Evangelos Pafilis

Dr. Evangelos Pafilis

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 February 2021 in mSystems
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PVPajau Vangay
Pajau Vangay
JBJosephine Burgin
Josephine Burgin
AJAnjanette Johnston
Anjanette Johnston
Kristen BeckKristen Beck
Kristen Beck
DBDaniel C. Berrios
Daniel C. Berrios
EEEmiley A. Eloe-Fadrosh
Emiley A. Eloe-Fadrosh
Microbiome samples are inherently defined by the environment in which they are found. Therefore, data that provide context and enable interpretation of measurements produced from biological samples, often referred to as metadata, are critical.

19 February 2016 in Database: The Journal of Biological Databases and Curation
Verified
Journal Article
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EPEvangelos Pafilis
Evangelos Pafilis
PBPier Luigi Buttigieg
Pier Luigi Buttigieg
BFBarbra Ferrell
Barbra Ferrell
EPEmiliano Pereira
Emiliano Pereira
JSJulia Schnetzer
Julia Schnetzer
LJLars Juhl Jensen
Lars Juhl Jensen
The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have therefore developed an interactive annotation tool, EXTRACT, which helps curators identify and extract standard-compliant terms for annotation of metagenomic records and other samples. Behind its web-based user interface, the system combines published methods for named entity recognition of environment, organism, tissue and disease terms. The evaluators in the BioCreative V Interactive Annotation Task found the system to be intuitive, useful, well documented and sufficiently accurate to be helpful in spotting relevant text passages and extracting organism and environment terms. Comparison of fully manual and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15–25% and helps curators to detect terms that would otherwise have been missed. Database URL : https://extract.hcmr.gr/

18 August 2021 in GigaScience
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Journal Article
Open access
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HZHaris Zafeiropoulos
Haris Zafeiropoulos
AGAnastasia Gioti
Anastasia Gioti
SNStelios Ninidakis
Stelios Ninidakis
APAntonis Potirakis
Antonis Potirakis
Savvas ParagkamianSavvas Paragkamian
Savvas Paragkamian
EPEvangelos Pafilis
Evangelos Pafilis
High-performance computing (HPC) systems have become indispensable for modern marine research, providing support to an increasing number and diversity of users. Pairing with the impetus offered by high-throughput methods to key areas such as non-model organism studies, their operation continuously evolves to meet the corresponding computational challenges. Here, we present a Tier 2 (regional) HPC facility, operating for over a decade at the Institute of Marine Biology, Biotechnology, and Aquaculture of the Hellenic Centre for Marine Research in Greece. Strategic choices made in design and upgrades aimed to strike a balance between depth (the need for a few high-memory nodes) and breadth (a number of slimmer nodes), as dictated by the idiosyncrasy of the supported research. Qualitative computational requirement analysis of the latter revealed the diversity of marine fields, methods, and approaches adopted to translate data into knowledge. In addition, hardware and software architectures, usage statistics, policy, and user management aspects of the facility are presented. Drawing upon the last decade’s experience from the different levels of operation of the Institute of Marine Biology, Biotechnology, and Aquaculture HPC facility, a number of lessons are presented; these have contributed to the facility’s future directions in light of emerging distribution technologies (e.g., containers) and Research Infrastructure evolution. In combination with detailed knowledge of the facility usage and its upcoming upgrade, future collaborations in marine research and beyond are envisioned.

20 December 2016 in PeerJ
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Journal Article
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LSLucas Sinclair
Lucas Sinclair
UIUmer Zeeshan Ijaz
Umer Zeeshan Ijaz
LJLars Juhl Jensen
Lars Juhl Jensen
Marco CoolenMarco Coolen
Marco Coolen
CGCecile Gubry-Rangin
Cecile Gubry-Rangin
EPEvangelos Pafilis
Evangelos Pafilis
Understanding the distribution of taxa and associated traits across different environments is one of the central questions in microbial ecology. High-throughput sequencing (HTS) studies are presently generating huge volumes of data to address this biogeographical topic. However, these studies are often focused on specific environment types or processes leading to the production of individual, unconnected datasets. The large amounts of legacy sequence data with associated metadata that exist can be harnessed to better place the genetic information found in these surveys into a wider environmental context. Here we introduce a software program, seqenv, to carry out precisely such a task. It automatically performs similarity searches of short sequences against the “nt” nucleotide database provided by NCBI and, out of every hit, extracts–if it is available–the textual metadata field. After collecting all the isolation sources from all the search results, we run a text mining algorithm to identify and parse words that are associated with the Environmental Ontology (EnvO) controlled vocabulary. This, in turn, enables us to determine both in which environments individual sequences or taxa have previously been observed and, by weighted summation of those results, to summarize complete samples. We present two demonstrative applications of seqenv to a survey of ammonia oxidizing archaea as well as to a plankton paleome dataset from the Black Sea. These demonstrate the ability of the tool to reveal novel patterns in HTS and its utility in the fields of environmental source tracking, paleontology, and studies of microbial biogeography. To install seqenv, go to: https://github.com/xapple/seqenv.

24 January 2015 in Bioinformatics
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Journal Article
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EPEvangelos Pafilis
Evangelos Pafilis
SFSune P. Frankild
Sune P. Frankild
JSJulia Schnetzer
Julia Schnetzer
LFLucia Fanini
Lucia Fanini
SFSarah Faulwetter
Sarah Faulwetter
LJLars Juhl Jensen
Lars Juhl Jensen
Summary: The association of organisms to their environments is a key issue in exploring biodiversity patterns. This knowledge has traditionally been scattered, but textual descriptions of taxa and their habitats are now being consolidated in centralized resources. However, structured annotations are needed to facilitate large-scale analyses. Therefore, we developed ENVIRONMENTS, a fast dictionary-based tagger capable of identifying Environment Ontology (ENVO) terms in text. We evaluate the accuracy of the tagger on a new manually curated corpus of 600 Encyclopedia of Life (EOL) species pages. We use the tagger to associate taxa with environments by tagging EOL text content monthly, and integrate the results into the EOL to disseminate them to a broad audience of users. Availability and implementation: The software and the corpus are available under the open-source BSD and the CC-BY-NC-SA 3.0 licenses, respectively, at http://environments.hcmr.gr Contact:pafilis@hcmr.gr or lars.juhl.jensen@cpr.ku.dk Supplementary information: Supplementary data are available at Bioinformatics online.

26 January 2022 in Microorganisms
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Journal Article
Open access
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HZHaris Zafeiropoulos
Haris Zafeiropoulos
Savvas ParagkamianSavvas Paragkamian
Savvas Paragkamian
SNStelios Ninidakis
Stelios Ninidakis
GPGeorgios Pavlopoulos
Georgios Pavlopoulos
LJLars Juhl Jensen
Lars Juhl Jensen
EPEvangelos Pafilis
Evangelos Pafilis
To elucidate ecosystem functioning, it is fundamental to recognize what processes occur in which environments (where) and which microorganisms carry them out (who). Here, we present PREGO, a one-stop-shop knowledge base providing such associations. PREGO combines text mining and data integration techniques to mine such what-where-who associations from data and metadata scattered in the scientific literature and in public omics repositories. Microorganisms, biological processes, and environment types are identified and mapped to ontology terms from established community resources. Analyses of comentions in text and co-occurrences in metagenomics data/metadata are performed to extract associations and a level of confidence is assigned to each of them thanks to a scoring scheme. The PREGO knowledge base contains associations for 364,508 microbial taxa, 1090 environmental types, 15,091 biological processes, and 7971 molecular functions with a total of almost 58 million associations. These associations are available through a web portal, an Application Programming Interface (API), and bulk download. By exploring environments and/or processes associated with each other or with microbes, PREGO aims to assist researchers in design and interpretation of experiments and their results. To demonstrate PREGO’s capabilities, a thorough presentation of its web interface is given along with a meta-analysis of experimental results from a lagoon-sediment study of sulfur-cycle related microbes.