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Author Leba, L.-J.; Musset, L.; Pelleau, S.; Estevez, Y.; Birer, C.; Briolant, S.; Witkowski, B.; Ménard, D.; Delves, M.J.; Legrand, E.; Duplais, C.; Popovici, J.
Title Use of Plasmodium falciparum culture-adapted field isolates for in vitro exflagellation-blocking assay Type Journal Article
Year 2015 Publication Malaria Journal Abbreviated Journal Malaria Journal
Volume 14 Issue Pages (up) 234
Keywords
Abstract Background: A major requirement for malaria elimination is the development of transmission-blocking interventions. In vitro transmission-blocking bioassays currently mostly rely on the use of very few Plasmodium falciparum reference laboratory strains isolated decades ago. To fill a piece of the gap between laboratory experimental models and natural systems, the purpose of this work was to determine if culture-adapted field isolates of P. falciparum are suitable for in vitro transmission-blocking bioassays targeting functional maturity of male gametocytes: exflagellation. Methods: Plasmodium falciparum isolates were adapted to in vitro culture before being used for in vitro gametocyte production. Maturation was assessed by microscopic observation of gametocyte morphology over time of culture and the functional viability of male gametocytes was assessed by microscopic counting of exflagellating gametocytes. Suitability for in vitro exflagellation-blocking bioassays was determined using dihydroartemisinin and methylene blue. Results: In vitro gametocyte production was achieved using two isolates from French Guiana and two isolates from Cambodia. Functional maturity of male gametocytes was assessed by exflagellation observations and all four isolates could be used in exflagellation-blocking bioassays with adequate response to methylene blue and dihydroartemisinin. Conclusion: This work shows that in vitro culture-adapted P. falciparum field isolates of different genetic background, from South America and Southeast Asia, can successfully be used for bioassays targeting the male gametocyte to gamete transition, exflagellation. © 2015 Leba et al.
Address Department of Life Sciences, Imperial College, London, United Kingdom
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Export Date: 16 July 2015 Approved no
Call Number EcoFoG @ webmaster @ Serial 612
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Author Brechet, L.; Ponton, S.; Roy, J.; Freycon, V.; Couteaux, M.M.; Bonal, D.; Epron, D.
Title Do tree species characteristics influence soil respiration in tropical forests? A test based on 16 tree species planted in monospecific plots Type Journal Article
Year 2009 Publication Plant and Soil Abbreviated Journal Plant Soil
Volume 319 Issue 1-2 Pages (up) 235-246
Keywords Fine root; Litter quality; Nutrient cycling; Plant soil interactions; Soil respiration; Tropical plantations
Abstract The high spatial variability of soil respiration in tropical rainforests is well evaluated, but influences of biotic factors are not clearly understood. This study underlines the influence of tree species characteristics on soil respiration across a 16-monospecific plot design in a tropical plantation of French Guiana. A large variability of soil CO2 fluxes was observed among plots (i.e. 2.8 to 6.8 μmol m(-2) s(-1)) with the ranking being constant across seasons. There were no significant relationships between soil respiration and soil moisture or soil temperature, neither spatially, nor seasonally. The variability of soil respiration was mainly explained by quantitative factors such as leaf litterfall and basal area. Surprisingly, no significant relationship was observed between soil respiration and root biomass. However, the influence of substrate quality was revealed by a strong relationship between soil respiration and litterfall P (and litterfall N, to a lesser extent).
Address [Ponton, Stephane] Natl Inst Agr Res INRA Ctr Rech Nancy, Forest Ecol & Ecophysiol Unit, UMR EEF, F-54280 Seichamps, France, Email: ponton@nancy.inra.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 0032-079X ISBN Medium
Area Expedition Conference
Notes ISI:000266143400020 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 110
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Author Ruelle, J.; Yamamoto, H.; Thibaut, B.
Title Growth Stresses and Cellulose Structural Parameters in Tension and Normal Wood from Three Tropical Rainforest Angiosperm Species Type Journal Article
Year 2007 Publication BioResources Abbreviated Journal BioResources
Volume 2 Issue 2 Pages (up) 235-251
Keywords Cellulose; Microfibril angle; Crystallite size; Tension wood; Tropical rainforest; Growth stresses
Abstract Few studies have been conducted about relation between cellulose parameters and biomechanical properties of wood in tropical angiosperms species. For this purpose, on 13 trees from 3 species of French Guyana tropical rainforest in a clear active process of restoring verticality, i) growth strains were measured in situ in order to determine the occurrence of tension wood within samples and ii) cellulose structural parameters were estimated on all the samples using X-ray diffraction method. Crystallite size was estimated from the full-width at half-maximum of the Miller index (002) arc diffraction and angle T was measured following Cave's method. Relationships between these parameters and growth stresses were good and the variations between normal and tension wood were significant, i. e. a lower angle T and a larger crystallite size in tension wood. In order to have a good estimation of the microfibril angle in the main layer of the secondary wall for each species, an experimental calibration was done between angle T and microfibril angle observed with scanning electron microscopy.
Address [Ruelle, Julien; Thibaut, Bernard] UMR EcoFoG, Kourou 97387, Guyana, Email: ruelle_j@kourou.cirad.fr
Corporate Author Thesis
Publisher NORTH CAROLINA STATE UNIV DEPT WOOD & PAPER SCI Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1930-2126 ISBN Medium
Area Expedition Conference
Notes ISI:000263689300009 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 122
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Author Picard, N.; Gourlet-Fleury, S.; Sist, P.
Title Using process-dependent groups of species to model the dynamics of a tropical rainforest Type Journal Article
Year 2003 Publication Modelling Forest Systems Abbreviated Journal
Volume Issue Pages (up) 237-248
Keywords
Abstract The high tree species diversity in tropical forests is difficult to take into account in models. The usual solution consists of defining groups of species and then adjusting a set of parameters for each group. In this study, we address this issue by allowing a species to move from one species group to another, depending on the biological process that is concerned. We developed this approach with a matrix model of forest dynamics, for a tropical rainforest in French Guiana, at Paracou, focusing on the methodological aspects. The forest dynamics is split into three components: recruitment, growth and mortality. We then built five recruitment groups, five growth groups and five mortality groups. One species is characterized by a combination of the three groups, thus yielding in total 5 X 5 X 5 = 125 possibilities, out of which 43 are actually observed. The resulting matrix model provides a better view of the floristic composition of the forest, and does not have more parameters than it would have with five global species groups. However, its predictions are no more precise than those of the matrix model based on five global groups.
Address Cirad Foret, Montpellier, France
Corporate Author Thesis
Publisher CABI PUBLISHING 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 ISI:000231866400021 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 249
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Author Charles-Dominique, P.; Chave, J.; Dubois, M.A.; De Granville, J.J.; Riera, B.; Vezzoli, C.
Title Colonization front of the understorey palm Astrocaryum sciophilum in a pristine rain forest of French Guiana Type Journal Article
Year 2003 Publication Global Ecology and Biogeography Abbreviated Journal Glob. Ecol. Biogeogr.
Volume 12 Issue 3 Pages (up) 237-248
Keywords Astrocaryum sciophilum; French Guiana; neotropical palaeoecology; palm ecology; population edge; refuges; scatter-hoarding; seed dispersal; spatial pattern
Abstract Aims Astrocaryum sciophilum (Miq.) Pulle (Arecaceae) is an understorey palm, endemic to north-eastern South America with a patchy distribution. We tested the hypothesis that the spatial distribution of this palm species is not in equilibrium but is slowly colonizing the forest understorey. Location Inventories and seed dispersal studies were conducted in the undisturbed tropical forest close to the Nouragues research station, French Guiana. Additional data were collected in the entire territory of French Guiana. Methods We studied the demography of A. sciophilum on a 20-ha plot located at the edge of its distribution. The age of the palms was estimated by postulating an exponentially decreasing abundance by age class. Direct seed dispersal experiments were also conducted, to estimate dispersal parameters. The seeds of A. sciophilum were dispersed only by rodents. This information was used to parameterize a forest growth simulator, to study the spatial spread of this species. Results Within the sampling plot, the density of A. sciophilum dropped sharply from about 500 individuals per hectare to zero. The maturation age was estimated to be 170+/-70 years, and over 55 years with 95% confidence. Seed-dispersal experiments yielded an average seed dispersal distance of 11 m and a maximum estimated dispersal distance of 125 m across a generational span of 55 years to maturity. Therefore, the maximal estimated colonization speed is 2.3 m/y. Conclusions Empirical results and numerical simulations suggest that the boundary of the A. sciophilum population is a colonization front, and that the range of this species is slowly expanding. The implications of this result in respect of palaeoenvironmental changes in this region are discussed.
Address Natl Museum Nat Hist, Lab Ecol Gen, F-91800 Brunoy, France
Corporate Author Thesis
Publisher BLACKWELL PUBLISHING LTD Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-7447 ISBN Medium
Area Expedition Conference
Notes ISI:000182184100006 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 273
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Author Millet, J.; Pascal, J.P.; Kiet, L.C.
Title Effects of Disturbance Over 60 Years on a Lowland Forest in Southern Vietnam Type Journal Article
Year 2010 Publication Journal of Tropical Forest Science Abbreviated Journal J. Trop. For. Sci.
Volume 22 Issue 3 Pages (up) 237-246
Keywords Lowland tropical forest; disturbance impact; floristic composition; forest structure; Tan Phu forest
Abstract MILLET J, PASCAL JP & MET LC. 2010. Effects of disturbance over 60 years on a lowland forest in southern Vietnam. Tropical lowland forests are some of the most threatened in the world and this is particularly the case in Vietnam. This study aimed to identify changes in species composition and forest structure in the Tan Phu lowland forest resulting from disturbance over a 60 year period. Analysis of forest composition and structure rely on data from 25 plots of 0.5-ha size established in a lowland secondary forest. The five forest stands described differed greatly from the three forest stand types described in 1943. Some long-lived shade-tolerant species had been replaced by pioneer species, such as Cratoxylon formosum and Shorea roxburghii. In addition to altering composition, forest disturbances had resulted in large changes in forest structure. While in the past, forest stands had a large number of exploitable trees, current forest stands have few trees in the diameter class > 50 cm and sometimes no trees in the diameter class > 80 cm. This paper provides notable results on forest tree ecology, forest dynamics and on the state of secondary forests in Vietnam. This is particularly important as future goods and services will increasingly have to come from such forests.
Address [Millet, J.] Univ Lyon 1, F-69622 Villeurbanne, France, Email: jerome.millet@ird.if
Corporate Author Thesis
Publisher FOREST RESEARCH INST MALAYSIA Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0128-1283 ISBN Medium
Area Expedition Conference
Notes ISI:000280653200003 Approved no
Call Number EcoFoG @ webmaster @ Serial 283
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Author Grangier, J.; Orivel, J.; Negrini, M.; Dejean, A.
Title Low intraspecific aggressiveness in two obligate plant-ant species Type Journal Article
Year 2008 Publication Insectes Sociaux Abbreviated Journal Insect. Soc.
Volume 55 Issue 3 Pages (up) 238-240
Keywords aggressiveness; Allomerus; myrmecophytes; plant-ants; recognition ability
Abstract Little is known about the aggressiveness of plant-ants typically living in isolated trees nor about how that aggressiveness varies based on this isolation. Here, we examine intra- and interspecific aggressiveness between workers of two Allomerus species associated with two different myrmecophytes. In both cases, the level of intraspecific aggressiveness is very low whatever the distance separating the tested nests, while interspecific conflicts are always violent. Similar patterns of aggressiveness have been reported in various ant species, but the strictly arboreal life of Allomerus ants associated with the isolation of their adult colonies highlight different ecological conditions that might explain the lack of aggressiveness between conspecifics.
Address [Grangier, J.; Orivel, J.; Negrini, M.; Dejean, A.] Univ Toulouse 3, CNRS, UMR 5174, Lab Evolut & Diversite Biol, F-31062 Toulouse 9, France, Email: grangier@cict.fr
Corporate Author Thesis
Publisher BIRKHAUSER VERLAG AG Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1812 ISBN Medium
Area Expedition Conference
Notes ISI:000258959300004 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 208
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Author Fayad, I.; Baghdadi, N.; Bailly, J.-S.; Barbier, N.; Gond, V.; Herault, B.; El Hajj, M.; Fabre, F.; Perrin, J.
Title Regional scale rain-forest height mapping using regression-kriging of spaceborne and airborne LiDAR data: Application on French Guiana Type Journal Article
Year 2016 Publication Remote Sensing Abbreviated Journal Remote Sensing
Volume 8 Issue 3 Pages (up) 240
Keywords Airborne LiDAR; Canopy height mapping; Forests; French Guiana; ICESat GLAS
Abstract LiDAR data has been successfully used to estimate forest parameters such as canopy heights and biomass. Major limitation of LiDAR systems (airborne and spaceborne) arises from their limited spatial coverage. In this study, we present a technique for canopy height mapping using airborne and spaceborne LiDAR data (from the Geoscience Laser Altimeter System (GLAS)). First, canopy heights extracted from both airborne and spaceborne LiDAR were extrapolated from available environmental data. The estimated canopy height maps using Random Forest (RF) regression from airborne or GLAS calibration datasets showed similar precisions (~6 m). To improve the precision of canopy height estimates, regression-kriging was used. Results indicated an improvement in terms of root mean square error (RMSE, from 6.5 to 4.2 m) using the GLAS dataset, and from 5.8 to 1.8 m using the airborne LiDAR dataset. Finally, in order to investigate the impact of the spatial sampling of future LiDAR missions on canopy height estimates precision, six subsets were derived from the initial airborne LiDAR dataset. Results indicated that using the regression-kriging approach a precision of 1.8 m on the canopy height map was achievable with a flight line spacing of 5 km. This precision decreased to 4.8 m for flight line spacing of 50 km. © 2016 by the authors.
Address BRGM, 3 Avenue Claude Guillemin, Orléans, France
Corporate Author Thesis
Publisher Place of Publication Editor
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Notes Export Date: 22 April 2016 Approved no
Call Number EcoFoG @ webmaster @ Serial 675
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Author Barantal, S.; Roy, J.; Fromin, N.; Schimann, H.; Hattenschwiler, S.
Title Long-term presence of tree species but not chemical diversity affect litter mixture effects on decomposition in a neotropical rainforest Type Journal Article
Year 2011 Publication Oecologia Abbreviated Journal Oecologia
Volume 167 Issue 1 Pages (up) 241-252
Keywords Amazonian rainforest; Chemical diversity; Decomposition; Functional diversity indices; Litter traits
Abstract Plant litter diversity effects on decomposition rates are frequently reported, but with a strong bias towards temperate ecosystems. Altered decomposition and nutrient recycling with changing litter diversity may be particularly important in tree species-rich tropical rainforests on nutrient-poor soils. Using 28 different mixtures of leaf litter from 16 Amazonian rainforest tree species, we tested the hypothesis that litter mixture effects on decomposition increase with increasing functional litter diversity. Litter mixtures and all single litter species were exposed in the field for 9 months using custom-made microcosms with soil fauna access. In order to test the hypothesis that the long-term presence of tree species contributing to the litter mixtures increases mixture effects on decomposition, microcosms were installed in a plantation at sites including the respective tree species composition and in a nearby natural forest where these tree species are absent. We found that mixture decomposition deviated from predictions based on single species, with predominantly synergistic effects. Functional litter diversity, defined as either richness, evenness, or divergence based on a wide range of chemical traits, did not explain the observed litter mixture effects. However, synergistic effects in litter mixtures increased with the long-term presence of tree species contributing to these mixtures as the home field advantage hypothesis assumes. Our data suggest that complementarity effects on mixed litter decomposition may emerge through long-term interactions between aboveground and belowground biota.
Address [Barantal, S; Roy, J; Fromin, N; Hattenschwiler, S] CEFE CNRS, UMR 5175, F-34293 Montpellier 5, France, Email: sandra.barantal@cefe.cnrs.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 0029-8549 ISBN Medium
Area Expedition Conference
Notes WOS:000293914000024 Approved no
Call Number EcoFoG @ webmaster @ Serial 336
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Author Houel, E.; Nardella, F.; Jullian, V.; Valentin, A.; Vonthron-Sénécheau, C.; Villa, P.; Obrecht, A.; Kaiser, M.; Bourreau, E.; Odonne, G.; Fleury, M.; Bourdy, G.; Eparvier, V.; Deharo, E.; Stien, D.
Title Wayanin and guaijaverin, two active metabolites found in a Psidium acutangulum Mart. ex DC (syn. P. persoonii McVaugh) (Myrtaceae) antimalarial decoction from the Wayana Amerindians Type Journal Article
Year 2016 Publication Journal of Ethnopharmacology Abbreviated Journal Journal of Ethnopharmacology
Volume 187 Issue Pages (up) 241-248
Keywords Antimalarial; Cytokines; French guiana; Glycosylated flavonols; Psidium acutangulum; Traditional remedy
Abstract Ethnopharmacological relevance Psidium acutangulum Mart. ex DC is a small tree used by the Wayana Amerindians from the Upper-Maroni in French Guiana for the treatment of malaria. Aim of the study In a previous study, we highlighted the in vitro antiplasmodial, antioxidant and anti-inflammatory potential of the traditional decoction of P. acutangulum aerial parts. Our goal was then to investigate on the origin of the biological activity of the traditional remedy, and eventually characterize active constituents. Materials and methods Liquid-liquid extractions were performed on the decoction, and the antiplasmodial activity evaluated against chloroquine-resistant FcB1 ([3H]-hypoxanthine bioassay) and 7G8 (pLDH bioassay) P. falciparum strains, and on a chloroquine sensitive NF54 ([3H]-hypoxanthine bioassay) P. falciparum strain. The ethyl acetate fraction (D) was active and underwent bioguided fractionation. All the isolated compounds were tested on P. falciparum FcB1 strain. In vitro anti-inflammatory activity (IL-1β, IL-6, IL-8, TNFα) of the ethyl acetate fraction and of an anti-Plasmodium active compound, was concurrently assessed on LPS-stimulated human PBMC and NO secretion inhibition was measured on LPS stimulated RAW murine macrophages. Cytotoxicity of the fractions and pure compounds was measured on VERO cells, L6 mammalian cells, PBMCs, and RAW cells. Results Fractionation of the ethyl acetate soluble fraction (IC50 ranging from 3.4 to <1 μg/mL depending on the parasite strain) led to the isolation of six pure compounds: catechin and five glycosylated quercetin derivatives. These compounds have never been isolated from this plant species. Two of these compounds (wayanin and guaijaverin) were found to be moderately active against P. falciparum FcB1 in vitro (IC50 5.5 and 6.9 μM respectively). We proposed the name wayanin during public meetings organized in June 2015 in the Upper-Maroni villages, in homage to the medicinal knowledge of the Wayana population. At 50 μg/mL, the ethyl acetate fraction (D) significantly inhibited IL-1β secretion (-46%) and NO production (-21%), as previously observed for the decoction. The effects of D and guiajaverin (4) on the secretion of other cytokines or NO production were not significant. Conclusions The confirmed antiplasmodial activity of the ethyl acetate soluble fraction of the decoction and of the isolated compounds support the previous results obtained on the P. acutangulum decoction. The antiplasmodial activity might be due to a mixture of moderately active non-toxic flavonoids. The anti-inflammatory activities were less marked for ethyl acetate fraction (D) than for the decoction. © 2016 Elsevier Ireland Ltd. All rights reserved.
Address Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), Observatoire Océanologique, Banyuls/Mer, France
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Publisher Place of Publication Editor
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Notes Export Date: 20 May 2016 Approved no
Call Number EcoFoG @ webmaster @ Serial 679
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