Vulnerability analysis of the global liner shipping network: from static structure to cascading failure dynamics

Robust maritime transportation networks are essential to the development of world economy. But vulnerability of the global liner shipping network (GLSN) to unexpected interruptions has become apparent since the COVID-19 pandemic began, in that a single port interruption could be sufficient to trigger a cascading failure (i.e., port congestion propagation). To understand the vulnerability of the GLSN under such cascading failures, we propose a novel cascading model, which incorporates the realistic factor of liner shipping service routes’ behavior of port rotation adjustments under port failures. We apply the model to an empirical GLSN, showing that the GLSN under cascading failures is significantly more vulnerable than its static structure. Regarding two common adjustments of service routes’ port rotations (i.e., skipping failed ports and choosing alternative ports), we find that choosing alternative ports increases the GLSN vulnerability to cascading failures. Within the proposed model, we also introduce a metric termed port dynamic criticality to characterize the contribution of each port to the overall network robustness against cascading failures, finding it significantly and positively associated with port’s topological centrality in the initial GLSN. These findings provide managerial insights into preventing or mitigating port congestion propagation in the GLSN.

Equity Promotion in Online Resource Allocation (preprint)

We consider online resource allocation under a typical non-profit setting, where limited or even scarce resources are administered by a not-for-profit organization like a government. We focus on the internal-equity by assuming that arriving requesters are homogeneous in terms of their external factors like demands but heterogeneous for their internal attributes like demographics. Specifically, we associate each arriving requester with one or several groups based on their demographics (i.e., race, gender, and age), and we aim to design an equitable distributing strategy such that every group of requesters can receive a fair share of resources proportional to a preset target ratio. We present two LP-based sampling algorithms and investigate them both theoretically (in terms of competitive-ratio analysis) and experimentally based on real COVID-19 vaccination data maintained by the Minnesota Department of Health. Both theoretical and numerical results show that our LP-based sampling strategies can effectively promote equity, especially when the arrival population is disproportionately represented, as observed in the early stage of the COVID-19 vaccine rollout.

Clinical Efficacy and Adverse Events of Baricitinib Treatment for Coronavirus Disease-2019 (COVID-19): A Systematic Review and Meta-Analysis (preprint)

Background: The benefits of baricitinib, which is a Janus kinase inhibitor, in coronavirus disease-2019 (COVID-19) are inadequately defined. We performed a systematic review and meta-analysis of randomised, controlled trials and observational studies of baricitinib to determine its clinical efficacy and adverse events in patients with COVID-19.Methods: Major databases were searched from 2019 to 2021 inclusive. The primary outcome was the coefficient of mortality. We also compared increasing different doses of baricitinib, intensive care unit admission, the requirement for mechanical ventilation, the oxygenation index, and adverse events between baricitinib treatment and placebo or other treatments.Findings: Twelve studies of 3564 patients were included and assessed qualitatively (Jadad and Newcastle–Ottawa Scale scores). Baricitinib effectively improved the mortality rate (relative risk of mortality = 0.56; 95% confidence interval: 0.46–0.69; P < 0.00001; I2 = 2%), and this result was unchanged by subgroup analysis. Baricitinib also improved intensive care unit admission, the requirement for invasive mechanical ventilation, and the oxygenation index. Data from these studies also showed that baricitinib slightly reduced the risk of adverse events. With regard to the choice of the drug dosage of baricitinib, the high-dose group appeared to have additional benefits for clinical efficacy.Interpretation: Our study shows that baricitinib may be a promising, safe, and effective anti-severe acute respiratory syndrome-coronavirus-2 drug candidate, with the advantages of a low cost, easy production, and convenient storage.Funding Information: We gratefully acknowledge the financial supports by the Basic research program of Guangzhou (202102010224), Clinical Transformation program of the first affiliated hospital of Guangzhou medical university (ZH201802, ZH201914), High-level university program of Guangzhou medical university (2017(160)) and Opening Project of State Key Laboratory of Respiratory Disease (SKLRD-0P-202115).Declaration of Interests: The authors have no potential conflict of interest to disclose.

Chloroquine, arbidol (umifenovir) or lopinavir/ritonavir as the antiviral monotherapy for COVID-19 patients: a retrospective cohort study (preprint)

Background: The severe acute respiratory syndrome coronavirus-2 outbreak was identified in China in December 2019 and spread worldwide, reaching the pandemic levels. However, a specific, effective and proven therapy for the patients with coronavirus disease 2019 (COVID-19) remains elusive. We aim to compare the efficacy and the safety of three antiviral monotherapies (chloroquine phosphate, arbidol (Umifenovir) or lopinavir/ritonavir) in non-severe, hospitalised COVID-19 patients.Methods: We retrospectively analysed the hospitalised, laboratory-confirmed COVID-19 patients, treated with antiviral monotherapies at Huizhou Municipal Central Hospital between Jan 19 and Mar 16, 2020. Demographic and clinical data were extracted from electronic medical records. The primary outcome of the study was the viral shedding interval.Results: Twenty-seven patients with COVID-19 were included in the study with 10 receiving chloroquine phosphate, 11 receiving arbidol and 6 receiving lopinavir/ritonavir. Baseline demographics and clinical data were similar between groups. The median viral shedding interval in the lopinavir/ritonavir group was 13.0 days (95% CI: 12.2-23.8), while significantly shorter in the chloroquine group at 5.0 days (95% CI: 0.4-9.6) (p=0.003). A reduced median interval was also observed in the arbidol group, with 8.0 days (95%CI: 4.9-11.1) (p=0.008). Moreover, the hospitalisation duration was shorter in the chloroquine (9.3 ± 1.8 days, p<0.001) and arbidol groups (11.7 ± 3.7 days, p<0.001), and the hospitalisation costs were significantly reduced in the chloroquine (USD 1327 ± 566, p=0.001) and arbidol groups (USD 1167 ± 434, p<0.001), when compared with the lopinavir/ritonavir group (hospitalisation length and costs: 19.7 ± 4.4 days and USD 3806 ± 2262, respectively). Conclusions: Chloroquine and arbidol could not only shorten the viral shedding interval but also decreased the hospitalisation duration and hospitalisation expenses.Trial registration: The ethics committee of the Huizhou Municipal Central Hospital approved this study, and the trial was registered with www.chictr.org.cn (ChiCTR2000030931).