928 research outputs found

    Discovering Implicational Knowledge in Wikidata

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    Knowledge graphs have recently become the state-of-the-art tool for representing the diverse and complex knowledge of the world. Examples include the proprietary knowledge graphs of companies such as Google, Facebook, IBM, or Microsoft, but also freely available ones such as YAGO, DBpedia, and Wikidata. A distinguishing feature of Wikidata is that the knowledge is collaboratively edited and curated. While this greatly enhances the scope of Wikidata, it also makes it impossible for a single individual to grasp complex connections between properties or understand the global impact of edits in the graph. We apply Formal Concept Analysis to efficiently identify comprehensible implications that are implicitly present in the data. Although the complex structure of data modelling in Wikidata is not amenable to a direct approach, we overcome this limitation by extracting contextual representations of parts of Wikidata in a systematic fashion. We demonstrate the practical feasibility of our approach through several experiments and show that the results may lead to the discovery of interesting implicational knowledge. Besides providing a method for obtaining large real-world data sets for FCA, we sketch potential applications in offering semantic assistance for editing and curating Wikidata

    Comparison of outcomes in patients with abandoned versus extracted implantable cardioverter defibrillator leads

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    SummaryBackgroundDespite the increased number of implantable cardioverter defibrillator (ICD) recipients and the frequent need for device upgrading and/or occurrence of lead malfunction, the optimal approach to managing abandoned leads remains debated. Aims To determine the rate and type of complications related to either abandoned or extracted ICD leads. Methods Patients with abandoned or extracted leads were identified retrospectively. Patient medical records were reviewed to assess long-term lead or device malfunction, defibrillation test values before and after lead abandonment or extraction, and appropriateness of delivered shocks and subsequent surgical procedures related to devices or leads. Results A total of 58 ICD patients with 47 extracted and 34 abandoned leads were identified. After a mean follow-up of 3.2 ± 2.6 years, the defibrillation test was not affected by either abandoned or extracted leads (23.4 ± 6.6 J vs 25.4 ± 4.9 J, respectively; P = 0.24). There were no differences in the number of ICD-related surgical procedures after extracting versus abandoning leads (22% vs 12%, respectively; P = 0.3) or in the thromboembolic event rate (7.7% vs 6.3%; P = 0.83). During follow-up, no differences in the occurrence of major complications or appropriate/inappropriate shocks were observed between patients with or without abandoned leads. Conclusion We observed no difference in rates of immediate or medium-term complications between extracting versus abandoning leads. Lead abandonment remains an alternative and safe option when extraction does not appear mandatory according to the age of the leads or experience of the operating centre

    What is Normal, What is Strange, and What is Missing in a Knowledge Graph: Unified Characterization via Inductive Summarization

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    Knowledge graphs (KGs) store highly heterogeneous information about the world in the structure of a graph, and are useful for tasks such as question answering and reasoning. However, they often contain errors and are missing information. Vibrant research in KG refinement has worked to resolve these issues, tailoring techniques to either detect specific types of errors or complete a KG. In this work, we introduce a unified solution to KG characterization by formulating the problem as unsupervised KG summarization with a set of inductive, soft rules, which describe what is normal in a KG, and thus can be used to identify what is abnormal, whether it be strange or missing. Unlike first-order logic rules, our rules are labeled, rooted graphs, i.e., patterns that describe the expected neighborhood around a (seen or unseen) node, based on its type, and information in the KG. Stepping away from the traditional support/confidence-based rule mining techniques, we propose KGist, Knowledge Graph Inductive SummarizaTion, which learns a summary of inductive rules that best compress the KG according to the Minimum Description Length principle---a formulation that we are the first to use in the context of KG rule mining. We apply our rules to three large KGs (NELL, DBpedia, and Yago), and tasks such as compression, various types of error detection, and identification of incomplete information. We show that KGist outperforms task-specific, supervised and unsupervised baselines in error detection and incompleteness identification, (identifying the location of up to 93% of missing entities---over 10% more than baselines), while also being efficient for large knowledge graphs.Comment: 10 pages, plus 2 pages of references. 5 figures. Accepted at The Web Conference 202

    Trichinella pseudospiralis outbreak in France.

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    Four persons became ill with trichinellosis after eating meat from a wild boar hunted in Camargue, France. Nonencapsulated larvae of Trichinella pseudospiralis were detected in meat and muscle biopsy specimens. The diagnoses were confirmed by molecular typing. Surveillance for the emerging T. pseudospiralis should be expanded

    Freshwater fish diversity in the western Amazon basin shaped by Andean uplift since the Late Cretaceous

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    South America is home to the highest freshwater fish biodiversity on Earth, and the hotspot of species richness is located in the western Amazon basin. The location of this hotspot is enigmatic, as it is inconsistent with the pattern observed in river systems across the world of increasing species richness towards a river’s mouth. Here we investigate the role of river capture events caused by Andean mountain building and repeated episodes of flooding in western Amazonia in shaping the modern-day richness pattern of freshwater fishes in South America, and in Amazonia in particular. To this end, we combine a reconstruction of river networks since 80 Ma with a mechanistic model simulating dispersal, allopatric speciation and extinction over the dynamic landscape of rivers and lakes. We show that Andean mountain building and consequent numerous small river capture events in western Amazonia caused freshwater habitats to be highly dynamic, leading to high diversification rates and exceptional richness. The history of marine incursions and lakes, including the Miocene Pebas mega-wetland system in western Amazonia, played a secondary role

    Physical training improves cardiopulmonary functional capacity and increases cytokine IL-10 levels in individuals with Chagas disease

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    Purpose: To evaluate cardiopulmonary functional capacity and the production of cytokines in patients with and without Chagas disease, and with and without hypertension, after short and long-term exercise.Methods: In a case-controlled study, 56 participants who attended the Chagas Disease Laboratory at the State University of Maringa (LDC/UEM) and Basic Health Units (UBS) in Maringa that agreed to participate. The participants were divided into the following groups: 16 with Chagas disease (CHD group), 21 with systemic arterial hypertension (SAH group) and 19 normal individuals without these morbidities (NI group). Each participant performed the 6-min walk test (6MWT), and a 12-week physical training program. Pro-inflammatory and anti-inflammatory cytokines were measured before and after physical training.Results: The CHD group presented good performance in the 6MWT, with no significant differences in distance traveled or perceived exertion (p > 0.05) compared with the NI group. After physical training, the 6MWT results were significantly better, with significant decreases in systolic and diastolic blood pressure, in the SAH group (p = 0.0409; and p = 0.0377, respectively) and NI group (p = 0.0180; and p = 0.0431, respectively) and a significant increase in the levels of the anti-inflammatory cytokine interleukin-10 (IL-10; p < 0.05) in all three groups. The NI group exhibited a significant increase (p < 0.05) in the serum levels of the pro-inflammatory cytokines IL-6, IL-17 and tumor necrosis factor (all p< 0.05).Conclusion: All of the participants presented improvements in cardiopulmonary functional capacity and good prognosis, indicating the protective effect of IL-10 production and the benefits of physical training.Keywords: Chagas disease, Six-minute walk test, Physical training, Cytokines, Cardiopulmonary function capacity, Hypertensio

    Incorporating dominant species as proxies for biotic interactions strengthens plant community models

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    1. Biotic interactions exert considerable influence on the distribution of individual species and should, thus, strongly impact communities. Implementing biotic interactions in spatial models of community assembly is therefore essential for accurately modelling assemblage properties. However, this remains a challenge due to the difficulty of detecting the role of species interactions and because accurate paired community and environment data sets are required to disentangle biotic influences from abiotic effects. 2. Here, we incorporate data from three dominant species into community-level models as a proxy for the frequency and intensity of their interactions with other species and predict emergent assemblage properties for the co-occurring subdominant species. By analysing plant community and fieldquantified environmental data from specially designed and spatially replicated monitoring grids, we provide a robust in vivo test of community models. 3. Considering this well-defined and easily quantified surrogate for biotic interactions consistently improved realism in all aspects of community models (community composition, species richness and functional structure), irrespective of modelling methodology. 4. Dominant species reduced community richness locally and favoured species with similar leaf dry matter content. This effect was most pronounced under conditions of high plant biomass and cover, where stronger competitive impacts are expected. Analysis of leaf dry matter content suggests that this effect may occur through efficient resource sequestration. 5. Synthesis. We demonstrate the strong role of dominant species in shaping multiple plant community attributes, and thus the need to explicitly include interspecific interactions to achieve robust predictions of assemblage properties. Incorporating information on biotic interactions strengthens our capacity not only to predict the richness and composition of communities, but also how their structure and function will be modified in the face of global change.Academy of Finland (Project Number 1140873) and The Danish Council for Independent Research grant number 12-126430http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2745hb201
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