Browsing by Author "Yang, David"

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    Krabbe disease: Two cases of multidisciplinary symptom management
    (2021-04-08) Yang, David; Gnanakumar, Vithya; Spencer, Adam; Livingstone, Margaret
    We present the comprehensive, multidisciplinary symptom management of two patients with infantile Krabbe disease. Krabbe disease is a rare autosomal recessive neurodegenerative condition, and is ultimately fatal. Initial symptoms and subsequent diagnoses of our patients are discussed. Supportive care for patients with this disease prioritizes symptomatic management of pain and irritability. Pharmacological management strategies are discussed including the implementation of various medications and doses, and proposed medication mechanisms of action in the context of Krabbe disease. Adverse effects of the introduction of morphine are discussed in one patient. Non-pharmacological management strategies including therapy programs are also discussed including the utilization of splinting, seating, and positioning. Patients with Krabbe disease benefit from a comprehensive team of multidisciplinary medical professionals. 
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    Parallelization of Bayesian Phylogenetics to Greatly Improve Run Times
    (2024-03-24) Yang, David; Zhang, Qingrun; Gordon, Paul; Liao, Wenyuan; van der Meer, Franciscus Johannes
    Phylogenetic analyses are invaluable to understanding the transmission of viruses, especially during disease outbreaks. In particular, Bayesian phylogenetics has great potential in modeling viral transmission due to the numerous phylogenetic models that can be incorporated. Currently, the availability of user-friendly software and accessibility to sequence data makes phylogenetic analyses easy to perform. However, to date, Bayesian phylogenetic analyses are still limited by long computational run-times which are especially unfavorable during ongoing and evolving disease outbreaks that demand real-time phylogeny results. Current optimization methods of Bayesian phylogenetic analysis mainly focus on iteration-level parallelization and mostly overlook the potential of larger-scale parallelization approaches. In this thesis, we provide an in-depth overview of topics including phylogenetic analysis, relevant biological information, and phylogenetic analysis optimization methods. We also proposed a novel parallelized Markov Chain Monte Carlo method that greatly improved Bayesian phylogenetic run times and integrated the approach into a data pipeline to allow for the direct analysis of viral samples. We demonstrated the validity of our methods by performing phylogenetic analyses on two sets of HIV simulation data and one set of real-world SARS-CoV-2 data. Our results suggested that the parallelization of MCMC in Bayesian phylogenetic analyses drastically reduces run times by 29-fold without causing significant deviations in parameter estimates and predicted phylogenetic trees.