An improvement of sufficient condition for kk-leaf-connected graphs

For integer $k\geq2,$ a graph $G$ is called $k$-leaf-connected if $|V(G)|\geq k+1$ and given any subset $S\subseteq V(G)$ with $|S|=k,$ $G$ always has a spanning tree $T$ such that $S$ is precisely the set of leaves of $T.$ Thus a graph is $2$-leaf-connected if and only if it is Hamilton-connected. In this paper, we present a best possible condition based upon the size to guarantee a graph to be $k$-leaf-connected, which not only improves the results of Gurgel and Wakabayashi [On $k$-leaf-connected graphs, J. Combin. Theory Ser. B 41 (1986) 1-16] and Ao, Liu, Yuan and Li [Improved sufficient conditions for $k$-leaf-connected graphs, Discrete Appl. Math. 314 (2022) 17-30], but also extends the result of Xu, Zhai and Wang [An improvement of spectral conditions for Hamilton-connected graphs, Linear Multilinear Algebra, 2021]. Our key approach is showing that an $(n+k-1)$-closed non-$k$-leaf-connected graph must contain a large clique if its size is large enough. As applications, sufficient conditions for a graph to be $k$-leaf-connected in terms of the (signless Laplacian) spectral radius of $G$ or its complement are also presented.Comment: 15 pages, 2 figure

Utilizing metagenomic next-generation sequencing for diagnosis and lung microbiome probing of pediatric pneumonia through bronchoalveolar lavage fluid in pediatric intensive care unit: results from a large real-world cohort

BackgroundMetagenomic next-generation sequencing (mNGS) is a powerful method for pathogen detection in various infections. In this study, we assessed the value of mNGS in the pathogen diagnosis and microbiome analysis of pneumonia in pediatric intensive care units (PICU) using bronchoalveolar lavage fluid (BALF) samples.MethodsA total of 104 pediatric patients with pneumonia who were admitted into PICU between June 2018 and February 2020 were retrospectively enrolled. Among them, 101 subjects who had intact clinical information were subject to parallel comparison of mNGS and conventional microbiological tests (CMTs) for pathogen detection. The performance was also evaluated and compared between BALF-mNGS and BALF-culture methods. Moreover, the diversity and structure of all 104 patients’ lung BALF microbiomes were explored using the mNGS data.ResultsCombining the findings of mNGS and CMTs, 94.06% (95/101) pneumonia cases showed evidence of causative pathogenic infections, including 79.21% (80/101) mixed and 14.85% (15/101) single infections. Regarding the pathogenesis of pneumonia in the PICU, the fungal detection rates were significantly higher in patients with immunodeficiency (55.56% vs. 25.30%, P =0.025) and comorbidities (40.30% vs. 11.76%, P=0.007). There were no significant differences in the α-diversity either between patients with CAP and HAP or between patients with and without immunodeficiency. Regarding the diagnostic performance, the detection rate of DNA-based BALF-mNGS was slightly higher than that of the BALF-culture although statistically insignificant (81.82% vs.77.92%, P=0.677) and was comparable to CMTs (81.82% vs. 89.61%, P=0.211). The overall sensitivity of DNA-based mNGS was 85.14% (95% confidence interval [CI]: 74.96%-92.34%). The detection rate of RNA-based BALF-mNGS was the same with CMTs (80.00% vs 80.00%, P>0.999) and higher than BALF-culture (80.00% vs 52.00%, P=0.045), with a sensitivity of 90.91% (95%CI: 70.84%-98.88%).ConclusionsmNGS is valuable in the etiological diagnosis of pneumonia, especially in fungal infections, and can reveal pulmonary microecological characteristics. For pneumonia patients in PICU, the mNGS should be implemented early and complementary to CMTs

Diagnosis of mixed infection and a primary immunodeficiency disease using next-generation sequencing: a case report

Major Histocompatibility Complex Class II (MHC II) deficiency is a rare primary immunodeficiency disorder (PID) with autosomal recessive inheritance pattern. The outcome is almost fatal owing to delayed diagnosis and lacking of effective therapy. Therefore, prompt diagnosis, timely and effective treatment are critical. Here, we report a 117-day-old boy with diarrhea, cough, cyanosis and tachypnea who was failed to be cured by empiric antimicrobial therapy initially and progressed to severe pneumonia and respiratory failure. The patient was admitted to the pediatric intensive care unit (PICU) immediately and underwent a series of tests. Blood examination revealed elevated levels of inflammatory markers and cytomegalovirus DNA. Imaging findings showed signs of severe infection of lungs. Finally, the diagnosis was obtained mainly through next-generation sequencing (NGS). We found out what pathogenic microorganism he was infected via repeated conventional detection methods and metagenomic next-generation sequencing (mNGS) of sputum and bronchoalveolar lavage fluid (BALF). And his whole exome sequencing (WES) examination suggested that CIITA gene was heterozygous mutation, a kind of MHC II deficiency diseases. After aggressive respiratory support and repeated adjustment of antimicrobial regimens, the patient was weaned from ventilator on the 56th day of admission and transferred to the immunology ward on the 60th day. The patient was successful discharged after hospitalizing for 91 days, taking antimicrobials orally to prevent infections post-discharge and waiting for stem cell transplantation. This case highlights the potential importance of NGS in providing better diagnostic testing for unexplained infection and illness. Furthermore, pathogens would be identified more accurately if conventional detection techniques were combined with mNGS

An emerging Asian model of governance and transnational knowledge transfer : an introduction

Although Asia has a long history of governance practice, its modern governance has been disproportionately influenced by the Western models. Given the shifting global political economic landscape and a re-emerging Asia in recent decades, there is an urgent need to explore the potential of Asian models of governance. Could there be an Asian model of governance that is distinct from the Western ones? If so, what are the key characteristics? In conjunction with the special issue, this introduction article attempts to partially answer these questions. Based upon the existing literature and critical reflections, the authors propose a preliminary analytical framework for an emerging Asian model of governance by incorporating two interlinked phenomena: shared cultural, historical norms and trajectories, and intra-regional transnational knowledge transfer. Six articles constituting the special issue are also briefly introduced within this framework, with the aim of contributing to a better understanding of Asian governance experiences and theoretical debates on the evolving modes of public governance.MOE (Min. of Education, S’pore)Published versio

China and the “Singapore Model” : perspectives from mid-level cadres and implications for transnational knowledge transfer

Over the past three decades, China has shown tremendous interest in the “Singapore model” through its sending of tens of thousands of cadres to Singapore for executive training and graduate education. Although this phenomenon has been studied, no attention has been drawn to the perspectives of those mid-level cadres who took part in the training and what those perspectives might imply. Utilizing a unique dataset of over 1,350 mid-level cadres graduating from the “Mayors’ Class” in Singapore from 1995 to 2016 and follow-up surveys and interviews, this article intends to fill this gap. We found that the most appealing characteristics of the “Singapore model” for these mid-level officials lay in practical governance lessons and their potential transferability rather than in ideologies. This finding challenges conventional wisdom that the most plausible rationale of China’s learning from Singapore is political. We also examine Xi Jinping’s view of Singapore and its relevance to China’s latest national agendas in building a “learning nation” and strengthening the CCP’s resilience through anticorruption and intra-party regeneration. The conclusion places the China– Singapore case within the context of the changing trend of transnational knowledge transfer in the non-Western world.MOE (Min. of Education, S’pore)Published versio

The institutionalization and effectiveness of transnational policy transfer : the China–Singapore Suzhou Industrial Park as a case study

Transnational policy transfer through cross-border government-to-government collaboration projects has been widely adopted as a tool to facilitate economic growth, especially by developing countries. Why did some transnational projects of policy transfer succeed while others fail? What are the facilitating and constraining factors in shaping their fates? What are their theoretical and policy implications for public administration and economic development in a globalizing world? This article examines the case of the China–Singapore Suzhou Industrial Park which has been in operation since its establishment in 1994. Challenging the previous studies and adopting a mixed research method utilizing a wide range of quantitative and qualitative data, we identify three major factors affecting the results of policy transfer: (1) a systemic combination of “hardware” and “software” in the conceptualization of transnational policy transfer; (2) localization of transnational policy and its enforcement; and mostly importantly, (3) institutionalization of key processes in both ends of policy exchanges and implementation.Ministry of Education (MOE)Nanyang Technological UniversityPublished versionThis study is funded by the Singapore Ministry of Education AcRF Tier 2 Grant (MOE2016-T2-02-87) and Nanyang Technological University Strategic Initiative (04INS000132C430; 04INS000136C430)

Mitochondria-Targeted Antioxidant Mito-Tempo Protects Against Aldosterone-Induced Renal Injury In Vivo

Background/Aims: Growing evidence suggests mitochondrial dysfunction (MtD) and the Nlrp3 inflammasome play critical roles in chronic kidney disease (CKD) progression. We previously reported that Aldosterone (Aldo)-induced renal injury in vitro is directly caused by mitochondrial reactive oxygen species (mtROS)-mediated activation of the Nlrp3 inflammasome. Here we aimed to determine whether a mitochondria-targeted antioxidant (Mito-Tempo) could prevent Aldo-induced kidney damage in vivo. Methods: C57BL/6J mice were treated with Aldo and/or Mito-Tempo (or ethanol as a control) for 4 weeks. Renal injury was evaluated by Periodic Acid-Schiff reagent or Masson’s trichrome staining and electron microscopy. ROS were measured by DCFDA fluorescence and ELISA. MtD was determined by real-time PCR and electron microscopy. Activation of the Nlrp3 inflammasome and endoplasmic reticulum stress (ERS) was detected via western blot. Results: Compared with control mice, Aldo-infused mice showed impaired renal function, increased mtROS production and MtD, Nlrp3 inflammasome activation, and elevated ERS. We showed administration of Mito-Tempo significantly improved renal function and MtD, and reduced Nlrp3 inflammasome activation and ERS in vivo. Conclusion: Mitochondria-targeted antioxidants may attenuate Aldo-infused renal injury by inhibiting MtD, the Nlrp3 inflammasome, and ERS in vivo. Therefore, targeting mtROS might be an effective strategy for preventing CKD