A non-intrusive and reactive architecture to support real-time ETL processes in data warehousing environments.

Nowadays, organizations are very interested to gather data for strategic decision-making. Data are disposable in operational sources, which are distributed, heterogeneous, and autonomous. These data are gathered through ETL processes, which occur traditionally in a pre-defined time, that is, once a day, once a week, once a month or in a specific period of time. On the other hand, there are special applications for which data needs to be obtained in a faster way and sometimes even immediately after the data are generated in the operation data sources, such as health systems and digital agriculture. Thus, the conventional ETL process and the disposable techniques are incapable of making the operational data delivered in real-time, providing low latency, high availability, and scalability. As our proposal, we present an innovative architecture, named Data Magnet, to cope with real-time ETL processes. The experimental tests performed in the digital agriculture domain using real and synthetic data showed that our proposal was able to deal in real-time with the ETL process. The Data Magnet provided great performance, showing an almost constant elapsed time for growing data volumes. Besides, Data Magnet provided significant performance gains over the traditional trigger technique.

ProvOER model: A provenance model for Open Educational Resources.

Open Educational Resources (OER) can be adapted and combined to create new resources that better meet the specific needs of different kinds of users and scenarios. In this sense, OER strongly contributes to generating and sharing educational knowledge. Due to the possibility of creating a new OER through the revision and remix activities, the original OER and the transformation process should be adequately identified. This way, the user of the OER has enough information about the history of the resource and, thus, can use it with confidence and security. In this context, determining data provenance, which describes the history of a data from its origin to its current state, becomes very relevant. For OER, there are examples of metadata standards and digital repositories that help to obtain the data provenance. However, the information collected is insufficient to identify the entire history of the provenance of OER. This article proposes a Provenance Model for OER called the ProvOER Model, which allows the documentation and identification of the provenance of OER. For this purpose, a minimum set of metadata was defined that reflects the OER intrinsic properties and the activities that created a new OER. The experiments showed that the ProvOER Model produced a suitable representation of the provenance of OER. In addition, the ProvOER Model allowed identifying the original OER used in a revise or remix activity and the continuous stretch used to create a new resource.

A similarity-based data warehousing environment for medical images.

A core issue of the decision-making process in the medical field is to support the execution of analytical (OLAP) similarity queries over images in data warehousing environments. In this paper, we focus on this issue. We propose imageDWE, a non-conventional data warehousing environment that enables the storage of intrinsic features taken from medical images in a data warehouse and supports OLAP similarity queries over them. To comply with this goal, we introduce the concept of perceptual layer, which is an abstraction used to represent an image dataset according to a given feature descriptor in order to enable similarity search. Based on this concept, we propose the imageDW, an extended data warehouse with dimension tables specifically designed to support one or more perceptual layers. We also detail how to build an imageDW and how to load image data into it. Furthermore, we show how to process OLAP similarity queries composed of a conventional predicate and a similarity search predicate that encompasses the specification of one or more perceptual layers. Moreover, we introduce an index technique to improve the OLAP query processing over images. We carried out performance tests over a data warehouse environment that consolidated medical images from exams of several modalities. The results demonstrated the feasibility and efficiency of our proposed imageDWE to manage images and to process OLAP similarity queries. The results also demonstrated that the use of the proposed index technique guaranteed a great improvement in query processing.

DNA bending in the replication zone of the C3 DNA puff amplicon of Rhynchosciara americana (Diptera: Sciaridae).

Intrinsic bent DNA sites were identified in the 4289 bp segment encompassing the replication zone which directs DNA amplification and transcription of the C3-22 gene of Rhynchosciara americana. Restriction fragments showed reduced electrophoretic mobility in polyacrylamide gels. The 2D modeling of the 3D DNA path and the ENDS ratio values obtained from the dinucleotide wedge model of Trifonov revealed the presence of four major bent sites, positioned at nucleotides -6753, -5433, -5133 and -4757. Sequence analysis showed that these bends are composed of 2-6 bp dA.dT tracts in phase with the DNA helical repeat. The circular permutation analysis permitted the verification that the fragments containing the bending sites promote curvature in other sequence contexts. Computer analyses of the 4289 bp sequence revealed low helical stability (DeltaG values), negative roll angles indicating a narrow minor groove and a putative matrix attachment region. The data presented in this paper add to information about the structural features involved in this amplified segment.