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  1. Book ; Online: Approximate Distance Oracles for Planar Graphs with Subpolynomial Error Dependency

    Le, Hung

    2022  

    Abstract: Thorup [FOCS'01, JACM'04] and Klein [SODA'01] independently showed that there exists a $(1+\epsilon)$-approximate distance oracle for planar graphs with $O(n (\log n)\epsilon^{-1})$ space and $O(\epsilon^{-1})$ query time. While the dependency on $n$ is ... ...

    Abstract Thorup [FOCS'01, JACM'04] and Klein [SODA'01] independently showed that there exists a $(1+\epsilon)$-approximate distance oracle for planar graphs with $O(n (\log n)\epsilon^{-1})$ space and $O(\epsilon^{-1})$ query time. While the dependency on $n$ is nearly linear, the space-query product of their oracles depend quadratically on $1/\epsilon$. Many follow-up results either improved the space \emph{or} the query time of the oracles while having the same, sometimes worst, dependency on $1/\epsilon$. Kawarabayashi, Sommer, and Thorup [SODA'13] were the first to improve the dependency on $1/\epsilon$ from quadratic to nearly linear (at the cost of $\log^*(n)$ factors). It is plausible to conjecture that the linear dependency on $1/\epsilon$ is optimal: for many known distance-related problems in planar graphs, it was proved that the dependency on $1/\epsilon$ is at least linear. In this work, we disprove this conjecture by reducing the dependency of the space-query product on $1/\epsilon$ from linear all the way down to \emph{subpolynomial} $(1/\epsilon)^{o(1)}$. More precisely, we construct an oracle with $O(n\log(n)(\epsilon^{-o(1)} + \log^*n))$ space and $\log^{2+o(1)}(1/\epsilon)$ query time. Our construction is the culmination of several different ideas developed over the past two decades.

    Comment: 34 pages, 10 figures
    Keywords Computer Science - Data Structures and Algorithms ; F.2.2
    Subject code 005
    Publishing date 2022-07-12
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Book ; Online: VC Set Systems in Minor-free (Di)Graphs and Applications

    Le, Hung / Wulff-Nilsen, Christian

    2023  

    Abstract: A recent line of work on VC set systems in minor-free (undirected) graphs, starting from Li and Parter, who constructed a new VC set system for planar graphs, has given surprising algorithmic results. In this work, we initialize a more systematic study ... ...

    Abstract A recent line of work on VC set systems in minor-free (undirected) graphs, starting from Li and Parter, who constructed a new VC set system for planar graphs, has given surprising algorithmic results. In this work, we initialize a more systematic study of VC set systems for minor-free graphs and their applications in both undirected graphs and directed graphs (a.k.a digraphs). More precisely: - We propose a new variant of Li-Parter set system for undirected graphs. - We extend our set system to $K_h$-minor-free digraphs and show that its VC dimension is $O(h^2)$. - We show that the system of directed balls in minor-free digraphs has VC dimension at most $h-1$. - On the negative side, we show that VC set system constructed from shortest path trees of planar digraphs does not have a bounded VC dimension. The highlight of our work is the results for digraphs, as we are not aware of known algorithmic work on constructing and exploiting VC set systems for digraphs.

    Comment: Fix typos and several minor issues; abstract shorten due to Arxiv limits. Extended abstract appeared in SODA24
    Keywords Computer Science - Data Structures and Algorithms ; Mathematics - Combinatorics ; F.2.2
    Subject code 511
    Publishing date 2023-04-04
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Current Recommendations on Returning to Youth Sports After COVID-19 Infection.

    Le, Hung M / Stracciolini, Andrea

    Pediatric annals

    2021  Volume 50, Issue 11, Page(s) e461–e464

    Abstract: Children represent a small fraction of total cumulative cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The potential health consequences related to infection for children are not inconsequential. For example, some may ... ...

    Abstract Children represent a small fraction of total cumulative cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The potential health consequences related to infection for children are not inconsequential. For example, some may develop multisystem inflammatory syndrome in children, which is commonly associated with cardiovascular involvement. Nevertheless, the short- and long-term effects of SARS-CoV-2 infection remain unknown. In particular, the impact on physical health and how it affects one's ability to return to physical activity are continuously evolving. As more youth sports organizations are lifting restrictions, the volume of youth athletes will increase and the demand for providing medical clearance will grow. This article aims to provide a review of return to physical activity guidelines for young athletes post-SARS-CoV-2 infection based on expert consensus statements and professional organization recommendations.
    MeSH term(s) Adolescent ; Athletes/psychology ; COVID-19/complications ; COVID-19/epidemiology ; COVID-19/prevention & control ; COVID-19/psychology ; Child ; Humans ; Return to Sport ; SARS-CoV-2 ; Systemic Inflammatory Response Syndrome ; Youth Sports
    Language English
    Publishing date 2021-11-01
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 195430-1
    ISSN 1938-2359 ; 0090-4481
    ISSN (online) 1938-2359
    ISSN 0090-4481
    DOI 10.3928/19382359-20211018-02
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Considering the Impact of Preparticipation Screening Guidelines on Health Equity for Collegiate Athletes.

    Honda, Trenton / Downey, Brian / Kerkhof, Deanna / Le, Hung M / McNaughton, Michael / Corrado, Gianmichel

    European journal of preventive cardiology

    2024  

    Language English
    Publishing date 2024-04-09
    Publishing country England
    Document type Journal Article
    ZDB-ID 2626011-6
    ISSN 2047-4881 ; 2047-4873
    ISSN (online) 2047-4881
    ISSN 2047-4873
    DOI 10.1093/eurjpc/zwae135
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Results from 228 Patients with Hemifacial Spasm Undergoing Microvascular Decompression without Intraoperative Neuroelectrophysiology Monitoring.

    Truong, Van Tri / Ngo, Minh Quan / Phan, Duy / Le, Hung / Tran Hoang, Ngoc Anh

    World neurosurgery

    2024  Volume 185, Page(s) e461–e466

    Abstract: Background: Intraoperative neuroelectrophysiology monitoring (IONM) has been used to decrease complications and to increase the successful rate of microvascular decompression (MVD) MVD for hemifacial spasm (HFS). Still, it is not available at limited ... ...

    Abstract Background: Intraoperative neuroelectrophysiology monitoring (IONM) has been used to decrease complications and to increase the successful rate of microvascular decompression (MVD) MVD for hemifacial spasm (HFS). Still, it is not available at limited resource centers. We report the outcome of patients undergoing MVD for HFS without using IONM.
    Methods: The variables concerning the patients' demographics (age and gender), clinical characteristics, offending vessels (vertebral artery type and non-vertebral artery type), postoperative grade of HFS, and postoperative complications of HFS patients undergoing MVD were retrospectively reviewed and collected. The scoring system provided by the Japan Society for MVD was used to evaluate the postoperative outcome of HFS. Postoperative hearing ability was evaluated according to a subjective assessment of the patients.
    Results: A total of 228 patients were recruited. Their median age was 51.0 (44.0-57.0) years old. The total cure effect was observed in 207 (90.8%) patients within the first week after the surgery and in 200 (96.1%) patients in a 2-year follow-up. Permanent hearing disturbance happened in 2 patients (0.9%). No patient had permanent unilateral deafness (0%). No postoperative permanent facial paralysis was reported.
    Conclusions: MVD without IONM may be performed safely and effectively to treat patients with HFS.
    MeSH term(s) Humans ; Hemifacial Spasm/surgery ; Microvascular Decompression Surgery/methods ; Female ; Male ; Middle Aged ; Adult ; Retrospective Studies ; Treatment Outcome ; Postoperative Complications/epidemiology ; Postoperative Complications/etiology ; Intraoperative Neurophysiological Monitoring/methods ; Monitoring, Intraoperative/methods
    Language English
    Publishing date 2024-02-16
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2534351-8
    ISSN 1878-8769 ; 1878-8750
    ISSN (online) 1878-8769
    ISSN 1878-8750
    DOI 10.1016/j.wneu.2024.02.053
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Using Targeted Nano-Antibiotics to Improve Antibiotic Efficacy against

    Le, Hung / Dé, Emmanuelle / Le Cerf, Didier / Karakasyan, Carole

    Antibiotics (Basel, Switzerland)

    2023  Volume 12, Issue 6

    Abstract: The poor bioavailability of antibiotics at infection sites is one of the leading causes of treatment failure and increased bacterial resistance. Therefore, developing novel, non-conventional antibiotic delivery strategies to deal with bacterial pathogens ...

    Abstract The poor bioavailability of antibiotics at infection sites is one of the leading causes of treatment failure and increased bacterial resistance. Therefore, developing novel, non-conventional antibiotic delivery strategies to deal with bacterial pathogens is essential. Here, we investigated the encapsulation of two fluoroquinolones, ciprofloxacin and levofloxacin, into polymer-based nano-carriers (nano-antibiotics), with the goal of increasing their local bioavailability at bacterial infection sites. The formulations were optimized to achieve maximal drug loading. The surfaces of nano-antibiotics were modified with anti-staphylococcal antibodies as ligand molecules to target
    Language English
    Publishing date 2023-06-16
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2681345-2
    ISSN 2079-6382
    ISSN 2079-6382
    DOI 10.3390/antibiotics12061066
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Book ; Online: A PTAS for subset TSP in minor-free graphs

    Le, Hung

    2018  

    Abstract: We give the first PTAS for the subset Traveling Salesperson Problem (TSP) in $H$-minor-free graphs. This resolves a long standing open problem in a long line of work on designing PTASes for TSP in minor-closed families initiated by Grigni, Koutsoupias ... ...

    Abstract We give the first PTAS for the subset Traveling Salesperson Problem (TSP) in $H$-minor-free graphs. This resolves a long standing open problem in a long line of work on designing PTASes for TSP in minor-closed families initiated by Grigni, Koutsoupias and Papadimitriou in FOCS'95. The main technical ingredient in our PTAS is a construction of a nearly light subset $(1+\epsilon)$-spanner for any given edge-weighted $H$-minor-free graph. This construction is based on a necessary and sufficient condition given by \emph{sparse spanner oracles}: light subset spanners exist if and only if sparse spanner oracles exist. This relationship allows us to obtain two new results: _ An $(1+\epsilon)$-spanner with lightness $O(\epsilon^{-d+2})$ for any doubling metric of constant dimension $d$. This improves the earlier lightness bound $\epsilon^{-O(d)}$ obtained by Borradaile, Le and Wulff-Nilsen. _ An $(1+\epsilon)$-spanner with sublinear lightness for any metric of constant correlation dimension. Previously, no spanner with non-trivial lightness was known.

    Comment: 43 pages, 7 figures, complete revision of the old version, with new results
    Keywords Computer Science - Data Structures and Algorithms ; 68Q25 ; 68W25
    Publishing date 2018-04-04
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Book ; Online: Low Treewidth Embeddings of Planar and Minor-Free Metrics

    Filtser, Arnold / Le, Hung

    2022  

    Abstract: Cohen-Addad, Filtser, Klein and Le [FOCS'20] constructed a stochastic embedding of minor-free graphs of diameter $D$ into graphs of treewidth $O_{\epsilon}(\log n)$ with expected additive distortion $+\epsilon D$. Cohen-Addad et al. then used the ... ...

    Abstract Cohen-Addad, Filtser, Klein and Le [FOCS'20] constructed a stochastic embedding of minor-free graphs of diameter $D$ into graphs of treewidth $O_{\epsilon}(\log n)$ with expected additive distortion $+\epsilon D$. Cohen-Addad et al. then used the embedding to design the first quasi-polynomial time approximation scheme (QPTAS) for the capacitated vehicle routing problem. Filtser and Le [STOC'21] used the embedding (in a different way) to design a QPTAS for the metric Baker's problems in minor-free graphs. In this work, we devise a new embedding technique to improve the treewidth bound of Cohen-Addad et al. exponentially to $O_{\epsilon}(\log\log n)^2$. As a corollary, we obtain the first efficient PTAS for the capacitated vehicle routing problem in minor-free graphs. We also significantly improve the running time of the QPTAS for the metric Baker's problems in minor-free graphs from $n^{O_{\epsilon}(\log(n))}$ to $n^{O_{\epsilon}(\log\log(n))^3}$. Applying our embedding technique to planar graphs, we obtain a deterministic embedding of planar graphs of diameter $D$ into graphs of treewidth $O((\log\log n)^2)/\epsilon)$ and additive distortion $+\epsilon D$ that can be constructed in nearly linear time. Important corollaries of our result include a bicriteria PTAS for metric Baker's problems and a PTAS for the vehicle routing problem with bounded capacity in planar graphs, both run in almost-linear time. The running time of our algorithms is significantly better than previous algorithms that require quadratic time. A key idea in our embedding is the construction of an (exact) emulator for tree metrics with treewidth $O(\log\log n)$ and hop-diameter $O(\log \log n)$. This result may be of independent interest.
    Keywords Computer Science - Data Structures and Algorithms
    Subject code 005
    Publishing date 2022-03-29
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Obturator internus muscle strain in an adolescent skier.

    Le, Hung M / Jackson, Sarah S

    The Journal of sports medicine and physical fitness

    2020  Volume 60, Issue 10, Page(s) 1412–1414

    Abstract: There are many causes of acute hip pain. Obturator internus (OI) muscle strain is a rare cause of the presentation. We report a case of OI muscle strain in a 15-year-old ski racer who presented with new onset acute right hip pain. Magnetic resonance ... ...

    Abstract There are many causes of acute hip pain. Obturator internus (OI) muscle strain is a rare cause of the presentation. We report a case of OI muscle strain in a 15-year-old ski racer who presented with new onset acute right hip pain. Magnetic resonance imaging showed enhancement of the obturator internus muscle indicating muscle injury. Patient was treated conservatively with target physical therapy and NSAIDs for pain management. This case illustrates an atypical diagnosis for a common chief complaint.
    MeSH term(s) Adolescent ; Arthralgia/etiology ; Hip Joint/diagnostic imaging ; Humans ; Magnetic Resonance Imaging ; Male ; Muscle, Skeletal/diagnostic imaging ; Muscle, Skeletal/injuries ; Physical Therapy Modalities ; Skiing/injuries ; Sprains and Strains/diagnostic imaging ; Sprains and Strains/therapy
    Language English
    Publishing date 2020-06-23
    Publishing country Italy
    Document type Case Reports ; Journal Article
    ZDB-ID 410823-1
    ISSN 1827-1928 ; 0022-4707
    ISSN (online) 1827-1928
    ISSN 0022-4707
    DOI 10.23736/S0022-4707.20.10981-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Book ; Online: SurvTimeSurvival

    Le, Hung / Eng-Jon, Ong / Miroslaw, Bober

    Survival Analysis On The Patient With Multiple Visits/Records

    2023  

    Abstract: The accurate prediction of survival times for patients with severe diseases remains a critical challenge despite recent advances in artificial intelligence. This study introduces "SurvTimeSurvival: Survival Analysis On Patients With Multiple Visits/ ... ...

    Abstract The accurate prediction of survival times for patients with severe diseases remains a critical challenge despite recent advances in artificial intelligence. This study introduces "SurvTimeSurvival: Survival Analysis On Patients With Multiple Visits/Records", utilizing the Transformer model to not only handle the complexities of time-varying covariates but also covariates data. We also tackle the data sparsity issue common to survival analysis datasets by integrating synthetic data generation into the learning process of our model. We show that our method outperforms state-of-the-art deep learning approaches on both covariates and time-varying covariates datasets. Our approach aims not only to enhance the understanding of individual patient survival trajectories across various medical conditions, thereby improving prediction accuracy, but also to play a pivotal role in designing clinical trials and creating new treatments.

    Comment: Accepted as Findings Track in Machine Learning For Health (ML4H) 2023
    Keywords Computer Science - Machine Learning ; Computer Science - Artificial Intelligence ; Mathematics - Numerical Analysis
    Subject code 006
    Publishing date 2023-11-16
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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