4,399 results on '"TUNG T."'
Search Results
2. Optimizing traffic management in Danang: a comparative study of multi-object tracking techniques for real-time vehicle flow monitoring
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Hai T. Ton, Hung V. Nguyen, Hanh T. M. Tran, Tien V. Thai, Phong-Phu Le, Tung T. Huynh, and Duy-Tuan Dao
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traffic flow monitoring ,object detection ,yolov8 ,multiple object tracking (mot) ,Technology - Abstract
This study evaluates the effectiveness of various detection-based object-tracking algorithms to optimize accuracy and efficiency in traffic flow monitoring. Due to its high accuracy in detecting objects, YOLOv8 was chosen as the vehicle detector for this research, where precise and rapid vehicle detection was critical. Regarding object tracking, our focus centered on the evaluation of five prominent Multiple Object Tracking (MOT) algorithms, including BoTSORT, ByteTrack, DeepOCSORT, OCSORT, and StrongSORT. We introduce a comprehensive traffic urban dataset collected from intricate street networks in Danang City. Our experimental results show that the system has practical applicability in urban traffic monitoring. Notably, the best model achieves a detection accuracy of 0.721 on mAP@0.5-0.95, and the High Overlap Tracking Accuracy (HOTA) surpasses 72% for tracking performance across diverse traffic scenarios. This shows the applicability of MOT algorithms and provides a detailed view of traffic flow monitoring, especially in Danang City, Vietnam.
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- 2024
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3. Protocol for effective surface passivation for single-molecule studies of chromatin and topoisomerase II
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Tung T. Le, Xiang Gao, Seong Ha Park, Jaeyoon Lee, James T. Inman, and Michelle D. Wang
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biophysics ,single-molecule assays ,molecular biology ,Science (General) ,Q1-390 - Abstract
Summary: For single-molecule studies requiring surface anchoring of biomolecules, poorly passivated surfaces can result in alterations of biomolecule structure and function that lead to artifacts. Here, we present a surface passivation assay for single-molecule studies of chromatin and topoisomerase II. We detail steps for preparing a nucleosome array and hydrophobic nitrocellulose-coated flow cell. We then describe procedures for chromatin stretching with an angular optical trap (AOT) and performing a chromatin-topoisomerase experiment. This method is cost effective and potentially applicable to other biomolecules.For complete details on the use and execution of this protocol, please refer to Le et al. 1 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.
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- 2025
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4. TetR-like regulator BP1026B_II1561 controls aromatic amino acid biosynthesis and intracellular pathogenesis in Burkholderia pseudomallei
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Ian A. McMillan, Michael H. Norris, Yun Heacock-Kang, Jan Zarzycki-Siek, Zhenxin Sun, Brooke A. Hartney, Liliana K. Filipowska, M. Nurul Islam, Dean C. Crick, Bradley R. Borlee, and Tung T. Hoang
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bacteriology ,Burkholderia pseudomallei ,melioidosis ,transcriptional regulation ,pathogenesis ,Microbiology ,QR1-502 - Abstract
Burkholderia pseudomallei (Bp) causes the tropical disease melioidosis that afflicts an estimated 165,000 people each year. Bp is a facultative intracellular pathogen that transits through distinct intracellular stages including attachment to host cells, invasion through the endocytic pathway, escape from the endosome, replication in the cytoplasm, generation of protrusions towards neighboring cells, and host cell fusion allowing Bp infection to spread without exiting the intracellular environment. We have identified a TetR-like transcriptional regulator, BP1026B_II1561, that is up-regulated during the late stages of infection as Bp protrudes toward neighboring cells. We have characterized BP1026B_II1561 and determined that it has a role in pathogenesis. A deletional mutant of BP1026B_II1561 is attenuated in RAW264.7 macrophage and BALB/c mouse models of infection. Using RNA-seq, we found that BP1026B_II1561 controls secondary metabolite biosynthesis, fatty acid degradation, and propanoate metabolism. In addition, we identified that BP1026B_II1561 directly controls expression of an outer membrane porin and genes in the shikimate biosynthetic pathway using ChIP-seq. Transposon mutants of genes within the BP1026B_II1561 regulon show defects during intracellular replication in RAW264.7 cells confirming the role of this transcriptional regulator and the pathways it controls in pathogenesis. BP1026B_II1561 also up-regulates the majority of the enzymes in shikimate and tryptophan biosynthetic pathways, suggesting their importance for Bp physiology. To investigate this, we tested fluorinated analogs of anthranilate and tryptophan, intermediates and products of the shikimate and tryptophan biosynthetic pathways, respectively, and showed inhibition of Bp growth at nanomolar concentrations. The expression of these pathways by BP1026b_II1561 and during intracellular infection combined with the inhibition of Bp growth by fluorotryptophan/anthranilate highlights these pathways as potential targets for therapeutic intervention against melioidosis. In the present study, we have identified BP1026B_II1561 as a critical transcriptional regulator for Bp pathogenesis and partially characterized its role during host cell infection.
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- 2024
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5. Rapid recognition and optimal management of hemophilia in the emergency department: A quality improvement project
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Asinamai M. Ndai, Brandon R. Allen, Tung T. Wynn, Anita Rajasekhar, Ziad Saqr, Ina Sandeli, Scott M. Vouri, and Rachel Reise
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bleeding ,emergency department ,factor replacement therapy ,hemophilia ,quality improvement ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Objectives This study aimed to assess the effectiveness of a continuous quality improvement initiative at the University of Florida Health Physicians practice in reducing the time to administer factor replacement therapy (FRT) for hemophilia patients presenting with bleeding in the emergency department (ED). Methods The study, a quasi‐experimental, interventional design, was conducted between January 2020 and January 2023. The intervention, implemented in September 2021, involved training ED physicians, creating a specialized medication order set within the electronic health record (EHR), and a rapid triage system. The effectiveness was measured by comparing the time from ED arrival to factor administration before and after the intervention and benchmarking it against the National Bleeding Disorders Foundation's Medical and Scientific Advisory Council (MASAC)‐recommended 1‐hour timeline for factor administration. An interrupted time series (ITS) analysis with a generalized least squares model assessed the intervention's impact. Results A total of 43 ED visits (22 pre‐intervention and 21 post‐intervention) were recorded. Post‐intervention, the average time from ED arrival to factor administration decreased from 5.63 to 3.15 hours. There was no significant increase (27% vs. 29%) in the patients receiving factor within 1‐hour of ED arrival. The ITS analysis predicted a 20‐hour reduction in the average quarterly time to administer factor by the end of the study, an 84% decrease. Conclusions The quality improvement program decreased the time to administer FRT for patients with hemophilia in the ED. However, the majority of patients did not achieve the 1‐hour MASAC‐recommended timeline for factor administration after ED arrival.
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- 2024
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6. Correlates of supportive care needs among Asian Americans with colorectal, liver, or lung cancer from a web‐based patient navigation portal intervention: The Patient COUNTS study
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Katarina Wang, Janet N. Chu, Debora L. Oh, Salma Shariff‐Marco, Laura Allen, Mei‐Chin Kuo, Ching Wong, Hoan Bui, Junlin Chen, Feng Ming Li, Carmen Ma, Angeline Truong, Scarlett L. Gomez, Tung T. Nguyen, and Janice Y. Tsoh
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Asian American ,cancer ,cultural competence ,cultural humility ,multilingual ,patient navigation ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Cancer is the leading cause of death among Asian Americans, who often face barriers to cancer care. Cancer supportive care needs among Asian Americans remain understudied. Aims We examined cancer supportive care needs and participant factors correlated with these needs, identified profiles of supportive care needs, and examined whether needs profiles are associated with quality of life among Asian American adults. Methods and Results We recruited 47 Asian American adults with colorectal, liver, or lung cancer who spoke Chinese, English, or Vietnamese, and were starting or undergoing cancer treatment. We assessed cancer supportive care needs in four domains: cancer information, daily living, behavioral health, and language assistance. Hierarchical cluster analysis was used to identify clusters of participants based on their supportive need profiles to further examine the association between need profiles and quality of life (QoL) assessed by the Functional Assessment of Cancer Therapy. Participants (mean age = 57.6) included 72% males and 62% spoke English less than very well. Older participants (age ≥ 65) and those with annual income
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- 2024
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7. Mucosal vaccines for SARS-CoV-2: scientific gaps and opportunities—workshop report
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Jane M. Knisely, Lucas E. Buyon, Rebecca Mandt, Rebecca Farkas, Shobana Balasingam, Karin Bok, Ursula J. Buchholz, M. Patricia D’Souza, Jennifer L. Gordon, Deborah F. L. King, Tung T. Le, Wolfgang W. Leitner, Robert A. Seder, Alkis Togias, Stig Tollefsen, David W. Vaughn, Daniel N. Wolfe, Kimberly L. Taylor, and Anthony S. Fauci
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Immunologic diseases. Allergy ,RC581-607 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
On November 7th and 8th, 2022, The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), The Coalition for Epidemic Preparedness Innovation (CEPI), The Bill & Melinda Gates Foundation (BMGF), The Biomedical Advanced Research and Development Authority (BARDA), and the Wellcome Trust hosted a virtual workshop entitled “Mucosal Vaccines for SARS-CoV-2: Scientific Gaps and Opportunities.” During the workshop, researchers and vaccine developers from around the world discussed the potential of mucosal vaccines to block SARS-CoV-2 transmission and reviewed the status of SARS-CoV-2 mucosal vaccine research. Here, we summarize key challenges and opportunities in basic, translational, and clinical research that were highlighted during the meeting. We also provide recommendations to advance the field and accelerate the development of mucosal vaccines for SARS-CoV-2.
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- 2023
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8. Learning From Multiple Expert Annotators for Enhancing Anomaly Detection in Medical Image Analysis
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Khiem H. Le, Tuan V. Tran, Hieu H. Pham, Hieu T. Nguyen, Tung T. Le, and Ha Q. Nguyen
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Computer-aided diagnosis ,deep learning ,object detection ,multiple annotators ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Recent years have experienced phenomenal growth in computer-aided diagnosis systems based on machine learning algorithms for anomaly detection tasks in the medical image domain. However, the performance of these algorithms greatly depends on the quality of labels since the subjectivity of a single annotator might decline the certainty of medical image datasets. In order to alleviate this problem, aggregating labels from multiple radiologists with different levels of expertise has been established. In particular, under the reliance on their own biases and proficiency levels, different qualified experts provide their estimations of the “true” bounding boxes representing the anomaly observations. Learning from these nonstandard labels exerts negative effects on the performance of machine learning networks. In this paper, we propose a simple yet effective approach for the enhancement of neural networks’ efficiency in abnormal detection tasks by estimating the actually hidden labels from multiple ones. A re-weighted loss function is also used to improve the detection capacity of the networks. We conduct an extensive experimental evaluation of our proposed approach on both simulated and real-world medical imaging datasets, MED-MNIST and VinDr-CXR. The experimental results show that our approach is able to capture the reliability of different annotators and outperform relevant baselines that do not consider the disagreements among annotators. Our code is available at https://github.com/huyhieupham/learning-from-multiple-annotators.
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- 2023
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9. Two new Drawida (Oligochaeta, Moniligastridae) earthworms from Vietnam
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Tung T. Nguyen, Dang H. Lam, Binh T. T. Tran, and Anh D. Nguyen
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Zoology ,QL1-991 - Abstract
Two new earthworm species are described, namely Drawida angiang sp. nov. and Drawida cochinchina sp. nov. The former can be recognized by having male pores on spiniform penises in intersegment 10/11, an erect and sac-shaped spermathecal atrium, glandular prostate, the capsule coiled one round, the vas deferens strongly coiled but small, two large, round, genital markings on segments ix–x, and three gizzards in xiii–xv. The latter species is distinguished in having the male pores placed on highly elevated, backwardly directed, conical penises in 10/11, a slender spermathecal atrium, a glandular prostate, a somewhat folded capsule, the vas deferens strongly coiled as a bunch and equal size to the testis sacs, a pair of genital markings located closely anterior to the penises with 1–3 additional ones in xi–xii, and three or four gizzards in xiii–xvi. The DNA barcode fragment of the COI gene was extracted for each species, and the COI genetic distances and phylogenetic analysis also supported two new species..
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- 2022
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10. Exploring factors associated with hepatitis B screening in a multilingual and diverse population
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Janet N. Chu, Tung T. Nguyen, Natalie A. Rivadeneira, Robert A. Hiatt, and Urmimala Sarkar
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Hepatitis B ,Screening ,Language preference ,Race/ethnicity ,Preventive medicine ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Racial/ethnic minorities bear a disproportionate burden of hepatitis B virus (HBV) infection and disease. Disparities in HBV screening contribute to worse outcomes for communities of color. We examined the impact of race/ethnicity, language preference, and having a usual place of care on HBV screening in a multilingual, urban cohort. Methods We used questions from the Health Information National Trends Survey and added validated questions about healthcare access and health literacy. We administered this survey in English, Spanish, and Chinese to a selected convenience sample of San Francisco city/county residents in 2017, with pre-specified targets for populations with known cancer disparities: 25% Spanish-speaking, 25% Chinese-speaking, and 25% Black Americans. Using weighted multivariable logistic regression analyses, we assessed how race/ethnicity, language preference, and having a usual place of care impacts self-report of HBV screening. Results Overall, 1027 participants completed the survey (50% of surveys administered in English, 25% in Spanish, and 25% in Chinese). Only 50% of participants reported HBV screening. In multivariable analysis, Black (OR = 0.20, 95% CI 0.08–0.49), Latinx (OR = 0.33, 95% CI 0.13–0.85), Asian (OR = 0.31, 95% CI 0.10, 0.94), and ‘Other’ race/ethnicity (OR = 0.17, 95% CI 0.05–0.53) respondents had lower odds of HBV screening compared to non-Hispanic White respondents. Participants who had insurance had increased odds of HBV screening (OR = 2.70, 95% CI 1.48–4.93). Conclusions HBV screening disparities persist for Black Americans, Asian Americans, Latinx, and the uninsured. Future studies should explore reasons why current strategies have not been implemented or are not successful, particularly in addressing racial/ethnic and insurance disparities.
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- 2022
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11. A virulence activator of a surface attachment protein in Burkholderia pseudomallei acts as a global regulator of other membrane-associated virulence factors
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Zhenxin Sun, Yun Heacock-Kang, Ian A. McMillan, Darlene Cabanas, Jan Zarzycki-Siek, and Tung T. Hoang
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Burkholderia pseudomallei ,transposon mutagenesis ,Tn-Seq ,RNA-Seq ,bacterial cell envelope ,gene regulation ,Microbiology ,QR1-502 - Abstract
Burkholderia pseudomallei (Bp), causing a highly fatal disease called melioidosis, is a facultative intracellular pathogen that attaches and invades a variety of cell types. We previously identified BP1026B_I0091 as a surface attachment protein (Sap1) and an essential virulence factor, contributing to Bp pathogenesis in vitro and in vivo. The expression of sap1 is regulated at different stages of Bp intracellular lifecycle by unidentified regulator(s). Here, we identified SapR (BP1026B_II1046) as a transcriptional regulator that activates sap1, using a high-throughput transposon mutagenesis screen in combination with Tn-Seq. Consistent with phenotypes of the Δsap1 mutant, the ΔsapR activator mutant exhibited a significant reduction in Bp attachment to the host cell, leading to subsequent decreased intracellular replication. RNA-Seq analysis further revealed that SapR regulates sap1. The regulation of sap1 by SapR was confirmed quantitatively by qRT-PCR, which also validated the RNA-Seq data. SapR globally regulates genes associated with the bacterial membrane in response to diverse environments, and some of the genes regulated by SapR are virulence factors that are required for Bp intracellular infection (e.g., type III and type VI secretion systems). This study has identified the complex SapR regulatory network and its importance as an activator of an essential Sap1 attachment factor.
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- 2023
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12. Identification of a PadR-type regulator essential for intracellular pathogenesis of Burkholderia pseudomallei
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Ian A. McMillan, Michael H. Norris, Jan Zarzycki-Siek, Yun Heacock-Kang, Zhenxin Sun, Bradley R. Borlee, and Tung T. Hoang
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Medicine ,Science - Abstract
Abstract Burkholderia pseudomallei (Bp) is the causative agent of melioidosis, a disease endemic to the tropics. Melioidosis manifests in various ways ranging from acute skin lesions to pneumonia and, in rare cases, infection of the central nervous system. Bp is a facultative intracellular pathogen and it can infect various cell types. The Bp intracellular lifecycle has been partially elucidated and is highly complex. Herein, we have identified a transcriptional regulator, BP1026B_II1198, that is differentially expressed as Bp transits through host cells. A deletion mutant of BP1026B_II1198 was attenuated in RAW264.7 cell and BALB/c mouse infection. To further characterize the function of this transcriptional regulator, we endeavored to determine the regulon of BP1026B_II1198. RNA-seq analysis showed the global picture of genes regulated while ChIP-seq analysis identified two specific BP1026B_II1198 binding regions on chromosome II. We investigated the transposon mutants of these genes controlled by BP1026B_II1198 and confirmed that these genes contribute to pathogenesis in RAW264.7 murine macrophage cells. Taken together, the data presented here shed light on the regulon of BP1026B_II1198 and its role during intracellular infection and highlights an integral portion of the highly complex regulation network of Bp during host infection.
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- 2021
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13. The Burkholderia pseudomallei intracellular ‘TRANSITome’
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Yun Heacock-Kang, Ian A. McMillan, Michael H. Norris, Zhenxin Sun, Jan Zarzycki-Siek, Andrew P. Bluhm, Darlene Cabanas, Robert E. Norton, Natkunam Ketheesan, Jeff F. Miller, Herbert P. Schweizer, and Tung T. Hoang
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Science - Abstract
Prokaryotic cell transcriptomics has been limited to mixed or sub-population dynamics and individual cells within heterogeneous populations. Here the authors develop a ‘TRANSITomic’ approach to profile transcriptomes of single Burkholderia pseudomallei cells as they transit through host cell infection.
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- 2021
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14. Isomorphic gcd-graphs over polynomial rings
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Mináč, Ján, Nguyen, Tung T., and Tân, Nguyen Duy
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Mathematics - Number Theory - Abstract
Gcd-graphs over the ring of integers modulo $n$ are a simple and elegant class of integral graphs. The study of these graphs connects multiple areas of mathematics, including graph theory, number theory, and ring theory. In a recent work, inspired by the analogy between number fields and function fields, we define and study gcd-graphs over polynomial rings with coefficients in finite fields. We discover that, in both cases, gcd-graphs share many similar and analogous properties. In this article, we extend this line of research further. Among other topics, we explore an analog of a conjecture of So and a weaker version of Sander-Sander, concerning the conditions under which two gcd-graphs are isomorphic or isospectral. We also provide several constructions showing that, unlike the case over $\mathbb{Z}$, it is not uncommon for two gcd-graphs over polynomial rings to be isomorphic., Comment: Comments are welcome!
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- 2024
15. Integral Cayley graphs over a finite symmetric algebra
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Nguyen, Tung T. and Tân, Nguyen Duy
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Mathematics - Number Theory ,Mathematics - Combinatorics ,11R58, 05E40, 05C50 - Abstract
A graph is called integral if its eigenvalues are integers. In this article, we provide the necessary and sufficient conditions for a Cayley graph over a finite symmetric algebra $R$ to be integral. This generalizes the work of So who studies the case where $R$ is the ring of integers modulo $n.$ We also explain some number-theoretic constructions of finite symmetric algebras arising from global fields, which we hope could pave the way for future studies on Paley graphs associated with a finite Hecke character., Comment: To appear in Archiv der Mathematik
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- 2024
16. On the gcd graphs over polynomial rings and related topics
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Mináč, Ján, Nguyen, Tung T., and Tân, Nguyen Duy
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Mathematics - Number Theory ,Mathematics - Commutative Algebra ,Mathematics - Combinatorics - Abstract
Gcd-graphs over the ring of integers modulo $n$ are a natural generalization of unitary Cayley graphs. The study of these graphs has foundations in various mathematical fields, including number theory, ring theory, and representation theory. Using the theory of Ramanujan sums, it is known that these gcd-graphs have integral spectra; i.e., all their eigenvalues are integers. In this work, inspired by the analogy between number fields and function fields, we define and study gcd-graphs over polynomial rings with coefficients in finite fields. We establish some fundamental properties of these graphs, emphasizing their analogy to their counterparts over $\mathbb{Z}.$, Comment: Comments are welcome!
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- 2024
17. A complete classification of perfect unitary Cayley graphs
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Mináč, Ján, Nguyen, Tung T., and Tân, Nguyen Duy
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Mathematics - Combinatorics ,Mathematics - Rings and Algebras - Abstract
Due to their elegant and simple nature, unitary Cayley graphs have been an active research topic in the literature. These graphs are naturally connected to several branches of mathematics, including number theory, finite algebra, representation theory, and graph theory. In this article, we study the perfectness property of these graphs. More precisely, we provide a complete classification of perfect unitary Cayley graphs associated with finite rings., Comment: Comments are welcome!
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- 2024
18. Suspected heparin-induced thrombocytopenia in a COVID-19 patient on extracorporeal membrane oxygenation support: a case report
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Xuan T. Phan, Tuan H. Nguyen, Tung T. Tran, Thu-Hien T. Huynh, Thuy-Ha T. Hoang, Vinh-Chau V. Nguyen, and Thao N. T. Pham
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HIT ,ECMO ,Extracorporeal ,COVID-19 ,Thrombocytopenia ,Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
Abstract Background Extracorporeal membrane oxygenation (ECMO) support can be life-saving in critically ill COVID-19 patients. However, there are many complications associated with this procedure, including Heparin-induced thrombocytopenia (HIT.) Despite its rarity in ECMO cases, HIT can lead to devastating consequences and is difficult to manage. Case presentation In this report, we present a case of a COVID-19 patient on ECMO support who was diagnosed with HIT and required intensive treatment. Initially, HIT was only suspected due to newly-developed thrombocytopenia and oxygenator dysfunction, with thrombi observed later. Regarding his treatment, since there was no recommended replacement to heparin available to us at the time of diagnosis, we decided to use rivaroxaban temporarily. No adverse events were recorded during that period. The patient was able to make a full recovery. Conclusion HIT may jeopardize patient’s care during ECMO. As COVID-19 may bring about a surge in the number of patients requiring ECMO support, we need consented guidance to optimize treatment in this specific situation.
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- 2020
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19. The megascolecid earthworms (Annelida, Oligochaeta, Megascolecidae) in the Phu Quoc island, Vietnam, with descriptions of three new species
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Tung T. Nguyen, Dang H. Lam, Binh T. K. Trinh, and Anh D. Nguyen
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Zoology ,QL1-991 - Abstract
The megascolecid earthworms of the Phu Quoc island are intensively investigated. Twelve species in three genera (Lampito Kinberg, 1867, Amynthas Kinberg, 1867, and Metaphire Sims & Easton, 1972) are recorded. Of these, Metaphire doiphamon Bantaowong & Panha, 2016 is recorded for the first time in Vietnam, and three species are newly described, namely Amynthas catenatus sp. nov., A. phuquocensis sp. nov., and A. poropapillatus sp. nov. An identification key to 12 megascolecid species is provided as well.
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- 2020
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20. Barriers and facilitators to implementation of epilepsy self-management programs: a systematic review using qualitative evidence synthesis methods
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Allison A. Lewinski, Abigail Shapiro, Jennifer M. Gierisch, Karen M. Goldstein, Dan V. Blalock, Matthew W. Luedke, Adelaide M. Gordon, Hayden B. Bosworth, Connor Drake, Jeffrey D. Lewis, Saurabh R. Sinha, Aatif M. Husain, Tung T. Tran, Megan G. Van Noord, and John W. Williams
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Epilepsy ,Self-management ,Qualitative research ,Medicine - Abstract
Abstract Background Epilepsy affects nearly 50 million people worldwide. Self-management is critical for individuals with epilepsy in order to maintain optimal physical, cognitive, and emotional health. Implementing and adopting a self-management program requires considering many factors at the person, program, and systems levels. We conducted a systematic review of qualitative and mixed-methods studies to identify facilitators and barriers that impact implementation and adoption of self-management programs for adults with epilepsy. Methods We used established systematic review methodologies for qualitative and mixed-methods studies. We included studies addressing facilitators (i.e., factors that aided) or barriers (i.e., factors that impeded) to implementation and adoption of self-management interventions for adults with epilepsy. We conducted a narrative thematic synthesis to identify facilitators and barriers. Results The literature search identified 2700 citations; 13 studies met eligibility criteria. Our synthesis identified five themes that categorize facilitators and barriers to successful implementation epilepsy self-management: (1) relevance, intervention content that facilitates acquisition of self-management skills; (2) personalization, intervention components that account for the individual’s social, physical, and environmental characteristics; (3) intervention components, components and dosing of the intervention; (4) technology considerations, considerations that account for individual’s use, familiarity with, and ownership of technology; and (5) clinician interventionist, role and preparation of the individual who leads intervention. We identified facilitators in 11 of the 13 studies and barriers in 11 of the 13 studies and classified these by social-ecological level (i.e., patient/caregiver, program, site/system). Conclusion Identification of facilitators and barriers at multiple levels provides insight into disease-specific factors that influence implementation and adoption of self-management programs for individuals with epilepsy. Our findings indicate that involving individuals with epilepsy and their caregivers in intervention development, and then tailoring intervention content during the intervention, can help ensure the content is relevant to intervention participants. Our findings also indicate the role of the clinician (i.e., the individual who provides self-management education) is important to intervention implementation, and key issues with clinicians were identified as barriers and opportunities for improvement. Overall, our findings have practical value for those seeking to implement and adopt self-management interventions for epilepsy and other chronic illnesses. Systematic review registration PROSPERO registration number is CRD42018098604 .
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- 2020
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21. Severe COVID-19 during pregnancy treated with pulse corticosteroid therapy and mid-trimester termination: A case report
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Thinh N. Bui, Nhat M. Huynh, Nguyen-Huy Do-Tran, Hoang-Anh Ngo, Hung Tran, Nhan T. Nguyen, Tung T. Pham, Kha D. Le, and Thu-Anh Nguyen
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COVID-19 ,Pregnancy ,Pulse corticosteroid therapy ,Mid-trimester termination ,Case report ,Surgery ,RD1-811 ,Gynecology and obstetrics ,RG1-991 - Abstract
Background: At the early stage of the pandemic, severe COVID-19 was thought to be rare among pregnant women. However, cumulating data showed that gestational state is a risk factor for severe pneumonia, particularly due to the hyperinflammatory state. Recent reports suggested the efficacy of pulse corticosteroids in stopping the cytokine storm in people infected with SARS-CoV-2, but limited data exists regarding its use in pregnant women. Moreover, pregnancy termination is a treatment option in this population, but it has been reported mainly in the third trimester and rarely in the second trimester. Case Presentation: A 37-year-old woman infected with SARS-CoV-2 at 23 weeks of gestation presented with fatigue and dyspnea but soon deteriorated to severely acute respiratory failure and cytokine storm requiring mechanical ventilation combined with hemodialysis just one day after hospitalization. Low-dose corticosteroids and antibiotics were initiated, followed by antiviral therapy, anticoagulant and high-dose corticosteroid therapy. On hospital day 3, a decision to terminate her pregnancy was made; termination led to significant improvement in her clinical condition and a gradual decrease in demand for oxygen supplementation as well as the corticosteroid dose. She was discharged two weeks after admission. Conclusions: Due to the specific immune response, pregnant women with COVID-19 may differ from others in their clinical presentation, especially the probability of classic acute respiratory distress syndrome (ARDS). This report provides evidence related to the efficacy of pulse corticosteroids on this group and the influence of the mid-trimester termination on recovery.
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- 2022
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22. Analytical prediction of specific spatiotemporal patterns in nonlinear oscillator networks with distance-dependent time delays
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Roberto C. Budzinski, Tung T. Nguyen, Gabriel B. Benigno, Jacqueline Đoàn, Ján Mináč, Terrence J. Sejnowski, and Lyle E. Muller
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Physics ,QC1-999 - Abstract
We introduce an analytical approach that allows predictions and mechanistic insights into the dynamics of nonlinear oscillator networks with heterogeneous time delays. We demonstrate that time delays shape the spectrum of a matrix associated with the system, leading to the emergence of waves with a preferred direction. We then create analytical predictions for the specific spatiotemporal patterns observed in individual simulations of time-delayed Kuramoto networks. This approach generalizes to systems with heterogeneous time delays at finite scales, which permits the study of spatiotemporal dynamics in a broad range of applications.
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- 2023
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23. Policy Reuse for Dialog Management Using Action-Relation Probability
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Tung T. Nguyen, Koichiro Yoshino, Sakriani Sakti, and Satoshi Nakamura
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Dialog management ,reinforcement learning ,transfer learning ,policy adaptation ,mixture density network ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
We study the problem of policy adaptation for reinforcement-learning-based dialog management. Policy adaptation is a commonly used technique to alleviate the problem of data sparsity when training a goal-oriented dialog system for a new task (the target task) by using knowledge when learning policies in an existing task. The methods used by current works in dialog policy adaptation need much time and effort for adapting because they use reinforcement learning algorithms to train a new policy for the target task from scratch. In this paper, we show that a dialog policy can be learned without training by reinforcement learning in the target task. In contrast to existing works, our proposed method learns the relation in the form of probability distribution between the action sets of the source and the target tasks. Thus, we can immediately derive a policy for the target task, which significantly reduces the adaptation time. Our experiments show that the proposed method learns a new policy for the target task much more quickly. In addition, the learned policy achieves higher performance than policies created by fine-tuning when the amount of available data on the target task is limited.
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- 2020
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24. User-to-User Interference Mitigation in Dynamic TDD MIMO Systems with Multi-Antenna Users
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Andersson, Martin, Vu, Tung T., Frenger, Pål, and Larsson, Erik G.
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Electrical Engineering and Systems Science - Signal Processing ,Computer Science - Information Theory - Abstract
We propose a novel method for user-to-user interference (UUI) mitigation in dynamic time-division duplex multiple-input multiple-output communication systems with multi-antenna users. Specifically, we consider the downlink data transmission in the presence of UUI caused by a user that simultaneously transmits in uplink. Our method introduces an overhead for estimation of the user-to-user channels by transmitting pilots from the uplink user to the downlink users. Each downlink user obtains a channel estimate that is used to design a combining matrix for UUI mitigation. We analytically derive an achievable spectral efficiency for the downlink transmission in the presence of UUI with our mitigation technique. Through numerical simulations, we show that our method can significantly improve the spectral efficiency performance in cases of heavy UUI., Comment: Accepted for presentation at the 25th IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Lucca, Italy, September 10-13, 2024
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- 2024
25. Joint Optimization of Switching Point and Power Control in Dynamic TDD Cell-Free Massive MIMO
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Andersson, Martin, Vu, Tung T., Frenger, Pål, and Larsson, Erik G.
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Electrical Engineering and Systems Science - Signal Processing ,Computer Science - Information Theory - Abstract
We consider a cell-free massive multiple-input multiple-output (CFmMIMO) network operating in dynamic time division duplex (DTDD). The switching point between the uplink (UL) and downlink (DL) data transmission phases can be adapted dynamically to the instantaneous quality-of-service (QoS) requirements in order to improve energy efficiency (EE). To this end, we formulate a problem of optimizing the DTDD switching point jointly with the UL and DL power control coefficients, and the large-scale fading decoding (LSFD) weights for EE maximization. Then, we propose an iterative algorithm to solve the formulated challenging problem using successive convex approximation with an approximate stationary solution. Simulation results show that optimizing switching points remarkably improves EE compared with baseline schemes that adjust switching points heuristically., Comment: Presented at the Asilomar Conference on Signals, Systems, and Computers 2023
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- 2024
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26. Notes on the earthworm species, Metaphire anomala (Michaelsen, 1907) (Clitellata, Megascolecidae) in Southern Vietnam, with descriptions of two new species
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Tung T. Nguyen, Dang H. Lam, and Anh D. Nguyen
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Metaphire ,taxonomy ,biodiversity ,COI genetic divergence ,Vietnam ,Zoology ,QL1-991 ,Botany ,QK1-989 - Abstract
Integrative taxonomy was employed to exploit the differences between the known Metaphire anomala (Michaelsen, 1907) and other specimens collected in Vietnam. The results brought to light two new species, namely Metaphire iranomala sp. nov. and Metaphire decemtheca sp. nov. The former is easily recognised by having male pores on xix and four pairs of spermathecal pores on 5/6/7/8/9 while the latter is distinguished by having five pairs of spermathecal pores on 4/5/6/7/8/9. The K2P distances of the fragment of the cytochrome c oxidase subunit I (COI) gene are 13.1% between M. iranomala sp. nov. and M. anomala (Michaelsen, 1907) and 18% between M. decemtheca sp. nov. and Metaphire grandiverticulata Nguyen & Lam, 2017. The intraspecific divergences are 1.5%–10.6% for M. iranomala sp. nov. and 2.1%–11.4% for M. decemtheca sp. nov.
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- 2021
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27. The heritable natural competency trait of Burkholderia pseudomallei in other Burkholderia species through comE and crp
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Yun Heacock-Kang, Ian A. McMillan, Jan Zarzycki-Siek, Zhenxin Sun, Andrew P. Bluhm, Darlene Cabanas, and Tung T. Hoang
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Medicine ,Science - Abstract
Abstract Natural competency requires uptake of exogenous DNA from the environment and the integration of that DNA into recipient bacteria can be used for DNA-repair or genetic diversification. The Burkholderia genus is unique in that only some of the species and strains are naturally competent. We identified and characterized two genes, comE and crp, from naturally competent B. pseudomallei 1026b that play a role in DNA uptake and catabolism. Single-copies of rhamnose-inducible comE and crp genes were integrated into a Tn7 attachment-site in non-naturally competent Burkholderia including pathogens B. pseudomallei K96243, B. cenocepacia K56-2, and B. mallei ATCC23344. Strains expressing comE or crp were assayed for their ability to uptake and catabolize DNA. ComE and Crp allowed non-naturally competent Burkholderia species to catabolize DNA, uptake exogenous gfp DNA and express GFP. Furthermore, we used synthetic comE and crp to expand the utility of the λ-red recombineering system for genetic manipulation of non-competent Burkholderia species. A newly constructed vector, pKaKa4, was used to mutate the aspartate semialdehyde dehydrogenase (asd) gene in four B. mallei strains, leading to the complete attenuation of these tier-1 select-agents. These strains have been excluded from select-agent regulations and will be of great interest to the field.
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- 2018
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28. On certain properties of the $p$-unitary Cayley graph over a finite ring
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Nguyen, Tung T. and Tân, Nguyen Duy
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Mathematics - Combinatorics ,05C25, 05C50, 05C51 - Abstract
In recent work, we study certain Cayley graphs associated with a finite commutative ring and their multiplicative subgroups. Among various results that we prove, we provide the necessary and sufficient conditions for such a Cayley graph to be prime. In this paper, we continue this line of research. Specifically, we investigate some basic properties of certain $p$-unitary Cayeley graphs associated with a finite commutative ring. In particular, under some mild conditions, we provide the necessary and sufficient conditions for this graph to be prime., Comment: Comments are welcome!
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- 2024
29. Alternative pathways to α,β-unsaturated ketones via direct oxidative coupling transformation using Sr-doped LaCoO3 perovskite catalyst
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Khang H. Trinh, Son H. Doan, Tien V. Huynh, Phuong H. Tran, Diep N. Pham, Minh-Vien Le, Tung T. Nguyen, and Nam T. S. Phan
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αβ-unsaturated ketones ,alkenes ,perovskite ,oxidative coupling ,lacoo3 ,catalysis ,Science - Abstract
A strontium-doped lanthanum cobaltite perovskite material was prepared, and used as a recyclable and effective heterogeneous catalyst for the direct oxidative coupling of alkenes with aromatic aldehydes to produce α,β-unsaturated ketones. The reaction afforded high yields in the presence of di-tert-butylperoxide as oxidant. Single oxides or salts of strontium, lanthanum and cobalt, and the undoped perovskite offered a lower catalytic activity than the strontium-doped perovskite. Benzaldehyde could be replaced by benzyl alcohol, dibenzyl ether, 2-oxo-2-phenylacetaldehyde, 2-bromoacetophenone or (dimethoxymethyl) benzene in the oxidative coupling reaction with alkenes. To our best knowledge, reactions between these starting materials with alkenes are new and unknown in the literature.
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- 2019
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30. Development of a highly sensitive magneto-enzyme lateral flow immunoassay for dengue NS1 detection
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Tien V. Tran, Ba V. Nguyen, Thao T.P. Nguyen, Tung T. Tran, Khanh G. Pham, Quang B. Le, Binh N. Do, Hung N. Pham, Chuyen V. Nguyen, Duong P.H. Dinh, Van T. Ha, Trang H.T. Doan, and Hoa Q. Le
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Dengue virus ,NS1 protein ,Magnetic lateral flow immunoassay ,Signal amplification ,Rapid method ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background Dengue infection represents a global health issue of growing importance. Dengue non-structural protein 1 (NS1) plays a central role in the early detection of the disease. The most common method for NS1 detection is testing by lateral flow immunoassays (LFIAs) with varying sensitivity. In this study, we present a highly sensitive magneto-enzyme LFIA for prompt diagnosis of dengue. Methods We have demonstrated the development of a magneto-enzyme LFIA combining super-paramagnetic nanoparticles as labels and Biotin–Streptavidin signal amplification strategy to detect dengue NS1. Factors affecting the test performance including antibody pair, super-paramagnetic nanoparticle size, nitrocellulose membrane type, amounts of detection and capture antibodies, and amounts of Streptavidin-polyHRP were optimized. Analytical sensitivity and cross-reactivity were determined. Clinical performance of the novel assay was evaluated using a panel of 120 clinical sera. Results This newly developed assay could detect NS1 of all four serotypes of dengue virus (DENV). The limit of detection (LOD) was found to be as low as 0.25 ng ml−1 for DENV-1 and DENV-3, 0.1 ng ml−1 for DENV-2, and 1.0 ng ml−1 for DENV-4. The LOD for DENV-2 was a 50-fold improvement over the best values previously reported. There was an absence of cross-reactivity with Zika NS1, Hepatitis B virus, Hepatitis C virus, and Japanese encephalitis virus. The sensitivity and specificity of the novel assay were 100% when tested on clinical samples. Conclusions We have successfully developed a magneto-enzyme LFIA, allowing rapid and highly sensitive detection of dengue NS1, which is essential for proper management of patients infected with DENV.
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- 2019
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31. Symptoms and risk factors for stroke in a community-based observational sample in Viet Nam
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Annette L. Fitzpatrick, Quang Van Ngo, Kiet A. Ly, Thanh G.N. Ton, WT Longstreth, Tung T. Vo, Kristen Heitzinger, Chien H. Pham, and David L. Tirschwell
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Stroke ,Symptoms ,Viet Nam ,Community-based ,Risk factors ,Public aspects of medicine ,RA1-1270 - Abstract
Background: Viet Nam is experiencing a health transition from infectious to chronic disease. Data on cardiovascular diseases, including strokes, are limited. Methods: Data were randomly collected from six communities in Da Nang, Viet Nam, on participant demographics, medical history, blood pressure, anthropometrics and health behavior using World Health Organization (WHO) guidelines. Stroke symptoms were collected by self-report with the standardized Questionnaire for Verifying Stroke Free Status. Multivariate logistic regression was used to identify factors associated with the presence of stroke symptoms. Results: One thousand six hundred and twenty one adults were examined with a mean age of 52.0 years (±12.5 years), of which 56.1% were women. 27.3% of the participants were found to have hypertension, 26.2% used tobacco, and 16.1% were overweight. More than two-thirds of the participants with hypertension were unaware of their condition. Almost one fourth of the participants were identified by the questionnaire as previously experiencing at least one stroke symptom. Age, rural residence, and education were associated with the presence of stroke symptoms. Models adjusted for demographics found hypertension, high cholesterol, reported severe chest pain, former smoking, and being overweight to be associated with a higher prevalence of stroke symptoms. Conclusions: The high frequency of stroke symptoms in Da Nang calls for further evaluation and interventions to reduce hypertension and other risk factors for chronic disease in Viet Nam and other health transition countries.
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- 2019
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32. On prime Cayley graphs
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Chudnovsky, Maria, Cizek, Michal, Crew, Logan, Mináč, Ján, Nguyen, Tung T., Spirkl, Sophie, and Tân, Nguyên Duy
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Mathematics - Combinatorics ,Mathematics - Group Theory - Abstract
The decomposition of complex networks into smaller, interconnected components is a central challenge in network theory with a wide range of potential applications. In this paper, we utilize tools from group theory and ring theory to study this problem when the network is a Cayley graph. In particular, we answer the following question: Which Cayley graphs are prime?
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- 2024
33. A Note on Finite Number Rings
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Hwang, Suk-Geun, Jeon, Woo, Nam, Ki-Bong, and Nguyen, Tung T.
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Mathematics - Rings and Algebras ,11T06, 11T30, 11Z05, 97H40 - Abstract
We define the finite number ring ${\Bbb Z}_n [\sqrt [m] r]$ where $m,n$ are positive integers and $r$ in an integer akin to the definition of the Gaussian integer ${\Bbb Z}[i]$. This idea is also introduced briefly in [7]. By definition, this finite number ring ${\Bbb Z}_n [\sqrt [m] r]$ is naturally isomorphic to the ring ${\Bbb Z}_n[x]/{\langle x^m-r \rangle}$. From an educational standpoint, this description offers a straightforward and elementary presentation of this finite ring, making it suitable for readers who do not have extensive exposure to abstract algebra. We discuss various arithmetical properties of this ring. In particular, when $n=p$ is a prime number and $\mathbb{Z}_p$ contains a primitive $m$-root of unity, we describe the structure of $\mathbb{Z}_n[\sqrt[m]{r}]$ explicitly., Comment: Expository paper. Comments are welcome!
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- 2023
34. Correlates of supportive care needs among Asian Americans with colorectal, liver, or lung cancer from a web‐based patient navigation portal intervention: The Patient COUNTS study
- Author
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Wang, Katarina, Chu, Janet N, Oh, Debora L, Shariff‐Marco, Salma, Allen, Laura, Kuo, Mei‐Chin, Wong, Ching, Bui, Hoan, Chen, Junlin, Li, Feng Ming, Ma, Carmen, Truong, Angeline, Gomez, Scarlett L, Nguyen, Tung T, and Tsoh, Janice Y
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Clinical Research ,Colo-Rectal Cancer ,Lung ,Digestive Diseases ,Lung Cancer ,Behavioral and Social Science ,Liver Disease ,Cancer ,7.1 Individual care needs ,Good Health and Well Being ,Adult ,Female ,Humans ,Male ,Middle Aged ,Asian ,Colorectal Neoplasms ,Internet ,Lung Neoplasms ,Patient Navigation ,Quality of Life ,Liver Neoplasms ,Patient Portals ,Asian American ,cancer ,cultural competence ,cultural humility ,multilingual ,patient navigation ,supportive care needs ,Oncology and carcinogenesis - Abstract
BackgroundCancer is the leading cause of death among Asian Americans, who often face barriers to cancer care. Cancer supportive care needs among Asian Americans remain understudied.AimsWe examined cancer supportive care needs and participant factors correlated with these needs, identified profiles of supportive care needs, and examined whether needs profiles are associated with quality of life among Asian American adults.Methods and resultsWe recruited 47 Asian American adults with colorectal, liver, or lung cancer who spoke Chinese, English, or Vietnamese, and were starting or undergoing cancer treatment. We assessed cancer supportive care needs in four domains: cancer information, daily living, behavioral health, and language assistance. Hierarchical cluster analysis was used to identify clusters of participants based on their supportive need profiles to further examine the association between need profiles and quality of life (QoL) assessed by the Functional Assessment of Cancer Therapy. Participants (mean age = 57.6) included 72% males and 62% spoke English less than very well. Older participants (age ≥ 65) and those with annual income
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- 2024
35. On the arithmetic of the join rings over finite fields
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Chebolu, Sunil K., Merzel, Jonathan, Mináč, Ján, Nguyen, Tung T., Pasini, Federico, and Tân, Nguyên Duy
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Mathematics - Rings and Algebras ,Mathematics - Number Theory - Abstract
Given a collection $\{ G_i\}_{i=1}^d$ of finite groups and a ring $R$, we have previously introduced and studied certain foundational properties of the join ring $\mathcal{J}_{G_1, G_2, \ldots, G_d}(R)$. This ring bridges two extreme worlds: matrix rings $M_n(R)$ on one end, and group rings $R[G]$ on the other. The construction of this ring was motivated by various problems in graph theory, network theory, nonlinear dynamics, and neuroscience. In this paper, we continue our investigations of this ring, focusing more on its arithmetic properties. We begin by constructing a generalized augmentation map that gives a structural decomposition of this ring. This decomposition allows us to compute the zeta function of the join of group rings. We show that the join of group rings is a natural home for studying the concept of simultaneous primitive roots for a given set of primes. This concept is related to the order of the unit group of the join of group rings. Finally, we characterize the join of group rings over finite fields with the property that the order of every unit divides a fixed number. Remarkably, Mersenne and Fermat primes unexpectedly emerge within the context of this exploration., Comment: 21 pages
- Published
- 2023
36. Fekete polynomials of principal Dirichlet characters
- Author
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Chidambaram, Shiva, Mináč, Ján, Nguyen, Tung T., and Tân, Nguyen Duy
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Mathematics - Number Theory - Abstract
Fekete polynomials associated to quadratic Dirichlet characters have interesting arithmetic properties, and have been studied in many works. In this paper, we study a seemingly simpler yet rich variant: the Fekete polynomial $F_n(x) = \sum_{a=1}^n \chi_n(a) x^a$ associated to a principal Dirichlet character $\chi_n$ of modulus $n$. We investigate the cyclotomic factors of $F_n$ and conjecturally describe all of them. One interesting observation from our computations is that the non-cyclotomic part $f_n$ of $F_n(x)/x$ seems to be always irreducible. We study this factor closely in the special case that $n$ is a product of two odd primes, proving separability in specific cases, and studying its coefficients and special values. Combining these theoretical results with computational evidence lets us identify the Galois group of $f_n$ for small $n$, and raises precise questions in general., Comment: Comments are welcome
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- 2023
37. Spectral perturbation by rank-$m$ matrices
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Merzel, Jonathan L., Mináč, Ján, Nguyen, Tung T., and Pasini, Federico W.
- Subjects
Mathematics - Spectral Theory - Abstract
Let $A$ and $B$ designate $n\times n$ matrices with coefficients in a field $F$. In this paper, we completely answer the following question: For $A$ fixed, what are the possible characteristic polynomials of $A+B$, where $B$ ranges over matrices of rank $\le m$?, Comment: To appear in Operators and Matrices
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- 2023
38. Composed solutions of synchronized patterns in multiplex networks of Kuramoto oscillators
- Author
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Jain, Priya B., Nguyen, Tung T., Mináč, Ján, Muller, Lyle E., and Budzinski, Roberto C.
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Mathematics - Dynamical Systems - Abstract
Networks with different levels of interactions, including multilayer and multiplex networks, can display a rich diversity of dynamical behaviors and can be used to model and study a wide range of systems. Despite numerous efforts to investigate these networks, obtaining mathematical descriptions for the dynamics of multilayer and multiplex systems is still an open problem. Here, we combine ideas and concepts from linear algebra and graph theory with nonlinear dynamics to offer a novel approach to study multiplex networks of Kuramoto oscillators. Our approach allows us to study the dynamics of a large, multiplex network by decomposing it into two smaller systems: one representing the connection scheme within layers (intra-layer), and the other representing the connections between layers (inter-layer). Particularly, we use this approach to compose solutions for multiplex networks of Kuramoto oscillators. These solutions are given by a combination of solutions for the smaller systems given by the intra and inter-layer system and, in addition, our approach allows us to study the linear stability of these solutions.
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- 2023
39. Effect of the COVID‐19 pandemic on meaningful activity engagement in racially and ethnically diverse older adults
- Author
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Oh, Anna, Gan, Siqi, Boscardin, W John, Neilands, Torsten B, Stewart, Anita L, Nguyen, Tung T, and Smith, Alexander K
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Allied Health and Rehabilitation Science ,Health Sciences ,Clinical Research ,Social Determinants of Health ,Coronaviruses Disparities and At-Risk Populations ,Minority Health ,Aging ,Behavioral and Social Science ,Emerging Infectious Diseases ,Health Disparities ,Infectious Diseases ,Coronaviruses ,Good Health and Well Being ,Humans ,Female ,Aged ,Male ,Pandemics ,Quality of Life ,COVID-19 ,Ethnicity ,meaningful activities ,racially and ethnically diverse older adults ,Medical and Health Sciences ,Geriatrics ,Biomedical and clinical sciences ,Health sciences ,Psychology - Abstract
BackgroundParticipation and active engagement in meaningful activities support the emotional and physical well-being of older adults. In 2020, the onset of the COVID-19 pandemic altered lives, including the ability to participate in meaningful activities. This study compared meaningful activity engagement before and at the beginning of the COVID-19 pandemic in a nationally representative, diverse sample >65 years between 2015 and 2020.MethodsWe described the proportions and characteristics of National Health and Aging Trends Study participants and their engagement in four activities: visiting friends or family, attending religious services, participating in clubs/classes/other organized activities, and going out for enjoyment. We used mixed effects logistic regressions to compare probabilities of activity engagement before 2020 and in 2020, adjusting for age, sex, functional status, income, geographic region, anxiety-depression, and transportation issues.ResultsOf 6815 participants in 2015, the mean age was 77.7 (7.6) years; 57% of participants were female; 22% were Black, 5% Hispanic, 2% were American Indian, and 1% were Asian; 20% had disability; and median income was $33,000. Participation in all four activities remained consistent between 2015 and 2019 and declined in 2020. Significant differences existed in attending religious services (p
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- 2023
40. Network-Assisted Full-Duplex Cell-Free Massive MIMO: Spectral and Energy Efficiencies
- Author
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Mohammadi, Mohammadali, Vu, Tung T., Ngo, Hien Quoc, and Matthaiou, Michail
- Subjects
Computer Science - Information Theory - Abstract
We consider network-assisted full-duplex (NAFD) cell-free massive multiple-input multiple-output (CF-mMIMO) systems, where full-duplex (FD) transmission is virtually realized via half-duplex (HD) hardware devices. The HD access points (APs) operating in uplink (UL) mode and those operating in downlink (DL) mode simultaneously serve DL and UL user equipments (UEs) in the same frequency bands. We comprehensively analyze the performance of NAFD CF-mMIMO from both a spectral efficiency (SE) and energy efficiency (EE) perspectives. Specifically, we propose a joint optimization approach that designs the AP mode assignment, power control, and large-scale fading (LSFD) weights to improve the sum SE and EE of NAFD CF-mMIMO systems. We formulate two mixed-integer nonconvex optimization problems of maximizing the sum SE and EE, under realistic power consumption models, and the constraints on minimum individual SE requirements, maximum transmit power at each DL AP and UL UE. The challenging formulated problems are transformed into tractable forms and two novel algorithms are proposed to solve them using successive convex approximation techniques. More importantly, our approach can be applied to jointly optimize power control and LSFD weights for maximizing the sum SE and EE of HD and FD CF-mMIMO systems, which, to date, has not been studied. Numerical results show that: (a) our joint optimization approach significantly outperforms the heuristic approaches in terms of both sum SE and EE; (b) in CF-mMIMO systems, the NAFD scheme can provide approximately 30\% SE gains, while achieving a remarkable EE gain of up to 200\% compared with the HD and FD schemes., Comment: 18 pages, 8 figures, accepted for publication in the IEEE Journal on Selected Areas in Communications
- Published
- 2023
41. Perceptions of the Role of Living Alone in Providing Services to Patients With Cognitive Impairment
- Author
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Portacolone, Elena, Nguyen, Tung T, Bowers, Barbara J, Johnson, Julene K, Kotwal, Ashwin A, Stone, Robyn I, Keiser, Sahru, Tran, Thi, Rivera, Elizabeth, Martinez, Paula, Yang, Yulin, Torres, Jacqueline M, and Covinsky, Kenneth E
- Subjects
Health Services and Systems ,Health Sciences ,Clinical Research ,Aging ,Health Services ,Behavioral and Social Science ,7.1 Individual care needs ,8.1 Organisation and delivery of services ,Management of diseases and conditions ,Health and social care services research ,Generic health relevance ,Good Health and Well Being ,Humans ,Female ,Aged ,Middle Aged ,Male ,Home Environment ,Social Work ,Social Workers ,Black People ,Cognitive Dysfunction ,Attitude of Health Personnel ,Adult ,Delivery of Health Care ,Health Services Accessibility ,United States ,Facilities and Services Utilization ,White ,Biomedical and clinical sciences ,Health sciences - Abstract
ImportanceThe potential role of living alone in either facilitating or hampering access to and use of services for older adults with cognitive impairment is largely unknown. Specifically, it is critical to understand directly from health care and social services professionals how living alone creates barriers to the access and use of supportive health care and social services for racially and ethnically diverse patients with cognitive impairment.ObjectiveTo identify the potential role of living alone in the access and use of health care and social services for diverse patients with cognitive impairment by investigating professionals' perceptions of caring for such patients who live alone in comparison with counterparts living with others.Design, setting, and participantsThis qualitative study of 76 clinicians, social workers, and other professionals used semistructured interviews conducted between February 8, 2021, and June 8, 2022, with purposively sampled professionals providing services to diverse patients with cognitive impairment in Michigan, California, and Texas.Main outcomes and measuresClinicians, social workers, and other professionals compared serving patients with cognitive impairment and living alone vs counterparts living with others. An inductive content analysis was used to analyze the interview transcripts.ResultsA total of 76 professionals were interviewed (mean [SD] age, 49.3 [12.7] years); 59 were female (77.6%), 8 were Black or African American (11%), and 35 were White (46%). Participants included physicians, nurses, social workers, and home-care aides, for a total of 20 professions. Participants elucidated specific factors that made serving older adults living alone with cognitive impairment more challenging than serving counterparts living with others (eg, lacking an advocate, incomplete medical history, requiring difficult interventions), as well as factors associated with increased concerns when caring for older adults living alone with cognitive impairment, such as isolation and a crisis-dominated health care system. Participants also identified reasons for systematic unmet needs of older adults living alone with cognitive impairment for essential health care and social services, including policies limiting access and use to public home-care aides.Conclusions and relevanceIn this qualitative study of professionals' perspectives, findings suggest that living alone is a social determinant of health among patients with cognitive impairment owing to substantial barriers in access to services. Results raised considerable concerns about safety because the US health care system is not well equipped to address the unique needs of older adults living alone with cognitive impairment.
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- 2023
42. Recent Advances in the Computational Discovery of Transcription Factor Binding Sites
- Author
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Ioannis P. Androulakis and Tung T. Nguyen
- Subjects
transcription factor binding sites ,binding site representation ,promoter analysis ,phylogenetic footprinting ,context-specific ,transcriptional regulatory networks ,Industrial engineering. Management engineering ,T55.4-60.8 ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
The discovery of gene regulatory elements requires the synergism between computational and experimental techniques in order to reveal the underlying regulatory mechanisms that drive gene expression in response to external cues and signals. Utilizing the large amount of high-throughput experimental data, constantly growing in recent years, researchers have attempted to decipher the patterns which are hidden in the genomic sequences. These patterns, called motifs, are potential binding sites to transcription factors which are hypothesized to be the main regulators of the transcription process. Consequently, precise detection of these elements is required and thus a large number of computational approaches have been developed to support the de novo identification of TFBSs. Even though novel approaches are continuously proposed and almost all have reported some success in yeast and other lower organisms, in higher organisms the problem still remains a challenge. In this paper, we therefore review the recent developments in computational methods for transcription factor binding site prediction. We start with a brief review of the basic approaches for binding site representation and promoter identification, then discuss the techniques to locate physical TFBSs, identify functional binding sites using orthologous information, and infer functional TFBSs within some context defined by additional prior knowledge. Finally, we briefly explore the opportunities for expanding these approaches towards the computational identification of transcriptional regulatory networks.
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- 2009
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43. On the Paley graph of a quadratic character
- Author
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Mináč, Ján, Muller, Lyle, Nguyen, Tung T., and Tân, Nguyen Duy
- Subjects
Mathematics - Combinatorics ,Mathematics - Number Theory ,05C25, 05C50, 11M06 - Abstract
Paley graphs form a nice link between the distribution of quadratic residues and graph theory. These graphs possess remarkable properties which make them useful in several branches of mathematics. Classically, for each prime number $p$ we can construct the corresponding Paley graph using quadratic and non-quadratic residues modulo $p$. Therefore, Paley graphs are naturally associated with the Legendre symbol at $p$ which is a quadratic Dirichlet character of conductor $p$. In this article, we introduce the generalized Paley graphs. These are graphs that are associated with a general quadratic Dirichlet character. We will then provide some of their basic properties. In particular, we describe their spectrum explicitly. We then use those generalized Paley graphs to construct some new families of Ramanujan graphs. Finally, using special values of $L$-functions, we provide an effective upper bound for their Cheeger number., Comment: To appear in Mathematica Slovaca
- Published
- 2022
44. Broadcasting solutions on networked systems of phase oscillators
- Author
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Nguyen, Tung T., Budzinski, Roberto C., Pasini, Federico W., Delabays, Robin, Mináč, Ján, and Muller, Lyle E.
- Subjects
Mathematics - Dynamical Systems - Abstract
Networked systems have been used to model and investigate the dynamical behavior of a variety of systems. For these systems, different levels of complexity can be considered in the modeling procedure. On one hand, this can offer a more realistic and rich modeling option. On the other hand, it can lead to intrinsic difficulty in analyzing the system. Here, we present an approach to investigate the dynamics of Kuramoto oscillators on networks with different levels of connections: a network of networks. To do so, we utilize a construction in network theory known as the join of networks, which represents ``intra-area" and ``inter-area" connections. This approach provides a reduced representation of the original, multi-level system, where both systems have equivalent dynamics. Then, we can find solutions for the reduced system and broadcast them to the original network of networks. Moreover, using the same idea we can investigate the stability of these states, where we can obtain information on the Jacobian of the multi-level system by analyzing the reduced one. This approach is general for arbitrary connection schemes between nodes within the same area. Finally, our work opens the possibility of studying the dynamics of networked systems using a simpler representation, thus leading to a better understanding of the dynamical behavior of these systems.
- Published
- 2022
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45. On the joins of group rings
- Author
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Chebolu, Sunil K., Merzel, Jonathan L., Mináč, Ján, Muller, Lyle, Nguyen, Tung T., Pasini, Federico W., and Tân, Nguyen Duy
- Subjects
Mathematics - Rings and Algebras ,22D20 - Abstract
Given a collection $\{ G_i\}_{i=1}^d$ of finite groups and a ring $R$, we define a subring of the ring $M_n(R)$ ($n = \sum_{i=1}^d|G_i|)$ that encompasses all the individual group rings $R[G_i]$ along the diagonal blocks as $G_i$-circulant matrices. The precise definition of this ring was inspired by a construction in graph theory known as the joined union of graphs. We call this ring the join of group rings and denote it by $\mathcal{J}_{G_1,\dots, G_d}(R)$. In this paper, we present a systematic study of the algebraic structure of $\mathcal{J}_{G_1,\dots, G_d}(R)$. We show that it has a ring structure and characterize its center, group of units, and Jacobson radical. When $R=k$ is an algebraically closed field, we derive a formula for the number of irreducible modules over $\mathcal{J}_{G_1,\dots, G_d}(k)$. We also show how a blockwise extension of the Fourier transform provides both a generalization of the Circulant Diagonalization Theorem to joins of circulant matrices and an explicit isomorphism between the join algebra and its Wedderburn components., Comment: 33 pages, Accepted for publication in the Journal of Pure and Applied Algebra
- Published
- 2022
46. Joins of normal matrices, their spectrum, and applications
- Author
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Mináč, Jan, Muller, Lyle, Nguyen, Tung T., and Pasini, Federico W.
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Mathematics - Combinatorics ,Mathematics - Spectral Theory ,05C50, 15B05, 15A18 - Abstract
Motivated by studies of oscillator networks, we study the spectrum of the join of several normal matrices with constant row sums. We apply our results to compute the characteristic polynomial of the join of several regular graphs. We then use this theorem to study several problems in spectral graph theory. In particular, we provide some simple constructions of Ramanujan graphs and give new proofs for some theorems in the classical book of Cvetkovi\'{c}, Rowlinson, and Slobodan., Comment: To appear in Mathematica Slovaca
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- 2022
47. On the arithmetic of generalized Fekete polynomials
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Mináč, Ján, Nguyen, Tung T., and Tân, Nguyen Duy
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Mathematics - Number Theory - Abstract
For each prime number $p$ one can associate a Fekete polynomial with coefficients $-1$ or $1$ except the constant term, which is 0. These are classical polynomials that have been studied extensively in the framework of analytic number theory. In a recent paper, we showed that these polynomials also encode interesting arithmetic information. In this paper, we define generalized Fekete polynomials associated with quadratic characters whose conductors could be a composite number. We then investigate the appearance of cyclotomic factors of these generalized Fekete polynomials. Based on this investigation, we introduce a compact version of Fekete polynomials as well as their trace polynomials. We then study the Galois groups of these Fekete polynomials using modular techniques. In particular, we discover some surprising extra symmetries which imply some restrictions on the corresponding Galois groups. Finally, based on both theoretical and numerical data, we propose a precise conjecture on the structure of these Galois groups., Comment: To appear in Experimental Mathematics
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- 2022
48. A photo‐based communication intervention to promote diet‐related discussions among older adults with multi‐morbidity
- Author
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Jih, Jane, Nguyen, Antony, Woo, Jasmin, Tran, Wen‐Ching, Wang, Abby, Gonzales, Nikko, Fung, Jennifer, Callejas, Jackeline, Nguyen, Tung T, and Ritchie, Christine S
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Health Services and Systems ,Biomedical and Clinical Sciences ,Health Sciences ,Clinical Trials and Supportive Activities ,Nutrition ,Clinical Research ,Aging ,7.1 Individual care needs ,Good Health and Well Being ,Humans ,Aged ,Pilot Projects ,Multimorbidity ,Communication ,Morbidity ,Diet ,comprehensive geriatric assessment ,health communication ,patient-centered care ,Medical and Health Sciences ,Geriatrics ,Biomedical and clinical sciences ,Health sciences ,Psychology - Abstract
BackgroundLittle is known about how to best communicate with older adults about dietary behaviors and related factors in complex chronic disease care. Photo-based communication could promote efficient information exchange and activate patients to effectively communicate their lived experiences. We conducted a pilot study to assess the feasibility and acceptability of a photo-based patient-clinician communication intervention to promote dietary discussions in geriatric primary care.MethodsOlder adult patients with 2+ concurrent chronic conditions received in-person training on photo-taking with a smartphone before taking photos in response to the prompt, "What aspects of your everyday life affect what you eat and how much you have to eat?" Patients then shared photos and their narratives with their primary care clinician during a clinic visit. Patients and clinicians completed separate audio-recorded post-visit interviews to assess perspectives on the intervention. Interview transcripts were analyzed using a thematic analysis approach.ResultsFourteen patient-clinician dyads completed the study. All except one patient-clinician dyad (93%) completed the intervention as trained. 93% of patients and 86% of clinicians reported that they would "definitely" or "probably" be willing to engage in a future visit with photo-sharing. Patients and clinicians shared similar perspectives on how sharing of photos during the visit enhanced communication and information exchange about dietary practices and other health-related factors, influenced clinical recommendations made during the visits, and strengthened the patient-clinician relationship.ConclusionIncorporation of a photo-based patient-clinician communication intervention to promote discussions regarding diet and other health-related factors could be a patient-centered strategy to help deliver comprehensive geriatric primary care.
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- 2023
49. Efficacy of a Primary Care-Based Mobile Application to Increase Hepatitis C Screening Among Asian Americans: A Secondary Analysis of a Randomized Clinical Trial.
- Author
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Khalili, Mandana, Kim, Nicole J, Tsoh, Janice Y, Walsh, Judith ME, Elizabeth Goldman, L, Park, Helen, Lau, Ivy, Wong, Ching, Gildengorin, Ginny, and Nguyen, Tung T
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healthcare disparities ,language ,technology ,viral hepatitis ,Liver Disease ,Hepatitis - C ,Clinical Trials and Supportive Activities ,Prevention ,Digestive Diseases ,Hepatitis ,Clinical Research ,Infectious Diseases ,Health Services ,Emerging Infectious Diseases ,Chronic Liver Disease and Cirrhosis ,3.1 Primary prevention interventions to modify behaviours or promote wellbeing ,Prevention of disease and conditions ,and promotion of well-being ,Good Health and Well Being - Abstract
BackgroundHepatitis C virus (HCV) screening remains suboptimal. We assessed the efficacy of a mobile application and provider alert in enhancing HCV screening among Asian Americans.MethodsA secondary analysis of a cluster-randomized clinical trial was performed during the birth cohort screening era to assess the efficacy of a Hepatitis App (intervention), a multilingual mobile application delivering interactive video education on viral hepatitis and creating a Provider Alert printout, at primary care clinics within 2 healthcare systems in San Francisco from 2015 to 2017. A comparison group received usual care and a similar intervention on nutrition and physical activity. The outcome was electronic health record (EHR) documentation of HCV screening along with patient-provider communication about testing and test ordering.ResultsFour hundred fifty-two participants (mean age 57 years, 36% male, 80% foreign-born) were randomized by provider clusters to the intervention (n = 270) or comparison groups (n = 182). At 3-month follow up, the intervention group was more likely than the comparison group to be aware of HCV (75% vs 59%, P = .006), to discuss HCV testing with their providers (63% vs 13%, P < .001), to have HCV testing ordered (39% vs 10%, P < .001), and to have EHR-verified HCV testing (30% vs 6%, P < .001). Within the intervention group, being born between 1945 and 1965 (odds ratio, 3.15; 95% confidence interval, 1.35-7.32) was associated with increased HCV testing.ConclusionsThe Hepatitis App delivered in primary care settings was effective in increasing HCV screening in a socioeconomically diverse Asian American cohort. This highlights the importance of mobile technology as a patient-centered strategy to address gaps in HCV care.
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- 2023
50. Exploring factors associated with hepatitis B screening in a multilingual and diverse population
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Chu, Janet N, Nguyen, Tung T, Rivadeneira, Natalie A, Hiatt, Robert A, and Sarkar, Urmimala
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Health Services and Systems ,Public Health ,Health Sciences ,Behavioral and Social Science ,Liver Disease ,Digestive Diseases ,Infectious Diseases ,Hepatitis ,Minority Health ,Clinical Research ,Health Disparities ,Hepatitis - B ,Basic Behavioral and Social Science ,Health Services ,Social Determinants of Health ,Good Health and Well Being ,Humans ,Ethnicity ,Health Services Accessibility ,Healthcare Disparities ,Hepatitis B ,Screening ,Language preference ,Race ,ethnicity ,Preventive medicine ,Race/ethnicity ,Library and Information Studies ,Nursing ,Public Health and Health Services ,Health Policy & Services ,Health services and systems ,Public health - Abstract
BackgroundRacial/ethnic minorities bear a disproportionate burden of hepatitis B virus (HBV) infection and disease. Disparities in HBV screening contribute to worse outcomes for communities of color. We examined the impact of race/ethnicity, language preference, and having a usual place of care on HBV screening in a multilingual, urban cohort.MethodsWe used questions from the Health Information National Trends Survey and added validated questions about healthcare access and health literacy. We administered this survey in English, Spanish, and Chinese to a selected convenience sample of San Francisco city/county residents in 2017, with pre-specified targets for populations with known cancer disparities: 25% Spanish-speaking, 25% Chinese-speaking, and 25% Black Americans. Using weighted multivariable logistic regression analyses, we assessed how race/ethnicity, language preference, and having a usual place of care impacts self-report of HBV screening.ResultsOverall, 1027 participants completed the survey (50% of surveys administered in English, 25% in Spanish, and 25% in Chinese). Only 50% of participants reported HBV screening. In multivariable analysis, Black (OR = 0.20, 95% CI 0.08-0.49), Latinx (OR = 0.33, 95% CI 0.13-0.85), Asian (OR = 0.31, 95% CI 0.10, 0.94), and 'Other' race/ethnicity (OR = 0.17, 95% CI 0.05-0.53) respondents had lower odds of HBV screening compared to non-Hispanic White respondents. Participants who had insurance had increased odds of HBV screening (OR = 2.70, 95% CI 1.48-4.93).ConclusionsHBV screening disparities persist for Black Americans, Asian Americans, Latinx, and the uninsured. Future studies should explore reasons why current strategies have not been implemented or are not successful, particularly in addressing racial/ethnic and insurance disparities.
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- 2022
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