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Author Sommeria-Klein, G.; Zinger, L.; Coissac, E.; Iribar, A.; Schimann, H.; Taberlet, P.; Chave, J. doi  openurl
  Title Latent Dirichlet Allocation reveals spatial and taxonomic structure in a DNA-based census of soil biodiversity from a tropical forest Type Journal Article
  Year 2020 Publication Molecular Ecology Resources Abbreviated Journal Mol. Ecol. Resour.  
  Volume (up) 20 Issue 2 Pages 371-386  
  Keywords community ecology; environmental DNA; metabarcoding; OTU presence–absence; soil microbiome; topic modelling; bacterium; biodiversity; biology; classification; eukaryote; fungus; genetics; high throughput sequencing; isolation and purification; microbiology; parasitology; procedures; soil; Bacteria; Biodiversity; Computational Biology; Eukaryota; Fungi; High-Throughput Nucleotide Sequencing; Soil; Soil Microbiology  
  Abstract High-throughput sequencing of amplicons from environmental DNA samples permits rapid, standardized and comprehensive biodiversity assessments. However, retrieving and interpreting the structure of such data sets requires efficient methods for dimensionality reduction. Latent Dirichlet Allocation (LDA) can be used to decompose environmental DNA samples into overlapping assemblages of co-occurring taxa. It is a flexible model-based method adapted to uneven sample sizes and to large and sparse data sets. Here, we compare LDA performance on abundance and occurrence data, and we quantify the robustness of the LDA decomposition by measuring its stability with respect to the algorithm's initialization. We then apply LDA to a survey of 1,131 soil DNA samples that were collected in a 12-ha plot of primary tropical forest and amplified using standard primers for bacteria, protists, fungi and metazoans. The analysis reveals that bacteria, protists and fungi exhibit a strong spatial structure, which matches the topographical features of the plot, while metazoans do not, confirming that microbial diversity is primarily controlled by environmental variation at the studied scale. We conclude that LDA is a sensitive, robust and computationally efficient method to detect and interpret the structure of large DNA-based biodiversity data sets. We finally discuss the possible future applications of this approach for the study of biodiversity. © 2019 John Wiley & Sons Ltd  
  Address Laboratoire d’Ecologie des Forêts de Guyane (EcoFoG, UMR 745), INRA, AgroParisTech, CIRAD, CNRS, University of the French West Indies, University of French Guiana, Kourou, 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 1755098x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 981  
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Author Rutishauser, E.; Wagner, F.; Herault, B.; Nicolini, E.A.; Blanc, L. openurl 
  Title Contrasting above-ground biomass balance in a Neotropical rain forest Type Journal Article
  Year 2010 Publication Journal of Vegetation Science Abbreviated Journal J. Veg. Sci.  
  Volume (up) 21 Issue 4 Pages 672-682  
  Keywords Biomass balance; Biomass fluxes; Forest dynamics; Permanent plots; Tropical forests  
  Abstract Question What are the relative roles of tree growth, mortality and recruitment in variations of above-ground biomass in tropical forests? Location Paracou, French Guiana. Methods We quantified the contribution of growth, recruitment and mortality to total biomass of stands (trees DBH >= 10 cm) in six 6.25-ha permanent plots over 16 yr. Live biomass stocks and fluxes were computed for four separate size classes. Results All plots showed increasing biomass stocks over the study period, with an average value of +0.9 Mg ha-1 yr-1. Plots aggrading biomass were characterized by either minor biomass losses due to mortality or substantial increases in the biomass of large trees (DBH >= 60 cm). Conclusions Within the study period, the rarity of mortality events could not counter-balance the slow permanent increase in biomass, resulting in an apparent increase in biomass. Accounting for such rare events results in no net change in biomass balance.  
  Address [Rutishauser, Ervan; Nicolini, Eric-Andre] Cirad, UMR AMAP, Kourou 97379, French Guiana, Email: ervan.rutishauser@cirad.fr  
  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 1100-9233 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000279450200005 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 52  
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Author Ruelle, J.; Yoshida, M.; Clair, B.; Thibaut, B. openurl 
  Title Peculiar tension wood structure in Laetia procera (Poepp.) Eichl. (Flacourtiaceae) Type Journal Article
  Year 2007 Publication Trees-Structure and Function Abbreviated Journal Trees-Struct. Funct.  
  Volume (up) 21 Issue 3 Pages 345-355  
  Keywords tension wood; tropical rainforest species; UV microspectrophotometry; scanning electron microscopy; cellulose microfibril angle  
  Abstract Tension wood of Laetia procera (Poepp.) Eichl. (Flacourtiaceae), a neo-tropical forest species, shows a peculiar secondary wall structure, with an alternance of thick and thin layers, while opposite wood of this species has a typical secondary wall structure (S1 + S2 + S3). Samples for the study of microstructural properties were collected upon the estimation of growth stresses in the living tree, in order to analyze the correlation of the former with the latter. Investigation using optical microscopy, scanning electron microscopy and UV microspectrophotometry allowed the description of the anatomy, ultra-structure and chemistry of this peculiar polylaminate secondary wall. In the thick layers, cellulose microfibril angle is very low (i.e., microfibril orientation is close to fibre axis) and cellulose microfibrils are well organized and parallel to each other. In the thin layers, microfibrils (only observable in the inner layer) are less organized and are oriented with a large angle relative to the axis of the cell. Thick layers are lightly lignified although thin layers show a higher content of lignin, close to that of opposite wood secondary wall. The more the wood was under tensile stress, the less the secondary wall was lignified, and lower the syringyl on guaiacyl lignin units' ratio was. The innermost layer of the secondary wall looks like a typical S3 layer with large microfibril angle and lignin occurrence. The interest of this kind of structure for the understanding of stress generation is discussed.  
  Address UMR EcoFoG, Kourou 97387, French Guiana, Email: ruelle_j@kourou.cirad.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 0931-1890 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000246206200009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 163  
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Author Bereau, M.; Bonal, D.; Louisanna, E.; Garbaye, J. openurl 
  Title Do mycorrhizas improve tropical tree seedling performance under water stress and low light conditions? A case study with Dicorynia guianensis (Caesalpiniaceae) Type Journal Article
  Year 2005 Publication Journal of Tropical Ecology Abbreviated Journal J. Trop. Ecol.  
  Volume (up) 21 Issue Pages 375-381  
  Keywords French Guiana; leaf gas exchange; mycorrhizal symbiosis; tropical forest; water limitation  
  Abstract We tested the response of seedlings of Diconyina guianensis, a major timber tree species of French Guiana, to mycorrhizal symbiosis and water limitation in a semi-con trolled experiment under natural light conditions. Under well-watered conditions, mycorrhizal colonization resulted in an increase of net photosynthesis, growth and phosphorus uptake. When submitted to water stress, no growth reduction of mycorrhizal seedlings was observed. Mycorrhizal seedlings were more sensitive to drought than non-mycorrhizal ones in terms of carbon assimilation, but not with regard to stomatal closure. In contrast to previous studies on temperate tree seedlings, this result precludes a mycorrhizal effect on the hydraulic properties of this species. Furthermore, our results suggest that below a specific threshold of soil moisture, carbon assimilation of D. guianensis seedlings was decreased by the mycorrhizal symbiosis. This is probably related to the competition between the plant and its host fungus for carbon allocation under low light intensity, even though it did not seem to have a significant effect on mortality in our experiment.  
  Address UMR Ecofog, Kourou 97387, French Guiana, Email: bercau.m@kourou.cirad.fr  
  Corporate Author Thesis  
  Publisher CAMBRIDGE UNIV PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0266-4674 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000231009300003 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 232  
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Author Lenoir, A.; Touchard, A.; Devers, S.; Christidès, J.-P.; Boulay, R.; Cuvillier-Hot, V. doi  openurl
  Title Ant cuticular response to phthalate pollution Type Journal Article
  Year 2014 Publication Environmental Science and Pollution Research Abbreviated Journal Environ. Sci. Pollut. Res.  
  Volume (up) 21 Issue 23 Pages 13446-13451  
  Keywords Absorption; Ants; Bbp; Bioindicator; Cuticle; Dbp; Dehp; DiBP; Phthalates; Pollutants  
  Abstract Phthalates are common atmospheric contaminants used in the plastic industry. Ants have been shown to constitute good bioindicators of phthalate pollution. Hence, phthalates remain trapped on ant cuticles which are mostly coated with long-chain hydrocarbons. In this study, we artificially contaminated Lasius niger ants with four phthalates: dibutyl phthalate (DBP), diisobutyl phthalate (DiBP), di(2-ethylhexyl) phthalate (DEHP), and benzyl butyl phthalate (BBP). The first three have previously been found on ants in nature in Touraine (France), while the fourth has not. The four phthalates disappeared rapidly (less than 5 days) from the cuticles of live ants. In contrast, on the cuticles of dead ants, DEHP quantities remained unchanged over time. These results indicate that phthalates are actively absorbed by the cuticles of live ants. Cuticular absorption of phthalates is nonspecific because eicosane, a nonnatural hydrocarbon on L. niger cuticle, was similarly absorbed. Ants are important ecological engineers and may serve as bioindicators of ecosystem health. We also suggest that ants and more generally terrestrial arthropods may contribute to the removal of phthalates from the local environment.  
  Address CNRS, UMR Écologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316Kourou Cedex, France  
  Corporate Author Thesis  
  Publisher Springer Verlag Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 09441344 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 5 December 2014; Coden: Esple; Correspondence Address: Lenoir, A.; IRBI, Institut de Recherche sur la Biologie de l’Insecte, UMR CNRS 7261, Université François RabelaisFrance Approved no  
  Call Number EcoFoG @ webmaster @ Serial 570  
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Author Honorio Coronado, E.N.; Dexter, K.G.; Pennington, R.T.; Chave, J.; Lewis, S.L.; Alexiades, M.N.; Alvarez, E.; Alves de Oliveira, A.; Amaral, I.L.; Araujo-Murakami, A.; Arets, E.J.M.M.; Aymard, G.A.; Baraloto, C.; Bonal, D.; Brienen, R.; Cerón, C.; Cornejo Valverde, F.; Di Fiore, A.; Farfan-Rios, W.; Feldpausch, T.R.; Higuchi, N.; Huamantupa-Chuquimaco, I.; Laurance, S.G.; Laurance, W.F.; López-Gonzalez, G.; Marimon, B.S.; Marimon-Junior, B.H.; Monteagudo Mendoza, A.; Neill, D.; Palacios Cuenca, W.; Peñuela Mora, M.C.; Pitman, N.C.A.; Prieto, A.; Quesada, C.A.; Ramirez Angulo, H.; Rudas, A.; Ruschel, A.R.; Salinas Revilla, N.; Salomão, R.P.; Segalin de Andrade, A.; Silman, M.R.; Spironello, W.; ter Steege, H.; Terborgh, J.; Toledo, M.; Valenzuela Gamarra, L.; Vieira, I.C.G.; Vilanova Torre, E.; Vos, V.; Phillips, O.L. url  openurl
  Title Phylogenetic diversity of Amazonian tree communities Type Journal Article
  Year 2015 Publication Diversity and Distributions Abbreviated Journal Diversity and Distributions  
  Volume (up) 21 Issue 11 Pages 1295-1307  
  Keywords Amazon basin; Eudicots; Magnoliids; Monocots; Phylogenetic diversity; Species richness  
  Abstract Aim: To examine variation in the phylogenetic diversity (PD) of tree communities across geographical and environmental gradients in Amazonia. Location: Two hundred and eighty-three c. 1 ha forest inventory plots from across Amazonia. Methods: We evaluated PD as the total phylogenetic branch length across species in each plot (PDss), the mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardized for species richness (ses.PDss, ses.MPD, ses.MNTD). We compared PD of tree communities growing (1) on substrates of varying geological age; and (2) in environments with varying ecophysiological barriers to growth and survival. Results: PDss is strongly positively correlated with species richness (SR), whereas MNTD has a negative correlation. Communities on geologically young- and intermediate-aged substrates (western and central Amazonia respectively) have the highest SR, and therefore the highest PDss and the lowest MNTD. We find that the youngest and oldest substrates (the latter on the Brazilian and Guiana Shields) have the highest ses.PDss and ses.MNTD. MPD and ses.MPD are strongly correlated with how evenly taxa are distributed among the three principal angiosperm clades and are both highest in western Amazonia. Meanwhile, seasonally dry tropical forest (SDTF) and forests on white sands have low PD, as evaluated by any metric. Main conclusions: High ses.PDss and ses.MNTD reflect greater lineage diversity in communities. We suggest that high ses.PDss and ses.MNTD in western Amazonia results from its favourable, easy-to-colonize environment, whereas high values in the Brazilian and Guianan Shields may be due to accumulation of lineages over a longer period of time. White-sand forests and SDTF are dominated by close relatives from fewer lineages, perhaps reflecting ecophysiological barriers that are difficult to surmount evolutionarily. Because MPD and ses.MPD do not reflect lineage diversity per se, we suggest that PDss, ses.PDss and ses.MNTD may be the most useful diversity metrics for setting large-scale conservation priorities. © 2015 John Wiley & Sons Ltd.  
  Address Universidad Autónoma del Beni, Av. Ejército Nacional, Riberalta, Riberalta, Bolivia  
  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 Export Date: 22 October 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 634  
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Author Courtois, E.A.; Stahl, C.; Van den Berge, J.; Bréchet, L.; Van Langenhove, L.; Richter, A.; Urbina, I.; Soong, J.L.; Peñuelas, J.; Janssens, I.A. url  doi
openurl 
  Title Spatial Variation of Soil CO2, CH4 and N2O Fluxes Across Topographical Positions in Tropical Forests of the Guiana Shield Type Journal Article
  Year 2018 Publication Ecosystems Abbreviated Journal  
  Volume (up) 21 Issue 7 Pages 1445-1458  
  Keywords  
  Abstract The spatial variation of soil greenhouse gas fluxes (GHG; carbon dioxide—CO2, methane—CH4 and nitrous oxide—N2O) remains poorly understood in highly complex ecosystems such as tropical forests. We used 240 individual flux measurements of these three GHGs from different soil types, at three topographical positions and in two extreme hydric conditions in the tropical forests of the Guiana Shield (French Guiana, South America) to (1) test the effect of topographical positions on GHG fluxes and (2) identify the soil characteristics driving flux variation in these nutrient-poor tropical soils. Surprisingly, none of the three GHG flux rates differed with topographical position. CO2 effluxes covaried with soil pH, soil water content (SWC), available nitrogen and total phosphorus. The CH4 fluxes were best explained by variation in SWC, with soils acting as a sink under drier conditions and as a source under wetter conditions. Unexpectedly, our study areas were generally sinks for N2O and N2O fluxes were partly explained by total phosphorus and available nitrogen concentrations. This first study describing the spatial variation of soil fluxes of the three main GHGs measured simultaneously in forests of the Guiana Shield lays the foundation for specific studies of the processes underlying the observed patterns.  
  Address  
  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 1435-0629 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Courtois2018 Serial 847  
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Author Coutant, Opale ; Richard-Hansen, Cecile ; de Thoisy, Benoit ; Decotte, Jean-Baptiste ; Valentini, Alice ; Dejean, Tony ; Vigouroux, Régis ; Murienne, Jérôme ; Brosse, Sébastien doi  openurl
  Title Amazonian mammal monitoring using aquatic environmental DNA Type Journal Article
  Year 2021 Publication Molecular Ecology Resources Abbreviated Journal  
  Volume (up) 21 Issue 6 Pages 1875-1888  
  Keywords  
  Abstract Environmental DNA (eDNA) metabarcoding has emerged as one of the most efficient methods to assess aquatic species presence. While the method can in theory be used to investigate nonaquatic fauna, its development for inventorying semi-aquatic and terrestrial fauna is still at an early stage. Here we investigated the potential of aquatic eDNA metabarcoding for inventorying mammals in Neotropical environments, be they aquatic, semi-aquatic or terrestrial. We collected aquatic eDNA in 96 sites distributed along three Guianese watersheds and compared our inventories to expected species distributions and field observations derived from line transects located throughout French Guiana. Species occurrences and emblematic mammalian fauna richness patterns were consistent with the expected distribution of fauna and our results revealed that aquatic eDNA metabarcoding brings additional data to line transect samples for diurnal nonaquatic (terrestrial and arboreal) species. Aquatic eDNA also provided data on species not detectable in line transect surveys such as semi-aquatic, aquatic and nocturnal terrestrial and arboreal species. Although the application of eDNA to inventory mammals still needs some developments to optimize sampling efficiency, it can now be used as a complement to traditional surveys.  
  Address  
  Corporate Author Thesis  
  Publisher Wiley 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 1015  
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Author Christensen-Dalsgaard, K.K.; Ennos, A.R.; Fournier, M. openurl 
  Title Are radial changes in vascular anatomy mechanically induced or an ageing process? Evidence from observations on buttressed tree root systems Type Journal Article
  Year 2008 Publication Trees-Structure and Function Abbreviated Journal Trees-Struct. Funct.  
  Volume (up) 22 Issue 4 Pages 543-550  
  Keywords wood; anatomy; mechanical loading; tree development; vessels  
  Abstract To investigate the effect of changes in mechanical loading conditions on radial anatomical patterns, we here compare the trunk with the roots in two locations of three species of buttressed trees. The proximal part of the buttress roots is highly mechanically loaded throughout juvenile growth whereas the distal part of the buttresses is though to be mechanically unimportant at formation but become progressively more mechanically loaded during growth. We measured the frequency and diameter of the vessels and the vessel area fraction, and from this calculated the specific conductivity of tissue samples of the core-, intermediate- and outer wood. As in previous studies there was an increase in vessel size, vessel area fraction and specific conductivity from the pith to the bark in the trunk. In the proximal part of the buttress roots, however, there was no increase in vessel size and conductivity from core wood and out in agreement with the high mechanical loading found here throughout growth. There was instead a decrease in vessel size, vessel area fraction and specific conductivity from core- to outer wood in the distal part of the buttress roots in accordance with the increase in mechanical loading. Hence, it appears that the radial anatomical patterns are not a passive function of cambial ageing but may be modified in response to local mechanical loading.  
  Address [Christensen-Dalsgaard, Karen K.] Univ Alberta, Edmonton, AB T6G 2E3, Canada, Email: kkchrist@ualberta.ca  
  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 0931-1890 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000257385200014 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 136  
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Author Baraloto, C.; Bonal, D.; Goldberg, D.E. openurl 
  Title Differential seedling growth response to soil resource availability among nine neotropical tree species Type Journal Article
  Year 2006 Publication Journal of Tropical Ecology Abbreviated Journal J. Trop. Ecol.  
  Volume (up) 22 Issue Pages 487-497  
  Keywords biomass allocation; Dicorynia; drought stress; Eperua; French Guiana; Goupia; Jacaranda; plasticity; Qualea; Recordorylon; relative growth rate; Sextonia; soil phosphorus; specific leaf area; Virola  
  Abstract Although the potential contribution to tropical tree species coexistence of niche differentiation along light gradients has received much attention, the degree to which species perform differentially along soil resource gradients remains unclear. To examine differential growth response to soil resources, we grew seedlings of nine tropical tree species at 6.0% of full sun for 12 mo in a factorial design of two soil types (clay and white sand), two phosphate fertilization treatments (control and addition of 100 mg P kg(-1)) and two watering treatments (field capacity and water limitation to one-third field capacity). Species differed markedly in biomass growth rate, but this hierarchy was almost completely conserved across all eight treatments. All species grew more slowly in sand than clay soils. and no species grew faster with phosphate additions. Only Eperua grandiflora and E. falcata showed significant growth increases in the absence of water limitation. Faster-growing species were characterized by high specific leaf area, high leaf allocation and high net assimilation rate but not lower root allocation. Slower-growing species exhibited greater plasticity in net assimilation rate. suggesting that tolerance of edaphic stress in these species is related more to stomatal control than to whole-plant carbon allocation. Although relative growth rate for biomass was correlated with both its physiological and morphological components. interspecific differences were best explained by differences in net assimilation rate across six of the eight treatments. A suite of traits including high assimilation and high specific leaf area maintains rapid growth rate of faster-growing species across a wide gradient of soil resources, but the lack of plasticity they exhibit may compromise their survival in the poorest soil environments.  
  Address Univ Michigan, Dept Ecol & Evolutionary Biol, Ann Arbor, MI 48109 USA, Email: baraloto.c@kourou.cirad.fr  
  Corporate Author Thesis  
  Publisher CAMBRIDGE UNIV PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0266-4674 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000239975200001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 178  
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