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Publications

2012

RNA secondary structure mediates alternative 3 ' ss selection in Saccharomyces cerevisiae

Authors
Plass, M; Codony Servat, C; Gabriel Ferreira, PG; Vilardell, J; Eyras, E;

Publication
RNA-A PUBLICATION OF THE RNA SOCIETY

Abstract
Alternative splicing is the mechanism by which different combinations of exons in the pre-mRNA give rise to distinct mature mRNAs. This process is mediated by splicing factors that bind the pre-mRNA and affect the recognition of its splicing signals. Saccharomyces species lack many of the regulatory factors present in metazoans. Accordingly, it is generally assumed that the amount of alternative splicing is limited. However, there is recent compelling evidence that yeast have functional alternative splicing, mainly in response to environmental conditions. We have previously shown that sequence and structure properties of the pre-mRNA could explain the selection of 3' splice sites (ss) in Saccharomyces cerevisiae. In this work, we extend our previous observations to build a computational classifier that explains most of the annotated 3'ss in the CDS and 5' UTR of this organism. Moreover, we show that the same rules can explain the selection of alternative 3'ss. Experimental validation of a number of predicted alternative 3'ss shows that their usage is low compared to annotated 3'ss. The majority of these alternative 3'ss introduce premature termination codons (PTCs), suggesting a role in expression regulation. Furthermore, a genome-wide analysis of the effect of temperature, followed by experimental validation, yields only a small number of changes, indicating that this type of regulation is not widespread. Our results are consistent with the presence of alternative 3'ss selection in yeast mediated by the pre-mRNA structure, which can be responsive to external cues, like temperature, and is possibly related to the control of gene expression.

2012

Bigraphical modelling of architectural patterns

Authors
Sanchez, A; Barbosa, LS; Riesco, D;

Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Abstract
Archery is a language for behavioural modelling of architectural patterns, supporting hierarchical composition and a type discipline. This paper extends Archery to cope with the patterns' structural dimension through a set of (re-)configuration combinators and constraints that all instances of a pattern must obey. Both types and instances of architectural patterns are semantically represented as bigraphical reactive systems and operations upon them as reaction rules. Such a bigraphical semantics provides a rigorous model for Archery patterns and reduces constraint verification in architectures to a type-checking problem. © 2012 Springer-Verlag.

2012

PETCHA: A programming exercises teaching assistant

Authors
Queiros, RAP; Leal, JP;

Publication
Annual Conference on Innovation and Technology in Computer Science Education, ITiCSE

Abstract
This paper presents a tool called Petcha that acts as an automated Teaching Assistant in computer programming courses. The ultimate objective of Petcha is to increase the number of programming exercises effectively solved by students. Petcha meets this objective by helping both teachers to author programming exercises and students to solve them. It also coordinates a network of heterogeneous systems, integrating automatic program evaluators, learning management systems, learning object repositories and integrated programming environments. This paper presents the concept and the design of Petcha and sets this tool in a service oriented architecture for managing learning processes based on the automatic evaluation of programming exercises. The paper presents also a case study that validates the use of Petcha and of the proposed architecture. © 2012 ACM.

2012

SIMULTANEOUS DETECTION OF PROMINENT POINTS ON BREAST CANCER CONSERVATIVE TREATMENT IMAGES

Authors
Oliveira, HP; Cardoso, JS; Magalhaes, A; Cardoso, MJ;

Publication
2012 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP 2012)

Abstract
Breast Cancer Conservative Treatment (BCCT) is now the preferred technique for breast cancer treatment. The limited reproducibility of standard aesthetic evaluation methods led to the development of objective methods, such as Breast Cancer Conservative Treatment. cosmetic results (BCCT. core) software tool. Although the satisfying results, there are still limitations concerning complete automation and the inability to measure volumetric information. With the fundamental premise of maintaining the system as a low-cost tool, the incorporation of the Microsoft Kinect sensor in BCCT evaluations was studied. The aim with this work is to enable the simultaneous detection of breast contour and breast peak points using depth-map data. Experimental results show that the proposed algorithm is accurate and robust for a wide number of patients. Additionally, comparatively to previous research, the procedure for detecting prominent points was automated.

2012

Detecting abnormal patterns in call graphs based on the aggregation of relevant vertex measures

Authors
Alves, R; Ferreira, P; Ribeiro, J; Belo, O;

Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Abstract
Graphs are a very important abstraction to model complex structures and respective interactions, with a broad range of applications including web analysis, telecommunications, chemical informatics and bioinformatics. In this work we are interested in the application of graph mining to identify abnormal behavior patterns from telecom Call Detail Records (CDRs). Such behaviors could also be used to model essential business tasks in telecom, for example churning, fraud, or marketing strategies, where the number of customers is typically quite large. Therefore, it is important to rank the most interesting patterns for further analysis. We propose a vertex relevant ranking score as a unified measure for focusing the search of abnormal patterns in weighted call graphs based on CDRs. Classical graph-vertex measures usually expose a quantitative perspective of vertices in telecom call graphs. We aggregate wellknown vertex measures for handling attribute-based information usually provided by CDRs. Experimental evaluation carried out with real data streams, from a local mobile telecom company, showed us the feasibility of the proposed strategy. © 2012 Springer-Verlag.

2012

Outsourcing in long-term care - a risk management approach

Authors
Guimaraes, CM; de Carvalho, JC;

Publication
CIENCIA & SAUDE COLETIVA

Abstract
This article seeks to investigate outsourcing decisions in supply chain management of healthcare organizations, namely the motives and constraints behind the decision, the selection criteria for activities to be outsourced to third parties, the type of possible agreements, and the impact of this decision on the organization per se. A case study of the start-up phase of a Longterm Care unit with an innovative approach and high levels of customization was conducted to understand the outsourcing process in a start-up context (not in the standard context of organizational change) and a risk evaluation matrix was created for outsourcing activities in order to define and implement a performance monitoring process. This study seeks to understand how to evaluate and assess the risks of an outsourcing strategy and proposes a monitoring model using risk management tools. It was shown that the risk management approach can be a solution for monitoring outsourcing in the organizational start-up phase. Conclusions concerning dissatisfaction with the results of outsourcing strategies adopted are also presented.

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