Scholarly Publications - BCBI

Permanent URI for this collectionhttps://hdl.handle.net/11693/115591

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Browsing Scholarly Publications - BCBI by Author "Ayaz, Aslı"

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    Microarray data analysis and pathway activity inference in PATIKA
    (ISCB Org, 2004) Babur, Özgün; Demir, Emek; Ayaz, Aslı; Doğrusöz, Uğur; Sakarya, Onur
    Pathway activity inference attempts to infer differential activity of cellular networks, given a qualitative state - transition model of the network and an expression profile of RNA molecules. We present an efficient algorithm for this problem, implemented as part of microarray data analysis component of PATIKA, a pathway analysis tool.
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    An ontology for collaborative construction and analysis of cellular pathways
    (Oxford University Press, 2004-02-12) Demir, Emek; Babur, Özgün; Doğrusöz, Uğur; Gürsoy, Atilla; Ayaz, Aslı; Güleşır, Gürcan; Nişancı, Gürkan; Çetin Atalay, Rengül
    Motivation: As the scientific curiosity in genome studies shifts toward identification of functions of the genomes in large scale, data produced about cellular processes at molecular level has been accumulating with an accelerating rate. In this regard, it is essential to be able to store, integrate, access and analyze this data effectively with the help of software tools. Clearly this requires a strong ontology that is intuitive, comprehensive and uncomplicated. Results: We define an ontology for an intuitive, comprehensive and uncomplicated representation of cellular events. The ontology presented here enables integration of fragmented or incomplete pathway information via collaboration, and supports manipulation of the stored data. In addition, it facilitates concurrent modifications to the data while maintaining its validity and consistency. Furthermore, novel structures for representation of multiple levels of abstraction for pathways and homologies is provided. Lastly, our ontology supports efficient querying of large amounts of data. We have also developed a software tool named pathway analysis tool for integration and knowledge acquisition (PATIKA) providing an integrated, multi-user environment for visualizing and manipulating network of cellular events. PATIKA implements the basics of our ontology. © Oxford University Press 2004; All rights reserved.
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    Pathway activity inference using microarray data
    (Bilkent Center for Bioinformatics (BCBI), 2004) Babur, Özgün; Demir, Emek; Ayaz, Aslı; Doğrusöz, Uğur; Sakarya, Onur
    Motivation: Microarray technology provides cell-scale expression data; however, analyzing this data is notoriously difficult. It is becoming clear that system-oriented methods are needed in order to best interpret this data. Combining microarray expression data with previously built pathway models may provide useful insight about the cellular machinery and reveal mechanisms that govern diseases. Given a qualitative state - transition model of the cellular network and an expression profile of RNA molecules, we would like to infer possible differential activity of the other molecules such as proteins on this network. Results: In this paper an efficient algorithm using a new approach is proposed to attack this problem. Using the regulation relations on the network, we determine possible scenarios that might lead to the expression profile, and qualitatively infer the activity differences of the molecules between test and control samples. Availability: This new analysis method has been implemented as part of a microarray data analysis component within PATIKA (Pathway Analysis Tool for Integration and Knowledge Acquisition), which is a software environment for pathway storage, integration and analysis. Facilities for easy analysis and visualization of the results is also provided. Contact: http://www.patika.org.
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    PATIKA: An informatics infrastructure for cellular networks
    (ISCB Org, 2004) Aksay, Çağrı; Ayaz, Aslı; Babur, Özgün; Bilgin, C.; Çetintaş, Ahmet; Çivril, Ali; Çolak, Recep; Çözen, G.; Demir, Emek; Doğrusöz, Uğur; Erson, Zeynep; Gerdaneri, Ozan; Giral, Erhan; Güleşır, Gürcan; Nişancı, Gürkan; Sakarya, O.; Yıldırım, Hilmi
    The PATIKA Project aims for an informatics infrastructure to cope with the inherently complex cellular pathway data and provides software tools with sophisticated visualization technology around a central database using an extensive ontology and data integration mechanisms. It also features advanced database querying, microarray data analysis, and automatic layout components.
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    PATIKAweb: a Web service for querying, visualizing and analyzing a graph-based pathway database
    (ISCB Org, 2005-06) Aksay, Çağrı; Arık, Fatma; Ataer, Esra; Ayaz, Aslı; Babur, Özgün; Belviranlı, Mehmet E.; Çetintaş, Ahmet; Çolak, Recep; Çözen, G.; Demir, Emek; Dilek, Alptuğ; Doğrusöz, Uğur; Giral, Erhan; Kaya, Engin; Küçük, Evren; Tekin, A. S.; Yıldırım, Hilmi; Erson, Zeynep
    PATIKAweb provides a Web service for retrieving and analyzing biological pathways in PATIKA database, which currently contains data integrated from popular public pathway databases like Reactome. It features a user-friendly interface, dynamic visualization, advanced graph-theoretic queries for extracting biologically important phenomena and exporting facilities to various exchange formats.