33 research outputs found

    Partitioning the effects of habitat loss hunting and climate change on the endangered Chacoan peccary

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    Aim: Land-use change and overexploitation are major threats to biodiversity, and cli mate change will exert additional pressure in the 21st century. Although there are strong interactions between these threats, our understanding of the synergistic and compensatory effects on threatened species' range geography remains limited. Our aim was to disentangle the impact of habitat loss, hunting and climate change on spe cies, using the example of the endangered Chacoan peccary (Catagonus wagneri). Location: Gran Chaco ecoregion in South America. Methods: Using a large occurrence database, we integrated a time-calibrated species distribution model with a hunting pressure model to reconstruct changes in the distri bution of suitable peccary habitat between 1985 and 2015. We then used partitioning analysis to attribute the relative contribution of habitat change to land-use conver sion, climate change and varying hunting pressure. Results: Our results reveal widespread habitat deterioration, with only 11% of the habitat found in 2015 considered suitable and safe. Hunting pressure was the strong est single threat, yet most habitat deterioration (58%) was due to the combined, rather than individual, effects of the three drivers we assessed. Climate change would have led to a compensatory effect, increasing suitable habitat area, yet this effect was ne gated by the strongly negative and interacting threats of land-use change and hunting. Main Conclusions: Our study reveals the central role of overexploitation, which is often neglected in biogeographic assessments, and suggests that addressing overex ploitation has huge potential for increasing species' adaptive capacity in the face of climate and land-use change. More generally, we highlight the importance of jointly assessing extinction drivers to understand how species might fare in the 21st century. Here, we provide a simple and transferable framework to determine the separate and joint effects of three main drivers of biodiversity loss.Fil: Torres, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Diversidad y Ecología Animal ; Argentina.Fil: Kuemmerle, Tobias. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems. Geography Department; AlemaniaFil: Baumann, Matthias. Humboldt-University. Geography Department; Alemania.Fil: Romero Muñoz, Alfredo. Humboldt University. Geography Departament; Alemania. University of British Columbia. Institute for Resources, Environment and Sustainability (IRES); Canada. Helmholtz Centre for Environmental Research. Department Computational Landscape Ecology; Alemania. Transformations of Human-Environment Systems (IRI THESys). Integrative Research Institute; AlemaniaFil: Altrichter, Mariana. IUCN SSC Peccary Specialist Group; Suiza. Prescott College. Environmental Studies; Estados UnidosFil: Boaglio, Gabriel Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Cabral, Hugo. Universidade Estadual Paulista. Programa de Pós-Graduação em Biologia Animal; Brasil. Instituto de Investigación Biológica del Paraguay; ParaguayFil: Camino, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Ecología del Litoral. Laboratorio de Biología de la Conservación; ArgentinaFil: Campos Kraver, Juan M. University of Florida. College of Veterinary Medicine & Department of Wildlife Ecology and Conservation. Department of Large Animal Clinical Sciences; Estados UnidosFil: Giordano, Anthony. Society for the Preservation of Endangered Carnivores and their International Ecological Study (S.P.E.C.I.E.S); Estados Unidos. University of Los Angeles. Institute of the Environment and Sustainability. Center for Tropical Research; Estados UnidosFil: Cartes, José L. Guyra Paraguay, Parque del Río; ParaguayFil: Cuéllar, Rosa L. Fundación para la Conservación del Bosque Chiquitano; BoliviaFil: Decarre, Julieta. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Gallegos, Marcelo. Provincia de Salta. Secretaría de Ambiente; ArgentinaFil: Lizárraga, Leónidas. Administración De Parques Nacionales. Dirección Regional Noroeste. Salta; Argentina.Fil: Maffei, Leonardo. Biósfera Consultores Ambientales, Lima, Perú.Fil: Neris, Nora N. Secretaria del Ambiente; ParaguayFil: Quiroga, Verónica. Universidad Nacional de Córdoba. Inst. de Diversidad y Ecología Animal (IDEA – CONICET), Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Saldivar, Silvia. ITAIPU Binacional. Dirección de Coordinación. División de Áreas Protegidas; ParaguayFil: Tamburini, Daniela Maria. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Ecología y Recursos Naturales Renovables; Argentin

    2-Tridecanone impacts surface-associated bacterial behaviours and hinders plant-bacteria interactions

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    Surface motility and biofilm formation are behaviours which enable bacteria to infect their hosts and are controlled by different chemical signals. In the plant symbiotic alpha‐proteobacterium Sinorhizobium meliloti, the lack of long‐chain fatty acyl‐coenzyme A synthetase activity (FadD) leads to increased surface motility, defects in biofilm development, and impaired root colonization. In this study, analyses of lipid extracts and volatiles revealed that a fadD mutant accumulates 2‐tridecanone (2‐TDC), a methylketone known as a natural insecticide. Application of pure 2‐TDC to the wild‐type strain phenocopies the free‐living and symbiotic behaviours of the fadD mutant. Structural features of the methylketone determine its ability to promote S. meliloti surface translocation, which is mainly mediated by a flagella‐independent motility. Transcriptomic analyses showed that 2‐TDC induces differential expression of iron uptake, redox, and stress‐related genes. Interestingly, this methylketone also influences surface motility and impairs biofilm formation in plant and animal pathogenic bacteria. Moreover, 2‐TDC not only hampers alfalfa nodulation but also the development of tomato bacterial speck disease. This work assigns a new role to 2‐TDC as an infochemical that affects important bacterial traits and hampers plant‐bacteria interactions by interfering with microbial colonization of plant tissues

    Latino Communities in the United States: Place-Making in the Pre-World War II, Postwar, and Contemporary City

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    Scholarship on Latino communities in the United States has yet to catch up with the rapid growth of this ethnic population in the country. Understanding the Latino urban experience and developing plans to better respond to both the needs of Latino communities and their integration within society is not only relevant, but also urgently necessary. Using the city of Los Angeles as a main lens, in addition to a general look at the urban Southwest, we contribute to the scholarship on the subject with a review of literature on Latino communities. We structure the review as an assessment of the various challenges and opportunities for urban Latinos in the pre-war, postwar, and contemporary city. Focusing on space, culture, economy, and governance, we chart the various roles both the private and public sectors play in meeting these challenges. Our reading of the literature shows that particular government actions in the economic and governance domains in the past had positive impacts on Latino integration, and we call for a similar effort today in addressing contemporary challenges. We conclude by suggesting that future planning scholarship on Latino communities engage the wider urban studies literature, focus on emerging forms of urbanization, and call on planners to sustain increased academic and practical interest in the topic

    Modelling the potential impacts of climate change on the hydrology of the Aipe river basin in Huila, Colombia

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    [EN] The dynamics of a global world, and humans performing as a new geological force, require that an effort is undertaken to make robust decisions in order to devise strategies for the management and adaptation to climate change. This study aims to investigate the potential impact of climate change on the hydrology of the Aipe river basin in Huila, Colombia. The abcd Thomas model (four parameters) was calibrated and validated for the stream flows of the Aipe catchment (1992¿2012). The sensitivity and identifiability of the parameters were evaluated using the Monte Carlo Analysis Toolbox (MCAT). The results show the ability of the model to simulate the monthly stream flow (Nash¿Sutcliffe efficiency coefficient of 0,89). The most influential parameters are: a (water storage in the soil) and c (contribution to the aquifer). From the simulated scenarios, the baseline (1992¿2012) was estimated to be an average flow of 15,44 m3s¿1; the trend extrapolation scenario estimated a rate 13,79 m3s¿1 (¿10,64%); while for the multi-model assembly scenario it was 9,34 m3s¿1 (¿39,47%) and for the A2 scenario it was 5,74 m3s¿1 (¿62,60%). Lastly, we propose a set of strategies for adaptation to climate change that are committed to the integral management of water resources.[ES] La dinámica de un mundo global y el hombre como nueva fuerza geológica plantean la necesidad de tomar decisiones robustas, diseñar estrategias de manejo y de adaptarse al cambio climático. Este estudio investiga la respuesta hidrológica de la cuenca hidrográfica del río Aipe (688.9 km2 ), en Huila, Colombia, en acorde con los escenarios de cambio climático desde 2011 a 2040. El modelo hidrológico abcd de Thomas (4 parámetros) fue calibrado y validado comparando el caudal simulado y lo observado en el punto de cierre de la cuenca (en la estación Puente Carretera), usando series históricas mensuales (1992¿2012). Realizamos la evaluación de la sensibilidad e identificabilidad de los parámetros con la herramienta `Monte Carlo Analysis Toolbox¿ (MCAT). Los resultados muestran que el modelo es capaz de representar adecuadamente los caudales mensuales observados en el punto de desagüe de la cuenca, al encontrarse un índice de eficiencia de Nash¿Sutcliffe (NSE) de 0,89. Los parámetros más influyentes son a (almacenamiento del agua en el suelo) y c (aporte al acuífero). Con respecto a la simulación de los escenarios, la línea base (1992¿2012) estimó un caudal medio de 15,44 m3 s ¿1 ; el escenario de extrapolación de tendencias estimó un caudal de 13,79 m3 s ¿1 (¿10,64%); el escenario de ensamble multi-modelo de 9,34 m3 s ¿1 (¿39,47%) y el escenario A2 de 5,74 m3 s ¿1 (¿62,60%). Proponemos una batería de medidas de adaptación al cambio climático que buscan la gestión integral del recurso hídrico.Romero-Cuellar, J.; Buitrago-Vargas, A.; Quintero-Ruiz, T.; Francés, F. (2018). Simulación hidrológica de los impactos potenciales del cambio climático en la cuenca hidrográfica del río Aipe, en Huila, Colombia. RIBAGUA - Revista Iberoamericana del Agua. 5(1):63-78. https://doi.org/10.1080/23863781.2018.1454574S63785

    Approximate Bayesian Computation for Forecasting in Hydrological models

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    Approximate Bayesian Computation (ABC) is a statistical tool for handling parameter inference in a range of challenging statistical problems, mostly characterized by an intractable likelihood function. In this paper, we focus on the application of ABC to hydrological models, not as a tool for parametric inference, but as a mechanism for generating probabilistic forecasts. This mechanism is referred as Approximate Bayesian Forecasting (ABF). The abcd water balance model is applied to a case study on Aipe river basin in Columbia to demonstrate the applicability of ABF. The predictivity of the ABF is compared with the predictivity of the MCMC algorithm. The results show that the ABF method as similar performance as the MCMC algorithm in terms of forecasting. Despite the latter is a very flexible tool and it usually gives better parameter estimates it needs a tractable likelihoo

    Towards an Extension of the Model Conditional Processor: Predictive Uncertainty Quantification of Monthly Streamflow via Gaussian Mixture Models and Clusters

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    ABSTRACT: This research develops an extension of the Model Conditional Processor (MCP), which merges clusters with Gaussian mixture models to offer an alternative solution to manage heteroscedastic errors. The new method is called the Gaussian mixture clustering post-processor (GMCP). The results of the proposed post-processor were compared to the traditional MCP and MCP using a truncated Normal distribution (MCPt) by applying multiple deterministic and probabilistic verification indices. This research also assesses the GMCP's capacity to estimate the predictive uncertainty of the monthly streamflow under different climate conditions in the "SecondWorkshop on Model Parameter Estimation Experiment" (MOPEX) catchments distributed in the SE part of the USA. The results indicate that all three post-processors showed promising results. However, the GMCP post-processor has shown significant potential in generating more reliable, sharp, and accurate monthly streamflow predictions than the MCP and MCPt methods, especially in dry catchments. Moreover, the MCP and MCPt provided similar performances for monthly streamflow and better performances in wet catchments than in dry catchments. The GMCP constitutes a promising solution to handle heteroscedastic errors in monthly streamflow, therefore moving towards a more realistic monthly hydrological prediction to support effective decision-making in planning and managing water resources.This research was funded by the department of Huila Scholarship Program No. 677 (Colombia) and Colciencias, the Vice-Presidents Research and Social Work office of the Universidad Surcolombiana, the Spanish Ministry of Science and Innovation through research project TETISCHANGE (ref. RTI2018-093717-B-I00). Cristina Prieto acknowledges the financial support from the Government of Cantabria through the Fénix Program

    Complete Genome Sequence of Rice hoja blanca tenuivirus Isolated from a Susceptible Rice Cultivar in Colombia

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    We describe here the complete genome of Rice hoja blanca tenuivirus. The sequenced isolate was obtained by insect vector transmission from a symptomatic rice sample grown in Colombia. Sequence data from the four RNA components were obtained by deep sequencing (Illumina), and infections were confirmed by enzyme-linked immunosorbent assay and Sanger sequencing

    Sinorhizobium meliloti DnaJ Is Required for Surface Motility, Stress Tolerance, and for Efficient Nodulation and Symbiotic Nitrogen Fixation

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    Bacterial surface motility is a complex microbial trait that contributes to host colonization. However, the knowledge about regulatory mechanisms that control surface translocation in rhizobia and their role in the establishment of symbiosis with legumes is still limited. Recently, 2-tridecanone (2-TDC) was identified as an infochemical in bacteria that hampers microbial colonization of plants. In the alfalfa symbiont Sinorhizobium meliloti, 2-TDC promotes a mode of surface motility that is mostly independent of flagella. To understand the mechanism of action of 2-TDC in S. meliloti and unveil genes putatively involved in plant colonization, Tn5 transposants derived from a flagellaless strain that were impaired in 2-TDC-induced surface spreading were isolated and genetically characterized. In one of the mutants, the gene coding for the chaperone DnaJ was inactivated. Characterization of this transposant and newly obtained flagella-minus and flagella-plus dnaJ deletion mutants revealed that DnaJ is essential for surface translocation, while it plays a minor role in swimming motility. DnaJ loss-of-function reduces salt and oxidative stress tolerance in S. meliloti and hinders the establishment of efficient symbiosis by affecting nodule formation efficiency, cellular infection, and nitrogen fixation. Intriguingly, the lack of DnaJ causes more severe defects in a flagellaless background. This work highlights the role of DnaJ in the free-living and symbiotic lifestyles of S. meliloti

    "Modernidad" y polarización de la salud en México. Condiciones de vida de los trabajadores y sus familias "Modernity" and polarization of health in Mexico. Living conditions for workers and their families

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    Se analizan las características del proceso de modernización en México y el deterioro y polarización que ha producido en las condiciones de vida y salud de la población general y de los trabajadores y sus familias. Para ello se muestran diversos indicadores socioeconómicos y de salud. Respecto a la morbilidad, las enfermedades infecciosas ocupan un porcentaje muy elevado, pero otros fenómenos como diabetes, cirrosis hepática, infarto cardiaco, tumores malignos y accidentes y violencias son también serios problemas de salud pública. En regiones del país con características socioeconómicas bien diferenciadas, como los estados de Chiapas y Nuevo León, la polarización de la salud resulta más evidente aún. Por otra parte, el deterioro de las condiciones laborales y la información existente respecto a la salud de los trabajadores, a pesar de sus limitaciones, indican que los trabajadores deben ser considerados como un grupo prioritario. Se muestra el comportamiento paradójico de los accidentes y enfermedades laborales objetos de compensación, con menos accidentes pero más graves, y detección de enfermedades en grados muy avanzados, así como diferencias significativas en la morbilidad laboral en distintas ramas de la producción manufacturera.<br>This article analyzes the characteristics of the modernization process in Mexico and the polarization produced in living and health conditions for the general population as well as workers and their families. We studied socioeconomic and health indicators for this purpose. Infectious diseases occupy a high percentage of general morbidity, yet diseases such as diabetes, hepatic cirrhosis, myocardial infarction, malignant tumors, and accidents and violence are also serious public health problems as causes of morbidity and mortality. In some regions of the country with specific socioeconomic characteristics, polarization of health conditions is even more evident, as in the state of Chiapas as compared to Nuevo León. Deterioration of working conditions and available data on workers' health indicate that the latter should be considered a priority group for health measures. Such data also show the paradoxical trend of the more severe but less frequent work-related accidents and diseases that are subject to compensation as compared to the detection of chronic work-related diseases at an advanced stage, as well as significant differences in occupational morbidity among different branches of manufacturing
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