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Gao, H., Grüschow, S., Barke, J., Seipke, R. F., Hill, L. M., Orivel, J., et al. (2014). Filipins: The first antifungal “weed killers” identified from bacteria isolated from the trap-ant. RSC Adv., 4(100), 57267–57270.
Abstract: Allomerus ants ensure that they have sufficient nitrogen in their diet by trapping and consuming other insects. In order to construct their traps, like the more extensively studied leaf cutter ants, they employ fungal farming. Pest management within these fungal cultures has been speculated to be due to the ants' usage of actinomycetes capable of producing antifungal compounds, analogous to the leafcutter ant mutualism. Here we report the first identification of a series of antifungal compounds, the filipins, and their associated biosynthetic genes isolated from a bacterium associated with this system.
Keywords: Anti-fungal
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Hudson, L. N., Newbold, T., Contu, S., Hill, S. L. L., Lysenko, I., De Palma, A., et al. (2014). The PREDICTS database: A global database of how local terrestrial biodiversity responds to human impacts. Ecology and Evolution, 4(24), 4701–4735.
Abstract: Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015. The collation of biodiversity datasets with broad taxonomic and biogeographic extents is necessary to understand historical declines and to project – and hopefully avert – future declines. We describe a newly collated database of more than 1.6 million biodiversity measurements from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world.
Keywords: Data sharing; Global change; Habitat destruction; Land use
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Lebrini, M., Robert, F., & Roos, C. (2010). Inhibition Effect of Alkaloids Extract from Annona Squamosa Plant on the Corrosion of C38 Steel in Normal Hydrochloric Acid Medium. Int. J. Electrochem. Sci., 5(11), 1698–1712.
Abstract: In this work, an alkaloids extract from Annona squamosa plant have been studied as possible corrosion inhibitor for C38 steel in molar hydrochloric acid (1 M HCl). Potentiodynamic polarization and AC impedance methods have been used. The corrosion inhibition efficiency increases on increasing plant extract concentration. Polarisation studies showed that Annona squamosa extract was mixed-type inhibitor in 1 M HCl. The inhibition efficiency of Annona squamosa extract was temperature-dependent and its addition led to an increase of the activation corrosion energy revealing a physical adsorption between the extract and the metal surface. The adsorption of the Annona squamosa extract followed Langmuir's adsorption isotherm. The inhibitive effect of Annona squamosa is ascribed to the presence of organic compounds in the extract. The examined extract is considered as non-cytotoxic substance.
Keywords: Plant extract; corrosion inhibitors; C38 steel; acidic media; adsorption
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Revel, M., Dejean, A., Cereghino, R., & Roux, O. (2010). An Assassin among Predators: The Relationship between Plant-Ants, Their Host Myrmecophytes and the Reduviidae Zelus annulosus. PLoS One, 5(10), e13110.
Abstract: Tropical plants frequently live in association with ants that protect their foliage from defoliators. Among them, myrmecophytes have evolved mutualisms with a limited number of plant-ants that they shelter and feed, and, in return, benefit from some protection. Hirtella physophora (Chrysobalanaceae), for example, houses Allomerus decemarticulatus (Myrmicinae) that build gallery-shaped traps to catch large prey. In French Guiana, we frequently observed the assassin bug Zelus annulosus (Reduviidae, Harpactorinae) on the leaves of H. physophora. Here, we studied the distribution of Zelus annulosus among understory plants in the Guianese rainforest and found it only on pubescent plants, including H. Physophora, whether or not it was sheltering an A. decemarticulatus colony, but only rarely on other myrmecophytes. The relationship between Z. annulosus and its host plants is, then, also mutualistic, as the plant trichomes act as an enemy-free space protecting the nymphs from large predatory ants, while the nymphs protect their host-plants from herbivorous insects. Through their relationship with A. decemarticulatus colonies, Z. annulosus individuals are protected from army ants, while furnishing nothing in return. In those cases where H. physophora sheltered both an A. decemarticulatus colony and Z. annulosus nymphs, certain plant individuals repeatedly sheltered nymphs, indicating that female bugs may select not only pubescent plants but also particular H. physophora treelets having characteristics more favourable to the development of their progeny.
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Dejean, A., Leroy, C., Corbara, B., Roux, O., Cereghino, R., Orivel, J., et al. (2010). Arboreal Ants Use the "Velcro (R) Principle'' to Capture Very Large Prey. PLoS One, 5(6), e11331.
Abstract: Plant-ants live in a mutualistic association with host plants known as "myrmecophytes'' that provide them with a nesting place and sometimes with extra-floral nectar (EFN) and/or food bodies (FBs); the ants can also attend sap-sucking Hemiptera for their honeydew. In return, plant-ants, like most other arboreal ants, protect their host plants from defoliators. To satisfy their nitrogen requirements, however, some have optimized their ability to capture prey in the restricted environment represented by the crowns of trees by using elaborate hunting techniques. In this study, we investigated the predatory behavior of the ant Azteca andreae which is associated with the myrmecophyte Cecropia obtusa. We noted that up to 8350 ant workers per tree hide side-by-side beneath the leaf margins of their host plant with their mandibles open, waiting for insects to alight. The latter are immediately seized by their extremities, and then spread-eagled; nestmates are recruited to help stretch, carve up and transport prey. This group ambush hunting technique is particularly effective when the underside of the leaves is downy, as is the case for C. obtusa. In this case, the hook-shaped claws of the A. andreae workers and the velvet-like structure of the underside of the leaves combine to act like natural Velcro (R) that is reinforced by the group ambush strategy of the workers, allowing them to capture prey of up to 13,350 times the mean weight of a single worker.
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Dejean, A., Fisher, B. L., Corbara, B., Rarevohitra, R., Randrianaivo, R., Rajemison, B., et al. (2010). Spatial Distribution of Dominant Arboreal Ants in a Malagasy Coastal Rainforest: Gaps and Presence of an Invasive Species. PLoS One, 5(2), e9319.
Abstract: We conducted a survey along three belt transects located at increasing distances from the coast to determine whether a non-random arboreal ant assemblage, such as an ant mosaic, exists in the rainforest on the Masoala Peninsula, Madagascar. In most tropical rainforests, very populous colonies of territorially dominant arboreal ant species defend absolute territories distributed in a mosaic pattern. Among the 29 ant species recorded, only nine had colonies large enough to be considered potentially territorially dominant; the remaining species had smaller colonies and were considered non-dominant. Nevertheless, the null-model analyses used to examine the spatial structure of their assemblages did not reveal the existence of an ant mosaic. Inland, up to 44% of the trees were devoid of dominant arboreal ants, something not reported in other studies. While two Crematogaster species were not associated with one another, Brachymyrmex cordemoyi was positively associated with Technomyrmex albipes, which is considered an invasive species-a non-indigenous species that has an adverse ecological effect on the habitats it invades. The latter two species and Crematogaster ranavalonae were mutually exclusive. On the other hand, all of the trees in the coastal transect and at least 4 km of coast were occupied by T. albipes, and were interconnected by columns of workers. Technomyrmex albipes workers collected from different trees did not attack each other during confrontation tests, indicating that this species has formed a supercolony along the coast. Yet interspecific aggressiveness did occur between T. albipes and Crematogaster ranavalonae, a native species which is likely territorially dominant based on our intraspecific confrontation tests. These results suggest that the Masoala rainforest is threatened by a potential invasion by T. albipes, and that the penetration of this species further inland might be facilitated by the low density of native, territorially dominant arboreal ants normally able to limit its progression.
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Roux, O., Billen, J., Orivel, J., & Dejean, A. (2010). An Overlooked Mandibular-Rubbing Behavior Used during Recruitment by the African Weaver Ant, Oecophylla longinoda. PLoS One, 5(2), e8957.
Abstract: In Oecophylla, an ant genus comprising two territorially dominant arboreal species, workers are known to (1) use anal spots to mark their territories, (2) drag their gaster along the substrate to deposit short-range recruitment trails, and (3) drag the extruded rectal gland along the substrate to deposit the trails used in long-range recruitment. Here we study an overlooked but important marking behavior in which O. longinoda workers first rub the underside of their mandibles onto the substrate, and then-in a surprising posture-tilt their head and also rub the upper side of their mandibles. We demonstrate that this behavior is used to recruit nestmates. Its frequency varies with the rate at which a new territory, a sugary food source, a prey item, or an alien ant are discovered. Microscopy analyses showed that both the upper side and the underside of the mandibles possess pores linked to secretory glands. So, by rubbing their mandibles onto the substrate, the workers probably spread a secretion from these glands that is involved in nestmate recruitment.
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Baraloto, C., Ferreira, E., Rockwell, C., & Walthier, F. (2007). Limitations and Applications of Parataxonomy for Community Forest Management in Southwestern Amazonia. Ethnobotany Research & Applications, 5, 77–84.
Abstract: We examined the limitations of parataxonomic inventories for developing management plans for woody plant resources in tropical rain forests of southwestern Amazonia. Using compilations of herbarium labels, forest personnel interviews and published species descriptions, we assessed the accuracy of common names as parataxonomic units (PUs). We identified 384 common names for 310 harvested woody plant species in the Brazilian state of Acre, of which only 50% were unique to a single taxonomic species. About 10% of common names referred to more than one species, more than half of which included multiple genera. For the 106 species from the Acre sample common to the MAP region including Madre de Dios, Peru and Pando, Bolivia, we identified 198 common names. Splitting was much more frequent in this sample, with more than 80% of species having more than one common name. When the Acre sample was expanded to 131 species from the Brazilian Amazon region, including the states of Amazonas and Para, we identified 740 common names, with nearly 90% of species being represented by more than one common name. Errors and inaccuracy of parataxonomy may contribute to market instability if product orders can not be homogenized within regional markets, and to unsustainable harvests if species are mistakenly lumped into single parataxonomic units. We discuss several programs currently being implemented by our collaborative team in the region to address this issue, including field guides based on digital photography, field courses, and workshops featuring discussions between regional inventory personnel and botanists.
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Petillon, J., Montaigne, W., & Renault, D. (2009). Hypoxic coma as a strategy to survive inundation in a salt-marsh inhabiting spider. Biol. Lett., 5(4), 442–445.
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Cachet, N., Ho-A-Kwie, F., Rivaud, M., Houel, E., Deharo, E., Bourdy, G., et al. (2012). Picrasin K, a new quassinoid from Quassia amara L. (Simaroubaceae). Phytochem. Lett., 5(1), 162–164.
Abstract: A new quassinoid Picrasin K 1 was isolated from a decoction made of Quassia amara leaves, traditionally used in French Guyana to treat malaria. The structure and relative stereochemistry of 1 was determined through extensive NMR analysis. Picrasin K showed a low activity against Plasmodium falciparum in vitro (IC 50 = 8 μM), and a similar low activity on human cancerous cells line (IC 50 = 7 μM on MCF-7 cells line). © 2011 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.
Keywords: Malaria; P. falciparum; Quassia amara; Quassinoids; Simaroubaceae
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