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Houel, E.; Gonzalez, G.; Bessière, J.-M.; Odonne, G.; Eparvier, V.; Deharo, E.; Stien, D. |
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Therapeutic switching: From antidermatophytic essential oils to new leishmanicidal products |
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Journal Article |
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2015 |
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Memorias do Inst. Oswaldo Cruz |
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110 |
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1 |
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106-113 |
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Antifungal agents; Antiparasitic agents; Leishmania; Peritoneal macrophages – sesquiterpenes; Therapeutic switching |
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This study examined whether the antidermatophytic activity of essential oils (EOs) can be used as an indicator for the discovery of active natural products against Leishmania amazonensis. The aerial parts of seven plants were hydrodistilled. Using broth microdilution techniques, the obtained EOs were tested against three strains of dermatophytes (Trichophyton mentagrophytes, Microsporum gypseum and Microsporum canis). To compare the EOs antifungal and antiparasitic effects, the EOs activities against axenic amastigotes of L. amazonensis were concurrently evaluated. For the most promising EOs, their antileishmanial activities against parasites infecting peritoneal macrophages of BALB/c mice were measured. The most interesting antifungal candidates were the EOs from Cymbopogon citratus, Otacanthus azureus and Protium heptaphyllum, whereas O. azureus, Piper hispidum and P. heptaphyllum EOs exhibited the lowest 50% inhibitory concentration (IC50) values against axenic amastigotes, thus revealing a certain correspondence between both activities. The P. hispidum EO was identified as the most promising product in the results from the infected macrophages model (IC50: 4.7 μg/mL, safety index: 8). The most abundant compounds found in this EO were sesquiterpenes, notably curzerene and furanodiene. Eventually, the evaluation of the antidermatophytic activity of EOs appears to be an efficient method for identifying new potential drugs for the treatment of L. amazonensis. |
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Export Date: 17 March 2015 |
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EcoFoG @ webmaster @ |
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587 |
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Talaga, S.; Murienne, J.; Dejean, A.; Leroy, C. |
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Online database for mosquito (Diptera, Culicidae) occurrence records in French guiana |
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Journal Article |
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Year |
2015 |
Publication |
ZooKeys |
Abbreviated Journal |
ZooKeys |
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2015 |
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532 |
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107-115 |
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Diversity; French guiana; Mosquitoes; Neotropics; Occurrence |
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A database providing information on mosquito specimens (Arthropoda: Diptera: Culicidae) collected in French Guiana is presented. Field collections were initiated in 2013 under the auspices of the CEnter for the study of Biodiversity in Amazonia (CEBA: http://www.labexceba.fr/en/). This study is part of an ongoing process aiming to understand the distribution of mosquitoes, including vector species, across French Guiana. Occurrences are recorded after each collecting trip in a database managed by the laboratory Evolution et Diversité Biologique (EDB), Toulouse, France. The dataset is updated monthly and is available online. Voucher specimens and their associated DNA are stored at the laboratory Ecologie des Forêts de Guyane (Ecofog), Kourou, French Guiana. The latest version of the dataset is accessible through EDB’s Integrated Publication Toolkit at http://130.120.204.55:8080/ipt/resource.do?r=mosquitoesof french_guiana or through the Global Biodiversity Information Facility data portal at http://www.gbif.org/ dataset/5a8aa2ad-261c-4f61-a98e-26dd752fe1c5 It can also be viewed through the Guyanensis platform at http://guyanensis.ups-tlse.fr © Stanislas Talaga et al. |
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IRD, Laboratoire de botAnique et Modélisation de l’Architecture des Plantes et des végétations (AMAP; UMR 123), Boulevard de la Lironde, TA A-51/PS2, Montpellier, France |
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Export Date: 25 November 2015 |
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EcoFoG @ webmaster @ |
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640 |
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Ghislain, B.; Alméras, T.; Prunier, J.; Clair, B. |
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Contributions of bark and tension wood and role of the G-layer lignification in the gravitropic movements of 21 tropical tree species |
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Journal Article |
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2019 |
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Annals of Forest Science |
Abbreviated Journal |
Ann. Forest Sci. |
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76 |
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4 |
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107 |
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Bark; Biomechanics; G-layer; Lignification; Tension wood; Tropical rainforest; Magnoliophyta |
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Key message: Gravitropic movements in angiosperm woody stems are achieved through the action of bark and/or wood motor, depending on the bark and wood fibre anatomy (with trellis structure or not; with G-layers or not). Bark motor is as efficient as wood motor to recover from tilting in young trees of 21 tropical species. Context: Angiosperm trees produce tension wood to control their orientation through changes in stem curvature. Tension wood is classified into 3 anatomical groups: with unlignified G-layer, with lignified G-layer and without G-layer. Aims: This study aimed at assessing whether this anatomical diversity reflects a diversity in efficiency of gravitropic movement. Methods: The study was conducted on tropical seedling from the three anatomical groups. Seedlings were staked and grown tilted. At the end of the experiment, changes in curvature when releasing the stem from the stake and when removing bark were measured. Three parameters were computed to compare the global efficiency of gravitropism (stem gravitropic efficiency) and the specific efficiency of motor mechanism based on wood (maturation strain of tension wood) and bark (standardized debarking curvature). Results: The maturation strain of tension wood was similar between species with unlignified and lignified G-layer. Species without G-layer exhibited low maturation strain and large debarking curvature, showing they rely on bark for gravitropism. Bark and wood achieved similar motor efficiency. Conclusion: Lignin does not affect the generation of tensile stress in the G-layer. Bark can be as efficient as wood as a motor of gravitropic movements. © 2019, The Author(s). |
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Laboratoire de Mécanique et Génie Civil (LMGC), Université de Montpellier, CNRS, Montpellier, 34095, France |
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Springer |
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12864560 (Issn) |
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EcoFoG @ webmaster @ |
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900 |
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Rockwell, C.A.; Kainer, K.A.; Staudhammer, C.L.; Baraloto, C. |
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Future crop tree damage in a certified community forest in southwestern Amazonia |
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2007 |
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Forest Ecology and Management |
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For. Ecol. Manage. |
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242 |
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2-3 |
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108-118 |
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bamboo; community forest management; forest certification; Guadua; liana; marking; reduced-impact logging; RIL; timber management; tropical forest |
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Field studies in Acre, Brazil assessed logging impacts of a certified community timber management project. The main objectives of the study were: (1) to determine if damage incidence to future crop trees (FCTs; >= 20 cm diameter at breast height (dbh)) differs between (a) forest with and without bamboo (Guadua spp.), and (b) trees with and without lianas; (2) to what extent harvesting can be conducted more intensely (m(3)ha(-1)), without incurring greater FCT damage; and (3) to what extent marking diminishes FCT damage. Full inventories of FCTs of 50 commercial species complexes were conducted before and after logging in 50 m-radius zones of impact around each designated harvest tree in three 10 ha (200 m x 500 m) logging blocks. We also mapped all forested areas potentially influenced by logging, including skid trails, log landings and felling gaps, throughout the 30 ha logged. More than 28% of the forest area was disturbed by logging, with 12.1% in skid trails and 16.8% in gap clearings, indicating that the forest gap mosaic can be significantly altered even when reduced-impact logging guidelines are followed. Overall, 15% of FCTs inventoried were damaged. Damage rates were not significantly reduced by marking treatment, location in bamboo-dominated forest, or liana load on FCT damage. Harvest intensity did not influence the probability of FCT damage. For future studies, it would be prudent to address impacts of timber extraction on other livelihood activities, such as non-timber forest product collection, particularly in such regions as the Brazilian Amazon, where many communities are attempting to integrate a suite of income-generating activities. (C) 2007 Elsevier B.V. All rights reserved. |
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Univ Florida, Sch Forest Resources & Conservat, Gainesville, FL 32611 USA, Email: crockwel@ufl.edu |
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ELSEVIER SCIENCE BV |
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0378-1127 |
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ISI:000246268100003 |
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EcoFoG @ eric.marcon @ |
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217 |
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Kenne, M.; Feneron, R.; Djieto-Lordon, C.; Malherbe, M.C.; Tindo, M.; Ngnegueu, P.R.; Dejean, A. |
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Nesting and foraging habits in the arboreal ant Atopomyrmex mocquerysi ANDRE, 1889 (Hymenoptera: Formicidae: Myrmicinae) |
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Journal Article |
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2009 |
Publication |
Myrmecological News |
Abbreviated Journal |
Myrmecol. News |
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12 |
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109-115 |
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Cameroon; wood-excavating ant; nest site selection; pest ant; predatory behavior; rhythm of activity; life history |
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Atopomyrmex mocquerysi ANDRE, 1889 is a West-Central African wood-excavating myrmicine species whose colonies construct galleries in the main live branches of their host trees, causing the distal parts of these branches to dry out. In southeastern Cameroon, this species was mainly found in woody savannahs that are burned annually. It was also present in the canopy of a secondary forest, but was relatively rare on trees growing along forest edges and entirely absent from the canopy of an old-growth forest. It was absent from oil palm and coffee tree plantations, rare on cocoa trees. present on 0.2% to 5.3% of the avocado, guava, mango and Citrus spp. trees monitored, and frequent on safoo trees (12.4%). A fire in a mango plantation seems to have favored its presence. The colonies generally exploit Aleyrodidae, Aphididae, Coccidae, and Stictococcidae. Workers forage for prey diurnally, mostly on the ground. Their predatory behavior is characterized by detection through contact. Workers recruit nestmates at short-range (within range of an alarm pheromone), rarely at long-range, after which they spread-eagle the prey and immediately cut it up on the spot. Individual workers retrieve the prey pieces. Unlike other territorially-dominant arboreal ants, A. mocquerysi is a threat to host trees because. in addition to being a wood-excavating species, its workers only slightly protect the foliage of their host tree from herbivorous insects since they mostly hunt on the ground. |
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[Kenne, Martin; Tindo, Maurice] Univ Douala, Fac Sci, Dept Biol Organismes Anim, Douala, Cameroon, Email: medoum68@yahoo.fr |
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OESTERREICHISCHE GESELL ENTOMOFAUNISTIK, C/O NATURHISTOR MUSEUM WIEN |
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1994-4136 |
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ISI:000271357700012 |
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EcoFoG @ eric.marcon @ |
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97 |
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Siebicke, L.; Hunner, M.; Foken, T. |
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Aspects of CO 2 advection measurements |
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2012 |
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Theoretical and Applied Climatology |
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Theor. Appl. Climatol. |
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109 |
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1-2 |
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109-131 |
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Observations of vegetation-atmosphere exchange of carbon dioxide (CO 2) by the eddy covariance (EC) technique are limited by difficult conditions such as nighttime and heterogeneous terrain. Thus, advective flux components are included into the net ecosystem exchange (NEE) budget. However, advection measurements are experimentally challenging and do not always help to solve the night flux problem of the EC technique. This study investigates alternative methods for the observation of horizontal advection, in particular horizontal concentration gradients, as well as different approaches to coordinate rotation and vertical advection. Continuous high-frequency measurements of the horizontal CO 2 concentration field are employed and compared to the often used discontinuous sequential sampling. Significant differences were found in the case of 30-min mean concentration values between the conventional discontinuous sampling approach and the complete observation of the time series by continuous sampling. Estimates of vertical advection rely on accurate estimates of vertical wind velocity (W). Therefore, different approaches to the planar fit coordinate rotation have been investigated. Sector-wise rotation was able to eliminate directional dependencies of mean W. Furthermore, the effect of the data set length used for rotation (window length) was investigated and was found to have significant impact on estimates of vertical advection, with larger window lengths yielding about 50% larger vertical advection. A sequential planar fit with controlled window length is proposed to give reproducible results. The different approaches to the measurement and calculation of horizontal and vertical advection presented are applied to data obtained during the exchange processes in mountainous region experiment at the FLUXNET site Waldstein-Weidenbrunnen (DE-Bay). Estimates of NEE including advection are compared to NEE from turbulent and storage flux alone without advection. NEE including vertical advection with sector-wise planar fit rotation and controlled window length and including horizontal advection from continuous gradient measurements, which were comprehensively bias corrected by a new approach, did compare well with the expected night flux error, with meteorological drivers of the fluxes and with soil chamber measurements. Unrealistically large and noisy values of horizontal advection from the conventional discontinuous sampling approach, which lead to unrealistic values of NEE, could be eliminated by the alternative approaches presented. We therefore suggest the further testing of those approaches at other sites in order to improve the accuracy of advection measurements and, subsequently, estimates of NEE. © 2011 Springer-Verlag. |
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Wind Cert Services, TÜV SÜD Industrie Service GmbH, Ludwig-Eckert-Str. 10, 93049 Regensburg, Germany |
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0177798x (Issn) |
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Export Date: 27 June 2012; Source: Scopus; doi: 10.1007/s00704-011-0552-3; Language of Original Document: English; Correspondence Address: Siebicke, L.; Department of Micrometeorology, University of Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany; email: lukas.siebicke@uni-bayreuth.de |
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406 |
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Lamarre, G.P.A.; Mendoza, I.; Rougerie, R.; Decaëns, T.; Herault, B.; Bénéluz, F. |
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Title |
Stay Out (Almost) All Night: Contrasting Responses in Flight Activity Among Tropical Moth Assemblages |
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Journal Article |
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2015 |
Publication |
Neotropical Entomology |
Abbreviated Journal |
Neotropical Entomology |
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44 |
Issue |
2 |
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109-115 |
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Behavior; diel activity; light trap; monitoring; moth; tropical forest |
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Variations in diel activity among hyperdiverse tropical communities of moths, despite representing a key component of niche partitioning between species, have barely been studied so far. Using light trapping from dawn to sunset over a 1-year period in French Guiana, we investigated these variations within and between two families of moths (Sphingidae and Saturniidae). Our results revealed contrasting patterns in flight activity at night between Sphingidae and Saturniidae. Sphingidae reached their peak in species richness and abundance between 7:00 and 8:00 p.m., followed by a decrease around 11:00 p.m. to midnight, whereas Saturniidae were continuously present throughout the night, with a peak around midnight. In addition, we found changes in diel activity among some of the most common genera in each family, highlighting distinct behavioral, physiological, and functional traits among taxa. Given differences in flight activity at different taxonomic levels, it is strongly recommended to monitor by light trapping throughout the night to effectively sample saturniid and sphingid assemblages, even though the activity of Sphingidae sharply declines after midnight. These results improve the general natural history information of tropical moths and reinforce the need of further research on the ecological and taxonomic consequences of differences in diel activity. © 2015, Sociedade Entomológica do Brasil. |
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Centre d’Ecologie Fonctionnelle et Evolutive, UMR 5175 CNRSMontpellier Cedex 5, France |
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Export Date: 9 April 2015 |
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EcoFoG @ webmaster @ |
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592 |
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Leroy, C.; Gril, E.; Si Ouali, L.; Coste, S.; Gérard, B.; Maillard, P.; Mercier, H.; Stahl, C. |
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Water and nutrient uptake capacity of leaf-absorbing trichomes vs. roots in epiphytic tank bromeliads |
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Journal Article |
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2019 |
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Environmental and Experimental Botany |
Abbreviated Journal |
Environ. Exp. Bot. |
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163 |
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112-123 |
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15 N labelling; Carbon metabolism; Nutrient uptake; Plant performance; Tank bromeliad; Water status; Aechmea |
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The water and nutrient uptake mechanisms used by vascular epiphytes have been the subject of a few studies. While leaf absorbing trichomes (LATs) are the main organ involved in resource uptake by bromeliads, little attention has been paid to the absorbing role of epiphytic bromeliad roots. This study investigates the water and nutrient uptake capacity of LATs vs. roots in two epiphytic tank bromeliads Aechmea aquilega and Lutheria splendens. The tank and/or the roots of bromeliads were watered, or not watered at all, in different treatments. We show that LATs and roots have different functions in resource uptake in the two species, which we mainly attributed to dissimilarities in carbon acquisition and growth traits (e.g., photosynthesis, relative growth rate, non-structural carbohydrates, malate), to water relation traits (e.g., water and osmotic potentials, relative water content, hydrenchyma thickness) and nutrient uptake (e.g., 15 N-labelling). While the roots of A. aquilega did contribute to water and nutrient uptake, the roots of L. splendens were less important than the role played by the LATs in resource uptake. We also provide evidenced for a synergistic effect of combined watering of tank and root in the Bromelioideae species. These results call for a more complex interpretation of LATs vs. roots in resource uptake in bromeliads. © 2019 Elsevier B.V. |
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INRA, UMR EcoFoG, CNRS, CIRAD, AgroParisTech, Université des Antilles, Université de Guyane, Kourou, 97310, France |
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Elsevier B.V. |
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00988472 (Issn) |
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EcoFoG @ webmaster @ |
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871 |
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Houel, E.; Bertani, S.; Bourdy, G.; Deharo, E.; Jullian, V.; Valentin, A.; Chevalley, S.; Stien, D. |
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Quassinoid constituents of Quassia amara L. leaf herbal tea. Impact on its antimalarial activity and cytotoxicity |
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Journal Article |
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2009 |
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Journal of Ethnopharmacology |
Abbreviated Journal |
J. Ethnopharmacol. |
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126 |
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1 |
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114-118 |
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Quassia amara L.; Simaroubaceae; Leaf tea; Antimalarial activity; Cytotoxicity; Simalikalactone D |
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Aim of the study: Our objective was to assess whether it could be contemplated to recommend Quassia amara young leaf tea for treatment against malaria. and if yes. set up a standard protocol for preparing the herbal tea. Materials and methods: The leaf tea was extracted with methylene chloride and the organic extract was fractionated with HPLC. Pure compounds were characterized and their in vitro cytotoxicity and antiplasmodial activity was determined. Results and discussion: We discovered that antimalarial Quassia amara young leaf tea contains several quassinoids: simalikalactone D (SkD. 1), picrasin B (2). picrasin H (3), neoquassin (4), quassin (5), picrasin 1(6) and picrasin J (7). These last two compounds are new. In addition. our experiments demonstrate that both biological activity and cytotoxicity of the remedy may be attributed solely to the presence of SkD. Conclusion: In conclusion, this preparation Should not be recommended for treatment of malaria until a clinical Study in humans is performed with SkD. (C) 2009 Elsevier Ireland Ltd. All rights reserved |
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[Stien, Didier] Univ Antilles Guyane, CNRS, UMR Ecofog, Inst Enseignement Super Guyane, F-97337 Cayenne, France, Email: didier.stien@guyane.cnrs.fr |
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ELSEVIER IRELAND LTD |
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ISI:000271790800015 |
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EcoFoG @ eric.marcon @ |
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94 |
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Aguilos, M.; Hérault, B.; Burban, B.; Wagner, F.; Bonal, D. |
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What drives long-term variations in carbon flux and balance in a tropical rainforest in French Guiana? |
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2018 |
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Agricultural and Forest Meteorology |
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253–254 |
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114-123 |
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Tropical rainforest; Nee; Gpp; Ecosystem respiration; Radiation; Drought |
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A thorough understanding of how tropical forests respond to climate is important to improve ecosystem process models and to reduce uncertainties in current and future global carbon balance calculations. The Amazon rainforest, a major contributor to the global carbon cycle, is subject to strong intra- and interannual variations in climate conditions. Understanding their effect on carbon fluxes between the ecosystem and the atmosphere and on the resulting carbon balance is still incomplete. We examined the long-term (over a 12-year period; 2004–2015) variations in gross primary productivity (GPP), ecosystem respiration (RE) and net ecosystem exchange (NEE) in a tropical rainforest in French Guiana and identified key climatic drivers influencing the changes. The study period was characterized by strong differences in climatic conditions among years, particularly differences in the intensity of the dry and wet seasons, as well as differences in annual carbon fluxes and balance. Annual average GPP varied from 3384.9?g?C?m-2?yr?1 (95% CI [3320.7, 3445.9]) to 4061.2?g?C?m-2?yr?1 (95% CI [3980.1, 4145.0]). RE varied even more than GPP, with a difference of 933.1?C?m-2?yr?1 between the minimum (3020.6?g?C?m-2?yr?1; 95% CI [2889.4, 3051.3]) and maximum (3953.7?g?C?m-2?yr?1; 95% CI [3887.6, 4019.6]) values. Although NEE showed large interannual variability (nine-fold), from ?65.6?g?C?m-2?yr?1 (95% CI [?4.4, ?126.0]) to ?590.5?g?C?m-2 yr?1 (95% CI [?532.3, ?651.6]), the forest remained a carbon sink over the 12-year period. A combination of global radiation (Rg), relative extractable water (REW) and soil temperature (Ts) explained 51% of the daily variations for GPP, 30% for RE and 39% for NEE. Global radiation was always the best predictor of these variations, but soil water content and temperature did also influence carbon fluxes and balance. Seasonally, Rg was the major controlling factor for GPP, RE and NEE during the wet season. During the dry season, variations in carbon fluxes and balance were poorly explained by climate factors. Yet, REW was the key driver of variations in NEE during the dry season. This study highlights that, over the long-term, carbon fluxes and balance in such tropical rainforest ecosystems are largely controlled by both radiation and water limitation. Even though variations in Rg have a greater impact on these fluxes, water limitation during seasonal droughts is enough to reduce ecosystem productivity, respiration and carbon uptake. The reduced precipitation expected in tropical rainforest areas under future climatic conditions will therefore strongly influence carbon fluxes and carbon uptake. This study also highlights the importance for land surface or dynamic global vegetation models to consider the main drivers of carbon fluxes and balance separately for dry and wet seasons. |
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0168-1923 |
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