Ship tracking provides crucial on-site microscopic kinematic traffic information which benefits maritime traffic flow analysis, ship safety enhancement, traffic control, etc., and thus has attracted considerable research attentions in the maritime surveillance community. Conventional ship tracking methods yield satisfied results by exploring distinct visual ship features in maritime images, which may fail when the target ship is partially or fully sheltered by obstacles (e.g., ships, waves, etc.) in maritime videos. To overcome the difficulty, we propose an augmented ship tracking framework via the kernelized correlation filter (KCF) and curve fitting algorithm. First, the KCF model is introduced to track ships in the consecutive maritime images and obtain raw ship trajectory dataset. Second, the data anomaly detection and rectification procedure are implemented to rectify the contaminated ship positions. For the purpose of performance evaluation, we implement the proposed framework and another three popular ship tracking models on the four typical ship occlusion videos. The experimental results show that our proposed framework successfully tracks ships in maritime video clips with high accuracy (i.e., the average root mean square error (RMSE), root mean square percentage error (RMSPE), mean absolute deviation (MAD) and mean absolute percentage error (MAPE) are less than 10), which significantly outperforms the other popular ship trackers.INDEX TERMS Smart ship, curve fitting, kernelized correlation filter, visual ship tracking, ship occlusion.

Background and purpose Since the outbreak of the coronavirus pandemic in 2019 (COVID-19), healthcare systems around the world have been hit to varying degrees. As a neurologist team, for patients with acute ischemic stroke (AIS), we compared the situations of intravenous thrombolysis (IVT) treatment from 2019 to 2020 to investigate the influence of COVID-19 pandemic on the attendance and prognosis of the IVT patients. Methods We collected the messages of objects who had received IVT (Bridging surgery was ruled out) during 2019–2020. We analyzed differences in age, gender, time from onset to start IVT, door to needle time (DNT), pretreatment NIHSS score, postoperative NIHSS score, and so on. Statistical tests were also performed to respectively compare the discharged modified Rankin score (mRS) and discharged NIHSS score between two years. Results Since the onset of COVID-19 restrictions in Wenzhou, we observed a significant reduction of 24.7% ( p = 0.023) from 267(2019) to 201(2020) of received IVT on hospital admission. We compared the DNT between two years and it reflected that the DNT (min) in 2020 was obviously longer than in 2019 (51.60 ± 23.80 vs 46.80 ± 21.90, p = 0.026). We also compared the discharged mRS, which reflected much more IVT patients in 2020 during the COVID-19 pandemic had a poor short-term functional prognosis (38.2% vs 29.2%, p = 0.043). Conclusions The COVID-19 pandemic caused the decrease of admissions and prolonged the time of the green channel for stroke, which led to the worse short-term prognosis of AIS patients during the pandemic. It’s necessary to ensure an effective green channel and provide adequate medical resources during the pandemic period to reduce the damage caused by COVID-19.

Background: Stroke-associated pneumonia (SAP) is associated with poor prognosis after acute ischemic stroke (AIS).Purpose: This study aimed to describe the parameters of coagulation function and evaluate the association between the fibrinogen-to-albumin ratio (FAR) and SAP in patients with AIS.Patients and methods: A total of 932 consecutive patients with AIS were included. Coagulation parameters were measured at admission. All patients were classified into two groups according to the optimal cutoff FAR point at which the sum of the specificity and sensitivity was highest. Propensity score matching (PSM) was performed to balance potential confounding factors. Univariate and multivariate logistic regression analyses were applied to identify predictors of SAP.Results: A total of 100 (10.7%) patients were diagnosed with SAP. The data showed that fibrinogen, FAR, and D-dimer, prothrombin time (PT), activated partial thromboplastin time (aPTT) were higher in patients with SAP, while albumin was much lower. Patients with SAP showed a significantly increased FAR when compared with non-SAP (P < 0.001). Patients were assigned to groups of high FAR (≥0.0977) and low FAR (<0.0977) based on the optimal cut-off value. Propensity score matching analysis further confirmed the association between FAR and SAP. After adjusting for confounding and risk factors, multivariate regression analysis showed that the high FAR (≥0.0977) was an independent variable predicting the occurrence of SAP (odds ratio =2.830, 95% CI = 1.654–4.840, P < 0.001). In addition, the FAR was higher in the severe pneumonia group when it was assessed by pneumonia severity index (P = 0.008).Conclusions: High FAR is an independent potential risk factor of SAP, which can help clinicians identify high-risk patients with SAP after AIS.

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BackgroundThe coronavirus disease 2019 (COVID-19) pandemic is having a dramatic impact on acute stroke care. Its effects may accompany stroke care for a long time. We compared the treatment, short-term and long-term functional outcomes of patients with AIS from 2019 to 2020. Our objective was to evaluate the effect of COVID-19 epidemic on mechanical thrombectomy (MT) in patients in our hospital.MethodsWe collected information on subjects treated with MT in 2019–2020, including age, sex, time from the onset to arterial sheath insertion, time from the onset to recanalization, the rate of lung infection and hemorrhagic transformation, modified Rankin scale (mRS), NHISS, and ASPECTS.ResultsThe number of patients with MT decreased significantly by 26.6% in 2020 (p = 0.025). The pretreatment ASPECTS score for 2020 was significantly higher than 2019 (p = 0.004). Besides, the patients were more likely to develop lung infection (65 vs. 54.1%, p = 0.042) and had a higher risk of hemorrhagic transformation (47.4% vs. 30.4%, p = 0.005) in 2019. The discharged mRS reflected the worse short-term functional prognosis of patients with MT in 2019 (66 vs. 44.9%, p = 0.046). In the subgroup analysis of bridging thrombolysis (BT), more patients with BT are expected to have a poor short-term functional prognosis in 2020, according to the discharged mRS (62.5 vs. 37.5%, p = 0.024). However, there was no difference in mRS at 180 days between the two groups (p = 0.094).ConclusionFor patients with MT, both short- and long-term functional outcomes were not significantly affected due to the mild condition of patients admitted to hospital in 2020. For patients with BT, the COVID-19 pandemic has prolonged the green channel time of stroke, leading to a poor short-term functional prognosis of patients with stroke in the pandemic period. There was no difference in the effectiveness of direct MT and BT during the COVID-19 pandemic.

PurposeGlobally, intracerebral hemorrhage (ICH) is a common cerebrovascular disease. At the beginning of 2020, due to the coronavirus disease 2019 (COVID-19) pandemic, the allocation of medical resources and the patient treatment and referrals were affected to varying degrees. We aimed to determine the characteristics and prognoses and associated factors of patients with ICH.Patients and MethodsThe baseline demographic characteristics and ICH outcomes were compared between patients diagnosed with ICH between January and June 2020 (the 2020 group) and between January and June 2019 (the 2019 group). COVID-19 positive patients were excluded from the study. A 30-day data from patients in the 2019 and 2020 groups were analyzed to create survival curves for these patients. We also used regression models to identify the significant determinants of poor outcomes [modified Rankin score (mRS): 3–6] and death.ResultsThe number of patients diagnosed with ICH was slightly lower in the 2020 group (n = 707) than in the 2019 group (n = 719). During the lockdown period (February 2020), the admission rates for ICH decreased greatly by 35.1%. The distribution of the patients' domicile (P = 0.002) and the mRS (P < 0.001) differed significantly between the years. The survival curve revealed that the highest risk of death was in the acute stage (especially in the first 5 days) of ICH. At 30 days, mortality was 19.8% in February 2019 and 29.4% in February 2020 (P = 0.119). Multivariate analysis revealed age, baseline mRS, postoperative complications, massive brainstem hemorrhage, and creatinine as factors significantly associated with poor outcomes and death following ICH. Neurosurgery and massive supratentorial hemorrhage were only correlated with the risk of death.ConclusionDuring the lockdown period, the COVID-19 pandemic caused a decrease in the admission rates and severe conditions at admission due to strict traffic constraints for infection control. This led to high mortality and disability in patients with ICH. It is necessary to ensure an effective green channel and allocate adequate medical resources for patients to receive timely treatment and neurosurgery.

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