Context-Free Path Queries on RDF Graphs

Navigational graph queries are an important class of queries that canextract implicit binary relations over the nodes of input graphs. Most of the navigational query languages used in the RDF community, e.g. property paths in W3C SPARQL 1.1 and nested regular expressions in nSPARQL, are based on the regular expressions. It is known that regular expressions have limited expressivity; for instance, some natural queries, like same generation-queries, are not expressible with regular expressions. To overcome this limitation, in this paper, we present cfSPARQL, an extension of SPARQL query language equipped with context-free grammars. The cfSPARQL language is strictly more expressive than property paths and nested expressions. The additional expressivity can be used for modelling graph similarities, graph summarization and ontology alignment. Despite the increasing expressivity, we show that cfSPARQL still enjoys a low computational complexity and can be evaluated efficiently.Comment: 25 page

Workflow Quality Of Service

Workflow management systems (WfMSs) have been used to support various types of business processes for more than a decade now. In ecommerce processes, suppliers and customers define a binding agreement or contract between the two parties, specifying quality of service (QoS) items such as products or services to be delivered, deadlines, quality of products, and cost of service. Management of such QoS directly impacts success of organizations participating in e-commerce. Organizations operating in modem markets require an excellent degree of quality of service management. Products and services must be available to customers with well-defined specifications. A good management of quality leads to the creation of quality products and services, which in mm fulfills customer expectations and achieves customer satisfaction. Therefore, when services or products are created or managed using workflow processes, the underlying WfMS must accept the specification, be able to predict, monitor, and control the QoS rendered to customers. To achieve these objectives the first step is to develop an adequate QoS model for workflow processes and develop methods to compute QoS

Graph query processing

While being eminently useful in a wide variety of application domains, the high expressiveness of graph queries makes them hard to optimize and, hence, challenging to process efficiently. We discuss a number of state-of-the-art approaches which aim to overcome these challenges, focusing specifically on planning, optimization, and execution of two commonly used types of declarative graph queries: subgraph queries and regular path queries

The interplay of extracellular matrix and microbiome in urothelial bladder cancer

Many pathological changes in solid tumours are caused by the accumulation of genetic mutations and epigenetic molecular alterations. In addition, tumour progression is profoundly influenced by the environment surrounding the transformed cells. The interplay between tumour cells and their microenvironment has been recognized as one of the key determinants of cancer development and is being extensively investigated. Data suggest that both the extracellular matrix and the microbiota represent microenvironments that contribute to the onset and progression of tumours. Through the introduction of omics technologies and pyrosequencing analyses, a detailed investigation of these two microenvironments is now possible. In urological research, assessment of their dysregulation has become increasingly important to provide diagnostic, prognostic and predictive biomarkers for urothelial bladder cancer. Understanding the roles of the extracellular matrix and microbiota, two key components of the urothelial mucosa, in the sequelae of pathogenic events that occur in the development and progression of urothelial carcinomas will be important to overcome the shortcomings in current bladder cancer treatment strategies