1,067 research outputs found

    Decomposition patterns and nitrogen dynamics of black mangrove (Avicennia germinans)leaf litter in disturbed estuaries linked to the Lower Laguna Madre, Texas

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    Estuaries are among the most productive aquatic systems in the world but are subject to both anthropogenic and natural disturbances. With increasing environmental concerns, efforts have become commonplace in assessing the status and trends of environmental conditions. In this study, an assessment of ecosystem status of various estuaries affected by different disturbances, was attempted through the examination of key functional processes such as leaf litter decomposition and nutrient dynamics during decay. Three estuaries located along the Brownsville Ship Channel near the southern terminus of the Lower Laguna Madre in Texas were studied. The overlying goal of this study was to compare the functional state of these estuaries, utilizing leaf litter decomposition rates and nitrogen dynamics. Black mangrove (Avicennia germinans) leaves were used as the decomposition substrate since it is endogenous to the Lower Laguna Madre system. Several aims were addressed in this investigation: 1) determine decomposition patterns (decay rates, half-­‐lives, recalcitrant pool sizes); 2) compare N content changes in decomposing mangrove leaves; 3) evaluate N immobilization/release during decay processes; and 4) appraise the value of decomposition process and N dynamics measurements as functional indicators in estuaries linked to LLM. Metrics derived from the decomposition process and concurrent N dynamics of leaf litter did discriminate among sites with different known disturbance histories. The ranking of the studied sites based in decomposition patterns did not fully correspond to the ranking obtained through the variables of N dynamics. v While these processes are linked by the activity of the decomposer community, they should be looked at separately to further classify the stability and ecological status of this type of estuarine systems in terms of ecosystem function

    Fully Automated Fact Checking Using External Sources

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    Given the constantly growing proliferation of false claims online in recent years, there has been also a growing research interest in automatically distinguishing false rumors from factually true claims. Here, we propose a general-purpose framework for fully-automatic fact checking using external sources, tapping the potential of the entire Web as a knowledge source to confirm or reject a claim. Our framework uses a deep neural network with LSTM text encoding to combine semantic kernels with task-specific embeddings that encode a claim together with pieces of potentially-relevant text fragments from the Web, taking the source reliability into account. The evaluation results show good performance on two different tasks and datasets: (i) rumor detection and (ii) fact checking of the answers to a question in community question answering forums.Comment: RANLP-201

    Subsidiariedad y gobernanza en el desarrollo turístico del centro histórico de Pachuca de Soto: diagnóstico y propuesta

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    El caso se refiere al centro histórico de la ciudad de Pachuca de Soto, ubicada a 96 kilómetros al noreste de la ciudad de México, con una población de 267 mil 852 habitantes según el censo de población de 2010. El centro histórico de Pachuca de Soto es una opción importante para la recreación de fin de semana de los habitantes localizados en la zona centro del país, se ubica en un valle angosto en el sentido orienteponiente y alargado de norte a sur. Sus once plazas agrupan el patrimonio histórico cuyo origen va desde la etapa colonial española hasta la era post revolucionaria, enmarcado por el caserío que se asentó en las laderas debido a la actividad minera

    Differential evolution in shortest path problems

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    This paper proves that the Differential Evolution (DE) algorithm is valid to solve the Shortest Path (SP) problem in random, median sized networks. From the trials, we have obtained an 9% accuracy, in the worst case scenario.info:eu-repo/semantics/publishedVersio

    Presencia y abundancia de aves acuáticas en la Meseta Strobel, Patagonia, Argentina

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    La meseta Strobel, ubicada en la estepa patagónica, alberga más de 1500 lagunas que son utilizadas regularmente por aves acuáticas, incluyendo una de las principales poblaciones reproductivas del Macá Tobiano (Podiceps gallardoi), una especie endémica de la Patagonia austral. Se registró la presencia y abundancia de aves acuáticas en 41 lagunas, cubriendo el amplio espectro de la variabilidad ambiental de la región. Se llevaron a cabo seis campañas de campo desde fines de primavera a principios de otoño en el período 2004–2006. Se registraron un total de 18 especies de aves acuáticas correspondientes a cinco familias. La familia Anatidae fue la más representada con 12 especies, constituyendo el 85% de las aves acuáticas observadas. La distribución de las aves entre las lagunas fue variable, desde un 2.4% de lagunas ocupadas por el Falaropo Común (Steganopus tricolor) y el Pato Zambullidor Grande (Oxyura jamaicensis) hasta un 80% ocupadas por el Cisne Cuello Negro (Cygnus melanocorypha), y la abundancia varió mucho entre especies y estaciones. El Macá Tobiano, en particular, fue observado en 14 lagunas (1–81 individuos). Seis especies fueron detectadas reproduciéndose en la meseta: el Macá Tobiano, el Macá Plateado (Podiceps occipitalis), el Quetro Volador (Tachyeres patachonicus), el Pato Crestón (Anas specularioides), el Cauquén Común (Chloephaga picta) y la Gallareta Chica (Fulica leucoptera). El Macá Tobiano nidificó en cuatro lagunas, tres de las cuales no habían sido reportadas previamente como sitio de reproducción. Los resultados evidencian la necesidad de generar estudios futuros basados en la dinámica de uso de las lagunas para determinar adecuadamente la importancia de la meseta Strobel como hábitat para la avifauna acuática.The Strobel Plateau is a conspicuous and representative basaltic plateau (“meseta”) in the Patagonian steppe, Argentina. This plateau is dotted with more than 1500 shallow lakes, which are regularly used by waterbirds and support one of the main breeding populations of the near threatened Hooded Grebe (Podiceps gallardoi). We collected data on bird presence and abundance in 41 shallow lakes, covering a wide spectrum of the wetland environmental variability found in the area. We conducted six surveys from spring to fall between 2004 and 2006. We recorded a total of 18 waterbird species, which represent 5 different families. Anatidae was the family most represented with 12 species, accounting for 85% of the observed waterbirds. Waterbird distribution among lakes was variable, from 2.4% occupied lakes for Wilson’s Phalarope (Steganopus tricolor) and Andean Ruddy-Duck (Oxyura jamaicensis) to 80% for Black-necked Swan (Cygnus melanocorypha), and abundance varied greatly both between species and seasons. The Hooded Grebe, in particular, was recorded in 14 lakes (1–81 individuals). Six species were detected breeding in the area: Hooded Grebe, Silvery Grebe (Podiceps occipitalis), Flying Steamer-Duck (Tachyeres patachonicus), Crested Duck (Anas specularioides), Upland Goose (Chloephaga picta), and White-winged Coot (Fulica leucoptera). The Hooded Grebe nested at four lakes, three of them not previously known to hold breeding birds. Results point to the need of further studies on the dynamic nature of waterbird lake use to adequately assess the importance of the Strobel Plateau as waterbird habitat.Fil: Lancelotti, Julio Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Pozzi, Luciana Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Marquez, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados UnidosFil: Pascual, Miguel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentin

    Fact Checking in Community Forums

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    Community Question Answering (cQA) forums are very popular nowadays, as they represent effective means for communities around particular topics to share information. Unfortunately, this information is not always factual. Thus, here we explore a new dimension in the context of cQA, which has been ignored so far: checking the veracity of answers to particular questions in cQA forums. As this is a new problem, we create a specialized dataset for it. We further propose a novel multi-faceted model, which captures information from the answer content (what is said and how), from the author profile (who says it), from the rest of the community forum (where it is said), and from external authoritative sources of information (external support). Evaluation results show a MAP value of 86.54, which is 21 points absolute above the baseline.Comment: AAAI-2018; Fact-Checking; Veracity; Community-Question Answering; Neural Networks; Distributed Representation

    A near zero consumption building as an urban acupuncture for a vertical slum. A case study in the city of Malaga, Spain

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    Vertical slum is defined as a particularly vulnerable height building, with serious problems of functionality, safety and habitability. Venezuela’s Tower of David is a famous example. Vertical slums are associated with an important level of physical degradation, coupled with a precarious socioeconomic situation of its occupants. Their inability to create a community for proper and mandatory maintenance increases their physical deterioration. The abandonment of the original owners is replaced by a system of occupation and illegal activities. In many cases, with an interest in maintaining the building in a state of precariousness, which annuls any attempt to rehabilitate it Facing this situation, the intervention is proposed through an urban acupuncture project, understood as a project of expropriation and physical rehabilitation of the building, associated to a project of social rehabilitation in a disadvantaged environment. It is about creating a hybrid building associated with four objectives 1- Create a hybrid building with a mixed offer of social and housing services: sheltered housing for seniors, residence and accommodation for young entrepreneurs. The idea of a social condenser is related to studies of the hybrid building such as the Downtown Athletic Club in New York, or the Rokade Tower and Maartenshof residence (Groningen, The Netherlands). 2- Incorporate the sustainability parameters directed to a building almost zero. 3- Incorporate a model of provision of housing services, managed by the municipality, but with the possibility of incorporating NGOs 4- Design a social rehabilitation project that facilitates the creation of a web of social-based companies or cooperatives that fosters entrepreneurship, and that can actively participate in the rehabilitation and maintenance of the neighborhood itself. This paper applies these principles to a building in Malaga as a case study and 10 strategies are developed and analysed in regards to its physical, social and sustainable transformation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    DANTE - The combination between an ant colony optimization algorithm and a depth search method

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    The ε-DANTE method is an hybrid meta-heuristic. In combines the evolutionary Ant Colony Optimization (ACO) algorithms with a limited Depth Search. This Depth Search is based in the pheromone trails used by the ACO, which allows it to be oriented to the more promising areas of the search space. Some results are presented for the multiple objective k-Degree Spanning Trees problem, proving the effectiveness of the method when compared with other already tested evolutionary methods. © 2008 IEEE

    Analysis of Resistance to Vine Decline Disease Caused by Monosporascus cannonballus in Melons (Cucumis melo L)

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    Vine decline disease (VDD) caused by the fungus Monosporascus cannonballus, is a major threat to melons (Cucumis melo L.) production worldwide. Resistance has been identified in some melon accessions, yet little is known abouts its genetic control and mode of action. Thus, the goals of this project were to determine the mode of inheritance and the type of gene action of the resistance found in the USDA accession: PI 124104 as well as to identify metabolites involved in it. The F1, F2, BC1 and BC2 populations from the cross of VDD-susceptible parent, TAM-Uvalde with a resistant VDD-USDA PI 124104. Generation means analysis indicated that additive and dominant effects were present in the inheritance of the VDD resistance trait. Broad-sense heritability estimate of this trait was high (0.74) and narrow-sense heritability estimate was moderate (0.47). Chi-square analysis indicates that the resistance is controlled by three independent genes. Additionally, mid parent-offspring regression showed that some hybrids developed with the variety USDA PI 124104 exhibited medium to high narrow sense heritability values (0.6 and 0.66). However, these results may be inflated due to the presence of heterosis. Several metabolites were differentially accumulated in resistant and susceptible genotypes in response to pathogen infection. Particularly, results shows that phthalic acid is constitutive and induced in VDD-resistant genotype in response to pathogen infection suggesting a putative role on VDD-resistance reaction. However, further research using forward, and reverse genetic approaches are needed to determine the role of phthalic acid in the resistance to Monosporascus cannonballus, in melons
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