Berk Alpay

Mr. Berk Alpay

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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22 May 2020 in Forecasting
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Journal Article
Open access
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BABerk Alpay
Berk Alpay
DWDavid Wanik
David Wanik
PWPeter Watson
Peter Watson
DCDiego Cerrai
Diego Cerrai
GLGuannan Liang
Guannan Liang
EAEmmanouil Anagnostou
Emmanouil Anagnostou
Thunderstorms are complex weather phenomena that cause substantial power outages in a short period. This makes thunderstorm outage prediction challenging using eventwise outage prediction models (OPMs), which summarize the storm dynamics over the entire course of the storm into a limited number of parameters. We developed a new, temporally sensitive outage prediction framework designed for models to learn the hourly dynamics of thunderstorm-caused outages directly from weather forecasts. Validation of several models built on this hour-by-hour prediction framework and comparison with a baseline model show abilities to accurately report temporal and storm-wide outage characteristics, which are vital for planning utility responses to storm-caused power grid damage.

15 February 2024 in Blood Neoplasia
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Journal Article
Open access
AJAshwini Jambhekar
Ashwini Jambhekar
EAEmily E. Ackerman
Emily E. Ackerman
BABerk Alpay
Berk Alpay
GLGalit Lahav
Galit Lahav
SLScott B. Lovitch
Scott B. Lovitch
• TP53 mutations in myelodysplastic syndrome and acute myeloid leukemia differ significantly in distribution and functional consequences. • These differences suggest distinct biological roles for mutated p53 in initiation of myeloid dysplasia and progression to acute leukemia.

14 October 2024 in PLOS ONE
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Journal Article
Open access
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BABerk Alpay
Berk Alpay
MDMichael M Desai
Michael M Desai
Directed evolution makes mutant lineages compete in climbing complicated sequence-function landscapes. Given this underlying complexity it is unclear how selection stringency, a ubiquitous parameter of directed evolution, impacts the outcome. Here we approach this question in terms of the fitnesses of the candidate variants at each round and the heterogeneity of their distributions of fitness effects. We show that even if the fittest mutant is most likely to yield the fittest mutants in the next round of selection, diversification can improve outcomes by sampling a larger variety of fitness effects. We find that heterogeneity in fitness effects between variants, larger population sizes, and evolution over a greater number of rounds all encourage diversification.

14 September 2022 in Drug Discovery Today
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Journal Article
Closed access
BABerk Alpay
Berk Alpay
MGMark Gosink
Mark Gosink
DADerek Aguiar
Derek Aguiar

9 June 2024 in bioRxiv
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Preprint
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BABerk Alpay
Berk Alpay
MDMichael M. Desai
Michael M. Desai
Directed evolution makes mutant lineages compete in climbing complicated sequence-function landscapes. Given this underlying complexity it is unclear how selection stringency, a ubiquitous parameter of directed evolution, impacts the outcome. Here we approach this question in terms of the fitnesses of the candidate variants at each round and the heterogeneity of their distributions of fitness effects. We show that even if the fittest mutant is most likely to yield the fittest mutants in the next round of selection, diversification can improve outcomes by sampling a larger variety of fitness effects. We find that heterogeneity in fitness effects between variants, larger population sizes, and evolution over a greater number of rounds all encourage diversification.

1 July 2020 in Bioinformatics
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Journal Article
Open access
BABerk Alpay
Berk Alpay
PDPinar Demetci
Pinar Demetci
SISorin Istrail
Sorin Istrail
DADerek Aguiar
Derek Aguiar
Motivation: Genome-wide association studies (GWAS) have discovered thousands of significant genetic effects on disease phenotypes. By considering gene expression as the intermediary between genotype and disease phenotype, expression quantitative trait loci studies have interpreted many of these variants by their regulatory effects on gene expression. However, there remains a considerable gap between genotype-to-gene expression association and genotype-to-gene expression prediction. Accurate prediction of gene expression enables gene-based association studies to be performed post hoc for existing GWAS, reduces multiple testing burden, and can prioritize genes for subsequent experimental investigation.Results: In this work, we develop gene expression prediction methods that relax the independence and additivity assumptions between genetic markers. First, we consider gene expression prediction from a regression perspective and develop the HAPLEXR algorithm which combines haplotype clusterings with allelic dosages. Second, we introduce the new gene expression classification problem, which focuses on identifying expression groups rather than continuous measurements; we formalize the selection of an appropriate number of expression groups using the principle of maximum entropy. Third, we develop the HAPLEXD algorithm that models haplotype sharing with a modified suffix tree data structure and computes expression groups by spectral clustering. In both models, we penalize model complexity by prioritizing genetic clusters that indicate significant effects on expression. We compare HAPLEXR and HAPLEXD with three state-of-the-art expression prediction methods and two novel logistic regression approaches across five GTEx v8 tissues. HAPLEXD exhibits significantly higher classification accuracy overall; HAPLEXR shows higher prediction accuracy on approximately half of the genes tested and the largest number of best predicted genes (r2>0.1) among all methods. We show that variant and haplotype features selected by HAPLEXR are smaller in size than competing methods (and thus more interpretable) and are significantly enriched in functional annotations related to gene regulation. These results demonstrate the importance of explicitly modeling non-dosage dependent and intragenic epistatic effects when predicting expression.Availability and implementation: Source code and binaries are freely available at https://github.com/rapturous/HAPLEX.Supplementary information: Supplementary data are available at Bioinformatics online.