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Author Dejean, A. pdf  openurl
  Title Prey Capture Behavior in an Arboreal African Ponerine Ant Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS One  
  Volume (up) 6 Issue 5 Pages e19837  
  Keywords  
  Abstract I studied the predatory behavior of Platythyrea conradti, an arboreal ponerine ant, whereas most species in this subfamily are ground-dwelling. The workers, which hunt solitarily only around dusk, are able to capture a wide range of prey, including termites and agile, nocturnal insects as well as diurnal insects that are inactive at that moment of the Nyctemeron, resting on tree branches or under leaves. Prey are captured very rapidly, and the antennal palpation used by ground-dwelling ponerine species is reduced to a simple contact; stinging occurs immediately thereafter. The venom has an instant, violent effect as even large prey (up to 30 times the weight of a worker) never struggled after being stung. Only small prey are not stung. Workers retrieve their prey, even large items, singly. To capture termite workers and soldiers defending their nest entrances, ant workers crouch and fold their antennae backward. In their role as guards, the termites face the crouching ants and end up by rolling onto their backs, their legs batting the air. This is likely due to volatile secretions produced by the ants' mandibular gland. The same behavior is used against competing ants, including territorially-dominant arboreal species that retreat further and further away, so that the P. conradti finally drive them from large, sugary food sources.  
  Address [Dejean, Alain] CNRS, Ecol Forets Guyane UMR 8172, Kourou, France, Email: alain.dejean@wanadoo.fr  
  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:000290483600033 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 316  
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Author Brouard, O.; Le Jeune, A.H.; Leroy, C.; Cereghino, R.; Roux, O.; Pelozuelo, L.; Dejean, A.; Corbara, B.; Carrias, J.F. pdf  openurl
  Title Are Algae Relevant to the Detritus-Based Food Web in Tank-Bromeliads? Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS One  
  Volume (up) 6 Issue 5 Pages e20129  
  Keywords  
  Abstract We assessed the occurrence of algae in five species of tank-bromeliads found in contrasting environmental sites in a Neotropical, primary rainforest around the Nouragues Research Station, French Guiana. The distributions of both algal abundance and biomass were examined based on physical parameters, the morphological characteristics of bromeliad species and with regard to the structure of other aquatic microbial communities held in the tanks. Algae were retrieved in all of the bromeliad species with mean densities ranging from similar to 10(2) to 10(4) cells/mL. Their biomass was positively correlated to light exposure and bacterial biomass. Algae represented a tiny component of the detrital food web in shaded bromeliads but accounted for up to 30 percent of the living microbial carbon in the tanks of Catopsis berteroniana, located in a highly exposed area. Thus, while nutrient supplies are believed to originate from wind-borne particles and trapped insects (i.e., allochtonous organic matter), our results indicate that primary producers (i.e., autochtonous organic matter) are present in this insectivorous bromeliad. Using a 24-h incubation of size-fractionated and manipulated samples from this plant, we evaluated the impact of mosquito foraging on algae, other microorganisms and rotifers. The prey assemblages were greatly altered by the predation of mosquito larvae. Grazing losses indicated that the dominant algal taxon, Bumilleriopsis sp., like protozoa and rotifers, is a significant part of the diet of mosquito larvae. We conclude that algae are a relevant functional community of the aquatic food web in C. berteroniana and might form the basis of a complementary non-detrital food web.  
  Address [Brouard, Olivier; Le Jeune, Anne-Helene; Corbara, Bruno; Carrias, Jean-Francois] Univ Clermont Ferrand, CNRS, Lab Microorganismes Genome & Environm, LMGE,UMR 6023, Aubiere, France, Email: j-francois.carrias@univ-bpclermont.fr  
  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:000290720200066 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 319  
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Author Roux, O.; Cereghino, R.; Solano, P.J.; Dejean, A. pdf  openurl
  Title Caterpillars and Fungal Pathogens: Two Co-Occurring Parasites of an Ant-Plant Mutualism Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS One  
  Volume (up) 6 Issue 5 Pages e20538  
  Keywords  
  Abstract In mutualisms, each interacting species obtains resources from its partner that it would obtain less efficiently if alone, and so derives a net fitness benefit. In exchange for shelter (domatia) and food, mutualistic plant-ants protect their host myrmecophytes from herbivores, encroaching vines and fungal pathogens. Although selective filters enable myrmecophytes to host those ant species most favorable to their fitness, some insects can by-pass these filters, exploiting the rewards supplied whilst providing nothing in return. This is the case in French Guiana for Cecropia obtusa (Cecropiaceae) as Pseudocabima guianalis caterpillars (Lepidoptera, Pyralidae) can colonize saplings before the installation of their mutualistic Azteca ants. The caterpillars shelter in the domatia and feed on food bodies (FBs) whose production increases as a result. They delay colonization by ants by weaving a silk shield above the youngest trichilium, where the FBs are produced, blocking access to them. This probable temporal priority effect also allows female moths to lay new eggs on trees that already shelter caterpillars, and so to occupy the niche longer and exploit Cecropia resources before colonization by ants. However, once incipient ant colonies are able to develop, they prevent further colonization by the caterpillars. Although no higher herbivory rates were noted, these caterpillars are ineffective in protecting their host trees from a pathogenic fungus, Fusarium moniliforme (Deuteromycetes), that develops on the trichilium in the absence of mutualistic ants. Therefore, the Cecropia treelets can be parasitized by two often overlooked species: the caterpillars that shelter in the domatia and feed on FBs, delaying colonization by mutualistic ants, and the fungal pathogen that develops on old trichilia. The cost of greater FB production plus the presence of the pathogenic fungus likely affect tree growth.  
  Address [Roux, Olivier; Dejean, Alain] CNRS, Ecol Forets Guyane UMR 8172, Kourou, France, Email: olivier.roux@ird.fr  
  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:000291097600091 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 322  
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Author Lebrini, M.; Robert, F.; Blandinieres, P.A.; Roos, C. pdf  openurl
  Title Corrosion Inhibition by Isertia coccinea Plant Extract in Hydrochloric Acid Solution Type Journal Article
  Year 2011 Publication International Journal of Electrochemical Science Abbreviated Journal Int. J. Electrochem. Sci.  
  Volume (up) 6 Issue 7 Pages 2443-2460  
  Keywords Isertia coccinea; corrosion inhibitors; C38 steel; acidic media; adsorption  
  Abstract The effect of alkaloids extracted from Isertia coccinea plant (AEIC) on the corrosion of C38 steel in 1 M hydrochloric acid was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Potentiodynamic polarization curves indicated that the extract behave as mixed-type inhibitor. The experimental data obtained from EIS method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The inhibition efficiencies of the extract calculated by three methods show the same tendency. Inhibition was found to increase with increasing concentration of the plant extract. The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion of C38 steel in hydrochloric acid solution. The apparent activation energy of the process taking place in inhibitor presence was determined on the ground of four temperature values in the range from 25 degrees C to 55 degrees C using the data obtained by two independent methods. Theoretical fitting of different isotherms, Langmuir, Temkin and Frunkin, were tested to clarify the nature of adsorption.  
  Address [Lebrini, M.; Robert, F.; Blandinieres, P. A.; Roos, C.] UAG UMR ECOFOG, Lab Mat & Mol Milieu Amazonien, Cayenne 97337, French Guiana, Email: florent.robert@guyane.univ-ag.fr  
  Corporate Author Thesis  
  Publisher Electrochemical Science Group Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1452-3981 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000292331400014 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 324  
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Author Hibert, F.; Sabatier, D.; Andrivot, J.; Scotti-Saintagne, C.; Gonzalez, S.; Prévost, M.-F.; Grenand, P.; Chave, J.; Caron, H.; Richard-Hansen, C. pdf  url
openurl 
  Title Botany, genetics and ethnobotany: A crossed investigation on the elusive tapir's diet in French guiana Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS ONE  
  Volume (up) 6 Issue 10 Pages e25850  
  Keywords  
  Abstract While the populations of large herbivores are being depleted in many tropical rainforests, the importance of their trophic role in the ecological functioning and biodiversity of these ecosystems is still not well evaluated. This is due to the outstanding plant diversity that they feed upon and the inherent difficulties involved in observing their elusive behaviour. Classically, the diet of elusive tropical herbivores is studied through the observation of browsing signs and macroscopic analysis of faeces or stomach contents. In this study, we illustrate that the original coupling of classic methods with genetic and ethnobotanical approaches yields information both about the diet diversity, the foraging modalities and the potential impact on vegetation of the largest terrestrial mammal of Amazonia, the lowland tapir. The study was conducted in the Guianan shield, where the ecology of tapirs has been less investigated. We identified 92 new species, 51 new genera and 13 new families of plants eaten by tapirs. We discuss the relative contribution of our different approaches, notably the contribution of genetic barcoding, used for the first time to investigate the diet of a large tropical mammal, and how local traditional ecological knowledge is accredited and valuable for research on the ecology of elusive animals. © 2011 Hibert et al.  
  Address INRA, Université de Bordeaux, UMR1202 BIOGECO, Cestas, France  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 19326203 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 21 October 2011; Source: Scopus; Art. No.: e25850; doi: 10.1371/journal.pone.0025850; Language of Original Document: English; Correspondence Address: Hibert, F.; Direction Etudes et Recherches Guyane, Office National de la Chasse et de la Faune Sauvage, Kourou, French Guiana, France; email: fabricenz@gmail.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial 343  
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Author Lebrini, M.; Roos, C.; Vezin, H.; Robert, F. pdf  url
openurl 
  Title Electrochemical and theoretical studies of adsorption of some indole derivates at C38 Steel/Sulfuric acid interface as corrosion inhibitors Type Journal Article
  Year 2011 Publication International Journal of Electrochemical Science Abbreviated Journal Int.J.Electrochem.Sci.  
  Volume (up) 6 Issue 9 Pages 3844-3857  
  Keywords Acidic media; Adsorption; C38 steel; Corrosion inhibitors; Theoretical calculations  
  Abstract The inhibitive action of 9H-pyrido[3,4-b]indole (norharmane) and 1-Methyl-9H-pyrido[3,4-b]indole (harmane) on corrosion of C38 steel in 0.5 M H2SO4 solution was investigated through electrochemical techniques. The experimental results obtained revealed that these compounds inhibited the steel corrosion in acid solution for all concentrations studied. Polarization measurements indicate that the examined compounds act as a mixed inhibitor and its inhibition efficiency increases with inhibitor concentration. Data obtained from ac impedance technique show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE), has been used. The adsorption of used compounds on the steel surface obeys Langmuir's isotherm. The ΔG°ads values were calculated and discussed for both inhibitors. Significant correlations are obtained between inhibition efficiency and quantum chemical parameters using quantitative structure-activity relationship (QSAR) method. © 2011 by ESG.  
  Address Laboratoire de Chimie Organique et Macromoléculaire, UMR-CNRS 8009, USTL BâtC4, F-59655 Villeneuve d'Ascq Cedex, France  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 14523981 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 21 October 2011; Source: Scopus; Language of Original Document: English; Correspondence Address: Robert, F.; Laboratoire Matériaux et Molécules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana; email: florent.robert@guyane.univ-ag.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 347  
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Author Faustin, M.; Lebrini, M.; Robert, F.; Roos, C. pdf  url
openurl 
  Title Corrosion studies of C38 steel by alkaloids extract of a tropical plant type Type Journal Article
  Year 2011 Publication International Journal of Electrochemical Science Abbreviated Journal Int.J.Electrochem.Sci.  
  Volume (up) 6 Issue 9 Pages 4095-4113  
  Keywords Acidic media; C38 steel; Corrosion inhibitor; Plant extract  
  Abstract Alkaloids extract of Aspidosperma album was tested as corrosion inhibitor for C38 steel in 1 M HCl by using polarization and electrochemical impedance spectroscopy (EIS). Potentiodynamic polarization curves indicated that the plant extract behaves as mixed-type inhibitors. Impedance measurements showed that the double-layer capacitance decreased and charge-transfer resistance increased with increase in the inhibitors concentration and hence increasing in inhibition efficiency. The effect of temperature on the corrosion behavior of C38 steel in 1 M HCl with and without addition of plant extract was studied in the temperature range 25 – 55°C. The adsorption of the inhibitor molecules was in accordance with the Langmuir adsorption isotherm. The results obtained show that this plant extract could serve as an effective inhibitor for the corrosion of C38 steel in hydrochloric acid. © 2011 by ESG.  
  Address Laboratoire Matériaux et Molécules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 14523981 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 21 October 2011; Source: Scopus; Language of Original Document: English; Correspondence Address: Roos, C.; Laboratoire Matériaux et Molécules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana; email: florent.robert@guyane.univ-ag.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 348  
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Author Dejean, A.; Cereghino, R.; Carpenter, J.M.; Corbara, B.; Herault, B.; Rossi, V.; Leponce, M.; Orivel, J.; Bonal, D. pdf  url
openurl 
  Title Climate change impact on neotropical social wasps Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS ONE  
  Volume (up) 6 Issue 11 Pages e27004  
  Keywords  
  Abstract Establishing a direct link between climate change and fluctuations in animal populations through long-term monitoring is difficult given the paucity of baseline data. We hypothesized that social wasps are sensitive to climatic variations, and thus studied the impact of ENSO events on social wasp populations in French Guiana. We noted that during the 2000 La Niña year there was a 77.1% decrease in their nest abundance along ca. 5 km of forest edges, and that 70.5% of the species were no longer present. Two simultaneous 13-year surveys (1997-2009) confirmed the decrease in social wasps during La Niña years (2000 and 2006), while an increase occurred during the 2009 El Niño year. A 30-year weather survey showed that these phenomena corresponded to particularly high levels of rainfall, and that temperature, humidity and global solar radiation were correlated with rainfall. Using the Self-Organizing Map algorithm, we show that heavy rainfall during an entire rainy season has a negative impact on social wasps. Strong contrasts in rainfall between the dry season and the short rainy season exacerbate this effect. Social wasp populations never recovered to their pre-2000 levels. This is probably because these conditions occurred over four years; heavy rainfall during the major rainy seasons during four other years also had a detrimental effect. On the contrary, low levels of rainfall during the major rainy season in 2009 spurred an increase in social wasp populations. We conclude that recent climatic changes have likely resulted in fewer social wasp colonies because they have lowered the wasps' resistance to parasitoids and pathogens. These results imply that Neotropical social wasps can be regarded as bio-indicators because they highlight the impact of climatic changes not yet perceptible in plants and other animals. © 2011 Dejean et al.  
  Address INRA – Nancy, UMR EEF, Champenou, Nancy, France  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 19326203 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 29 November 2011; Source: Scopus; Art. No.: e27004; doi: 10.1371/journal.pone.0027004; Language of Original Document: English; Correspondence Address: Dejean, A.; CNRS – UMR 8172, Écologie des Forêts de Guyane (Ecofog), Campus Agronomique, BP 709, Kourou, France; email: alain.dejean@wanadoo.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 372  
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Author Lecante, A.; Robert, F.; Lebrini, M.; Roos, C. pdf  openurl
  Title Inhibitive Effect of Siparuna Guianensis Extracts on the Corrosion of Low Carbon Steel in Acidic Media Type Journal Article
  Year 2011 Publication International Journal of Electrochemical Science Abbreviated Journal Int.J.Electrochem.Sci.  
  Volume (up) 6 Issue 11 Pages 5249-5264  
  Keywords Alkaloids extract; corrosion inhibition; C38 steel; EIS; raman spectroscopy  
  Abstract The present study examines the effect of alkaloids extract from Siparuna guianensis leaves and stems on corrosion of C38 steel in 0.1 M HCl using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization technique and Raman spectroscopy. The protection efficiency is better with stems alkaloids extract. The inhibition was assumed to occur via adsorption of inhibitor molecules on the metal surface. The influence of stems alkaloids extract concentration on corrosion of low carbon steel in 0.1 M HCl was studied. The inhibition efficiency obtained from impedance and polarization measurements was in a good agreement and was found to increase with increasing concentration of alkaloids extract up to 50 mg/L for stems extract. The adsorption of the extract on the low carbon steel surface obeys the Langmuir adsorption.  
  Address Laboratoire Matériaux et Molécules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 374  
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Author Rifflet, A.; Tene, N.; Orivel, J.; Treilhou, M.; Dejean, A.; Vetillard, A. pdf  url
openurl 
  Title Paralyzing Action from a Distance in an Arboreal African Ant Species Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS ONE  
  Volume (up) 6 Issue 12 Pages e28571  
  Keywords  
  Abstract Due to their prowess in interspecific competition and ability to catch a wide range of arthropod prey (mostly termites with which they are engaged in an evolutionary arms race), ants are recognized as a good model for studying the chemicals involved in defensive and predatory behaviors. Ants' wide diversity of nesting habits and relationships with plants and prey types implies that these chemicals are also very diverse. Using the African myrmicine ant Crematogaster striatula as our focal species, we adopted a three-pronged research approach. We studied the aggressive and predatory behaviors of the ant workers, conducted bioassays on the effect of their Dufour gland contents on termites, and analyzed these contents. (1) The workers defend themselves or eliminate termites by orienting their abdominal tip toward the opponent, stinger protruded. The chemicals emitted, apparently volatile, trigger the recruitment of nestmates situated in the vicinity and act without the stinger having to come into direct contact with the opponent. Whereas alien ants competing with C. striatula for sugary food sources are repelled by this behavior and retreat further and further away, termites defend their nest whatever the danger. They face down C. striatula workers and end up by rolling onto their backs, their legs batting the air. (2) The bioassays showed that the toxicity of the Dufour gland contents acts in a time-dependent manner, leading to the irreversible paralysis, and, ultimately, death of the termites. (3) Gas chromatography-mass spectrometry analyses showed that the Dufour gland contains a mixture of mono- or polyunsaturated long-chain derivatives, bearing functional groups like oxo-alcohols or oxo-acetates. Electrospray ionization-mass spectrometry showed the presence of a molecule of 1584 Da that might be a large, acetylated alkaloid capable of splitting into smaller molecules that could be responsible for the final degree of venom toxicity.  
  Address  
  Corporate Author Thesis  
  Publisher Public Library of Science Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 376  
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