Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - Scopus: 3Prediction of Colorectal Cancer Based on Taxonomic Levels of Microorganisms and Discovery of Taxonomic Biomarkers Using the Grouping-Scoring (G-S-M) Approach(Elsevier Ltd, 2025-03) Bakir-Güngör, Burcu; Temiz, Mustafa; Canakcimaksutoglu, Beyza; Yousef, MalikColorectal cancer (CRC) is one of the most prevalent forms of cancer globally. The human gut microbiome plays an important role in the development of CRC and serves as a biomarker for early detection and treatment. This research effort focuses on the identification of potential taxonomic biomarkers of CRC using a grouping-based feature selection method. Additionally, this study investigates the effect of incorporating biological domain knowledge into the feature selection process while identifying CRC-associated microorganisms. Conventional feature selection techniques often fail to leverage existing biological knowledge during metagenomic data analysis. To address this gap, we propose taxonomy-based Grouping Scoring Modeling (G-S-M) method that integrates biological domain knowledge into feature grouping and selection. In this study, using metagenomic data related to CRC, classification is performed at three taxonomic levels (genus, family and order). The MetaPhlAn tool is employed to determine the relative abundance values of species in each sample. Comparative performance analyses involve six feature selection methods and four classification algorithms. When experimented on two CRC associated metagenomics datasets, the highest performance metric, yielding an AUC of 0.90, is observed at the genus taxonomic level. At this level, 7 out of top 10 groups (Parvimonas, Peptostreptococcus, Fusobacterium, Gemella, Streptococcus, Porphyromonas and Solobacterium) were commonly identified for both datasets. Moreover, the identified microorganisms at genus, family, and order levels are thoroughly discussed via refering to CRC-related metagenomic literature. This study not only contributes to our understanding of CRC development, but also highlights the applicability of taxonomy-based G-S-M method in tackling various diseases. © 2025 Elsevier B.V., All rights reserved.Article Citation - WoS: 2Citation - Scopus: 2Machine-Generated Hierarchical Structure of Human Activities to Reveal How Machines Think(IEEE-Inst Electrical Electronics Engineers Inc, 2021) Altin, Mahsun; Gursoy, Furkan; Xu, LinaDeep-learning based computer vision models have proved themselves to be ground-breaking approaches to human activity recognition (HAR). However, most existing works are dedicated to improve the prediction accuracy through either creating new model architectures, increasing model complexity, or refining model parameters by training on larger datasets. Here, we propose an alternative idea, differing from existing work, to increase model accuracy and also to shape model predictions to align with human understandings through automatically creating higher-level summarizing labels for similar groups of human activities. First, we argue the importance and feasibility of constructing a hierarchical labeling system for human activity recognition. Then, we utilize the predictions of a black box HAR model to identify similarities between different activities. Finally, we tailor hierarchical clustering methods to automatically generate hierarchical trees of activities and conduct experiments. In this system, the activity labels on the same level will have a designed magnitude of accuracy and reflect a specific amount of activity details. This strategy enables a trade-off between the extent of the details in the recognized activity and the user privacy by masking some sensitive predictions; and also provides possibilities for the use of formerly prohibited invasive models in privacy-concerned scenarios. Since the hierarchy is generated from the machine's perspective, the predictions at the upper levels provide better accuracy, which is especially useful when there are too detailed labels in the training set that are rather trivial to the final prediction goal. Moreover, the analysis of the structure of these trees can reveal the biases in the prediction model and guide future data collection strategies.Article Citation - WoS: 4Citation - Scopus: 4Biochemical Characterization and Genome Analysis of Pseudomonas Loganensis Sp. Nov., a Novel Endophytic Bacterium(Wiley, 2025-08) Karaman, Melisa Z.; Yetiman, Ahmet E.; Zhan, Jixun; Fidan, OzkanPseudomonas species are highly adaptable, thriving in diverse environments and exhibiting remarkable genetic and metabolic diversity. While some strains are pathogenic, others have significant ecological and industrial applications. Bioinformatics and biochemical analyses, including antibiotic sensitivity testing, revealed that Pseudomonas loganensis sp. nov. can tolerate NaCl concentrations up to 5% and pH ranges between 5 and 9. Antibiogram results corroborated genome data, demonstrating resistance to vancomycin, ampicillin, methicillin, oxacillin, and penicillin G. Phylogenetic analysis based on 16S rRNA, rpoB, rpoD, and gyrB genes, combined with average nucleotide identity (ANI) comparisons, confirmed P. loganensis sp. nov. as a novel species within the Pseudomonas genus. Genome analysis further revealed the presence of turnerbactin and carotenoid gene clusters. Turnerbactin, known to contribute to nitrogen fixation in plants, highlights the strain's potential as a biofertilizer. Additionally, the carotenoid gene cluster suggests potential applications in industrial carotenoid production. The discovery of a trehalose synthase (treS) gene indicates the capability for one-step conversion of maltose into trehalose, underscoring its potential utility in trehalose production.