385 research outputs found

    What can possibly go wrong? The risks of introducing soil microorganisms from Antarctica into South America = ¿Qué puede salir mal? : Los riesgos de introducir microorganismos del suelo de la Antártida en América del Sur

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    Endophytic fungi form mutualistic associations with plant roots which can increase plant survival and resistance to stress. Recently, it has been proposed that endophytic fungi from Antarctica should be used to facilitate reintroduction and establishment of native plants in xeric environments of northern Chile. In this note, we suggest this is a risky proposition and may lead to biological invasions. It is difficult to predict which endophytic fungi will become invasive, where they will invade, or what their impacts will be. Organisms that move across continents may or may not become invasive depending on the interaction between the species and the invaded community; unexpected outcomes may occur due to adaptation and novel interactions of the introduced species in the new environment. The fact that these endophytes are mutualistic does not imply that they will not have negative effects on the recipient community, since they might promote invasion of other non-native species or may change the competitive relationships among native species. Further, taxonomically uncharacterized fungal isolates from plant roots are likely to contain non-beneficial species. The fact that these endophytic fungi species are from Antarctica does not ensure that they cannot invade elsewhere. It should be recognized that invasive microorganisms are extremely difficult to control. We strongly suggest that the further translocation, use and spread of endophytes from Antarctica should be halted until a risk assessment is undertaken. Biosecurity measures must be taken when considering transcontinental experiments. Based on previous experiences, it is likely that the risk and potential costs of introducing these new species significantly exceed any potential benefits of their introductionsLos hongos endófitos forman asociaciones mutualísticas con raíces de plantas y pueden mejorar la sobrevivencia y resistencia al estrés. Recientemente se ha propuesto usar hongos endófitos de la Antártida para facilitar la reintroducción y establecimiento de plantas nativas en formaciones xerofíticas del norte de Chile. En esta nota se sugiere que aquello es una propuesta riesgosa y puede conducir a invasiones biológicas. Es difícil predecir qué especies se convertirán en invasoras, dónde lo harán o cuáles serán sus efectos. Los organismos transportados entre continentes pueden o no convertirse en invasores, según las interacciones entre especies y con la comunidad invadida, y pueden ocurrir resultados inesperados debido a adaptaciones de especies invasoras al nuevo ambiente y a novedosas interacciones con especies introducidas en el nuevo ambiente. Estos endófitos mutualistas pueden tener efectos negativos en la comunidad receptora, como promover invasiones de otras especies exóticas o cambiar relaciones de competencia entre especies nativas. Los hongos endófitos de la Antártida no garantizan que no puedan invadir otros lugares. La falta de identificación taxonómica de tales hongos impide saber si estos inóculos contienen especies no beneficiosas, como patógenos del suelo. Los microorganismos invasores son extremadamente difíciles de controlar. Por ello, se recomienda que la translocación, uso y dispersión de hongos endófitos antárcicos debiera detenerse hasta tener una evaluación del riesgo de su introducción. Medidas de bioseguridad deben tomarse en experimentos transcontinentales. Según experiencias anteriores, el riesgo y costos potenciales de introducir estas especies pueden superar ampliamente cualquier beneficio potencial de su uso.Fil: Nuñez, Martin A. Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad del Comahue. INIBIOMA. Grupo de Ecología de Invasiones; ArgentinaFil: Dimarco, Romina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas-Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Grupo de Ecología de Poblaciones de Insectos; ArgentinaFil: Dickie, Ian A. Lincoln University. Bio-Protection Research Centre; Nueva ZelandaFil: Pauchard, Anibal. Universidad de Concepción. Facultad de Ciencias Forestales. Laboratorio de Invasiones Biolóogicas; Chile. Institute of Ecology and Biodiversity (IEB); Chil

    What are the economic costs of biological invasions? A complex topic requiring international and interdisciplinary expertise

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    Biological invasions can cause substantial economic losses and expenses for management, as well as harm biodiversity, ecosystem services and human well-being. A comprehensive assessment of the economic costs of invasions is a challenging but essential prerequisite for efficient and sustainable management of invasive alien species. Indeed, these costs were shown to be inherently heterogeneous and complex to determine, and substantial knowledge gaps prevent a full understanding of their nature and distribution. Hence, the development of a still-missing global, standard framework for assessing and deciphering invasion costs is essential to identify effective management approaches and optimise legislation. The recent advent of the InvaCost database – the first comprehensive and harmonised compilation of the economic costs associated with biological invasions worldwide – offers unique opportunities to investigate these complex and diverse costs at different scales. Insights provided by such a dataset are likely to be greatest when a diverse range of experience and expertise are combined. For this purpose, an international and multidisciplinary workshop was held from 12th to 15th November 2019 near Paris (France) to launch several project papers based on the data available in InvaCost. Here, we highlight how the innovative research arising from this workshop offers a major step forward in invasion science. We collectively identified five core research opportunities that InvaCost can help to address: (i) decipher how existing costs of invasions are actually distributed in human society; (ii) bridge taxonomic and geographic gaps identified in the costs currently estimated; (iii) harmonise terminology and reporting of costs through a consensual and interdisciplinary framework; (iv) develop innovative methodological approaches to deal with cost estimations and assessments; and (v) provide cost-based information and tools for applied management of invasions. Moreover, we attribute part of the success of the workshop to its consideration of diversity, equity and societal engagement, which increased research efficiency, creativity and productivity. This workshop provides a strong foundation for substantially advancing our knowledge of invasion impacts, fosters the establishment of a dynamic collaborative network on the topic of invasion economics, and highlights new key features for future scientific meetings.Fil: Diagne, Christophe. Universite Paris-Saclay;Fil: Catford, Jane A.. King's College London; Reino UnidoFil: Essl, Franz. Universidad de Viena; AustriaFil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Courchamp, Franck. Universite Paris-Saclay

    Propagule pressure hypothesis not supported by an 80-year experiment on woody species invasion

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    Ecological filters and availability of propagules play key roles structuring natural communities. Propagule pressure has recently been suggested to be a fundamental factor explaining the success or failure of biological introductions. We tested this hypothesis with a remarkable data set on trees introduced to Isla Victoria, Nahuel Huapi National Park, Argentina. More than 130 species of woody plants, many known to be highly invasive elsewhere, were introduced to this island early in the 20th century, as part of an experiment to test their suitability as commercial forestry trees for this region. We obtained detailed data on three estimates of propagule pressure (number of introduced individuals, number of areas where introduced, and number of years during which the species was planted) for 18 exotic woody species. We matched these data with a survey of the species and number of individuals currently invading the island. None of the three estimates of propagule pressure predicted the current pattern of invasion. We suggest that other factors, such as biotic resistance, may be operating to determine the observed pattern of invasion, and that propagule pressure may play a relatively minor role in explaining at least some observed patterns of invasion success and failure

    Bimodal Nd-doped luVo4 nanoprobes functionalized with polyacrilic acid for x-ray computed tomography and NIR luminescent imaging

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    Uniform Nd3+-doped LuVO4 nanophosphors have been synthesized for the first time in literature by using a poliol-based method at 120 °C from Nd3+ and vanadate precursors. After optimizing the Nd doping level, these phosphors present intense luminescence in the near-infrared biological windows. The X-ray attenuation capacity of the optimum nanophosphor has been found to be higher than that of a commercial X-ray computed tomography contrast agent. After surface coating with polyacrylic acid, such nanoparticles present high colloidal stability in physiological pH medium and high cell viability. Because of these properties, the developed Nd3+-doped LuVO4 nanoparticles have potential applications as a bimodal probe for NIR luminescent bioimaging and X-ray computed tomography

    IKKα negatively regulates ASC-dependent inflammasome activation.

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    The inflammasomes are multiprotein complexes that activate caspase-1 in response to infections and stress, resulting in the secretion of pro-inflammatory cytokines. Here we report that IκB kinase α (IKKα) is a critical negative regulator of apoptosis-associated specklike protein containing a C-terminal caspase-activation-andrecruitment (CARD) domain (ASC)-dependent inflammasomes. IKKα controls the inflammasome at the level of the adaptor ASC, which interacts with IKKα in the nucleus of resting macrophages in an IKKα kinase-dependent manner. Loss of IKKα kinase activity results in inflammasome hyperactivation. Mechanistically, the downstream nuclear effector IKK-related kinase (IKKi) facilitates translocation of ASC from the nucleus to the perinuclear area during inflammasome activation. ASC remains under the control of IKKα in the perinuclear area following translocation of the ASC/IKKα complex. Signal 2 of NLRP3 activation leads to inhibition of IKKα kinase activity through the recruitment of PP2A, allowing ASC to participate in NLRP3 inflammasome assembly. Taken together, these findings reveal a IKKi-IKKα-ASC axis that serves as a common regulatory mechanism for ASC-dependent inflammasomes

    Global Invader Impact Network (GIIN): toward standardized evaluation of the ecological impacts of invasive plants

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    Terrestrial invasive plants are a global problem and are becoming ubiquitous components of most ecosystems. They are implicated in altering disturbance regimes, reducing biodiversity, and changing ecosystem function, sometimes in profound and irreversible ways. However, the ecological impacts of most invasive plants have not been studied experimentally, and most research to date focuses on few types of impacts, which can vary greatly among studies. Thus, our knowledge of existing ecological impacts ascribed to invasive plants is surprisingly limited in both breadth and depth. Our aim was to propose a standard methodology for quantifying baseline ecological impact that, in theory, is scalable to any terrestrial plant invader (e.g., annual grasses to trees) and any invaded system (e.g., grassland to forest). The Global Invader Impact Network (GIIN) is a coordinated distributed experiment composed of an observational and manipulative methodology. The protocol consists of a series of plots located in (1) an invaded area; (2) an adjacent removal treatment within the invaded area; and (3) a spatially separate uninvaded area thought to be similar to pre-invasion conditions of the invaded area. A standardized and inexpensive suite of community, soil, and ecosystem metrics are collected allowing broad comparisons among measurements, populations, and species. The method allows for one-time comparisons and for long-term monitoring enabling one to derive information about change due to invasion over time. Invader removal plots will also allow for quantification of legacy effects and their return rates, which will be monitored for several years. GIIN uses a nested hierarchical scale approach encompassing multiple sites, regions, and continents. Currently, GIIN has network members in six countries, with new members encouraged. To date, study species include representatives of annual and perennial grasses; annual and perennial forbs; shrubs; and trees. The goal of the GIIN framework is to create a standard yet flexible platform for understanding the ecological impacts of invasive plants, allowing both individual and synthetic analyses across a range of taxa and ecosystems. If broadly adopted, this standard approach will offer unique insight into the ecological impacts of invasive plants at local, regional, and global scales.Fil: Barney, Jacob N. Virginia Tech. Department of Plant Pathology, Physiology, and Weed Science; Estados UnidosFil: Tekiela, Daniel R. Virginia Tech. Department of Plant Pathology, Physiology, and Weed Science; Estados UnidosFil: Barrios Garcia Moar, Maria Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. CENAC-APN; ArgentinaFil: Dimarco, Romina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas-Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Grupo de Ecología de Poblaciones de Insectos; ArgentinaFil: Hufbauer, Ruth A. Colorado State University. Department of Bioagricultural Sciences and Pest Management and Graduate Degree Program in Ecology; Estados UnidosFil: Leipzig-Scott, Peter. Colorado State University. Department of Bioagricultural Sciences and Pest Management and Graduate Degree Program in Ecology; Estados UnidosFil: Nuñez, Martin A. Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad del Comahue. INIBIOMA. Laboratorio de Ecotono; ArgentinaFil: Pauchard, Anibal. Universidad de Concepción. Facultad de Ciencias Forestales. Laboratorio de Invasiones Biolóogicas; Chile. Institute of Ecology and Biodiversity (IEB); ChileFil: Pysek, Petr. The Czech Academy of Sciences. Institute of Botany. Department of Invasion Ecology; República Checa. Charles University in Prague. Faculty of Science. Department of Ecology; República ChecaFil: Viıtkov, Michaela. The Czech Academy of Sciences. Institute of Botany. Department of Invasion Ecology; República ChecaFil: Maxwell, Bruce D. Montana State University. Department of Land Resources and Environmental Sciences; Estados Unido

    Going up the Andes: patterns and drivers of non-native plant invasions across latitudinal and elevational gradients

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    The Andes mountain range in South America has a high level of endemism and is a major source of ecosystem services. The Andes is increasingly threatened by anthropogenic disturbances that have allowed the establishment of non-native plants, mainly in the lower elevation areas. However, synergies between climate change and anthropogenic pressure are promoting the spread of non-native plants to higher elevation areas. In this article, we evaluate and identify the main non-native plants invading Andean ecosystems, and assess their taxonomic families, growth forms and distribution patterns. Based on a systematic literature review, we identified the importance of climatic and anthropogenic factors as drivers of non-native species establishment in Andean ecosystems and the main impacts of non-native plants in the Andes. We then identified research gaps across each biogeographic region in the Andes. Finally, we highlight key elements to better tackle the problem of non-native plant invasions in Andean ecosystems, including the need for a systematic monitoring of invasion patterns and spread (e.g. MIREN protocol) and a common policy agenda across international borders for the prevention and management of non-native plants in this highly vulnerable region.Fil: Fuentes Lillo, Eduardo. Universidad de Concepción; Chile. Universiteit Antwerp; BélgicaFil: Lembrechts, Jonas J.. Universiteit Antwerp; BélgicaFil: Barros, Ana Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Aschero, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Bustamante, Ramiro O.. Universidad de Chile; ChileFil: Cavieres, Lohengrin A.. Universidad de Concepción; ChileFil: Clavel, Jan. Universiteit Antwerp; BélgicaFil: Herrera, Ileana. Universidad Espíritu Santo; EcuadorFil: Jiménez, Alejandra. Universidad de Concepción; ChileFil: Tecco, Paula Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Hulme, Philip E.. Lincoln University.; Nueva ZelandaFil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Rozzi, Ricardo. University of North Texas; Estados UnidosFil: García, Rafael A.. Universidad de Concepción; ChileFil: Simberloff, Daniel. University of Tennessee; Estados UnidosFil: Nijs, Ivan. Universiteit Antwerp; BélgicaFil: Pauchard, Aníbal. Universidad de Concepción; Chil

    RG flows from Spin(7), CY 4-fold and HK manifolds to AdS, Penrose limits and pp waves

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    We obtain explicit realizations of holographic renormalization group (RG) flows from M-theory, from E^{2,1} \times Spin(7) at UV to AdS_4 \times \tilde{S^7} (squashed S^7) at IR, from E^{2,1} \times CY4 at UV to AdS_4 \times Q^{1,1,1} at IR, and from E^{2,1} \times HK (hyperKahler) at UV to AdS_4 \times N^{0,1,0} at IR. The dual type IIA string theory configurations correspond to D2-D6 brane systems where D6 branes wrap supersymmetric four-cycles. We also study the Penrose limits and obtain the pp-wave backgrounds for the above configurations. Besides, we study some examples of non-supersymmetric and supersymmetric flows in five-dimensional gauge theories.Comment: 42 pages, 6 eps figures, typos and misprints correcte
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