades, such as the Laureae, and the Sapotaceae. A field test of the approach enabled us to detect 130 molecular operational taxonomic units in a sample of 252 juvenile trees. Including molecular markers increased the identification rate of juveniles from 72% (morphology alone) to 96% (morphology and molecular) of the individuals assigned to a known tree taxon. Conclusion/Significance: We conclude that while DNA barcoding is an invaluable tool for detecting errors in identifications and for identifying plants at juvenile stages, its limited ability to identify collections will constrain the practical implementation of DNA-based tropical plant biodiversity programs.  
  Address  
  Corporate Author Thesis  
  Publisher PUBLIC LIBRARY SCIENCE Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000270880700009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 189  
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