Analysis of students’ positive emotion in green campus during COVID-19 pandemic in China (preprint)

Green space in university campus is of paramount importance to students’ emotional and psychological restoration. Students’ positive emotion can be aroused when immersed in green space and naturalness. However, to what extent can perceived naturalness influence students’ positive emotion remains unclear, especially in the context of COVID-19 countermeasures. This study, therefore, attempts to investigate in-depth the nature and strength of the relationships between students’ positive emotion and their perceived naturalness, place attachment and landscape preference, which are potentially varying across universities in different social and environmental contexts and different restriction policies regarding the COVID-19 pandemic. A course of questionnaire-based surveys was administered in two university campuses in Heilongjiang and Hunan Provinces, China, resulting in 474 effective samples. Structural equation modeling was used to explore the hypothetical conceptual framework of latent variables and the indicators. The findings indicate that the higher students’ perceived naturalness results in the greater positive emotion. Students’ perceived naturalness in green spaces of campus has a positive effect on their place attachment and landscape preference. Moreover, the difference of mediate effects of place attachment and landscape preference were addressed which verifies the contextual influences.

Reinforced Contact Tracing and Epidemic Intervention (preprint)

The recent outbreak of COVID-19 poses a serious threat to people's lives. Epidemic control strategies have also caused damage to the economy by cutting off humans' daily commute. In this paper, we develop an Individual-based Reinforcement Learning Epidemic Control Agent (IDRLECA) to search for smart epidemic control strategies that can simultaneously minimize infections and the cost of mobility intervention. IDRLECA first hires an infection probability model to calculate the current infection probability of each individual. Then, the infection probabilities together with individuals' health status and movement information are fed to a novel GNN to estimate the spread of the virus through human contacts. The estimated risks are used to further support an RL agent to select individual-level epidemic-control actions. The training of IDRLECA is guided by a specially designed reward function considering both the cost of mobility intervention and the effectiveness of epidemic control. Moreover, we design a constraint for control-action selection that eases its difficulty and further improve exploring efficiency. Extensive experimental results demonstrate that IDRLECA can suppress infections at a very low level and retain more than 95% of human mobility.

A study on the clinical characteristics and management of patients with mild cases of COVID-19 in shelter hospitals from China (preprint)

Background: To review the clinical characteristics of patients with mild cases of novel coronavirus disease (COVID-19) pneumonia admitted to shelter hospitals and to investigate the management patterns of shelter hospitals. Methods: We collected and analyzed the case data of 931 patients of their general conditions, main clinical presentations, outcomes, laboratory results, imaging. Results: The average age of patients with mild cases of COVID-19 was （46.68 ± 12.13） years. There was no significant difference in incidence between males and females. The most common clinical presentations were fever (60.79%), cough (47.37%), myalgia and fatigue (17.40%), sore throat (13.86%), sputum (13.86%), diarrhea (9.98%), chest distress and dyspnea (8.38%), nasal congestion (6.02%), and runny nose (5.69%), while 10.10% were asymptomatic. In addition, anxiety and insomnia were present in 12.13% of cases. COVID-19 clinical type: mild, 248 cases (26.64%); moderate, 683 cases (73.36%). Blood biochemical examination showed that some patients exhibited WBC count (26.32%) lower to normal. Most patients tested positive for novel coronavirus nucleic acid (55.45%), while 44.55% tested negative. The rate of positive chest computed tomography (CT )examination findings was 94.36%. The most common change were ground-glass opacities (48.70%) and multiple patchy opacities (44.58%). Moreover, 65 patients (6.98%) were transferred to designated hospital, primarily due to exacerbation of novel coronavirus pneumonia (32 cases, 49.2%). Conclusions: COVID-19 patients in shelter hospitals were in a relatively mild overall condition and were predominantly of the moderate clinical type. Attention should be paid to asymptomatic positive patients and patients without respiratory symptoms. CT is still the main patient screening method. Shelter hospitals can carry the burden of epidemic prevention and treatment of patients with mild cases of COVID-19.