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  1. Article ; Online: coiaf: Directly estimating complexity of infection with allele frequencies.

    Paschalidis, Aris / Watson, Oliver J / Aydemir, Ozkan / Verity, Robert / Bailey, Jeffrey A

    PLoS computational biology

    2023  Volume 19, Issue 6, Page(s) e1010247

    Abstract: In malaria, individuals are often infected with different parasite strains. The complexity of infection (COI) is defined as the number of genetically distinct parasite strains in an individual. Changes in the mean COI in a population have been shown to ... ...

    Abstract In malaria, individuals are often infected with different parasite strains. The complexity of infection (COI) is defined as the number of genetically distinct parasite strains in an individual. Changes in the mean COI in a population have been shown to be informative of changes in transmission intensity with a number of probabilistic likelihood and Bayesian models now developed to estimate the COI. However, rapid, direct measures based on heterozygosity or FwS do not properly represent the COI. In this work, we present two new methods that use easily calculated measures to directly estimate the COI from allele frequency data. Using a simulation framework, we show that our methods are computationally efficient and comparably accurate to current approaches in the literature. Through a sensitivity analysis, we characterize how the distribution of parasite densities, the assumed sequencing depth, and the number of sampled loci impact the bias and accuracy of our two methods. Using our developed methods, we further estimate the COI globally from Plasmodium falciparum sequencing data and compare the results against the literature. We show significant differences in the estimated COI globally between continents and a weak relationship between malaria prevalence and COI.
    MeSH term(s) Humans ; Malaria, Falciparum/epidemiology ; Malaria, Falciparum/genetics ; Malaria, Falciparum/parasitology ; Bayes Theorem ; Plasmodium falciparum/genetics ; Gene Frequency/genetics ; Malaria/parasitology
    Language English
    Publishing date 2023-06-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2193340-6
    ISSN 1553-7358 ; 1553-734X
    ISSN (online) 1553-7358
    ISSN 1553-734X
    DOI 10.1371/journal.pcbi.1010247
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: IFIH1 (MDA5) is required for innate immune detection of intron-containing RNA expressed from the HIV-1 provirus.

    Guney, Mehmet Hakan / Nagalekshmi, Karthika / McCauley, Sean Matthew / Carbone, Claudia / Aydemir, Ozkan / Luban, Jeremy

    bioRxiv : the preprint server for biology

    2023  

    Abstract: Antiretroviral therapy (ART) suppresses HIV-1 viremia and prevents progression to AIDS. Nonetheless, chronic inflammation is a common problem for people living with HIV-1 on ART. One possible cause of inflammation is ongoing transcription from HIV-1 ... ...

    Abstract Antiretroviral therapy (ART) suppresses HIV-1 viremia and prevents progression to AIDS. Nonetheless, chronic inflammation is a common problem for people living with HIV-1 on ART. One possible cause of inflammation is ongoing transcription from HIV-1 proviruses, whether or not the sequences are competent for replication. Previous work has shown that intron-containing RNA expressed from the HIV-1 provirus in primary human blood cells, including CD4
    Language English
    Publishing date 2023-12-12
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.11.17.567619
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: HER2-driven breast cancer suppression by the JNK signaling pathway.

    Itah, Zeynep / Chaudhry, Shanzah / Raju Ponny, Sithara / Aydemir, Ozkan / Lee, Alexandra / Cavanagh-Kyros, Julie / Tournier, Cathy / Muller, William J / Davis, Roger J

    Proceedings of the National Academy of Sciences of the United States of America

    2023  Volume 120, Issue 4, Page(s) e2218373120

    Abstract: ... The ... ...

    Abstract The HER2
    MeSH term(s) Humans ; Female ; MAP Kinase Signaling System ; Breast Neoplasms/pathology ; Signal Transduction ; Cell Transformation, Neoplastic/genetics ; Mitogen-Activated Protein Kinase 8/metabolism ; Cell Line, Tumor
    Chemical Substances Mitogen-Activated Protein Kinase 8 (EC 2.7.11.24)
    Language English
    Publishing date 2023-01-19
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.2218373120
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Book ; Thesis: Sensory and synaptic specification of the olfactory receptor neurons of drosophila melanogaster

    Aydemir, Özkan

    2009  

    Author's details vorgelegt von Özkan Aydemir
    Language English
    Size IV, 85 Bl., Ill., graph. Darst.
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Univ, Diss.--Münster, 2009
    Database Former special subject collection: coastal and deep sea fishing

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  5. Book ; Thesis: Sensory and synaptic specification of the olfactory receptor neurons of drosophila melanogaster

    Aydemir, Özkan

    2009  

    Author's details vorgelegt von Özkan Aydemir
    Language English
    Size IV, 85 Bl., Ill., graph. Darst.
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Univ, Diss.--Münster, 2009
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  6. Article: Immediate pools of malaria infections at diagnosis combined with targeted deep sequencing accurately quantifies frequency of drug resistance mutations.

    Aydemir, Ozkan / Mensah, Benedicta / Marsh, Patrick W / Abuaku, Benjamin / Myers-Hansen, James Leslie / Bailey, Jeffrey A / Ghansah, Anita

    PeerJ

    2021  Volume 9, Page(s) e11794

    Abstract: Antimalarial resistance surveillance in sub-Saharan Africa is often constrained by logistical and financial challenges limiting its breadth and frequency. At two sites in Ghana, we have piloted a streamlined sample pooling process created immediately by ... ...

    Abstract Antimalarial resistance surveillance in sub-Saharan Africa is often constrained by logistical and financial challenges limiting its breadth and frequency. At two sites in Ghana, we have piloted a streamlined sample pooling process created immediately by sequential addition of positive malaria cases at the time of diagnostic testing. This streamlined process involving a single tube minimized clinical and laboratory work and provided accurate frequencies of all known drug resistance mutations after high-throughput targeted sequencing using molecular inversion probes. Our study validates this method as a cost-efficient, accurate and highly-scalable approach for drug resistance mutation monitoring that can potentially be applied to other infectious diseases such as tuberculosis.
    Language English
    Publishing date 2021-11-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2703241-3
    ISSN 2167-8359
    ISSN 2167-8359
    DOI 10.7717/peerj.11794
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Strong isolation by distance and evidence of population microstructure reflect ongoing

    Connelly, Sean V / Brazeau, Nicholas F / Msellem, Mwinyi / Ngasala, Billy E / Aydemir, Özkan / Goel, Varun / Niaré, Karamoko / Giesbrecht, David J / Popkin-Hall, Zachary R / Hennelly, Christopher M / Park, Zackary / Moormann, Ann M / Ong'echa, John Michael / Verity, Robert / Mohammed, Safia / Shija, Shija J / Mhamilawa, Lwidiko E / Morris, Ulrika / Mårtensson, Andreas /
    Lin, Jessica T / Björkman, Anders / Juliano, Jonathan J / Bailey, Jeffrey A

    medRxiv : the preprint server for health sciences

    2024  

    Abstract: The Zanzibar archipelago of Tanzania has become a low-transmission area ... ...

    Abstract The Zanzibar archipelago of Tanzania has become a low-transmission area for
    Language English
    Publishing date 2024-02-13
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.02.15.23285960
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Plasmodium falciparum gametocyte carriage in longitudinally monitored incident infections is associated with duration of infection and human host factors.

    Andolina, Chiara / Ramjith, Jordache / Rek, John / Lanke, Kjerstin / Okoth, Joseph / Grignard, Lynn / Arinaitwe, Emmanuel / Briggs, Jessica / Bailey, Jeffrey / Aydemir, Ozkan / Kamya, Moses R / Greenhouse, Bryan / Dorsey, Grant / Staedke, Sarah G / Drakeley, Chris / Jonker, Marianne / Bousema, Teun

    Scientific reports

    2023  Volume 13, Issue 1, Page(s) 7072

    Abstract: Malaria transmission depends on the presence of Plasmodium gametocytes that are the only parasite life stage that can infect mosquitoes. Gametocyte production varies between infections and over the course of infections. Infection duration is highly ... ...

    Abstract Malaria transmission depends on the presence of Plasmodium gametocytes that are the only parasite life stage that can infect mosquitoes. Gametocyte production varies between infections and over the course of infections. Infection duration is highly important for gametocyte production but poorly quantified. Between 2017 and 2019 an all-age cohort of individuals from Tororo, eastern Uganda was followed by continuous passive and routine assessments. We longitudinally monitored 104 incident infections from 98 individuals who were sampled once every 28 days and on any day of symptoms. Among infections that lasted ≥ 3 months, gametocyte appearance was near-universal with 96% of infections having detectable gametocytes prior to clearance. However, most infections were of much shorter duration; 55.7% of asymptomatic infections were detected only once. When considering all asymptomatic infections, regardless of their duration, only 36.3% had detectable gametocytes on at least one time-point prior to parasite clearance. Infections in individuals with sickle-cell trait (HbAS) were more likely to have gametocytes detected (Hazard Rate (HR) = 2.68, 95% CI 1.12, 6.38; p = 0.0231) and had gametocytes detected at higher densities (Density Ratio (DR) = 9.19, 95% CI 2.79, 30.23; p = 0.0002) compared to infections in wildtype (HbAA) individuals. Our findings suggest that a large proportion of incident infections is too short in duration and of too low density to contribute to onward transmission.
    MeSH term(s) Animals ; Humans ; Plasmodium falciparum ; Malaria, Falciparum/parasitology ; Asymptomatic Infections ; Uganda ; Culicidae
    Language English
    Publishing date 2023-05-01
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-023-33657-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Temporal and spatial analysis of Plasmodium falciparum genomics reveals patterns of parasite connectivity in a low-transmission district in Southern Province, Zambia.

    Fola, Abebe A / Moser, Kara A / Aydemir, Ozkan / Hennelly, Chris / Kobayashi, Tamaki / Shields, Timothy / Hamapumbu, Harry / Musonda, Michael / Katowa, Ben / Matoba, Japhet / Stevenson, Jennifer C / Norris, Douglas E / Thuma, Philip E / Wesolowski, Amy / Moss, William J / Bailey, Jeffrey A / Juliano, Jonathan J

    Malaria journal

    2023  Volume 22, Issue 1, Page(s) 208

    Abstract: Background: Understanding temporal and spatial dynamics of malaria transmission will help to inform effective interventions and strategies in regions approaching elimination. Parasite genomics are increasingly used to monitor epidemiologic trends, ... ...

    Abstract Background: Understanding temporal and spatial dynamics of malaria transmission will help to inform effective interventions and strategies in regions approaching elimination. Parasite genomics are increasingly used to monitor epidemiologic trends, including assessing residual transmission across seasons and importation of malaria into these regions.
    Methods: In a low and seasonal transmission setting of southern Zambia, a total of 441 Plasmodium falciparum samples collected from 8 neighbouring health centres between 2012 and 2018 were genotyped using molecular inversion probes (MIPs n = 1793) targeting a total of 1832 neutral and geographically informative SNPs distributed across the parasite genome. After filtering for quality and missingness, 302 samples and 1410 SNPs were retained and used for downstream population genomic analyses.
    Results: The analyses revealed most (67%, n = 202) infections harboured one clone (monogenomic) with some variation at local level suggesting low, but heterogenous malaria transmission. Relatedness identity-by-descent (IBD) analysis revealed variable distribution of IBD segments across the genome and 6% of pairs were highly-related (IBD ≥ 0.25). Some of the highly-related parasite populations persisted across multiple seasons, suggesting that persistence of malaria in this low-transmission region is fueled by parasites "seeding" across the dry season. For recent years, clusters of clonal parasites were identified that were dissimilar to the general parasite population, suggesting parasite populations were increasingly fragmented at small spatial scales due to intensified control efforts. Clustering analysis using PCA and t-SNE showed a lack of substantial parasite population structure.
    Conclusion: Leveraging both genomic and epidemiological data provided comprehensive picture of fluctuations in parasite populations in this pre-elimination setting of southern Zambia over 7 years.
    MeSH term(s) Animals ; Humans ; Plasmodium falciparum/genetics ; Parasites ; Malaria, Falciparum/parasitology ; Zambia/epidemiology ; Malaria ; Spatial Analysis ; Genomics
    Language English
    Publishing date 2023-07-07
    Publishing country England
    Document type Journal Article
    ZDB-ID 2091229-8
    ISSN 1475-2875 ; 1475-2875
    ISSN (online) 1475-2875
    ISSN 1475-2875
    DOI 10.1186/s12936-023-04637-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Epstein-Barr Virus Genomes Reveal Population Structure and Type 1 Association with Endemic Burkitt Lymphoma.

    Kaymaz, Yasin / Oduor, Cliff I / Aydemir, Ozkan / Luftig, Micah A / Otieno, Juliana A / Ong'echa, John Michael / Bailey, Jeffrey A / Moormann, Ann M

    Journal of virology

    2020  Volume 94, Issue 17

    Abstract: Endemic Burkitt lymphoma (eBL), the most prevalent pediatric cancer in sub-Saharan Africa, is distinguished by its inclusion of Epstein-Barr virus (EBV). In order to better understand the impact of EBV variation in eBL tumorigenesis, we improved viral ... ...

    Abstract Endemic Burkitt lymphoma (eBL), the most prevalent pediatric cancer in sub-Saharan Africa, is distinguished by its inclusion of Epstein-Barr virus (EBV). In order to better understand the impact of EBV variation in eBL tumorigenesis, we improved viral DNA enrichment methods and generated a total of 98 new EBV genomes from both eBL cases (
    MeSH term(s) Adolescent ; Burkitt Lymphoma/genetics ; Burkitt Lymphoma/virology ; Child ; Child, Preschool ; DNA, Viral ; Epstein-Barr Virus Infections/epidemiology ; Epstein-Barr Virus Infections/virology ; Epstein-Barr Virus Nuclear Antigens/genetics ; Female ; Genetic Variation ; Genome, Viral ; Genome-Wide Association Study ; Herpesvirus 4, Human/genetics ; Humans ; Infant ; Kenya/epidemiology ; Male ; Odds Ratio ; Receptor, Macrophage Colony-Stimulating Factor/genetics ; Sequence Analysis, DNA ; Viral Proteins/genetics
    Chemical Substances BARF1 protein, Human herpesvirus 4 ; DNA, Viral ; Epstein-Barr Virus Nuclear Antigens ; Viral Proteins ; Receptor, Macrophage Colony-Stimulating Factor (EC 2.7.10.1) ; EBV-encoded nuclear antigen 1 (O5GA75RST7)
    Language English
    Publishing date 2020-08-17
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 80174-4
    ISSN 1098-5514 ; 0022-538X
    ISSN (online) 1098-5514
    ISSN 0022-538X
    DOI 10.1128/JVI.02007-19
    Database MEDical Literature Analysis and Retrieval System OnLINE

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