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Publications

Publications by Pedro Gabriel Ferreira

2006

Query Driven Sequence Pattern Mining

Authors
Ferreira, PG; Azevedo, PJ;

Publication
XXI Simpósio Brasileiro de Banco de Dados, 16-20 de Outubro, Florianópolis, Santa Catarina, Brasil, Anais/Proceedings

Abstract

2009

Deterministic Motif Mining in Protein Databases

Authors
Ferreira, PG; Azevedo, PJ;

Publication
Database Technologies: Concepts, Methodologies, Tools, and Applications (4 Volumes)

Abstract

2005

A Hybrid Method for Discovering Distance-Enhanced Inter-Transactional Rules

Authors
Ferreira, PG; Alves, R; Azevedo, PJ; Belo, O;

Publication
Actas de las X Jornadas de Ingeniería del Software y Bases de Datos (JISBD 2005), September 14-16, 2005, Granada, Spain

Abstract

2010

Evolutionary patterns at the RNase based gametophytic self-incompatibility system in two divergent Rosaceae groups (Maloideae and Prunus)

Authors
Vieira, J; Ferreira, PG; Aguiar, B; Fonseca, NA; Vieira, CP;

Publication
BMC EVOLUTIONARY BIOLOGY

Abstract
Background: Within Rosaceae, the RNase based gametophytic self-incompatibility (GSI) system has been studied at the molecular level in Maloideae and Prunus species that have been diverging for, at least, 32 million years. In order to understand RNase based GSI evolution within this family, comparative studies must be performed, using similar methodologies. Result: It is here shown that many features are shared between the two species groups such as levels of recombination at the S-RNase ( the S-pistil component) gene, and the rate at which new specificities arise. Nevertheless, important differences are found regarding the number of ancestral lineages and the degree of specificity sharing between closely related species. In Maloideae, about 17% of the amino acid positions at the S-RNase protein are found to be positively selected, and they occupy about 30% of the exposed protein surface. Positively selected amino acid sites are shown to be located on either side of the active site cleft, an observation that is compatible with current models of specificity determination. At positively selected amino acid sites, non-conservative changes are almost as frequent as conservative changes. There is no evidence that at these sites the most drastic amino acid changes may be more strongly selected. Conclusions: Many similarities are found between the GSI system of Prunus and Maloideae that are compatible with the single origin hypothesis for RNase based GSI. The presence of common features such as the location of positively selected amino acid sites and lysine residues that may be important for ubiquitylation, raise a number of issues that, in principle, can be experimentally addressed in Maloideae. Nevertheless, there are also many important differences between the two Rosaceae GSI systems. How such features changed during evolution remains a puzzling issue.

2023

Soteria: Preserving Privacy in Distributed Machine Learning

Authors
Brito, C; Ferreira, P; Portela, B; Oliveira, R; Paulo, J;

Publication
38TH ANNUAL ACM SYMPOSIUM ON APPLIED COMPUTING, SAC 2023

Abstract
We propose Soteria, a system for distributed privacy-preserving Machine Learning (ML) that leverages Trusted Execution Environments (e.g. Intel SGX) to run code in isolated containers (enclaves). Unlike previous work, where all ML-related computation is performed at trusted enclaves, we introduce a hybrid scheme, combining computation done inside and outside these enclaves. The conducted experimental evaluation validates that our approach reduces the runtime of ML algorithms by up to 41%, when compared to previous related work. Our protocol is accompanied by a security proof, as well as a discussion regarding resilience against a wide spectrum of ML attacks.

2015

Synchronized age-related gene expression changes across multiple tissues in human and the link to complex diseases

Authors
Yang J.; Huang T.; Petralia F.; Long Q.; Zhang B.; Argmann C.; Zhao Y.; Mobbs C.V.; Schadt E.E.; Zhu J.; Tu Z.; Ardlie K.G.; Deluca D.S.; Segrè A.V.; Sullivan T.J.; Young T.R.; Gelfand E.T.; Trowbridge C.A.; Maller J.B.; Tukiainen T.; Lek M.; Ward L.D.; Kheradpour P.; Iriarte B.; Meng Y.; Palmer C.D.; Winckler W.; Hirschhorn J.; Kellis M.; MacArthur D.G.; Getz G.; Shablin A.A.; Li G.; Zhou Y.H.; Nobel A.B.; Rusyn I.; Wright F.A.; Lappalainen T.; Ferreira P.G.; Ongen H.; Rivas M.A.; Battle A.; Mostafavi S.; Monlong J.; Sammeth M.; Mele M.; Reverter F.; Goldman J.; Koller D.; Guigo R.; McCarthy M.I.; Dermitzakis E.T.; Gamazon E.R.; Konkashbaev A.; Nicolae D.L.; Cox N.J.; Flutre T.; Wen X.; Stephens M.; Pritchard J.K.; Lin L.; Liu J.; Brown A.; Mestichelli B.; Tidwell D.; Lo E.; Salvatore M.; Shad S.; Thomas J.A.; Lonsdale J.T.; Choi C.; Karasik E.; Ramsey K.; Moser M.T.; Foster B.A.; Gillard B.M.; Syron J.; Fleming J.; Magazine H.; Hasz R.; Walters G.D.; Bridge J.P.; Miklos M.; Sullivan S.; Barker L.K.; Traino H.; Mosavel M.; Siminoff L.A.; Valley D.R.; Rohrer D.C.; Jewel S.; Branton P.; Sobin L.H.; Qi L.; Hariharan P.; Wu S.; Tabor D.; Shive C.; Smith A.M.; Buia S.A.;

Publication
Scientific Reports

Abstract
Aging is one of the most important biological processes and is a known risk factor for many age-related diseases in human. Studying age-related transcriptomic changes in tissues across the whole body can provide valuable information for a holistic understanding of this fundamental process. In this work, we catalogue age-related gene expression changes in nine tissues from nearly two hundred individuals collected by the Genotype-Tissue Expression (GTEx) project. In general, we find the aging gene expression signatures are very tissue specific. However, enrichment for some well-known aging components such as mitochondria biology is observed in many tissues. Different levels of cross-tissue synchronization of age-related gene expression changes are observed, and some essential tissues (e.g., heart and lung) show much stronger "co-aging" than other tissues based on a principal component analysis. The aging gene signatures and complex disease genes show a complex overlapping pattern and only in some cases, we see that they are significantly overlapped in the tissues affected by the corresponding diseases. In summary, our analyses provide novel insights to the co-regulation of age-related gene expression in multiple tissues; it also presents a tissue-specific view of the link between aging and age-related diseases.

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